Singapore HDB Std Specifications - CE - 2012

STANDARD SPECIFICATIONS

FOR

CIVIL ENGINEERING WORKS

(2012 EDITION)

CE12/IND.DOC(1) oym(151211) DPD

Published by Housing & Development Board, Republic of Singapore. No part of this document may be reproduced or copied in any form or by any means without the prior written permission of the publisher.

CE12/IND.DOC(2) oym(151211) DPD

STANDARD SPECIFICATIONS FOR CIVIL ENGINEERING WORKS

CONTENTS

SECTION 1

GENERAL SPECIFICATIONS

1-1

TECHNICAL SPECIFICATIONS

SECTION 2

MATERIALS, WORKMANSHIP AND CONSTRUCTION IN GENERAL

2-1

SECTION 3

CONSTRUCTION AND WORKMANSHIP FOR ROADS AND DRAINS

3-1

SECTION 4

CONSTRUCTION AND WORKMANSHIP FOR SEWERS

4-1

SECTION 5

CONSTRUCTION AND WORKMANSHIP FOR EARTHWORKS

5-1

SECTION 6

LIST OF APPENDICES

6-1

The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract. HDB, being a ISO 14001 certified organisation, is committed to be the leader in environment management. The details of HDB's environmental policy can be found in the Corporate Philosophy at HDB Website http://www.hdb.gov.sg

CE12/IND.DOC(3) oym(151211) DPD

SECTION 1 : GENERAL SPECIFICATIONS

1.1

GENERAL

1.1.1

Definitions, Abbreviations and Interpretations

1-1

1.1.2

Payment of Employer's Bills, Expenses, Etc

1-2

1.1.3

Compliance with Technical Guidelines For Fire Safety In Temporary Buildings In Construction Worksites

1-2

1.1.4

Stamp Duties

1-2

1.1.5

Contract Payment by GIRO/EPS

1-3

1.1.6

Goods & Services Tax

1-3

1.1.7

Provisional Sums

1-3

1.1.8

Prime Cost Sums

1-3

1.1.9

Carriage By Sea

1-4

1.1.10

Bribery

1-4

1.1.11

Overclaim Leading to Overpayment

1-4

1.1.12

Work Methods

1-4

1.1.13

Office For Use By SO Rep

1-5

1.1.14

Precautionary Measures To Be Taken During A Disease Pandemic

1-5

1.1.15

Temporary Sanitary Facilities

1-5

1.1.16

Working Area, Position, Lines etc

1-6

1.1.17

TOL Fee for Land Outside Contract Boundary

1-7

1.1.18

Liaison with Town Council on Use of Common Property for Site Office and/or Store

1-7

1.1.19

Assignment of Copyright of Photographs, Etc.

1-8

1.1.20

Clearance Of Site, Turf And Topsoil

1-8

1.1.21

Preservation of Existing Trees During Construction & Development

1-8

1.1.22

Research Work

1-9

1.1.23

Site Management

1-10

1.1.24

Setting Out

1-10

1.1.25

Signboards

1-10

1.1.26

Air Pollution Control

1-10

1.1.27

Provision Of Bins For Waste And Debris

1-10

1.1.28

Periodic Cleaning Up

1-11

1.1.29

Pest Control and Surveillance

1-11

1.1.30

Temporary Services

1-11

1.1.31

Care of the Works and Materials

1-11

1.1.32

Fencing and Lighting

1-11

The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.

CE12/IND.DOC(4) oym(151211) DPD

CONTENTS

Clause No.

Clause

Page

1.1.33

Cables/Services Detection

1-12

1.1.34

Damage to Public/Private Property

1-12

1.1.35

Cleaning and Maintenance of Roads and Drains

1-13

1.1.36

Access Roads and Protective Crossings

1-13

1.1.37

Demolition and Making Good

1-13

1.1.38

Breaking Up Of Existing Work

1-14

1.1.39

Excavation Of Service Trenches And Storage of Cable Ducts

1-14

1.1.40

Reinstatement of Service Trenches

1-14

1.1.41

Dumping of Debris and Rubbish

1-15

1.1.42

Inspection of Works Prior to Certified Completion

1-15

1.1.43

Cleaning Upon Substantial Completion

1-16

1.1.44

Rectification of Defect During Defects Liability Period

1-16

1.1.45

Noise Nuisance

1-16

1.1.46

Recovery of Legal Costs For Court Proceedings

1-16

1.1.47

Machinery Boundary

1-16

1.1.48

Mobile Cranes

1-17

1.1.49

Work Site Computer Equipment

1-17

1.1.50

Workers' Quarters

1-21

1.1.51

Assessment of Extension of Time Due To Exceptionally Inclement Weather

1-23

1.1.52

Insurance Policies

1-23

1.1.53

Contract Documents On Site

1-25

1.1.54

Lightning Protection To Temporary Structures And Metal Structures

1-25

1.1.55

Environmental Public Health Measures

1-26

1.1.56

Trade Subcontractors

1-26

1.1.57

Work On MRT Reserve Area

1-27

1.1.58

Stationery For Resident Technical Officer

1-28

1.1.59

Earth Control Measures

1-29

1.1.60

Electronic Submission For Progress Payments Claims And Request

1.1.61

For Variation Works

1-31

Land Survey Services For CE Works

1-32

1.2

MATERIALS - GENERAL

1.2.1

Metric Components

1-34

1.2.2

Materials And Workmanship

1-34

1.2.3

Approval Of Samples and Trade Names

1-34

1.2.4

Samples

1-36

1.2.5

Precautions Against Materials Being Taken Out of Site

1-36

1.2.6

Approval For Use of Ready Mixed Concrete

1-36

The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.

CE12/IND.DOC(5) oym(151211) DPD

CONTENTS

1.3

LABOUR

1.3.1

Labour Laws

1-37

1.3.2

Keeping Records of Workmen

1-37

1.3.3

Employment of Illegal Immigrants

1-37

1.3.4

Employment of Civil Engineers

1-37

1.4

CONSTRUCTION EQUIPMENT

1.4.1

Maintenance Of Construction Equipment

1-40

1.4.2

Contractor's Construction Equipment

1-40

1.4.3

Movement of Construction Equipment

1-40

1.4.4

Age Limit for Mobile Crane

1-40

1.5

SAFETY

1.5.1

Site Safety Measures

1-41

1.5.2

Safety Infringement

1-49

1.5.3

Reporting Of Accidents

1-50

1.5.4

Approved Construction Equipment

1-51

1.5.5

Gas Cylinders and Related Equipment

1-51

1.5.6

Erection of Temporary Structures

1-51

1.5.7

Submission of Proposal and Certificate of Supervision

1-51

1.5.8

Excavation

1-52

1.5.9

Storage of Diesel, Oil and Chemical

1-52

1.5.10

Provision of Equipment, Apparatus, Devices, Etc

1-52

1.6

NUISANCE AND IRREGULARITIES

1.6.1

Nuisance And Irregularities

1-53

The contents of this index on this page shall not be deemed to be part of the Specifications or be taken into consideration in the interpretation or construction thereof or of the Contract.

CE12/IND.DOC(6) oym(151211) DPD

GENERAL SPECIFICATIONS

CE12/S1.DOC(1) oym(151211) DPD

CE Spec Page 1-1 HOUSING & DEVELOPMENT BOARD

SECTION 1 : GENERAL SPECIFICATIONS

1.1

GENERAL

1.1.1

Definitions, Abbreviations And Interpretations In the Specifications, the following words and expressions shall have the meanings hereby assigned to them except where the context otherwise requires : "SO Rep"

shall mean Superintending Officer's Representative.

"as approved"

shall mean as approved by the Superintending Officer's Representative.

"as directed"

shall mean as directed by the Superintending Officer's Representative.

"or other approved"

shall mean as approved by the Superintending Officer's Representative and as further defined in subclause 1.2.3 "Approval Of Samples And Trade Names".

"as required" or "as shown" or "as indicated" or "as specified"

shall mean as required or as shown or as indicated or as specified in the Drawings and/or Specifications.

The following abbreviations are used in the Specifications : ASTM BS BCA BCD cm 2 cm or cm2 3 cm or cm3 CP DIN ENV FSSD g HDB IDA ISO kg KN or kN LTA m m2 or m2 3 m or m3 2 mm or mm2 3 mm or mm3 Max or max MOM MRT N No. or no. NEA NParks Min or min PE

CE12/S1.DOC(1) oym(151211) DPD

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

American Society for Testing and Material British Standard Building and Construction Authority Building Control Division centimetre square centimetre cubic centimetre Code of Practice Deutche Industrie - Normen Ministry of the Environment Fire Safety and Shelter Department gram Housing & Development Board Info-communications Development Authority of Singapore International Organization for Standardization Kilogram Kilonewton Land Transport Authority metre square metre cubic metre square millimetre cubic millimetre maximum Ministry of Manpower Mass Rapid Transit newton number National Environment Agency National Parks Board minimum Professional Engineer registered under the Professional Engineers Board, Singapore

CE Spec Page 1-2 1.1.1

Definitions, Abbreviations And Interpretations (Cont'd) PowerGrid or Grid PUB PTL RC or rc SPRING Singapore SAC SLA SINGLAS SPSL SS ºC % +   < > v/v w/w µm

= = = = = = = = = = = = = = = = = = = =

Powergrid Ltd Public Utilities Board Public Telecommunications Licensees Reinforced Concrete Standards, Productivity & Innovation Board Singapore Accreditation Council Singapore Land Authority Singapore Laboratory Accreditation Scheme SP Services Ltd Singapore Standard degree Celsius percent plus or minus less than or equal greater than or equal less than greater than measured by volume measured by weight micrometre

Words importing the singular also include the plural and vice versa where the context requires. The clause headings in the Specifications shall not be deemed to be part thereof or be taken into consideration in the interpretation or construction thereof or of the Contract. All clauses in the Specifications shall be deemed to be directed at the Contractor unless expressly specified otherwise and the Contractor shall perform and/or comply with such instructions, directions, requirements and obligations specified in the Specifications and required under the Contract. All Acts of Parliament, statutes, regulations, bye-laws, orders, local and foreign standards and codes of practice specified shall be deemed to refer to the latest and shall be deemed to include any amendments, and/or modifications and/or additions and/or re-enactments thereto.

1.1.2

Payment Of Employer's Bills, Expenses, Etc The Contractor shall duly and punctually pay to the Employer the billed and any other expenses incurred by the Employer in respect of the supply of materials, services, etc. The Contractor shall pay to the Employer interest at the rate of seven percent per annum or such other rate as may be determined from time to time by the Employer in respect of any arrears of payment or other outstanding sums due and payable to the Employer, from the due dates until payment in full is received by the Employer. The Employer reserves the right to set off such bills and expenses against monies due or becoming due to the Contractor before payment of the balance, if any to the Contractor. In this respect, all Employer's bills and other expenses due from the Contractor shall have priority over debts due to third parties.

1.1.3

Compliance With The Technical Guidelines For Fire Safety In Temporary Buildings In Construction Worksites The Contractor shall comply with the Technical Guidelines for Fire Safety in Temporary Buildings in Construction Worksites, including any amendment thereto, issued by the FSSD, Singapore Civil Defence Force. In this connection, the Contractor's PE shall endorse on the plans for all temporary buildings to certify compliance with the said FSSD Guidelines.

1.1.4

Stamp Duties The Contractor shall have all documents required by or arising out of or in connection with this Contract properly stamped to comply with the Stamp Duties Act. The costs and expense arising out of this obligation, including all stamp duties required, shall be borne by the Contractor and shall be deemed to have been allowed for in the Contract Sum.

CE12/S1.DOC(2) oym(151211) DPD

CE Spec Page 1-3 1.1.5

Contract Payment By GIRO/EPS All payments under the Contract by the Employer to the Contractor shall be effected through the Inter-bank GIRO System and/or other Electronic Payment Systems. The Contractor shall submit all the necessary forms, such as Inter-bank GIRO (IBG) form, etc., duly completed and signed, to the Finance Department, HDB, HDB Hub, 480 Lorong 6 Toa Payoh, Singapore 310480; within fourteen days from the date of the Letter of Acceptance to effect payments through such Systems. In the event the payment arrangement through such Systems terminates for whatever reasons, the Contractor shall re-submit all the necessary forms to the Finance Department within 14 days from the date of the termination. The preceding requirements shall not be applicable to payments by the Employer to the Contractor in approved foreign currencies, where required under the Contract.

1.1.6

Goods & Services Tax The Contractor shall not include in the rates and prices quoted in the Contract Sum, the GST chargeable for the supply of goods, services or works required in the Contract. All rates and prices quoted shall be exclusive of the GST. The Employer shall reimburse the Contractor any GST charged on the goods, services or works supplied. The Contractor shall declare his GST status in his Tender. The Contractor shall clearly indicate whether he is, or whether he will be a taxable person under the GST Act. The Contractor shall, if available, furnish the GST registration number to the Employer. The Contractor will be deemed to be a taxable person if no declaration to the contrary is made in the Form of Tender. The Contractor who declares himself to be a non-taxable person under the GST Act but who becomes a taxable person after he has been awarded the Contract shall forthwith inform the Employer of his change in GST status. The Contractor shall be entitled to reimbursement by the Employer of any GST charged on the goods, services or works he supplies after his change in GST status.

1.1.7

Provisional Sums Where Provisional Sum Items are included in the Contract, they shall be inclusive of all costs necessary in carrying out or supplying the work, materials or goods. These Provisional Sum Items shall be inclusive of the Contractor's profit and overheads but shall be net of trade and cash discounts.

1.1.8

Prime Cost Sums Where Prime Costs Sums (P.C. Sums) are provided for any work, materials or goods, these sums shall be inclusive of carriage but exclusive of the Contractor's profit and attendance. These P.C. Sums shall also be net of trade and cash discounts. Allow and separately price for profit and attendance in respect of such P.C. Sums in the Form of Tender. P.C. Sums shall be deducted from the Contract Sum and in lieu thereof shall be added the sums due to the Contractor for the said work, materials or goods. The sum allowed by the Contractor in the Contract for attendance in respect of any P.C. Sums shall be fixed regardless of whether the actual sum expended is greater or less than the P.C. Sums. In respect of profit, the amount to be paid shall be the percentage quoted against the actual sum expended in relation to the P.C. Sums. Should the work, materials or goods for which a P.C. Sums is provided in the Contract be not required, or if the Employer chooses to carry out or supply the aforesaid work, materials or goods by his own workmen or by other contractors, which the Employer is contractually entitled so to choose, then such P.C. Sums together with the profit and attendance allowed by the Contractor in the Contract shall be deducted in full from the Contract Sum. Should the Contractor himself be engaged or instructed to carry out or supply any work, materials or goods under a P.C. Sums, the profit and attendance allowed by the Contractor in the Contract in respect of the P.C. Sums shall be deducted in full from the Contract Sum. In such event, the amount to be paid for the work, materials or goods shall be inclusive of the Contractor's overheads and profit for the work, materials and goods.

1.1.9

Carriage By Sea

CE12/S1.DOC(3) oym(151211) DPD

CE Spec Page 1-4

Ensure that the carriage by sea of all goods, materials, Plant and equipment imported for the purposes of this Contract shall be on vessels owned and operated by shipping lines which are approved lines at the time the contract of carriage is entered into. Other ships may be used only if no approved line: (a)

can deliver the goods, material, Plant and equipment in time to meet the delivery dates specified in the Contract; or

(b)

can provide the same measure of service at the same cost.

The Bills of Lading for the goods, material, Plant or equipment used by an approved line(s) shall be sufficient evidence of their carriage by an approved line(s) in compliance with this subclause. Where the carrier is not an approved line, the Contractor shall satisfy the SO Rep that the conditions herein stated have been satisfied. The SO Rep may require and the Contractor shall forthwith furnish to the SO Rep a letter from at least one approved line at the time the contract of carriage with the carrier is entered into stating that in respect of the shipment in issue they are either unable to quote or to provide the service required. Notwithstanding anything contained in this subclause, the Employer shall not be responsible for any act or default of the carrier or for any loss or damage sustained by the Contractor on account of having to comply with this subclause. The list of current approved lines can be obtained from the Procurement Office of the HDB's Contracts & Administration Department, Basement 1, HDB Hub, 480 Lorong 6 Toa Payoh, Singapore 310480

1.1.10

Bribery During the currency of this Contract, the Contractor and his authorized agents or representatives shall not offer or attempt to offer any bribes, commission or gift to the Employer's employees. Should it be discovered that bribes, commission or gift have been given to any of the Employer's employees, the employment of the Contractor under this Contract may be terminated. The decision of the Superintending Officer with regard to the interpretation and implementation of this subclause shall be final and binding on and conclusive against the Contractor.

1.1.11

Overclaim Leading To Overpayment If at any time during the Time for Completion and any time period where liquidated damages are imposed under the Contract, the Contractor is found to have over-claimed and was paid for more than the value of the Permanent Works carried out and/or approved unfixed materials at the Site, the SO Rep shall be empowered to deduct from the Contractor's subsequent payments the sum overpaid together with the Employer's charges, and interest calculated at seven percent per annum

1.1.12

Work Methods Submit to the SO Rep for his approval the work methods of the trades as required by the SO Rep to ensure good workmanship. A marking system, where applicable showing inter alia, the control, grid and level reference lines shall be included in the work methods. The Contractor shall ensure that sub-contractors engaged comply with the work methods approved by the SO Rep. Should it appear to the SO Rep at any time that the work methods proposed will not ensure good workmanship in the Works, the SO Rep may require the Contractor to make at his own cost and expense such modifications to the original work methods as the SO Rep may consider necessary or appropriate. Use or employ only workers who are skilled and capable of executing the Works in accordance with the work methods approved. Approval by the SO Rep of the Contractor's work methods, revised work methods or any details and information provided under this subclause shall not in any way affect, relieve or vary the Contractor's liabilities or obligations under the Contract.

CE12/S1.DOC(4) oym(151211) DPD

CE Spec Page 1-5 1.1.13

Office For Use By SO Rep A separate air-conditioned modular container site office, separate from the Contractor's site office, of at least 18 square metres with two tables of at least 1.5 m length and four chairs, a steel cabinet, a fire extinguisher of minimum 5A Rating, a white board of minimum 600mm x 900mm size and soft boards covering the entire office walls shall be provided for the use of the SO Rep. The modular container site office shall be submitted for approval by the SO Rep. The design of the office shall comply with the Technical Guidelines For The Fire Safety In Temporary Buildings In Construction Sites, including any amendment thereto, issued by FSSD and the Building Control (Temporary Buildings) Regulations including any latest requirements by BCD, BCA. The following shall also be included in the site office : (i)

False ceiling with concealed lightings (min 8 no. 40w fluorescent lighting).

(ii)

Power points : min 1 no. 15 amp for air conditioner, 2 no. 13 amp socket and 2 no. light switches.

(iii)

Lighting protection complying with Singapore Standards CP33:1996 and/or any latest requirements by the BCD, BCA.

One telephone with call transfer facility shall be provided during the Time for Completion and any time period where liquidated damages are imposed under the Contract. If the Contractor fails to provide the telephone, the SO Rep will make the arrangement and all costs and expenses shall be deducted from payment due or becoming due to the Contractor. Install a First Aid Kit and other safety appliances as directed. The First Aid Kit shall be adequately stocked with medicine for first aid at the site office. Provide "No Smoking" Stickers, ear plugs and a rubber stamp indicating particulars of the Contract for site use. The Contractor shall allow for the maintenance of the site office and all the facilities, furniture and fittings therein in a clean and good working condition to the satisfaction of SO Rep. The Contractor shall pay all charges for the provision and use of the telephone and electricity at the site offices during the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall be responsible for making arrangement and to obtain the approvals from the relevant authorities for the erection of site office and the related temporary facilities. Temporary Occupation Licence, fees, rental charges and all related costs in connection with the above shall be borne by the Contractor. 1.1.14

Precautionary Measures To Be Taken During A Disease Pandemic The contractor shall be required to implement necessary precautionary measures as advised by the Ministry of Health or other relevant Authorities during a disease pandemic. Based on the recommendations from the government's advisory, the contractor shall follow up expeditiously to plan for such contingency and stock up necessary supplies or equipment (eg thermometers) so as to be able to implement the required measures in a short notice.

1.1.15

Temporary Sanitary Facilities Within 21 days from the date of the Letter of Acceptance, the Contractor shall provide temporary sanitary facilities with adequate lighting on site in suitable structures to be approved by the SO Rep. The Contractor may use the Employer's Standard Drawings as a guide in designing the temporary sanitary facilities. The temporary sanitary facilities shall contain water closets and shower compartments in the proportion of 1 closet and 1 shower to every 25 workmen, for the duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract. In addition, the Contractor shall provide separate sanitary facilities with water closet and shower compartment for use by the Employer's officers. Prior written approval by the SO Rep shall be obtained before erection of these facilities.

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CE Spec Page 1-6 1.1.15

Temporary Sanitary Facilities (Cont’d) The water closets shall be of a type, make and pattern approved by the PUB. Provide and lay glazed wall tiles or other approved material to the internal walls of the temporary sanitary facilities up to a height of 1.8m from the floor. The doors to the cubicles of the temporary sanitary facilities shall be of approved material. All waste discharge from the water closets and all waste water from the temporary sanitary facilities and from the Site shall be discharged into a public sewer. Arrange with the PUB to carry out connection work from the temporary sanitary facilities to the public sewer and pay all charges and maintenance in connection therewith. The Contractor shall be responsible for all damage to and shall indemnify the Employer against all liabilities in respect of such sewer connections. Where a public sewer is not available or where it is not possible to connect to a public sewer, provide and install temporary septic tanks of a type, pattern and capacity approved by the PUB, to serve the water closets, showers and baths. Drawings of such septic tanks may be obtained from the PUB.

1.1.16

Working Area, Position, Lines Etc Where the Temporary Working Area is indicated in the Drawings, the Contractor will be allowed the working space and he shall confine his operations and temporary facilities such as site offices and sheds as he may require for executing the Works, within the area indicated. The Contractor shall be required to take out a Temporary Occupation Licence (TOL) from the Singapore Land Authority or Lands Management Section, HDB, for occupying the land as his temporary working area. The Contractor shall pay all TOL fees, and bear all costs and expenses for the use and maintenance of and access to his temporary working area and comply with all the conditions imposed by the Singapore Land Authority or Lands Management Section, HDB. Where the Contractor opts not to use the Temporary Working Area, or use a smaller Temporary Working Area than that indicated in the Drawings, there shall be no cost adjustment to the Contract Sum. Where no Temporary Working Area is indicated in the Drawings, the Contractor shall check on the availability of land and apply to the Singapore Land Authority or Lands Management Section, HDB or other relevant authority, for the use of land as temporary working area required for his operations and setting up of temporary facilities such as site offices and sheds as he may require for executing the Works. The Contractor shall pay all charges, TOL fees and bear all costs and expenses for the use and maintenance of and access to the said land and comply with all the conditions imposed by the Singapore Land Authority or Lands Management Section, HDB, or other relevant authority. The Temporary Working Area allocated shall only be used solely for the purpose of executing Works under the Contract. The whole of the Temporary Working Area shall be vacated and the land made good on Substantial Completion. In arriving at the Contract Sum the Contractor shall be deemed to have used as a basis the levels which are shown on the various cross-sections and longitudinal sections of the Drawings relative to the existing ground levels in determining his quantities of excavation or filling for the completed Works. The precise positions, lines, depths and directions of the Works are indicated within all practicable limit. If the Contractor wishes to make ground tests or other similar tests, then he shall state the extent and manner of carrying out these tests and obtain the approval of the SO Rep before he proceeds. Where trial borings or tests have been made by the Employer, the results may be made available to the Contractor. The results or any other information on strata is given in good faith but the Employer accepts no responsibility for the accuracy or reliability of such information. In all cases the Contractor shall be deemed to have satisfied himself as to the type of strata and ground conditions that he may encounter during the Works. Should the Contractor not agree with any level of existing land or other property as given in the Drawings, he shall submit his objection in writing within 2 weeks from the date of the Letter of Acceptance. Otherwise, the Drawings shall be taken as correct for the purposes of setting out and determination of variations (if any). Note that all existing ground levels are given as spot levels or contours on plan and that straight lines on the sections represent the average ground levels. Any small differences of levels therefore shall not be regarded as sufficient reason for the Contractor to disagree with the information as shown on the Drawings.

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CE Spec Page 1-7 1.1.17

TOL Fee For Land Outside Contract Boundary Where the Contractor requires land outside the contract boundary for the setting up of Construction Equipment and other temporary facilities for the Works, the Contractor shall check on the availability of such land and apply to the relevant Authority or Lands Management Section of HDB for the use of such land. In the event the relevant Authority or HDB's Lands Management Section allows the Contractor the use of such land, the Contractor shall at his own cost and expense comply with all the terms and conditions, pay all TOL (Temporary Occupation Licence) fees, bear all costs and expenses for the use and maintenance of and access to the said land imposed by the relevant Authority or HDB's Lands Management Section. Such land allocated shall solely be used for the purpose of executing Works under the Contract. Any payment for unused materials or goods stored at such land shall be subject to the provisions in Option Module B "Unused Materials or Goods not Delivered to Site" of the Conditions.

1.1.18

Liaison With Town Council On Use Of Common Property For Site Office and/or Store Consult with the SO Rep on the location of the site office and submit an application through the SO Rep to the Town Council to obtain permission before putting up the site office and/or store. The application shall include the following : (a)

Contractor's covering letter.

(b)

Site plan of proposed location of site office and/or store.

(c)

Layout plan with site indication of the site office and/or store.

(d)

Letter of undertaking with the following conditions : (i)

To put up and maintain the site office signboard.

(ii)

To open a PUB account for the use of water and electricity at the site office, if it is required by the Town Council.

(iii)

To maintain the cleanliness and orderliness of the site office and/or store and its surrounding areas during the Time for Completion and any time period where liquidated damages are imposed under the Contract.

(iv)

To reinstate any damage caused during the Time for Completion and any time period where liquidated damages are imposed under the Contract.

(v)

To remove the site office and/or store and reinstate the site to its original condition within 3 weeks from the Date of Substantial Completion.

and any other conditions that the Town Council may impose. If the location is not approved by the Town Council, amend and resubmit the application through the SO Rep. Ensure that those areas occupied by and surrounding the site office and/or store are maintained for the duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract. Upon Substantial Completion, remove the site office and/or store and reinstate the site to original condition within 3 weeks from the Date of Substantial Completion. After the SO Rep has inspected the site and assessed that the area where the site office and/or store were erected has been reinstated to original condition, arrange for the Town Council to take over. All cost, expenses and sums incurred by the Contractor howsoever arising or consequent upon shall be deemed to be included in the Contract Sum.

CE12/S1.DOC(7) oym(151211) DPD

CE Spec Page 1-8 1.1.19

Assignment Of Copyright Of Photographs, Etc The Contractor shall assign to the Employer, the copyright of the photographs (including the prints/slides/transparencies/ negatives) taken and all documents prepared under this Contract. The Employer shall have unfettered rights to use or reproduce all the photographs (including the prints/slides/transparencies/negatives) taken and all documents prepared by the Contractor under this Contract for any purpose other than for the purpose for which the Contract was entered into. In the event that the Contractor engages third parties to take the photographs (including the prints/slides/transparencies/negatives) or prepare the documents, the Contractor shall procure the assignment of the copyright from such third parties to himself and thereafter, assign the copyright to the Employer. The Contractor and/or any third parties are strictly prohibited from using or reproducing any of the photographs (including the prints/slides/transparencies/negatives) taken and all documents prepared under this Contract in any other publication or for any other purpose whatsoever.

1.1.20

Clearance Of Site, Turf And Topsoil Clear the Site at such time and to the extent required by the SO Rep and take down hedges, trees, hack up belukar, roots and any other obstruction from Site. All such waste materials removed shall be disposed off as directed. Should the quantity of work involved appear greater than that shown on the Drawings the Contractor shall make due allowance in the Contract Sum to cover such work and no adjustment to the Contract Sum shall be made. When digging and cutting of turfed ground are carried out, the turf and topsoil shall first be removed and stored nearby for re-use as directed. Turf and topsoil shall not be taken away from Site without prior permission of the SO Rep and they shall remain the property of the Employer.

1.1.21

Preservation Of Existing Trees During Construction & Development Where any existing tree(s) on the Site is stipulated to be preserved (hereinafter referred to as "preserved trees" for the purpose of this subclause), the Contractor shall take all necessary precautions to avoid damage or injury to such trees and its roots and comply with the following requirements : (A)

Treatment Of Preserved Trees In Area Of Fill (i)

Tolerable Depth Of Fill The area around preserved trees shall not be filled more than 300 mm in depth.

(ii)

Construction Of Well Around Trees Well not exceeding 1m in depth shall be constructed around preserved trees. The minimum diameter of well shall be 6 times the diameter of preserved trees measured at the trunk 0.5m above ground level. Details of well shall be as shown in the Drawings.

(B)

Treatment Of Preserved Trees In Area of Cut (i)

Tolerable Depth Of Cut The area around preserved trees shall not be cut to a depth exceeding 300 mm.

(ii)

Retention Of Raised Planter Around Tree An area around preserved trees shall be retained as raised planter to conserve the root system. The minimum diameter of raised planter shall be 6 times the diameter of preserved trees measured at the trunk 0.5m above ground level. Details of retention of raised planter are as shown in the Drawings.

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CE Spec Page 1-9 1.1.21

Preservation Of Existing Trees During Construction & Development (Cont'd) (C)

Protection Of Existing Trees From Physical Damage By Equipment Etc During Construction (i)

All preserved trees shall be protected against damage during construction operation by suitable fencing or armouring. The protection of preserved trees shall be placed before commencing any excavation or grading operation/work and shall be maintained in repair for the duration of the Time for Completion and any time period where liquidated damages are imposed under the Contract, unless otherwise directed. The extent of fencing shall be determined by the SO Rep. Fencing shall be erected all round not less than 1.2m from the trunk of preserved trees. Individual preserved trees near heavy construction traffic shall be wrapped with gunny sacks and 50 mm x 100 mm planks worn vertically as armour around the trunk and spaced at no more than 50 mm apart to a height of 1.5m above ground.

(D)

(ii)

Any damage to preserved trees root system shall be repaired immediately by the Contractor under the supervision of a qualified horticulturist. Roots that are exposed and/or damaged during grading operations shall be cut off immediately and the inside of the exposed and/or damaged area cleaned; cut surfaces shall be treated with approved sealing compound and topsoil spread over the exposed root area.

(iii)

Any damage to preserved trees branches shall be treated in accordance with the Drawings.

(iv)

If any preserved trees are severely injured by mechanical equipment, etc., the SO Rep shall impose charges against the Contractor in accordance with Clause 1.6 "Nuisance and Irregularities".

Health & Condition Of Preserved Trees (i)

The Contractor shall ensure that : (a) (b) (c) (d) (e) (f) (g)

1.1.22

Compaction of soil around preserved trees shall be avoided. No material shall be stored within the root system. There shall be no spillage of any nature within the spread of the preserved trees. There shall be no parking of vehicles underneath the preserved trees. There shall be no dumping of excavated materials, concrete, equipment etc. within the spread of the preserved trees crown. Soil around preserved trees is properly cultivated to ensure that adequate supply of air and water get to the roots. The site is drained in periods of heavy rainfall and irrigated during periods of drought.

(ii)

The Contractor shall also carry out any other routine maintenance of the preserved trees eg. branch trimming, pesticide spraying etc. as instructed by the SO Rep.

(iii)

If the growth of the preserved trees is stifled, the Contractor shall inter-alia bear the cost of making good. Charges in accordance with Clause 1.6 "Nuisance and Irregularities" shall also be imposed against the Contractor.

Research Work The Contractor shall provide and render all necessary assistance to the SO Rep or other authorised persons conducting research work or procuring publicity materials on any aspects of the construction work in progress. When directed by the SO Rep, the Contractor shall also provide all brochures, quotations, sub-contract agreements, invoices, etc from his sub-contractors, suppliers and specialists for goods and services provided for the Works, all at the Contractor's cost and expense.

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CE Spec Page 1-10 1.1.23

Site Management Within 14 days from the date of the Letter of Acceptance, submit to the SO Rep for his approval the following details on site planning : (a) (b) (c) (d) (e) (f)

Site organisation structure Names and roles of Contractor's staff Manpower schedule for each trade Materials purchase and delivery schedule for each trade Schedule of heavy equipment Schedule of Construction

Furnish the SO Rep with such further details and information as the SO Rep may require in regard to the above items. At least 14 days before the supply of the materials by manufacturers/suppliers, the Contractor shall submit the names of the manufacturers and suppliers to the SO Rep. At least 14 days before the commencement of the Works by the subcontractors, the Contractors shall submit the names and roles of his subcontractors to the SO Rep. Should it appear to the SO Rep at any time that the proposed site planning is not able to ensure a smooth progress of and good workmanship in the Works, the SO Rep is empowered to require the Contractor to make at the Contractor's own cost and expense all necessary modifications to the plans. Approval by the SO Rep of the Contractor's site planning details, revised site planning and further information provided under this subclause shall not in any way affect, relieve or vary the Contractor's liabilities or obligations under the Contract. 1.1.24

Reserved

1.1.25

Signboards Where erection of signboards with more than one language is required, all translations shall be carried out by competent translators approved by the SO Rep. All completed signboards shall be approved by the SO Rep before they are erected.

1.1.26

Air Pollution Control Comply with the relevant provisions of the Clean Air (Amendment) Act and/or requirements of other relevant Authorities. Take all necessary measures to abate the discharge of smoke, fumes or obnoxious gases or excessive noise from Construction Equipment on the Site. When notified by the SO Rep that a particular Construction Equipment or equipment is discharging excessive smoke, fumes or obnoxious gases, stop the use of that Construction Equipment, and replace the same with acceptable Construction Equipment. No claims from the Contractor shall be entertained on account of the foregoing requirements. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

1.1.27

Provision Of Bins For Waste And Debris The Contractor shall provide proper bulk bins of adequate size for storage of construction waste and debris in compliance with the requirements of ENV.

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CE Spec Page 1-11 1.1.28

Periodic Cleaning Up All rubbish and debris shall be cleared from the Site from time to time as they accumulate or as directed by the SO Rep. Particular attention shall be directed to those areas where other trades or statutory boards' contractors will be working in.

1.1.29

Pest Control And Surveillance Engage a Pest Control Operator who is registered with the BCA under the Work Head for Pest Control and NEA under the Control of Vector and Pesticide Act to provide comprehensive pest control and surveillance work on the Site. Submit the name of the Pest Control Operator and proof of BCA/NEA registration to the SO Rep for approval prior to carrying out the work. The SO Rep may disapprove the Pest Control Operator selected by the Contractor and the Contractor shall not be entitled to any claims arising from such decision. Pest control measures and surveillance programme shall fully comply with the requirements of the NEA as well as the following : (a)

Submit a detailed pest control and surveillance programme inclusive of “Source Reduction Regime/Strategy”, “Water bearing receptacle removal team” at the Site to the respective NEA’s regional office and the SO Rep prior to commencement of the Works. The frequency of fogging shall be in accordance with the requirements of the NEA. Fogging is to be carried out only by licensed Pest Operator using approved chemical.

(b)

Maintain a site register containing an up-to-date record of pest control and surveillance work that has been carried out. The site register shall be made available and ready for inspection by the SO Rep when required.

(c)

Submit monthly summarised returns of the site records required by NEA to the respective NEA regional office.

The work required under this subclause shall include all necessary measures to prevent the Site from becoming conducive to the breeding or harbouring of vectors. Carry out site checks at least once a week to detect and remove breeding and harbouring grounds. If breeding or harbouring of vectors is found at the Site, enforcement action may be taken against the Contractor by the NEA. The SO Rep may also exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

1.1.30

Temporary Services The Contractor shall provide and maintain all temporary services necessary for the execution of the Works. Give all notices and pay all dues in connection therewith. All water required for use on the Works shall be provided by the Contractor.

1.1.31

Care Of The Works And Materials The Contractor shall be responsible for the care of the Works and safe keep all materials delivered to the Site by the specialists, suppliers or sub-contractors against all risks arising from weather, negligence, damage or loss until Substantial Completion is certified by the SO Rep. Allow for all necessary watching and security lighting.

1.1.32

Fencing And Lighting Where necessary, the Contractor shall provide and fix adequate temporary fencing for fencing off the Works during construction on any part or parts of the sewers, drains, excavations, etc under the Contract and remove the fencing on Substantial Completion. Provide temporary cross bridges with proper handrails and lights over the trenches at such points and at such distances apart as in the opinion of the SO Rep may be necessary to give proper foot and vehicle access. Fencing and cross bridges shall be provided on such lengths of the sewers, drains, excavations, etc where children and others must be prevented from falling into the trenches, drains and excavations.

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CE Spec Page 1-12 1.1.33

Cables/Services Detection Visit and examine the Site carefully and ascertain its nature and make provision in the Contract Sum for the type of ground conditions, constraints and underground services. Provide cables/services detecting devices to locate all existing cables/services prior to the commencement of excavation or any other work such as driving of piles, piling of earth electrode and lightning conductors or poles and columns which are liable to damage existing buried services. Engage PUB licensed cables/services detection workers to carry out all cables/services detection work. The proposed line of excavation or area of other work shall be checked for existing services in a systematic manner by making sufficient passes in a grid formation to cover the entire area of work. The Contractor's attention is drawn to the requirements of the PowerGrid and IDA. The Contractor shall comply fully with the relevant provisions of the Public Utilities Act and Telecommunication Act or any amendment or re-enactment thereof. The Contractor shall comply fully with the Licensing Scheme for telecommunication cable detection workers by the IDA. Under the licensing scheme, the Contractor is required to engage qualified licensed telecommunication cable detection workers to locate all existing telecommunication cables/services before the commencement of excavation and earthworks (piling, dredging, boring, levelling, tunnelling, jacking, driving of any earth rod/casing/tube into the ground, etc) as defined under the Telecommunications Act 1999. The Contractor shall comply fully with the relevant provisions of the Telecommunications Act 1999 or any amendment or re-enactment thereof. The extent of the checking carried out shall be properly documented and countersigned by the SO Rep. Notwithstanding the precautions taken, the Contractor shall be liable for all costs and charges incurred if he damages any cables/services. The Contractor shall pay all charges, fees and bear all costs and expenses incurred in complying with the relevant provisions of the Telecommunications Act 1999 and Public Utilities Act or any amendment or re-enactment thereof. The Contractor shall seek assistance from the relevant Government Department or Statutory Boards if he has any query on the location of existing cables/services belonging to the Government Department or Statutory Boards. In the case of PowerGrid cables/services, the Contractor may seek assistance from the Cable Damage Prevention Unit, PowerGrid. For telecommunication cables/services, the Contractor may seek assistance from the telecommunication system licensees, PTL, SingTel, SCV and StarHub. Notify the SO Rep where mains, pipe or conduit are encountered with during excavation and where any excavation is carried out adjacent to or under any existing cable, pipe, structure; or any other such work that may be affected by subsidence as the SO Rep may direct, regardless of whether such work is shown in the Drawings or not. If it becomes essential, in the opinion of the SO Rep to permanently support the Works, build supports of grade 15 concrete or take such steps as the SO Rep may direct. Under such cases, the Contractor shall be paid for this additional work unless in the opinion of the SO Rep, such additional work has been necessitated by the Contractor's negligence, lack of foresight or faulty workmanship. In the event that damages have been caused to the public services due to the Contractor's work or otherwise, all expenditure for such necessary repairs etc incurred by the relevant public Authorities shall be borne by the Contractor regardless of whether such repairs are due to accident or otherwise. The cost and expense for such repairs shall be deducted from monies due or becoming due to the Contractor or by direct payment by the Contractor to the Authorities. If, in the opinion of the SO Rep, it is essential to permanently divert any cable, pipe or other services, such diversions shall be paid for by the Employer. Provided always that such diversions do not form part of the Works.

1.1.34

Damage To Public/Private Property In the event that damage is caused to public/private services or property such as cables, pipes, fittings and fixtures etc. by the Contractor whether by accident or otherwise leading to black-outs or other nuisance or inconvenience to the public or is likely to bring the Employer into disrepute, all costs and expenses incurred for necessary reinstatement or repairs shall be recoverable by the Employer by deduction from monies due or becoming due to the Contractor or as a debt due by the Contractor to the Employer. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

CE12/S1.DOC(12) oym(151211) DPD

CE Spec Page 1-13 1.1.35

Cleaning And Maintenance Of Roads And Drains The Contractor shall maintain the cleanliness of public roads and drains used by his vehicles throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. Construct washing bay for the cleaning of earth-laden lorries before they leave the Work Site. Clean up all deposits left by the vehicles on the road and employ sufficient workers for this operation every day. Earth droppings shall not be allowed to remain overnight either on the carriageways, pavements or in the drains. Where it is not feasible to remove deposits during normal working hours, carry out the cleaning operation during the hours between midnight and 6.00 a.m. The Contractor shall be responsible for paying any fines imposed by the relevant authorities eg. Public Health Department, Traffic Police etc. Ensure that the flow of traffic on the roads and access is maintained at all times during the Time for Completion and any time period where liquidated damages are imposed under the Contract. Provide such flagmen, approved signs and signalling equipment as may be necessary day and night to control the traffic to the satisfaction of the SO Rep and the appropriate Controlling Authority. In the planning and execution of any Temporary or Permanent Works which may affect the traffic flow and/or access to the Site or other properties, co-operate closely with the SO Rep and the appropriate Controlling Authority. Whenever required, remove with due compliance, Construction Equipment, machinery, staging and other materials which may interfere with traffic and the use of roads, footpaths or open spaces on the Site or adjacent thereto. Take every practical precaution to avoid interference with the flow of storm water through the drain, canal, culverts and other side drains etc. Any spoil, rubble, timber, rubbish or other materials which may fall into or brought into the drain, canal, culvert and other side drains etc by the storm water shall be removed forthwith. All necessary water tight flumes, cofferdams, chutes and/or other approved methods of controlling the flow of water shall be adequate for this purpose and subject to the approval of the SO Rep. Such works shall be constructed in a rigid, workmanlike manner, sufficient to withstand water pressure at its highest level. If the SO Rep considers that any temporary structure erected is obstructing the flow to an extent more than necessary, making it liable to cause flooding in the event of a rain storm, he may, one hour after notifying the Contractor or the Contractor's Representative, employ other labour and Construction Equipment to demolish such structures. All costs and expenses incurred shall be deducted from any monies, due or becoming due to the Contractor. The Contractor shall be liable for and indemnify the Employer against any actions, claims, costs and demands for damages caused by the Contractor's non-compliance of maintenance of roads and drains, flooding, slips, subsidences or other failures resulting from non-compliance by the Contractor with respect to the above. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

1.1.36

Access Roads And Protective Crossings The Contractor shall repair and maintain all access roads serving the Site and provide temporary protective crossings over existing drains, channels, footways, etc throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. Making good all damage and/or clearing away on Substantial Completion to the satisfaction of the relevant Authorities and SO Rep.

1.1.37

Demolition And Making Good The Contractor shall take care when demolishing or cutting away existing work such that no adjacent work is unnecessarily damaged in any way. Make good any work so damaged. Old materials may not be re-used in the new work, except where so specified or as directed. Exposed raw faces of existing concrete or brickwork which will not have new work built on them shall be made good with cement, rendering or new brickwork and finished to a neat, straight, vertical or plane surface in harmony with the adjoining surface.

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CE Spec Page 1-14 1.1.38

Breaking Up Of Existing Work If it is found necessary to break up existing pavement, road or footpath, etc for constructional purposes as required under the Contract, such intention of doing so shall be conveyed to the SO Rep prior to commencement of work. If construction work is to be carried out on public roads, first obtain permission from LTA. In the event that normal flow of traffic is interrupted due to the Works in progress, minimise the inconvenience caused to the public by constantly cleaning the roadway such that a steady flow of traffic is maintained. Temporary traffic directional signboards shall be installed at strategic points if required. All existing work broken up by the Contractor shall be made good to the satisfaction of the SO Rep. The reinstatement shall comply with all the requirements of LTA. Works which do not conform to the standard and requirements of the SO Rep or LTA shall be immediately removed and replaced or extended. On completion of the reinstatement, maintain all the road surfaces etc., affected during the Time for Completion and any time period where liquidated damages are imposed under the Contract. All faults, settlements etc., developed within this period shall be made good immediately upon receipt of an instruction from the SO Rep. Be liable for all claims for injury or damage arising from any Defect in the reinstated road surface during the Time for Completion and any time period where liquidated damages are imposed under the Contract and the Defects Liability Period. Adhere strictly to the requirement set out in the LTA specifications on Road Opening and Reinstatement of Trenches and the HDB Standard Conditions governing Trench Opening within HDB Estates when carrying out the Works required under this subclause.

1.1.39

Excavation Of Service Trenches And Storage Of Cable Ducts Excavate trenches for the laying of services within the contract Site. Such excavations and provision of cable ducts crossing the road shall be paid for according to the Rates if they are not indicated in the Drawings. If cable ducts are to be provided by the Service Department concerned, provide storage space on the Site and shall be responsible for their loss or damage.

1.1.40

Reinstatement Of Service Trenches All service trenches for the laying of cables, pipes, etc within the Contract boundary shall be reinstated immediately after the services have been laid and completed by the Services Authorities. All backfilling materials for cross or longitudinal trench within completed or partly completed road carriageway or carpark shall be of approved materials conforming to the following characteristics : (a)

The percentage passing 75 µm B.S. sieve shall be not more than 35%;

(b)

The fraction passing through 75 µm sieve shall have liquid limit not exceeding 35 and plasticity index not exceeding 12;

(c)

Dry density shall not be less than 1760 kg per m .

3

Dry excavated soil may be used for backfilling only in open field outside road carriageway and carparks. Backfilled materials shall be mechanically compacted in layers of 200mm and conform with the following requirements : (a)

Within 500mm of formation level - 95% of max dry density using Test No. 13 BS 1377:1975;

(b)

More than 500mm below formation level - 85% of max dry density using Test No. 12 BS 1377:1975;

Damages, directly or indirectly caused by the trench to carriageway, kerb, footpath, drain, sidetable, etc regardless of its existing condition shall be reinstated to conform to the current standard and practice of HDB.

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CE Spec Page 1-15 1.1.40

Reinstatement Of Service Trenches (Cont’d) Edges of all reinstated road pavement shall be cut straight with a power-saw. The saw-cut shall be of a minimum depth of 75mm and edge of cut shall be at least 150mm from the edge of the trench depending on the extent of damages to the road surface. Unless otherwise stated, the reinstated road pavements shall consist of the following : (a)

150mm asphalt premix

(b)

350mm compacted crusher run road base binded with granite fines

(c)

The layer below the road base to the bottom of trench shall be made up of compacted granite fines/cement dust.

The level of reinstated road shall be allowed a tolerance of + 5mm from the existing road surface level when measured with a 3m straight edge. Reinstatement of footpath shall cover the full width of the footpath. For turfed area, the reinstatement shall conform to the relevant clauses and subclause on turfing in the Specifications. The Contractor shall be paid for work done under this subclause priced in accordance with the Contract and the Rates. All backfilling materials not conforming to or not compacted according to this Specifications shall be removed and replaced with approved materials and recompacted to the stipulated standard.

1.1.41

Dumping Of Debris And Rubbish Dispose of all unwanted debris, rubble or excess earth at approved dumping grounds and bear the cost of all charges levied for the use of the dumping grounds. If the Contractor dumps debris, rubble or excess earth on land owned by the Employer or the Government without written permission, he shall have to remove all debris, rubble or excess earth from such land at his own cost and expense. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

1.1.42

Inspection Of Works Prior To Certified Completion Conduct detailed checks on the Works and rectify all Defect before arranging for the SO Rep to inspect the Works for the purpose of certifying Substantial Completion. Ensure that all items to be incorporated into the Works have been so incorporated before such inspection by the SO Rep. The SO Rep may not inspect the Works if any of the abovesaid items are not incorporated into the Works. The Contractor shall not be entitled to any claims and to any extension of time on account of such failure to ensure that all items are incorporated into the Works. After the first inspection by the SO Rep, the SO Rep shall give the Contractor a list of outstanding Defect and the Contractor shall rectify all Defect on the list within seven days. If any of the Defect in the list is not rectified on the second inspection by the SO Rep, the SO Rep may exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a charge against the Contractor. The Contractor shall be given another seven days to rectify these Defect. Should any of these Defect be found not rectified on the third inspection, the Employer may employ and pay another contractor to rectify the Defect and all costs and expenses incurred by the Employer shall be recovered from the Contractor. In addition, the SO Rep may exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a further charge against the Contractor.

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CE Spec Page 1-16 1.1.43

Cleaning Upon Substantial Completion On Substantial Completion, the Contractor shall remove all rubbish, Construction Equipment and surplus materials, wash and scrub clean all floors, pavings, drains and all parts of the Works and leave the Works in a clean and hygienic condition. The Site and periphery shall be cleared of all rubbish left from the Contractor's work.

1.1.44

Rectification Of Defect During Defects Liability Period The Contractor shall within fourteen working days from the date of the written notification by the SO Rep repair, rectify and make good to the satisfaction of the SO Rep all Defect, imperfections, shrinkages and other faults arising from or out of the use of materials or workmanship not in accordance with the Contract or from neglect or failure by the Contractor to comply with any obligation on his part under the Contract, which may become manifest. If the Contractor fails to carry out his obligation as aforesaid, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a charge on the Contractor. Without prejudice to the foregoing provisions, the Employer shall have the right to engage other person(s) or contractor(s) to repair, rectify and make good all such Defect, imperfections, shrinkages and other faults if the same are not repaired, rectified and make good after fourteen working days from the date of written notification by the SO Rep and the cost and expense incurred shall be recovered from the Contractor. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose a further charge on the Contractor.

1.1.45

Noise Nuisance Judicious management and control over the activities within the Site shall be exercised by the Contractor for the abatement of noise nuisance. All necessary actions shall be taken to ensure compliance to the latest noise control regulations imposed by the ENV or any relevant authorities.

1.1.46

Recovery Of Legal Costs For Court Proceedings All legal costs, charges and expenses (including but not limited to solicitors' fees as between solicitor and client) incurred by the Employer for the purpose of or incidental to the enforcement by the Employer of any rights and remedies under the Contract or any other contracts between the Employer and the Contractor or in respect of any garnishee proceedings which may be brought or commenced against the Employer by the Contractor's creditors may be deducted by the Employer from monies due or becoming due to the Contractor including any retention monies, financial bonds or security deposits or other bonds.

1.1.47

Machinery Boundary The Contractor shall comply with the Mass Rapid Transit Corporation Code Of Practice For Railway Protection when the works are carried out within Mass Rapid Transit Corporation protection zone. Submit proposals on effective measures for the protection of Mass Rapid Transit above ground structure together with the detail of activities of mobile cranes, tower cranes and other mechanical equipment adjacent to Mass Rapid Transit line structures to the SO Rep for approval at least one month prior to the use of such equipment. No jib or lifting appliance or any other moving or stationery part of the mechanical equipment shall encroach within 6m on plan from the edge of the nearest Mass Rapid Transit above-ground or atgrade structure unless the equipment is restricted to work beneath the structure. The foundation of the mechanical equipment shall be certified structurally sound and adequate by the Contractor's professional engineer prior to its installation. Auto cut-off system shall be installed for tower cranes to prevent the top of boom to swing closer than 6m from edge of viaduct structure. The jibs of the cranes must always be pointed away from Mass Rapid Transit line structure. The temporary access shall be stable and level for machinery to move on. Regular checks shall be carried out to ensure that all mechanised equipment are in good working condition at all times. Only experienced, trained and competent operators shall be employed for mobile cranes, tower cranes and other mechanical equipment. Temporary height restriction gantry with signboard shall be installed 6m away from the edge of both sides of viaduct structure for any access passing underneath the Mass Rapid Transit line structures.

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CE Spec Page 1-17 1.1.48

Mobile Cranes Before the use of mobile crane, the Contractor shall submit the following to the SO Rep for approval and record : (a) (b) (c) (d)

Layout and details of crane access endorsed by Contractor's PE. Technical data of cranes. Latest 3 - monthly maintenance certificate. Latest overhaul check certificate.

Before putting the crane into operation, the Contractor shall submit the following documents and data to the SO Rep for record. Copies of all relevant documents shall be kept in the site office or in the cabins of the cranes, as the case may be. (a) (b) (c) (d) (e) (f)

Certificate of test/thorough visual examination of lifting equipment. Inspection record for the construction of crane access. Rules for the safe use of cranes. Certificate of competency licensed for crane operator. A capacity chart for each type of crane used. Name of supervisor who supervises the hoisting operation, positioning and slewing.

The licensed crane operator must carry out daily inspection of cranes before use. The Contractor shall ensure that the construction of crane access is properly constructed and carry out daily check of crane access. Steel plates shall be laid over the compacted hardcore for the crane access if the Site is next to existing buildings, public roads and MRT lines. Barriers shall be installed next to the depression or excavated area. The Authorised Examiner shall submit the checklist of his inspection and testing of cranes to the Contractor. Test certificate, overhaul certificate, maintenance certificate, all inspection records by licensed crane operator, site engineers, Authorised Examiner shall be properly documented and kept on the Site for examination by the SO Rep upon request. Moment limiters shall be installed for all cranes. The Safety Factor for mobile crane shall have a minimum of 1.3 which includes the built-in factor of safety for the mobile crane. The lifting load shall include the weight of the component, the spreader beam and the lifting device. The tip load shall have the capacity to hoist the heaviest component including all necessary lifting appliances. A Permit-To-Hoist must be obtained before any hoisting operation is carried out. The Contractor shall station a supervisor full time on the Site to supervise and guide the licensed crane operator. The use of crane shall be stopped immediately should the Contractor fail to comply with all the above requirements.

1.1.49

Work Site Computer Equipment Provide the following computer hardware, accessories and software within the Time for Completion for the exclusive use of the SO Rep : Computer Hardware and Accessories (hereinafter referred to as `the Hardware' for the purposes of this clause including sub-clauses) :  1 number Pentium 4 PC;  1 number A4 Laser Printer;  1 number A4 Color Scanner;  1 number Broadband Modem with Broadband Communication Line, or a 56Kbps Data/Fax Modem with 1 additional Telephone Line, or a Wireless Device as required by the SO Rep;  1 number Uninterruptible Power System;  1 number PC Screen Filter;  10 numbers 3.5 inch Floppy Diskettes; Computer Software (hereinafter referred to as `the Software' for the purposes of this Clause including sub-clauses) :  1 number Microsoft Windows 2000 Professional Edition, or latest version;  1 number Microsoft Office 2000 Professional Edition, or latest version;  1 number Norton Internet Security software Version 3.0, or later,  1 number F-Secure Anti-Virus version 5.40, or later. Hardware previously approved for HDB work sites shall also be accepted provided that the approved PC is upgraded to (1) 512 MB RAM and installed with a 30 GB hard disk, a 48-speed CDROM drive and a 250MB Zip Drive, or better, (2) the modem is a broadband modem or 56Kbps modem, or a wireless device as required by the SO Rep. Software previously approved for HDB worksites shall be upgraded to the versions as described in this Clause.

CE12/S1.DOC(17) oym(151211) DPD

CE Spec Page 1-18 1.1.49

Work Site Computer Equipment (Cont’d) Ensure that the Hardware and Software are in good working condition to the satisfaction of the SO Rep, and pay for all maintenance and license fees for the Hardware and Software throughout the period from one week before contract commencement until three weeks after the Date of Substantial Completion. Also 2 pay for all expendable items including 80g per m A4 printing papers, toner cartridges, image drum, diskettes, screen cleaning kits, subscription, excess-hours usage and service maintenance fees related to communication devices etc during the same period. Also provide the necessary furniture, including separate table and chair for the computer equipment, and light partitions if required and as approved by the SO Rep. Also provide plastic dust covers, accessories, adequate power supply including uninterruptible power system and additional telephone line at the Contractor's own expense to accommodate and facilitate the usage of the Hardware and Software. Provide a communication device, either an broadband device, a 56Kbps modem device or a wireless device as required by the SO Rep. Pay for such device, all related charges including installation, registration, connection, subscription, usage, service maintenance, and expendable items including batteries etc for the device. Submit specifications and details of the Hardware and Software for approval by the SO Rep TWO WEEKS before contract commencement and BEFORE the purchase or leasing of the Hardware and Software. Also make and pay for such necessary arrangement for the hardware and software to be tested at the relevant Consultant’s office and subsequent delivery to work site upon request by the SO Rep. Ensure that only authorised software are used with the Hardware and obtain written approval from the SO Rep before installing any software other than the ones specified herein into the Hardware. Also ensure that the Hardware and Software are not used for any other purpose unless approved in writing by the SO Rep. If the Contractor fails to make available the Hardware and Software by one week before contract commencement or fails to rectify within 3 days any hardware or software faults, the SO Rep will make the necessary arrangement to acquire or to rectify and all expenses thus incurred shall be deducted from the payment due to or becoming due to the Contractor. Make all necessary arrangement and provision for securing the Hardware and Software in the site office. Replace any stolen or missing Hardware and Software within 3 days of such occurrence, failing which the SO Rep will make the necessary arrangement to acquire the Hardware and Software and all expenses thus incurred shall be deducted from the payment due to or becoming due to the Contractor. Make and pay for such necessary arrangement for the hardware to be delivered to the relevant Consultant’s office for trouble-shooting of PC problems, software upgrade and removal, and subsequent delivery to work site upon request by the SO Rep. All the Hardware and Software except the Zip disks, floppy diskettes, computer printed materials, working files and HDB application files created or installed by the SO Rep will be returned to the Contractor three weeks after the Date of Substantial Completion. The Hardware shall comply with the following technical specifications : (a)

IBM PC or compatible Shall be a PCI-bus Intel Pentium 4 PC, certified by Novell Testing Laboratory for working as a Netware 5.1x client workstation, or belongs to a PC family an earlier model of which was certified by the same authority, or certified under ISO 9001 or 9002 by the proper authority, or other approved by the SO Rep. Able to work with the Local Area Network located at the relevant Consultant’s office through broadband communication line, telephone line or wireless device. Able to withstand the current and voltage variations as supplied from ordinary power generator on the Site through uninterruptible power system. Appropriate protection against rough handling on construction site and RF interferences.

CE12/S1.DOC(18) oym(151211) DPD

CE Spec Page 1-19 1.1.49

Work Site Computer Equipment (Cont’d) (a)

IBM PC or compatible (Cont’d) The PC shall also comply at least with the following specifications :  Provided with Intel Pentium 4 2.0 GHz or higher processor;  Provided with 256 KB integrated, full-speed L2 cache;  Provided with Intel 845 Chipset. or better;  Provided with at least 512 MB of PC133 SDRAM or better, upgradeable to 3 GB or more.  Provided with flash system BIOS of the version not earlier than 12 months from the date of delivery.  Provided with at least two empty 32-bit PCI expansion slots, one AGP 4x slot, four USB 2.0 ports, one parallel port, two serial ports, and two PS/2 ports.  Provided with one AGP 4x or higher video card with at least 32 MB of video memory.  Provided with one Sound Blaster compatible sound card and amplified stereo speakers.  Provided with one 1.44 MB 3½-inch floppy diskette drive.  Provided with one 30 GB, 7200 rpm, IDE ATA100 hard drive, or better.  Provided with one 48x or higher internal IDE CD-ROM drive.  Provided with one 17-inch SVGA color monitor, 0.28 mm or smaller dot-pitch, 32-bit true color at 1024 x 768 pixels, 75 Hz or higher vertical frequency and 35 kHz or higher horizontal frequency.  Provided with one 104-key Windows keyboard.  Provided with one Microsoft optical wheel mouse or equivalent with one rubber-based mouse pad not smaller less than 8-inch by 9½-inch.  Provided with one power supply of at least 200 watt at 220/230V 50Hz.  Provided with one Netrust compatible smart card reader.  Provided with locking device for locking the system chassis and monitor to office furniture or fixtures.  Provided with locking device for locking up the system chassis to prevent access to internal components.  Preloaded with Microsoft Windows 2000 Professional or later.  Certified by Microsoft for compatibility with the provided Windows operating system.  Able to work with the other Hardware and Software as specified in this Specifications.

(b)

Laser Printer Shall be a A4 laser printer, or other approved by the SO Rep. The printer shall also comply with the following specifications :  Support PCL language.  Print at 8 pages per minute.  Print at 600 x 600 dpi resolution.  Provided with 45 scalable TrueType fonts, and support downloadable bitmap fonts.  Provided with 2 MB of RAM in additional to ROM memory.  Achieve a duty cycle of 2500 single-sided pages per month.  Provided with USB or Parallel Interface  Provided with 100-sheet Input Bin and 100-sheet Output Bin for A4-size paper.  Support A4, letter, legal and executive paper size.  Print on single sheet paper, envelopes, mailing labels and transparencies.  Support Windows Plug and Play installation.  Able to work with the Software as specified in this Specifications.

(c)

Colour Scanner Shall be a A4 flatbed colour scanner, or other approved by the SO Rep. The scanner shall also comply with the following specifications :  Provided with colour CCD photoelectric device.  Support A4 and letter document size.  Support Micro Step Drive technology.  Support colour 42-bit and grayscale 14-bit scanning depth.  Scan at 1200 x 2400 dpi optical resolution.  Scan at 32 sec per page for colour 300dpi A4 page and 11 sec per page for monochrome 300dpi A4 page.  Provided with USB interface.  Support film adaptor.  Able to work with the Software as specified in this Specifications.

CE12/S1.DOC(19) oym(151211) DPD

CE Spec Page 1-20 1.1.49

Work Site Computer Equipment (Cont’d) (d)

Communication Devices The communication device shall be a broadband modem with a broadband communication line, or a 56Kbps modem with one additional telephone line, or a wireless device as required by the SO Rep. The specifications for each mode of communication are specified below : (i)

Broadband Modem Communication  Shall subscribe to IDA-approved broadband provider in Singapore.  Shall provide one Broadband Modem, User Guide and Software CD.  Shall provide Splitter, Microfilters, or Dual-jack Adapter if applicable.  Shall provide communication line for broadband modem.  Shall pay for all one-time charges including modem and accessories, registration, installation, un-installation, un-registration and related fees for the broadband service.  Shall pay for recurrent charges throughout the period from one week before contract commencement until three weeks after the Date of Substantial Completion including subscription fee, usage fee, all excess-hours usage charges, and service maintenance charges for the broadband service.  Shall pay for the registration fee, installation fee, subscription fee, usage fee and related fees for the communication line used for the broadband communication.  Shall submit monthly broadband subscription bills to the SO Rep for record purpose.  Shall work with the communication infrastructure installed in the HDB and worked with the VPN software provided by the HDB.  Shall be compatible with the proposed hardware and software.

(ii)

56Kbps Modem Communication  Shall provide a ITU V.90 56Kbps data/fax modem with one additional telephone line.  Shall pay for all charges related to the use of the telephone line including registration fee, installation and connection fees, subscription fee, usage and related fees. The Modem shall also comply with the following specifications :  Shall pass a file-transfer benchmark test set by the Civil Engineering Department, HDB.  Shall transmit at speeds up to 56Kbps with throughput up to 115.2Kbps.  Shall be able to work with Class 1 or Class 2.0 fax software to exchange faxes with Group III fax machines worldwide at speeds up to 14.4Kbps.  Shall support basic AT command set.  Shall be provided with surge protector.  Shall be compatible with CISCO 3640 ISDN Communication Server.  Shall be compatible with other proposed Hardware.  Shall be compatible with ITU V.90 56 Kbps, and ITU V.34 33.6 Kbps.  Shall be compatible with ITU and Bell standards from 56 Kbps to 1.2 Kbps.  Shall have V.42/MNP 2-4 error control, V.42 bis/MNP 5 data compression.  Shall support Windows Plug and Play installation.

(iii)

Wireless Communication The proposed Wireless Device shall comprise of a Data Card with support software and drivers. Shall pay for all charges related to the use of the wireless communication including registration fee, installation and connection fees, subscription fee, usage and related fees. The Wireless Device shall comply with the following specifications :  Certified by Info-Communications Development Authority of Singapore for use in Singapore.  Shall be a GSM or GPRS or 3G device whichever approved by the SO Rep.  Shall support wireless data communication between the proposed PC and the Computer Servers located at HDB Hub.  Provided with all necessary support software for data communication with the Wide Area Network Servers located at HDB Hub.  Provide data and fax capability.  Shall be a PCMCIA card or equivalent.  Provided with necessary internal or external adapter for the PCMCIA card to work with the proposed PC;  Compatible with the proposed hardware and software.

CE12/S1.DOC(20) oym(151211) DPD

CE Spec Page 1-21 1.1.49

Work Site Computer Equipment (Cont’d) (e)

PC Screen Filter The Proposed PC Screen Filter shall comply with the following specifications :  Shall be full 17 inch diagonal viewing area.  Shall eliminate up to 99% VDT glare.  Shall block minimum 98% ELF/VLF E-Field radiation.  Shall block ultraviolet ray (UV `A' 90% UV `B' 100%).  Shall reduce reflection by up to 99%.  Shall eliminate static charge & dust build up.  Shall eliminate screen flicker.  Shall enhance contrast, color and resolution.  Shall have high efficiency anti-reflective (HEA) & anti-glare coating on both sides of filter.  Shall be made of durable tempered glass or equivalent.  Shall be made of flat frame with hangers.  Shall be life time warranty.

(f)

Uninterruptible Power System The proposed Uninterruptible Power System shall be able to protect the Hardware from voltage surges and provide a minimum 15 minutes backup time at full load from power failure. The Uninterruptible Power System shall also comply with the following specification :  Shall have input voltage of 230 Volt AC.  Shall have input frequency of 50/60 Hz single phase.  Shall have output power rating of 600/400 VA/Watts.  Shall have output voltage of 220 - 230 Volt AC.  Shall have sine wave output waveform.  Shall have output frequency of 50/60 Hz.  Shall sound alarm during power surges and when input power fails.  Shall have appropriate protection against power surges.  Shall have maintenance-free spill-proof sealed battery.

1.1.50

Workers' Quarters All workers' quarters erected on the Site shall be constructed using metal containers. If the Contractor does not wish to use metal container for the workers' quarters, he may propose to use suitable proprietary system/material (other than timber and plywood) for the design of the workers' quarters which shall be subject to approval by the SO Rep. The Contractor shall submit detailed drawings of the proposed workers' quarters, which shall be aesthetically acceptable. Proposals for the design, configuration and layout, taking full consideration of the site constraints and conditions, shall be submitted to the SO Rep for approval within two weeks upon taking over the Site. Qualified persons shall be appointed to look into the details pertaining to structural design, sanitary, water and electrical installations. These detailed plans for the proposed structure including design calculations shall be certified by the Contractor's Professional Engineers and submitted to the SO Rep prior to the construction. The design shall comply with all statutory (e.g. ENV & PUB) requirements and the Technical Guidelines for the Fire Safety in Temporary Buildings in Construction Sites, including any amendment thereto, issued by FSSD; and the Building Control (Temporary Buildings) Regulations including any latest requirements by BCD, BCA. The Contractor shall erect the workers' quarters strictly in accordance with the details pertaining to structural design, sanitary & water installations and electrical installations, as certified by his Professional Engineers and the HDB approved site layout plans. The Contractor shall submit to the SO Rep, the Certificates of Supervision endorsed by the Professional Engineers, for the erection of the workers' quarters. The workers' quarters shall comply with the following general requirements : 1.

Centralised cooking area shall be provided and shall be compartmentalised if there are more than one religious group staying in the workers' quarters. The cooking area shall be located away from the workers' quarters.

2.

One rubber bin shall be provided in each container and at each staircase for the disposal of rubbish. All refuse shall be cleared off from the Site daily.

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CE Spec Page 1-22 1.1.50

Workers' Quarters (Cont’d) 3.

Cabinets for each worker to put clothing within the container shall be provided.

4.

"No Smoking/No Littering" signboards shall be displayed at conspicuous location.

5.

No additional wiring shall be allowed within the container other than those provided.

6.

White lights and wall fans shall be installed in each container and also along the corridor.

7.

Two no. of casement/sliding glass windows shall be provided per container.

8.

Electrical installations/wiring shall be checked monthly by a qualified electrician.

9.

Properly zoned and covered area at the ground floor, near the workers' quarters, shall be provided for the hanging of wet clothing.

10.

The external facade of the workers' quarters shall be painted to a colour scheme as approved by the SO Rep. The Contractor shall submit the proposed colour scheme to the SO Rep for approval within two weeks upon taking over the Site.

11.

House rules in appropriate languages shall be displayed in workers' quarters.

12.

The container shall be of minimum size 3.0 m x 6.0 m and not more than six persons shall be allowed to stay in one room.

13.

The staircase and the corridor shall have a minimum clear width of 1.2 m.

14.

One chemical powder fire-extinguisher for every 3 containers shall be provided.

15.

One staircase shall be provided for every six containers.

16.

Proper apron, apron drain and rainwater downpipe shall be constructed along the perimeter of the workers' quarters, to cater for the expected high volume of roof water runoff. The Contractor shall ensure that any additional roof structures installed above the topmost container, is structurally stable and be able to resist any wind uplift.

17.

Durable and fire resistant materials with fire rating of not less than half hour shall be used for all the internal partitions of workers' quarters, e.g. container type, composite metal panels or other types approved by the SO Rep.

18.

The Contractors shall ensure that all occupants maintain their respective container and also keep the corridor clean at all times.

19.

Names and particulars of occupants shall be clearly displayed outside their rooms. Workers shall not be allowed to exchange rooms without prior approval from the Contractor's Project Manager or the Contractor's Representative.

20.

One first aid box with suitable materials, depending on the number of workers, shall be provided at every storey.

21.

Workers' quarters shall not be used for storage or handling of toxic and other harmful substances.

22.

Daily inspection shall be carried out by the site foreman or the Contractor's Representative to ensure compliance.

23.

Facilities around the workers' quarters like wash area, bathing area and clothes hanging areas are to be connected by a fully covered linkway to the workers' quarters.

24.

Organise training and awareness programs for the occupants in First Aid, health and safety, fire fighting technique and evacuation procedure.

Notwithstanding the above mentioned requirements, the Contractor shall maintain the workers' quarters in a clean, tidy and hygienic condition and ensure that fire safety shall be observed at all times. The Contractor shall also be responsible for all damages and shall indemnify the Employer against all liabilities in respect of the workers' quarters on the Site. On Substantial Completion of the Works or as and when instructed by the SO Rep, the Contractor shall remove the workers' quarters in a safe and orderly manner.

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CE Spec Page 1-23 1.1.51

Assessment Of Extension Of Time Due To Exceptionally Inclement Weather The assessment of exceptionally inclement weather shall not take place until the expiry of the Time for Completion or extended Time for Completion. Such assessment shall be made on the following basis :

1.1.52

(a)

There shall first be assessed the number of wet days on which the Contractor has been substantially delayed in the carrying out of the Works by rain (hereinafter called "delay days").

(b)

A wet day shall be one where the rainfall figure as calculated as described in this sub-paragraph exceeds 10.2 mm during the 24 hour period used by the Meteorological Service. The rainfall figure shall be the average island-wide rainfall calculated by the Employer using rainfall records received by the Employer monthly from the 5 Standard Stations of the Meteorological Service.

(c)

The expected number of wet days during the Time for Completion or extended Time for Completion as the case may be shall be derived from the following table which is deemed to record the average number of wet days for the respective months based on the Meteorological Service's records between 2001 and 2010 (hereinafter call "expected wet days") : Jan

Feb

Mar

Apr

May

Jun

8

3

9

9

6

5

Jul

Aug

Sep

Oct

Nov

Dec

7

6

7

7

9

9

(d)

For each month of the Time for Completion or extended Time for Completion as the case may be there shall be assessed whether the number of delay days in that month is more than (positive) or equal to (zero) or less than (negative) the expected wet days in that month.

(e)

The positive, zero and negative monthly assessments made in accordance with sub-paragraph (d) shall then be added together and a net total reached. If such total is a positive number then such total shall constitute the extension of time for exceptionally inclement weather.

Insurance Policies The Contractor shall warrant that the insurance policies issued in accordance with Clauses 27 and 28 of the Conditions shall include the following requirements : (A)

(B)

CE12/S1.DOC(23) oym(151211) DPD

Insurance For Work Injury Compensation (i)

The Policy shall be issued in the prescribed form as produced in Appendix A11.

(ii)

The Insured shall be "(Name of Contractor to insert) as Contractor and all his subcontractors, and the Housing & Development Board as Principal FTRR & I".

(iii)

The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.

Insurance For Personal Injury And Property Damage (i)

The Policy shall be issued in the joint names of the Employer, the Contractor and all his subcontractors.

(ii)

The limits of liability shall be read as follows : (a) In respect of any one accident : $2,000,000.00 (b) Unlimited for the period of insurance

(iii)

The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.

(iv)

The period of notice for cancellation of the Policy, if such period is stipulated, shall read 30 days.

CE Spec Page 1-24

1.1.52

Insurance Policies (Cont’d) (B)

Insurance For Personal Injury And Property Damage

(Cont’d)

(v) The Policy shall expressly include coverage of the following risks :

(vi)

CE12/S1.DOC(24) oym(151211) DPD

(a)

Death, bodily injury or damage to property caused or occasioned by the Insured's sub-contractors or by such sub-contractors' employees.

(b)

Death, bodily injury or damage to property caused or occasioned by or connected with or arising from the ownership, possession or use by or on behalf of the Insured of any equipment or machinery not expressly specified in the Schedule of such equipment or machinery.

(c)

Liability assumed by the Insured by agreement, unless such liability would have attached to the Insured notwithstanding such agreement.

(d)

Liability in respect of loss or damage to property belonging to or in the charge or control of the Insured or of any servant or agent of the Insured.

(e)

Liability in respect of injury to or illness of any person or loss or damage to any property or land or building caused by vibration or removal or weakening of support.

(f)

Liability in respect of injury, illness, loss or damage caused by or connected with or arising from any commodity, article or thing supplied, repaired, altered or treated by or to the order of the Insured, happening at any of the Insured's premises.

The Policy shall expressly contain the following endorsements : (a)

"This Policy shall cover all the Contractor's insurance obligations with regard to personal injuries or death and injury or damage to property real or personal (including property of the Housing & Development Board but not the Works themselves) arising out of or in the course of or by reasons of the carrying out of the Works stated in the Contract between the Housing & Development Board and the Contractor (name of Contractor to insert)"

(b)

"Each of the parties comprising the Insured shall for the purpose of this Policy be considered as a separate and distinct unit and the words "the Insured" shall be considered as applying to such party in the same manner as if a separate policy had been issued to each of the parties and the insurers hereby agree to waive all rights of subrogation action which they may have or acquire against any of the aforesaid parties arising out of any accident in respect of which any claim is made hereunder provided nevertheless that nothing in this clause shall be deemed to increase the limitation on extent of Insurer's liability in respect of any one accident or series of accidents as stated in the Schedule".

(c)

"This Policy is extended to cover the employees and/or representatives of the Housing & Development Board, consultants, other professional parties and Resident Technical Officer whilst on the contract site as third parties".

(d)

"Notwithstanding anything stated in the Policy to the contrary, cover under the Policy shall not be suspended in the event of stoppage of work by the Contractor on the contract site from any cause for a period not exceeding 90 days. In the event of partial or total cessation of work, the Insured shall use diligence and do all things reasonably practicable to protect the insured property. Subject otherwise to the Terms Exceptions and Conditions of this Policy".

(e)

"All deductibles shall be borne by the Contractor".

CE Spec Page 1-25

1.1.52

Insurance Policies (Cont’d) (C)

1.1.53

Insurance For Works (i)

The Policy shall be issued in the joint names of the Employer and the Contractor.

(ii)

The Works insured shall read the project title given in the Employer's Letter of Acceptance.

(iii)

The sum insured shall be the same as the Contract Sum.

(iv)

The period of insurance shall commence from the date the Site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract. The Policy shall firstly cover the whole of the original Time for Completion plus 6 months and plus a further 12 months for Defects Liability Period.

(v)

The period of notice for cancellation of the Policy, if such period is stipulated, shall read 30 days.

(vi)

The policy shall expressly contain the following endorsements : (a)

"This Policy shall cover all the Contractor's Works insurance obligations stated in the Contract between the Housing & Development Board and the Contractor (name of Contractor to insert)".

(b)

"Notwithstanding anything stated in the Policy to the contrary, cover under the Policy shall not be suspended in the event of stoppage of work by the Contractor on the contract site from any cause for a period not exceeding 90 days. In the event of partial or total cessation of work, the Insured shall use diligence and do all things reasonably practicable to protect the insured property. Subject otherwise to the Terms Exceptions and Conditions of this Policy".

(c)

"All deductibles shall be borne by the Contractor".

Contract Documents On Site The Contractor shall keep a complete set of the signed Contract documents described in the Agreement; and a complete set of the further or revised Drawings and instructions referred to in the Conditions, at the Site. The documents shall be made available for inspection and use by the Superintending Officer, SO Rep and any other person authorised by the Superintending Officer in writing.

1.1.54

Lightning Protection To Temporary Structures And Metal Structures The Contractor shall ensure that all temporary structures such as site office, workers' quarters, site canteen, carpenter and bar bending sheds, temporary structures with continuous metal such as steel framework, scaffolding, tower cranes and batching plants and mobile machineries such as crawler cranes and concrete pumps are adequately and effectively protected from lightning strike at all times. The lightning protection shall be in accordance with and complying with Singapore Standards CP 33:1985 and/or any latest requirements by the Building Control Division. Notwithstanding the provisions of CP33, reinforced concrete structure and foundation shall not be used as lightning conductors or earth electrodes. Lightning conductors shall not be embedded in any structural component and steel reinforcement shall not be used as part of the protection system.

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CE Spec Page 1-26 1.1.55

Environmental Public Health Measures (a)

General Requirements The Contractor shall allow for the compliance with the Environmental Public Health Act (hereafter referred to as "the Act" for the purposes of this sub-clause) and its Subsidiary Legislations including the Environmental Public Health (Employment of Environmental Control Officers) Order 1999, (hereafter referred to as "The Order" for the purposes of this sub-clause) and any amendment or reenactment thereto throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract.

(b)

Environmental Control Officer (ECO) The Contractor shall employ Environmental Control Officer (ECO) to comply with the Environmental Public Health Act - Environmental Public Health (Employment of Environmental Control Officers) Order 1999. The ECO shall be employed on a full-time basis for Contract Sum valued above $50 million or on a part-time basis for Contract Sum valued between $10 million and $50 million. The ECO shall be responsible for monitoring and advising the Contractor on the following main areas : (i) (ii) (iii) (iv) (v) (vi)

Control of disease-bearing vectors and rodents. proper management and disposal of solid waste. Control of noise and dust pollution. Drainage and silt control. Air and water pollution control. General housekeeping management of the project.

The ECO shall conduct regular site checks and take prompt corrective actions to ensure that the workers' quarters, canteens, toilets, site offices and other facilities and general surroundings of the Site are kept clean, tidy and hygienic at all times. In addition, the ECO shall also ensure that the Site is kept mosquito-free at all times. Any Workplace Safety & Health Officer who is registered with the MOM under the Workplace Safety & Health Officer Scheme and who is also registered as an ECO with the Director-General of Public Health, NEA, can be allowed to hold both the appointment of Workplace Safety and ECO concurrently for the Works at the Site provided that both officers' duties are performed with the same standard of supervision as that performed by different officers holding such appointment separately. If the Works have been certified more than 95% complete, the contractor may write to NEA’s Regional Office to seek approval to allow the ECO to perform on a part-time basis and copied to SO rep. There shall be no cost recovery from the contractor if NEA is agreeable to allow the ECO to perform on a part-time basis. 1.1.56

Trade Subcontractors The Contractor, with the exception of his own direct employed workers, shall engage only BCA registered contractors or corporations/firms listed in the HDB Materials List for executing the Works for the following trades : (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18)

CE12/S1.DOC(26) oym(151211) DPD

Timber formwork; Metal formwork; Steel reinforcement work; Structural steel fitting; Concreting; Bricklaying; Joinery; Painting; Plastering; Roofing; Tiling; Electrical engineering; Air-conditioning, refrigeration & ventilation works; Plumbing & sanitary and gas piping; Fire protection; Waterproofing; Piling; Concrete repairs;

CE Spec Page 1-27 1.1.56

Trade Subcontractors (Cont'd) (19) (20) (21) (22) (23)

Metal work; Cable installation & road reinstatement; Drain laying/Pavement & kerb construction; Curtain Wall/Cladding; Metal scaffolding (Erectors);

At least 14 days before the commencement of the Works by the subcontractors for the respective trades, the Contractor shall submit the name of his subcontractors for the Works to the SO Rep. Where the Contractor changes his subcontractor, he shall also submit such information to the SO Rep. For the purposes of this clause, the relevant BCA register and the HDB Materials List shall be those applicable at the commencement of work for the respective trades. The Contractor shall be responsible for any eventual delay in the progress of the Works owing to his failure to ensure the required on-time registration of his subcontractors and no extension to the Time for Completion shall be granted on account of such delays. 1.1.57

Work On MRT Reserve Area The Contractor shall provide and practise all precautionary measures for all works near or in within the MRT reserve area. The Contractor shall comply to all requirements as required by the Land Transport Authority for any extra precautionary construction activities to safe-guard the existing MRT structures/property involved. The Contractor shall also provide the PE design details if required to substantiate the work involved in the MRT Reserve area. All cost shall be borne by the Contractor and shall be included in the Contract Sum. The Contractor shall : (a)

Comply with all the general requirements of the Land Transport Authority and any other aspects of the proposed development that may affect the MRT and its operation.

(b)

The Contractor shall note the requirements for the works falls within the Land Transport Authority’s Railway Protection and Safety Zones as defined in the MRT Railway Protection, Restricted Activities Regulations 1994 or any amendment or re-enactment thereof. The Contractor shall comply with all conditions and requirements imposed by Land Transport Authority including the employment of Professional Engineer (Civil) to supervise all works within the Railway Protection Zone, engaging a Professional Engineer (Mechanical) to check and certify cranes and machinery, submission of plans to obtain clearance from Land Transport Authority before commencement of works, monitoring instrumentation and all other related works. All costs and expense are deemed to be included in the tender.

CE12/S1.DOC(27) oym(151211) DPD

CE Spec Page 1-28 1.1.58

Stationery For Resident Technical Officer The Contractor shall provide stationery for use on site by the Employer's officers upon commencement of the Works. The stationery to be provided shall be in accordance with the following schedule: Item No.

Description

Quantity

1

Ball Point Pen (Black/Blue/Red)

2 no. each per Resident Technical Officer.

2

Correction Fluid

1 no. per Resident Technical Officer

3

Eraser (Pencil)

1 no. per Resident Technical Officer

4

Exercise Book - 60 pages

1 no. per Resident Technical Officer

5

Glue Tube

1 no. per Resident Technical Officer

6

Hard cover Book – A4 size

1 no. per Resident Technical Officer

Manila File

2 no.

Paper Clip : a) Medium Size b) Large Size

a) b)

9

Pen Knife

2 no.

10

Pencil (2B)

2 no. per Resident Technical Officer.

11

Perforator

1 no.

12

Pocket Notebook

1 no. per Resident Technical Officer.

13

Ruler (300 mm)

1 no. per Resident Technical Officer

14

Scissors

1 no.

15

Staple (B3)

1 no.

16

Staples (B3)

1 no.

17

Calculator (without scientific functions)

1 no.

18

Highlighter of Assorted Colours

1 set

19

Scale Ruler

1 no.

20

Writing Pad (A4)

1 no. per Resident Technical Officer.

21

Ear Plugs

1 no. per Resident Technical Officer

22

Measuring Tape

1 no.

23

Measuring Tape of minimum 5 metre length

1 no.

24

Rubber Stamp (Contract Details)

1 no.

25

Rubber Pad (Violet)

1 no.

8

2 boxes. 2 boxes.

Should the Contractor fails to provide any of the aforementioned stationery after the commencement date of the Time for Completion, the SO Rep shall forthwith purchase and provide the same on the Contractor's behalf and all costs and expenses for such purchase and provision plus charges shall be recovered by the Employer from any monies due or becoming due to the Contractor or be recovered as a debt due by the Contractor to the Employer.

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CE Spec Page 1-29 1.1.59

Earth Control Measures The Contractor shall be responsible for preventing silt from being washed into public drains by implementing effective Earth Control Measures (ECM) for the construction site to meet the requirements under the latest Sewerage and Drainage Act Cap 294. (Information on ECM requirements can be found in the Code of Practice on Surface Water Drainage and the website www.pub.gov.sg/ECM). The Contractor shall note that the ECM are for the containment and treatment of silty discharges due to the impact of rainwater. ECM are not meant for the treatment of wastewater due to construction activities (such as slurry from tunnelling, pipe-jacking and bore-piling works) which shall be treated to comply with the requirements under Environmental Protection and Management Act (EPMA) (Chapter 94A). The Contractor shall submit in his Tender, the schematic ECM plans of the Site for the whole of the Time for Completion including any time periods where liquidated damages are imposed under the Contract, taking into account the different phases of construction activities. He shall also provide the name of the Qualified Erosion Control Professional (QECP) who will be endorsing the ECM plan after the tender is awarded. These schematic ECM plans shall make the Contractor aware of the ECM requirements to implement an effective ECM. Notwithstanding the submission of these schematic ECM plans, the Contractor shall be deemed to have included all costs and expenses for complying with all the ECM requirements in the Contract Sum Before construction works commence on site, the Contractor shall engage a QECP to plan and design the ECM, and he shall install the ECM according to the QECP's design. The ECM plan and design shall be submitted 1 week after the award of the contract. During the course of the construction works, the Contractor together with his QECP shall review the ECM proposal regularly to meet the changing needs of the construction activities. The Contractor shall improve the ECM as advised by his QECP. The planning and design of the ECM shall meet the minimum requirements stipulated and in accordance to the Code of Practice on Surface Water Drainage. The Contractor shall maintain the ECM for the whole duration of the Time for Completion including any time periods where liquidated damages are imposed under the Contract, to ensure that it is effective at all times. Proper records detailing the maintenance works, supported by dated photographs, shall be kept by the Contractor for verification. The Contractor shall not remove the ECM until all works are completed and upon the advice of his QECP. The Contractor shall submit the ECM proposal duly endorsed by his QECP to PUB for records. The proposed ECM shall consist of the following four parts: (i)

Project Particulars The following information shall be provided under the Project Particulars: (a) Project description; (b) Name and address of site occupier; (c) Site area and contract period; and (d) Location map and site plan.

(ii) Erosion Control Plan (as described in 1.1.59.1) (iii) Sediment Control Plan (as described in 1.1.59.2) (iv) Site ECM Management System (as described in 1.1.59.3)

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CE Spec Page 1-30 1.1.59.1

Erosion Control Measures During construction, the Contractor shall minimize the formation of bare surfaces under the ECM's Erosion Control Plan. The Plan shall depict graphically the activities, including sequence of work, type and duration for each phase of construction activities to include the following measures to: (a) sequence and schedule of the earthworks I demolition works in stages and progressively with the subsequent construction activities and building works. (b) minimise site disturbance by keeping site clearance works to a minimum by retaining as much of the existing vegetation as possible. (c) pave up the bare surfaces and all construction access by concrete or milled waste or other suitable materials. (d) protect the bare slopes with close-turfing, concrete grouting, or erosion control blanket. (e) protect the earth stockpiles with erosion control blanket. (f)

restore ground cover over disturbed areas, which are or have become bare, as soon as possible.

(g) cover up the active work surfaces with canvas sheet during rain or at the end of the workday. 1.1.59.2

Sediment Control Plan The Contractor shall put in place the ECM's Sediment Control Plan, which aims to capture the sediments washed down from the construction sites. Some of these sediment control measures and facilities, which must be in place before the works start, shall include but not limited to the following: (a) concrete-lined cut-off drains (minimum C7 precast channel) along the perimeter of the construction sites. (b) silt fence properly installed and embedded onto the ground along the perimeter cut-off drains (between the construction site and the cut-off drain). (c) sedimentation basins or any other sediment filtering or settling system of adequate size and sufficient numbers along the perimeter cut-off drain and before the discharge points into public drain. (d) a storage basin / tank may be required to temporarily store the large amount of rainwater falling on to the whole site before treatment. (e) a treatment system to treat silty discharge shall be provided before the discharge points into public drain. (f)

1.1.59.3

turbidity curtains shall be installed along all the exposed slopes / riverbanks for works in or adjacent to water bodies, such as canals, rivers, sea or in a reclamation work. The silty discharge trapped within the turbidity curtain shall be allowed to be settled / treated and removed.

Site ECM Management System The Contractor, shall at the advice of his QECP, put in place a site monitoring and reporting system including but not limited to the following: (a) Daily ECM inspection report by the QECP appointed site personnel (b) Regular site inspection by the QECP (c) Continuous monitoring and recording system shall be installed at the discharge point (after ECM) before public drain

1.1.59.4

Submission Of Design Basis And Calculations The QECP shall submit full basis of design back up with design calculations to show clearly how the perimeter cut-off drains, silt fence, sedimentation basins, storage basin / tank and treatment system are designed and sized as well as how such design will effectively filter off silt and allow only clean water to discharge into public drains. The QECP shall also submit the design specifications on the treatment system which can effectively treat the silty discharge from the construction site. The intensity of a one-intwo year storm should be adopted for the proposed design.

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CE Spec Page 1-31 1.1.60

Electronic Submission For Progress Payments Claims And Request For Variation Works. The Contractor may be required to use an online web-based electronic submission system provided by the Employer for the submission of the Monthly Claims for Progress Payment and Claim for Authorisation / Variation Order (collectively and hereinafter known as e-submission system). There will be no additional charges to be imposed by Employer for the use of the e-submission system. If the Employer decided that the e-submission system is to be used, the Contractor shall at his own expenses arrange to use e-submission system complying with the requirement hereinafter mentioned. The e-submission system shall be Secured Socket Layer encrypted, password-protected with role-based workflow security features at the document/form level and have an audit trail. The e-submission system shall be accessible by all relevant users from the Employer, Superintending Officer, SO Rep and Contractor concurrently and all data accessed shall be confined to the Project and the relevant role and scope of works. All relevant parties in the workflow shall be timely notified by email to complete their respective area of work. The e-submission system shall comprise the following modules: (A)

Monthly Claims For Progress Payment

This module allows the Contractor to submit online, the values of the monthly progressive valuation of work completed for the assessment and certification of the SO Rep as hereinafter described but not limited to the following: (a)

This module shall capture the monthly detailed breakdown of the scope of works and cost information as specified in the Contract showing both the Contractor’s claims and the SO Rep’s corresponding assessment in terms of individual percentage of work done for each work item.

(b)

The validation rules shall apply to each item of claim and shall be based on the following rules or such rules to be given by the SO Rep: i. ii.

The SO Rep's certification should not be more than Contractor’s claim. The values submitted/certified for current month should not be less than previous the month’s submission.

(c)

The Contractor shall not be allowed to amend the SO Rep’s valuation and vice-versa.

(d)

The following data shall be automatically uploaded each month into the e-submission system and shall include but not limited to the following: i. ii. iii. iv. v. vi. vii.

(B)

Nett Contract Sum (Less Provisional Quantities / Sums) Probable Actual Contract Value (Adjusted For Variation Orders) Contractor's Cumulative Total Claim (excludes Loss & Expense) Contractor's Nett Claim for Month (excludes Loss & Expense) Total SO Rep's Estimated Value Computed (excludes Loss & Expense) Cumulative Certified Value of Work Value for each work category for apportionment under respective activity account codes.

Authorisation / Variation Order

This module shall include but not limited to the following: (a)

Allow the SO Rep to submit an Authorisation / Variation Order for the approval of the SO for subsequent issue to the Contractor.

(b)

Allow the SO Rep to issue to the Contractor an Authorisation Order.

(c)

Allow the SO Rep to issue a Variation Order.

All the differences and/or disputes arising under this Clause (including questions relating to interpretation) shall be determined by the Superintending Officer whose decision shall be final and binding on and conclusive against the Contractor.

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CE Spec Page 1-32

1.1.61

LAND SURVEY SERVICES FOR CE WORKS

1.1.61.1

General Requirements For Land Survey Services The contractor shall engage a registered surveyor at its own cost and expense for the conduct of the survey works required for the project. The cost incurred shall include the purchase of information and equipments required for the survey works. Statutory Board fees such as processing fees chargeable by Urban Redevelopment Authority (URA) for application of Land and Strata subdivision and prescribed fees payable to the Chief Surveyor, Singapore Land Authority (SLA), under the Boundaries and Survey Maps Act for the conduct of Cadastral Survey of Land and strata survey will be borne by HDB. The Contractor shall be held fully responsible for the accuracy of all the survey works carried out by its registered surveyor and for ensuring the works fully comply with the following ;

1.1.61.2

(a)

the technical requirements and standards in the conduct of the surveys as specified in the latest version of the land surveyors board directive on engineering and hydrographic survey practices;

(b)

the technical requirements and standards in the conduct of the surveys as specified in the latest Singapore Land Authority (SLA) directive on cadastral survey practices;

(c)

circulars that are issued from time to time by the Chief Surveyor, Singapore, SLA.

(d)

all field works and office works are executed by the registered surveyor or qualified staff under the registered surveyor direct supervision and direction;

(e)

all documents and survey works pertaining to the survey are certified and dated by the registered surveyor supervising the survey;

(f)

The Registered Surveyor shall verify SVY21 datum and establishment of ISN markers, horizontal and vertical controls, at least 3 levels control benchmarks.

Engineering Survey Services All forms of land survey services required for the purpose of facilitating the planning and construction works or survey works requested by HDB in relation to the construction of the project are to be performed by the contractor’s registered surveyor.

1.1.61.3

Setting Out Survey (Construction Stage) The Contractor’s Registered Surveyor shall carry out survey setting out works including transferring and protecting of all reference pegs for the smooth execution of work on a full time basis throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The Contractor shall be held fully responsible for the accuracy of such setting out.

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CE Spec Page 1-33 1.1.61

LAND SURVEY SERVICES FOR CE WORKS (Cont’d)

1.1.61.4

Survey Of Completed Works (Post Construction Stage) Prior to certification of completion of the Works, the Contractor’s Registered Surveyor shall carry out "asbuilt" survey of the substantial completed works as directed by the SO Rep. The survey includes the verification of SVY 21 datum and establishment of horizontal and vertical controls, spot leveling, site features and boundaries details, establishment of at least 3 level control benchmarks (TBM’s) near to the designated site, preparation of cadastral based map information for overlaying onto the topographical plan, including the provision of digital files, DWG format. Details of the surveys, where applicable;

1.1.61.5

(a)

All visible details pertaining to the project are to be surveyed;

(b)

For sewer work, the sewer alignment, the manhole cover levels and invert levels, the tumbling bay & backdrop levels shall be surveyed. The type of manhole and direction of flow shall be reflected in the plan;

(c)

For drains work, the drain alignment, the invert levels and coping / top levels shall be surveyed generally at 20m intervals. For cascading drain, the drops between upstream & downstream levels shall be surveyed. Covered drains with iron grating shall be reflected in the plan;

(d)

For roads work, the longitudinal alignment, the cross-sectional spot levels at centre, edges, and sidetable at 20m intervals, at intersection and at all changes of grades shall be surveyed. Road spot levels, scupper drains & drop-inlet chambers top and invert levels, shall be surveyed. Trees along roadside table shall be surveyed and prescribed accordingly;

(e)

Vertical and horizontal levels of corners of the roof of bus shelters, linkways, pedestrian overhead bridges shall be surveyed;

(f)

Saplings and trees where required shall be surveyed and described accordingly. Trees to be surveyed including girth size, height and species;

(g)

Road names, road signage, traffic markings, arrows, lanes, wordings, etc painted on roads surface shall be surveyed.

Submission Of Survey Plans The Registered Surveyor shall produce and submit the following to the SO Rep including subsequent amendment, if any, for construction stage and post-construction stage respectively : (a)

Two CD ROMs containing the survey plans in DWG format;

(b)

Inside the same two CD ROMs, the survey plans in pdf format. Every pdf format drawing shall show Registered Surveyor’s endorsement on the plans;

(c)

Three sets of A1 size hardcopy plans and 1 set of A1 size tracings in 1:500/1:1000 scale with Registered Surveyor’s endorsement.

The setting-out survey plans shall be submitted to the SO Rep not more than one (1) week prior to actual commencement of the works. The as-built survey plans shall be submitted to the SO Rep not more than four (4) weeks upon certification of completion of the works. Should the Contractor fail to carry out the survey within the stipulated time, the SO Rep reserves the right to engage other surveyors to carry out the survey and preparation of survey plans. All costs and expenses resulting from the Contractor's failure or arising thereof shall be recovered from the Contractor.

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CE Spec Page 1-34 1.2

MATERIALS - GENERAL

1.2.1

Metric Components All components for incorporation into the Works shall be in metric units. However, when metric components are not available, their equivalent in imperial units may, subject to the approval of the SO Rep, be used and such substitution shall not constitute a variation to the Contract.

1.2.2

Materials And Workmanship When directed, furnish the SO Rep with approved documents to prove that materials are as specified. The documents shall include but not limited to any or all of the following, such that the authenticity of the materials can be easily ascertained : (a)

shipping documents

(b)

serial numbers

(c)

warranty certificates

In the event that any documents submitted are not original copies, they shall be duly certified by the originating parties. No information within the documents shall be tampered with, unless it is clearly discernible that the items are not related to the materials specified in the Contract. Where specific brand and model number are specified, or where alternative brands and model numbers are offered by the Contractor and accepted by the SO Rep, it shall be deemed that the finished products are entirely of original make by the registered Manufacturer and are fully supported by the Manufacturer's warranty. In the event that any alteration is made to the goods by a local agent or any other intermediary, the approval of the SO Rep shall be sought and the result of the alteration shall be fully supported by the Manufacturer such that the Manufacturer's warranty is maintained. All references to local or foreign standards and/or Codes of Practice shall be deemed to be inclusive of the prevailing amendments to these standards and/or Codes of Practice. Samples of materials shall be submitted to the SO Rep for approval before order is placed with the supplier. Such approval by the SO Rep shall not relieve the Contractor of its obligations under the Contract. The Contractor shall ensure that the materials are free from any defects, damages or any other flaws.

1.2.3

Approval Of Samples And Trade Names Where trade names or catalogue numbers are specified in the Specifications and/or shown in the Drawings, they are intended only to serve as a guide to the respective type and quality of material required. Other material proposed by the Contractor may be used subject to the prior approval of the SO Rep. In this respect, the Contractor shall submit samples of the proposed material to the SO Rep for approval.

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CE Spec Page 1-35 1.2.3

Approval Of Samples And Trade Names (Cont'd) When a sample is approved by the SO Rep and subsequently work is carried out in accordance with this approved sample, any cost difference resulting from the higher price of the approved sample as compared with the price of the material as required and/or as shown shall not be payable to the Contractor, unless the change of material is ordered by the SO Rep. With the exception of lighting luminares, where the requirements for cost recovery are provided for differently, in the event that the price of the approved sample is lower than that of the material as required and/or as shown, the cost difference shall be recovered by the Employer by way of contract variation in accordance with the following table : Recovery (or Non-Recovery) by the Employer from the Contractor in the event that the price of the approved material is lower than that of the material as required and/or as shown Material proposed by the Contractor and approved by the SO Rep

S/N

Material as required and/or as shown

1.

On the HDB Materials List

On the HDB Materials List

2.

On the HDB Materials List

Not On the HDB Materials List

Not On the HDB Materials List

On the HDB Materials List

3.

Not On the HDB Materials List

Not On the HDB Materials List

4.

Cost Adjustment

No cost recovery

) ) ) ) ) ) ) ) ) ) )

Cost Recovery by the Employer from the Contractor

For lighting luminaires, in the event that the price of the approved sample is lower than that of the material as required and/or as shown, the cost difference shall be recovered by the Employer by way of contract variation regardless of whether or not the approved sample and/or the material as required and/or as shown are shown in the HDB Materials List For the purposes of this subclause only, the applicable HDB Materials List shall be the prevailing HDB Materials List applicable at the time the Contractor submit the material for approval by the SO Rep. Where cost recovery is required, the basis for such adjustment shall be the difference between the price of the proposed material and that of the material as required and/or as shown (where one type of material is specified) or that of the cheapest of the materials as required and/or as shown (where more than one type of material is specified). The Contractor shall point out to the SO Rep all items in the approved sample which do not comply with the Specifications and/or Drawings. Notwithstanding approval of the sample by the SO Rep, the Contractor shall be liable for any items in the sample which do not comply with the Specifications and/or Drawings and which the Contractor has failed to point out to the SO Rep. Where the Contract requires the Contractor to obtain materials from the HDB Materials List or where it is specified that materials provided are subject to the approval of the SO Rep, such requirements shall not in any way affect, vary or relieve the Contractor's obligations under the Contract. The Contractor shall ensure that the materials used or selected by them: (a) are free from defects, damages or faults; (b) are of merchantable quality and fit for their intended purpose; and (c) comply with the Specifications and/or Drawings.

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CE Spec Page 1-36 1.2.4

Samples Samples of materials specified and proposed to be provided shall be submitted for the approval of the SO Rep as required. The SO Rep shall retain samples as and when approved by him and shall be at liberty to reject all materials not corresponding with the approved samples.

1.2.5

Precautions Against Materials Being Taken Out Of Site The Contractor shall be responsible for the safe custody of cement and all other materials delivered to the Site and ensure adequate protection and prevention of such materials from being taken out of the Site. The SO Rep will not accept any excuse for materials taken out of the Site by the Contractor, his foreman or other individual even without the knowledge of the Contractor who shall be deemed to have provided for proper control against such malpractice. If it is established that cement or any other material is taken out of the construction site without specific written approval from the SO Rep, this shall be deemed to be an irregularity and inter-alia, the right of the Contractor to compensation for price fluctuations for all materials shall lapse.

1.2.6

Approval For Use Of Ready-Mixed Concrete The Contractor shall seek the written approval of the SO Rep for the use of ready-mixed concrete. Such approval to use ready-mixed concrete shall be subject to the terms and conditions set by the Employer and all Delivery Orders for the ready-mixed concrete delivered to the Site shall be endorsed by the Resident Technical Officer and submitted to the SO Rep.

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CE Spec Page 1-37 1.3

LABOUR

1.3.1

Labour Laws Pay workmen promptly, and observe workmen's working hours and holidays in accordance with current laws and regulations. Keep records and produce them for inspection by the SO Rep.

1.3.2

Keeping Records Of Workmen The Contractor shall comply with all labour laws regarding the engagement of non-citizen workmen. Work Permits from MOM must be obtained for these workmen. Liable for and indemnify the Employer in respect of all actions against the Employer for employing foreign workmen without permits. Keep proper records of all workmen engaged on Site. These records shall include the following information : (a)

Name of Workmen (and alias if any)

(b)

Identity Card No./Passport No.

(c)

Address

(d)

Work Permit No., if any

(e)

Expiry date of work permit

This information must be recorded before any workman is allowed to commence duty. Severe action will be taken by the SO Rep if the Contractor fails to record any of the abovementioned information of any worker found at the Site.

1.3.3

Employment Of Illegal Immigrants For the purpose of this subclause, "illegal immigrant" means any person who enters the Republic of Singapore in contravention of the provisions of the Immigration Act or any statutory modification or reenactment thereof. The Contractor shall ascertain the legitimacy of all Foreign Workers employed by any sub-contractor prior to employment and throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. Clarifications as to the legitimacy of Foreign Workers may be made with the Immigration Authority, the Ministry of Manpower and/or Police. Ensure that no illegal immigrants are employed by him and/or any sub-contractor in the execution of the Works. The Employer shall not be responsible for any such act or acts by the Contractor and/or any of his sub-contractors and the Contractor shall indemnify the Employer for all consequences arising thereof.

1.3.4

Employment Of Civil Engineers The Contractor shall employ Civil Engineers with recognised and approved engineering degree or professional diploma acceptable for registration with the Professional Engineers' Board, to supervise the Works and manage the Site on a full-time basis throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The said Civil Engineers shall be stationed on Site on a full-time basis and shall be expected to manage the project efficiently and ensure a high standard of workmanship and site organisation.

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CE Spec Page 1-38 1.3.4

Employment Of Civil Engineers (Cont'd) The number of Civil Engineers to be employed for the purpose of this subclause shall be in accordance with the following table :

Type of Contract

Roads, Carparks, Sewers, Drains, Bridges, Earthworks & Other Related Works

Reclamation

Bored & Steel Piling

Soil Investigation

Contract Sum

Number of Civil Engineers to be employed per Contract

More than or equal to $3.0 million

1

Less than or equal to $50 million

2

More than $50 million but less than or equal to $100 million

3

More than $100 million

5

Less than or equal to $40 million

2

More than $40 million but less than or equal to $60 million

3

More than $60 million

4

All contracts regardless of Contract Sum Value

1

Include in the Contract Sum all costs and expenses to be incurred for compliance with the requirements stipulated in this subclause. In the event of the Contractor not employing the number of engineers required by the Contract or not employing such engineers for the period or periods required by the Contract, without prejudice to the Employer's rights under the Contract, the Contractor shall be indebted to the Employer at the rate of $6,400 per month per engineer not employed and such indebtedness shall be deducted by the Employer from any monies due or becoming due to the Contractor or be recovered by the Employer as a debt due from the Contractor. This rate shall be deemed to have been fully agreed and accepted by the Contractor and the Employer as the cost and expense allowed by the Contractor for the employment of an engineer for each month. For the purpose of this subclause a Civil Engineer shall be employed by the Contractor for at least 20 days within a calendar month before he can be considered as being employed for that particular month under the Contract. In the event that the first and last calendar month of the Time for Completion and any time period where liquidated damages are imposed under the Contract have less than twenty days, the Civil Engineers shall be employed for the full number of days in the said first and last calendar month. Notwithstanding other provisions in this subclause, if the Contractor incurs additional cost and expense over and above the agreed rate specified herein in complying with the requirements stipulated in this subclause, the Contractor alone shall bear such additional cost and expense in full. Submit to the SO Rep within one month from the date of the Letter of Acceptance, the names, identity card numbers and documentary evidence of the educational qualifications of the said Civil Engineers. The employment of the said Civil Engineers shall be subject to the approval of the SO Rep.

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CE Spec Page 1-39 1.3.4

Employment Of Civil Engineers (Cont'd) In addition, fulfill the following requirements : (a)

The Civil Engineers employed shall be on the Contractor's monthly payroll. Keep records indicating the number of days the engineers are employed for each month and the monthly contributions to CPF. Such information may be proof of employment of the Civil Engineers and shall be submitted to the SO Rep upon request;

(b)

A letter from every Civil Engineer employed shall be submitted to the SO Rep to testify that he is employed full-time for this Contract only;

(c)

Further to (b) above, if any Civil Engineer is found supervising more than one running contracts, the particular Civil Engineer will be barred from supervising all the Employer's contracts for a period of two years from the date of the breach.

It shall be the Contractor's duty to bring to the attention of the engineers the requirements of this subclause. The SO Rep may consider request by the Contractor in writing to release his Civil Engineer from the obligation of this subclause if the Contract has been certified more than 95% complete. It shall be up to the absolute discretion of the SO Rep to decide whether the Contractor's Civil Engineer can be released and the number of Civil Engineers to be released from the Contractor's contractual obligation under this subclause. A written approval from the SO Rep shall be obtained in this respect. All differences and/or disputes arising under this subclause (including questions relating to interpretation) shall be determined by the Superintending Officer whose decision shall be final and binding on and conclusive against the Contractor.

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CE Spec Page 1-40 1.4

CONSTRUCTION EQUIPMENT

1.4.1

Maintenance Of Construction Equipment During the progress of the Works, the Contractor shall put the Construction Equipment to proper use and carry out regular maintenance to avoid any breakdown. No extension of Time for Completion shall be granted for any breakdown or misuse of the Construction Equipment.

1.4.2

Contractor's Construction Equipment All mechanical Construction Equipment used in the execution of the Works shall be of such type, size and of such method of working as the SO Rep shall approve. The approval by the SO Rep for the use of mechanical Construction Equipment will not be unreasonably withheld, but if in the opinion of the SO Rep, any circumstances which make it desirable that the use of a Construction Equipment should be suspended either temporarily or permanently, the Contractor shall change the method of performing the Works affected at his own cost and expense and he shall be deemed to have no cause for claim against the Employer on account of having to carry out the Works by another method nor shall he be deemed to have cause for claim if any other instruction issued by the SO Rep results in the mechanical Construction Equipment having either to stand idle for a period of any duration whatsoever or to be removed. This sub clause shall apply also to Construction Equipment which, in the opinion of the SO Rep, are not as quiet in operation as warranted by the circumstances. Use every possible means to prevent noise and annoyance to the residents of the neighbourhood in which the Works and the Contractor's worksites are situated and all Construction Equipment and machinery shall be of such design and so arranged to be reasonably free of noise in working. In the event of air compressors or pneumatic tools being used on the Works, if and when required, arrange for such compressors or tools to be fitted with silencers of approved design or adopt other means approved by the SO Rep for the purpose of reducing noise as far as possible. The Contractor shall not be allowed to make any extra claim for work or cost and expense incurred in complying with the requirements of this subclause.

1.4.3

Movement Of Construction Equipment All heavy machinery and other Construction Equipment, such as excavator, grader, mixer etc required for the Works shall not be removed from Site without approval from the SO Rep notice. If progress of work is held up due to the absence of certain particular machinery, the Employer shall be at liberty to bring in the required machinery from other sources and the cost and expense thus incurred plus the Employer's charges shall be recovered from monies due or becoming due to the Contractor or as a debt due by the Contractor to the Employer.

1.4.4

Age limit for Mobile Crane The age of the crane used on the Site shall not exceed 15 years.

CE12/S1.DOC(40) oym(151211) DPD

CE Spec Page 1-41 1.5

SAFETY

1.5.1

Site Safety Measures The Contractor shall ensure that the requirements of the Regulations and the following requirements are strictly complied with at all times : (a)

General Requirements The Contractor shall allow for the compliance with the Workplace Safety And Health Act (hereafter referred to as the “the Act” for the purposes of this clause including all subclauses under it) and its Subsidiary Legislations including the provisions of the Workplace Safety and Health (Construction) Regulations (hereafter referred to as the “the Regulations” for the purposes of this clause including all subclauses under it) and any amendment or re-enactment thereto. The subsidiary legislations are:a) The Workplace Safety and Health (General Provisions) Regulations b) The Workplace Safety and Health (Registration of Factories) Regulations c) The Workplace Safety and Health (First-Aid) Regulations d) The Workplace Safety and Health (Exemption) Order e) The Workplace Safety and Health (Composition of Offences) Regulations f) The Workplace Safety and Health (Incident Reporting) Regulations g) The Workplace Safety and Health (Risk Management) Regulations Precedent to the commencement of the Works, the Contractor shall first obtain a Certificate Of registration, under the act subsidiary legislation, The Workplace Safety And Health (Registration Of Factories) Regulations It shall be the duty of the Contractor to comply with all such requirements of the Act and its Subsidiary Legislation, as affect him or any person or persons employed by him, and as related to any work, act or operation performed or about to be performed by him. The Contractor shall not permit any person to do anything not in accordance with the generally accepted principles of safe and sound practice.

The Contractor shall ensure a safe environment on the Site at all times. All safety provisions shall be properly maintained and shall not be removed without the written approval of the SO Rep. Ensure that necessary and sufficient precautions are taken by the workmen when safety provisions are used. The Contractor shall not allow any of the safety provision to be used, unless he has satisfied himself that the provision is safe. The Contractor shall submit a safety programme to the SO Rep within 14 days from the date of the Letter of Acceptance for approval prior to the commencement of the Works. The submission of the Safety Programme shall comply with and kept in the site office and made available for reference at all times. The Contractor shall display safety posters at the site office, site canteen, exit/entry points of buildings, passenger cum material hoist area and storage area. The Contractor shall submit safety drawings, certified by the Contractor's professional engineer for approval at least one month before the commencement of the Works. The approval of the SO Rep shall not relieve the Contractor and his professional engineer of the need to ensure the adequacy and sufficiency of the safety provisions. The Contractor shall allow for all costs and expenses of the safety provisions and for all additional costs that may arise from amendments to the Regulations and changes in the requirements of MOM and the HDB. (b)

Personal Protective Equipment The Contractor shall provide and maintain suitable personal protective equipment to all workmen employed on the Site. The Contractor shall ensure that such personal protective equipment comply with the requirements of the Regulations. The Contractor shall also ensure that all equipments are properly used by his workmen during the course of their work. The Contractor shall record the issuance of all equipment to the workmen in the prescribed forms and such forms shall be kept in the site office and made available for inspection at all times. The colour code of the safety helmets provided by the Contractor shall comply with the requirements of the Regulations. Three mirrors of sizes 600mm x 1500mm are to be installed for workers to check their personal protective equipment during Tool Box Meeting. The location of these mirrors shall be approved by the SO Rep.

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CE Spec Page 1-42 1.5.1

Site Safety Measures (Cont'd) (c)

Protective Hoardings And Covered Footways The Contractor shall erect and maintain all protective hoardings, covered pedestrian footways, cross bridges with proper handrails and fencing where the SO Rep considers it necessary. It shall be constructed in accordance with the design and drawings of his professional engineer and to the requirements of the BCA. During the hours of darkness, the hoardings, covered footways and fencing erected along roads shall be provided with suitable warning lights. The hoardings, footways and fencing shall be cleared away on Substantial Completion of the Works or upon the approval of the SO Rep.

(d)

Authorised Operators For Machinery and Vehicles The Contractor shall employ only qualified operators for his site machinery. The operator for the machinery shall possess a Skill Evaluation Certificate (SEC) from an accredited training provider or other approved training centre. For those machinery where accredited training providers do not conduct courses or practical tests for machinery operator, the Contractor shall only authorise an experienced and trained operator who has at least a minimum of 2 years experience in operating the machinery. In the case of vehicles, which are operated within the contract boundary, the authorised operator shall possess a minimum valid Class 3 driving licence from the Registrar of Vehicles (Singapore) or its equivalent from their originating countries. The equivalent of a minimum Class 3 driving licence shall first be verified by the respective embassy in Singapore and thereafter submitted to the SO Rep for approval. The Contractor shall record the particulars of the operators for the machinery and vehicles in the prescribed form and submit to the SO Rep for approval one week before the commencement of the Works. The prescribed form shall be updated and keep on the Site and made available for inspection at all times.

(e)

Safety Guards Provide safety guards to all moving machine parts that are likely to injure a workman.

(f)

Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer The Contractor shall employ Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer with recognised and approved certification in construction safety to take charge of all matters related to safety on a full-time basis throughout the Time for Completion and any time where liquidated damages are imposed under the contract. The said Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer shall spend their time fully on the Site and perform the following :

CE12/S1.DOC(42) oym(151211) DPD

(i)

To supervise safety and promote safety conduct;

(ii)

To inspect and rectify any unsafe place of work;

(iii)

To correct any unsafe practice; and

(iv)

To ensure that the provisions of the Workplace Safety & Health Act and its Subsidiary Legislation made thereunder are complied with.

CE Spec Page 1-43 1.5.1

Site Safety Measures (Cont'd) (f)

Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer (Cont'd) The number of Workplace Safety & Health Co-ordinator/Workplace Safety & Health Officer to be employed for the purpose of this Clause shall be in accordance with the following table : Number of Each Type of Personnel to be Employed Based On Contract Sum Type of Personnel

Workplace Safety & Health Coordinator Workplace Safety & Health Officer

Fully Agreed & Accepted Rate by the Contractor & the Employer for the Cost & Expense Deemed to be Allowed for by the Contractor for the Employment of Each Personnel

Not Exceeding $10 Million

Exceeding $10 Million But Not Exceeding $25 Million

Exceeding $25 Million But Not Exceeding $50 Million

Exceeding $50 Million But Not Exceeding $75 Million

Exceeding $75 Million But Not Exceeding $100 Million

Exceeding $100 Million

One

One

Two

Two

Three

Three

$4,500 per Site Safety Supervisor per month

One

One

One

One

One

One

$5,000 per Registered Safety Officer per Month

The Contractor is required to employ a full time Workplace Safety & Health Officer to comply with the requirements under the Workplace Safety & Health (WSH Officers) Regulations. The Workplace Safety & Health Officer shall implement appropriate safety measures and ensure a safe work environment and a safe work procedure in accordance with the Workplace Safety & Health Act and Subsidiary Legislation including the provisions of the Workplace Safety & Health (Construction) Regulations 2007 and the requirements under the contract. (g)

Metal Scaffolding All metal scaffolding used shall comply with the requirements of the Regulations. The cantilevered platform for the metal scaffolding shall be erected according to the Drawings of the Contractor's PE. The drawings shall be submitted to the SO Rep for approval at least one month before the erection of the metal scaffolding. Working platforms, overlay or screening debris nets and barricades to the open sides of the buildings shall be incorporated into the scaffolding. The installation of the net shall follow the erection of the scaffold closely. There shall be no opening between separate sets of the net and any torn net shall be replaced or repaired immediately. The net shall comply with the following requirements : (i)

Maximum mesh size(square):15mm

(ii)

Twine No: minimum 350D

(iii)

Knot type : single or English knot

(iv)

Minimum: 12 ply

All tiebacks for the scaffold shall be painted with a bright colour for easy identification. The scaffold and any components therein shall be erected, or substantially extended to or dismantled by scaffold erectors, under the immediate supervision of a qualified and competent scaffold supervisor according to the Regulations. The scaffold and its component shall only be dismantled and removed after the SO Rep has given his permission. All metal access scaffolds shall be prezinc galvanised or other approved by the SO Rep. The SO Rep may at his discretion select samples of the scaffold frames at the Site for testing to ensure compliance with relevant standards. The testing schedule of the scaffold components are shown in the Schedule Of Material Tests (CE Works) in the Supplementary Specifications.

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CE Spec Page 1-44 1.5.1

Site Safety Measures (Cont'd) (h)

Safety Training (i)

Safety Orientation Course The Contractor shall employ workmen who possess valid Safety Orientation Course Certificates. The Contractor shall be required to ensure that his workmen attend a prescribed safety refresher course at an interval of time to be decided by the SO Rep.

(ii)

Safety Training Course When directed by the SO Rep, the Contractor shall at its own cost and expense also send all his employees/staff as stipulated hereunder to accredited training providers for appropriate safety training as shown hereunder :  Safety Training Courses Conducted By MOM Accredited Training Providers

Course Specialist Diploma in Workplace Safety and Health / Workplace Safety & Health Officer (WSHO)Training Course Construction Safety Course for Project Managers Safety Management Course Advanced Certificate in Workplace Safety and Health Training Course for Safety Committee Members Building Construction Safety Supervisor Course SIC (Manhole) for Supervisors Lifting Supervisors Safety Course Industrial First Aid Course Industrial First Aid Refresher Course Crawler Crane Operator Course : - New Entrant Programme - Refresher Programme - Familiarisation Programme Erection of Metal Scaffold Slingers/Riggers Course Tower Crane Operator Course : - New Entrant Programme - Familiarisation Programme Supervision of Metal Scaffold Erection Climbing Work Platform Operation Explosive Powered Tools Operation

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Applicable to Safety Personnel for registration as Workplace Safety & Health Officer(WSHO) Chairman of Safety Committees, Project Managers, Engineers Chairman of Safety Committees, Managers, Engineers and Supervisory Staff Workplace Safety and Health Coordinator Safety Committee Members Building Construction Foremen and Supervisors Supervisors Supervisors and Foremen Workers, Safety Personnel and Supervisors Trained First Aiders

Crane Operators Erectors Workers, Foremen and Supervisors Crane Operators Supervisors Supervisors, Workers and Operators Workers and Operations

CE Spec Page 1-45 1.5.1

Site Safety Measures (Cont'd) (h)

Safety Training (Cont'd) (ii)

Safety Training Course (Cont'd) Particular attention shall be given to the needs of young employees/staff. Further training shall be required where : - Employees/staff are transferred or where employees/staff take on new responsibilities or where a change in the work activity or work environment could arise; and - There is a change in the work equipment or systems of work in use. Training shall be repeated periodically to ensure continued competence.

(i)

Warning Signboards, Cones And Lights The Contractor shall display warning signs of sizes 900mm x 600mm at strategic points around the periphery of the Site where trespassing is likely to occur. Such signs shall have the words "DANGER - KEEP OUT" in the four official languages painted in red on a white background in gloss finishing paint. Warning lights shall be placed at similar positions at night to serve as a warning. In addition, the Contractor shall display "SAFETY FIRST" signs at the Site. If work is carried out near public roads, all signage shall comply with the recommendations of Code of Practice for Temporary Traffic Control issued by the LTA.

(j)

Temporary Roads Signing Works carried out at or near gazetted roads shall comply with LTA Temporary Traffic Control recommendations.

(k)

Electronic Distance Meter Unless otherwise directed, use Electronic Distance Meter in the measurement of distances over public roads and in built-up areas accessible to the public where the use of measuring tapes may pose a danger to motorists and members of the public.

(l)

Safety Reflective Apparel (High Visibility Warning Clothing) All workmen engaged in any type of work on public roads shall wear approved type of reflective apparel during all hours of the day and night when so engaged. The Contractor shall also issue safety reflective apparels (with HDB logo) to the Resident Technical Officer and supervising engineers on site. The approved types of apparel shall be : (i)

sleeveless vests covering the top half of the body with or without perforations for wear comfort; and

(ii)

Design The design shall be lightweight and cool, and of 100% polyester knit fabric or woven mesh. The vest shall be fluorescent lime yellow embossed with organization identification/logo. The retro-reflectivity of the double vertical and horizontal bands shall comply with European Standard EN 471 Class 2 for high-visibility warning clothing.

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CE Spec Page 1-46 1.5.1

Site Safety Measures (Cont'd) (l)

Safety Reflective Apparel (High Visibility Warning Clothing) (Cont'd) (iii)

Application All personnel working on or near the road shall put on the vest to make them more conspicuous and to warn road users of their presence. Only fluorescent lime yellow shall be used on a work zone for ease of identification. Summary Visibility Enhancing Devices No.

(m)

Safety Reflective Apparel (High Visibility Warning Clothing)

Type

1

Size

Per requirement

2

Colour

HDB's staff and contractor's supervisors : Fluorescent lime yellow. Contractors' workers : Fluorescent lime yellow

3

Reflectivity

EN 471 Class 2

4

Material

100% polyester mesh

5

Standard

EN 471 Class 2

Ventilation Provide adequate ventilation and efficient safety and protective equipments to keep all excavations, trenches, tunnels and heading structures, sewers and manholes free from all gases whether generated in the strata, arising from the use of explosives for blasting, sewage gases or otherwise and take precautions to ascertain that conditions are safe before allowing workmen to proceed. No person shall enter any confined space (whether above or below ground) unless a responsible person has tested the space using an oxygen testing instrument and has certified to the satisfaction of the SO Rep and Water Reclamation (Network) Department, PUB that the space is suitable to enter. For work in sewers, pumping mains, manholes, chambers, sumps and other confined spaces, ensure that the following safety procedures are adhered to : (i)

Safety And Protective Equipment Provide the following equipment for the safety and protection of the workmen at the work Site before the commencement of any work. Ensure that all workmen are familiar with the use of all safety and protective equipment required :

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Safety Apparatus

-

Multi-gas monitor, lifting harness, torch light, first aid kit, life lines, aluminium ladder, air blower, breathing apparatus, oxygen meter;

Protective Equipment

-

Safety belt, safety helmet and gloves, knee length rubber boots, overall, illuminous vest;

Other Equipment and Tools

-

Portable air blower, traffic warning lights and signs barricades, pedestrian warning signs, manhole gratings, nonsparking tools, flame proof lights;

CE Spec Page 1-47 1.5.1

Site Safety Measures (Cont'd) (m)

Ventilation (Cont'd) (ii)

Preparatory Work Identify the position of the nearest telephone so that in the event of an emergency, help can be summoned immediately. Do not allow smoking or naked light or fire in the vicinity of any manhole or chamber. Place proper barricades and traffic warning signs around the working manhole. For safety of the public, place proper gratings over manholes that are opened. Where a sewer is at a downstream of a pump main discharge chamber, obtain prior clearance with the Pumping Station Unit. During the course of the work in this sewer, maintain close co-ordination with the Pumping Station Unit to ensure non-operation of the pumping station.

(iii)

Before Entering Manholes And Chambers Remove the cover of the working manhole and those immediately upstream and downstream to provide ventilation and to serve as emergency exits. Provide manhole gratings for public safety. Use air blowers of adequate capacity (min flow rate of 1200 m3 per hour) for ventilation. Place the blower as far as possible from the working manhole and vehicles exhausts and operate for a sufficient time to ensure that all gases are driven out. Test for the presence of gases by lowering the multi-gas monitor into the manhole. Do not enter the manhole if the multi-gas monitor indicates dangerous conditions. Inspecting team shall carry Multi-gas monitor in the sewer. Test oxygen deficiency. (The oxygen level must be maintained above 19% but not exceeding 23%). No workmen shall enter the manhole or sewer if they detect smell or if they feel giddy or suspicious even if safe conditions are indicated in the tests above. If a manhole is safe to enter, wear safety belt, helmet and protective footwear before entering. Allow no person to enter a manhole or sewer alone. Detail at least two men as top men. The top men shall carry breathing apparatus. The supervisor shall keep count of his men before entering the sewer. Use ladders for access into or out of any manhole which exceeds 1m deep. Allow only one man on a ladder at one time. If aluminium alloy ladder is used, provide the ladder with non-slip rungs to prevent slipping. Wooden ladder shall not be used.

(iv)

While Men Are In Manholes Or Sewers Do not allow any workman to work in a sewer alone. Use lifelines when working in sewers. The top man shall keep in touch with the men below by calling or signalling at frequent intervals. If dangerous conditions are encountered or if danger is suspected then the men below shall return to the surface immediately through the nearest manhole. During the whole of the time that the men are below ground, maintain proper and adequate ventilation.

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CE Spec Page 1-48 1.5.1

Site Safety Measures (Cont'd) (m)

Ventilation (Cont'd) (iv)

While Men Are In Manholes Or Sewers (Cont'd) No smoking or naked light in manholes or sewers shall be allowed. Wear safety belts and helmets at all times while working inside manholes and sewers. Test the air inside a manhole or sewer continuously with the use of "personal gas monitor" by those working below. The gas monitor shall be capable of measuring the concentration of Carbon Monoxide, Oxygen, Hydrogen Sulphide and combustible gases. Where the sewers are large enough to enter, keep guard bars or safety chains in position across the sewer downstream of the place of work. Where natural light is not adequate, use only artificial light of the explosive proof type.

(v)

After Working In Sewers Or Manholes The supervisory staff in charge shall check carefully that all men have left the sewer or manhole. Replace properly all manholes or sumps cover.

(vi)

In An Emergency Inform the Water Reclamation (Network) Department, PUB and the HDB's Safety Unit in the event of an emergency.

(n)

Housekeeping Maintain and ensure a safe working environment by keeping the Site neat and tidy and free from all hazards and debris. Materials shall be stacked up safely. All the material storage area are to be barricaded. All workstations and accesses thereto shall be kept free from hazards and debris. The Contractor shall submit such housekeeping technique to the SO Rep for approval at least one month before commencement of Works. Housekeeping shall be carried out in such a manner and at such times as not to cause any inconvenience to either the adjoining owners, occupiers and the public. Debris shall be wet to minimize the risk of dust. Containers for debris and rubbish are to be provided at the designated places.

(o)

Barricades To Lift Openings, Voids, The Open Sides Of Buildings And Excavations The Contractor shall barricade all lift openings, internal voids and the open sides of buildings and excavations where a person is liable to fall. The barricade shall be at least 1.1m high with 90mm high toeboard and shall have sufficient strength and rigidity to withstand a lateral point load of 50 kg. All services opening shall be fully covered and secured to prevent unauthorised removal.

(p)

Prefabricated Mesh Barricade The Contractor shall provide, erect and maintain a vertical prefabricated mesh barricade (hereafter referred to as “mesh barricade” for the purpose of this clause including all subclauses under it) for all peripheral open sides of construction level of building (excluding multi-storey carpark/garage) where a person is liable to fall from height. Metal access scaffold and working platforms shall be maintained for multi-storey carpark/garage where a person is liable to fall from height. Mesh barricade shall be of sound construction and produced in the factory and installed at the construction level from the inside of the building. Mesh barricade and its support shall be prezinc galvanised or other approved equivalent by the SO Rep, easily installed and dismantled, and reusable throughout the construction (super-structure) stage. External works of the building, such as painting, touching up works, repair and redecoration, and other minor works, shall be carried out using mechanical suspended scaffold or other vertical access equipment.

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CE Spec Page 1-49 1.5.1

(p)

Prefabricated Mesh Barricade (Cont'd) Where the use of mesh barricade is not feasible, as interpreted by SO Rep, during the construction (super-structure) stage, the contractor can counter-propose localised alternative system other than the use of metal access scaffold. Mesh barricade/ counter-proposals for localised alternative system, its vertical support and any components therein shall be in modular sizes and designed according to the Workplace Safety and Health (Construction) Regulations by a PE employed by the Contractor. The PE’s drawings and calculation shall then be submitted to the SO Rep for approval within six weeks from the Letter of Acceptance, before installation and use. Trial setting out of mesh barricade shall be carried out on Site two weeks after approval of submission. The mesh barricade shall be erected ahead of the structural work (including the construction of water tank rooms) from the second storey and held by a supporting system designed by the said PE. The height of the mesh barricade shall be at least 1.1m above the construction level. The Contractor and his PE shall ensure that the substrate at which the mesh barricade is affixed to, can resist the designed imposed loads. The PE shall satisfy himself that his proposal shall not duly overload the RC structure.

Where necessary, the Contractor shall provide, erect and maintain an overlying screening net to cover the entire internal face of the mesh barricade. The installation of the net shall follow the erection of the fence closely. Where necessary, a 90mm high toeboards shall be provided at the base of the net from the inside of mesh barricade. After installation, there shall be no opening between separate sets of the net and any torn net shall be replaced or repaired immediately. The net shall comply with the following requirements: (i) (ii) (iii) (iv)

Maximum mesh size (square) : 15mm square Twine No. : Minimum 350D Knot Type : Single or English knot Minimum 12 ply

The vertical supports of mesh barricade shall be effectively anchored to the building structure. All vertical supports shall be painted with a bright colour for easy identification. The mesh barricade shall be erected according to a pre-determined safe work procedure established by the Contractor, or substantially dismantled, by trained erectors, under the immediate supervision of a competent supervisor. The mesh barricade and its components shall only be erected and dismantled by workers using life-line and safety belts or other equivalent, if not better, means of preventing a fall. The Contractor shall under no circumstance, use the prefabricated mesh barricade and vertical supports for other purposes. 1.5.2

Safety Infringement The above provisions shall be made to the satisfaction of the SO Rep. The Contractor shall include in his Contract Sum all the costs and expenses for complying with the safety requirements. In the event of any accident or mishap occurring on Site, whether or not caused by the inadequacy of safety provision or non-compliance with safety regulations, the Contractor shall immediately notify the SO Rep and the HDB and any other relevant Authority.

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CE Spec Page 1-50 1.5.2

Safety Infringement (Cont'd) Depending on the nature and extent of the accident or mishap, the SO Rep, HDB or any other Authority may order a total or partial stoppage of work to allow investigations and/or remedial measures to be effected. In the event of such stoppage, or any stoppages of work due to safety violations, the Contractor shall not be entitled to any claims for compensation or extension of time for completion. The SO Rep will conduct periodic inspections on the provision of safety measures together with the Contractor's Workplace Safety & Health Co-ordinator or foreman. The Contractor shall rectify immediately all contraventions against the Workplace Safety & Health Act and its Subsidiary Legislation, Workplace Safety and Health (Construction) Regulations or safety measures specified. All Works or partial works may be stopped until further notice from the SO Rep if the total number of contraventions or non-compliance is four or more or when the SO Rep considers the working environment unsafe for Works to continue. If the contravention or non-compliance is not rectified at a subsequent inspection, the SO Rep shall exercise its rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor. The SO Rep shall at its absolute discretion exercise its rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for the following types of accidents occurring in the course of or arising out of or in the consequence of the Works:

1.5.3

(i)

For each instance of fatal accident, if the accident is established in part or in whole by the SO Rep or any local Authority, to be the result of the defaults, acts, omissions or negligence of the Contractor. This charge shall not be refunded to the Contractor;

(ii)

For each instance of accident, if the SO Rep, HDB or the Competent Authority is of the opinion that the accident is the result of the failure of the Contractor to provide necessary and sufficient safety measures stipulated in the Contract or Workplace Safety & Health Act and its Subsidiary Legislation, the Workplace Safety and Health (Incident Reporting) Regulations.

(iii)

Dangerous occurrence as classified in the Subsidiary Legislation, Workplace Safety and Health (Incident Reporting) Regulations, Part II if the SO Rep, HDB or the Competent Authority is of the opinion that the dangerous occurrence is the result of failure of the Contractor to provide necessary and sufficient safety measures stipulated in the Contract or the Workplace Safety and Health Act and its Subsidiary Legislation, the Workplace Safety and Health (Incident Reporting) Regulations.

Reporting Of Accidents In the case of an accident or a dangerous occurrence, as classified under Subsidiary Legislation, Workplace Safety and Health (Incident Reporting) Regulations, Part II, the Contractor shall notify the Commissioner and HDB within one hour of such accident or dangerous occurrence. Upon receipt of information of an accident or dangerous occurrence, the SO Rep or HDB may at its discretion make a preliminary investigation of the circumstances and record its finding upon such investigation. Notwithstanding the aforementioned requirements, the Contractor shall in addition, give written notice of such accident or dangerous occurrence in the form set out in the INCIDENT NOTICE - HDB and submit it to the HDB on a timely basis. The form is obtainable at the HDB. Upon submitting the INCIDENT NOTICE to the HDB, the Contractor shall arrange for the injured workman, witnesses and an interpreter, if necessary, to report to the HDB to furnish evidence relating to the accident or dangerous occurrence. If the Contractor fails to give any required notice or fails to furnish evidence of the accident or dangerous occurrence as required in this Clause, the SO Rep or HDB may at his absolute discretion exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor.

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CE Spec Page 1-51 1.5.4

Approved Construction Equipment All Construction Equipment used at the Site as specified hereunder shall be obtained from Approved Suppliers registered with the HDB. Such Construction Equipment are : (a) (b) (c) (d) (e)

mobile crane; tower crane; gondola; mast climbing platform; and metal scaffold.

The Approved Suppliers can be found on kmo.eptc.com.sg and/or HDB Materials List. For Construction Equipment from other sources, such Construction Equipment shall firstly be registered with the HDB before the Contractor can use such Construction Equipment at the Site. Where, such Construction Equipment is used at the Site for a duration of less than a week, the SO Rep may at his sole discretion, waive the aforementioned requirement. Under such a case, there shall be no adjustment to the Contract Sum.

1.5.5

Gas Cylinders And Related Equipment The Contractor shall use gas cylinders fitted with both a low pressure gauge and a high pressure gauge, a reducing valve with pressure regulator, and safety relief device. The gas cylinders shall not be kept in the same room where welding, cutting or heating is being carried out or placed within five metres of any source of heat. The gas cylinders shall always be kept upright in a wheeled-trolley. The hose connecting the gas cylinder to an apparatus for cutting, welding, heating or other related works shall be of good construction and sound material, free from defects, properly maintained, and not entangled or kinked. A flashback arrester or any other similar device which stops flashback that is acceptable to the Chief Inspector of the MOM shall be fitted at every outlet of a gas cylinder and every inlet of an apparatus. The gas cylinders and hoses shall be colour-coded to conform to Singapore Standard 152 : "Identification of Contents of Industrial Gas Containers" and any amendments thereof. The Contractor shall engage a competent person to check the safety devices referred to herein once in every 6 months. The competent person shall be any person who is competent by education, training and experience on the safety and operational aspects of the use of gas cylinders and related equipment.

1.5.6

Erection of Temporary Structures In addition to the submissions of the site layout plan, the contractor shall further submit detailed structural plans and design calculations, certified by his PE, for temporary structures of two storey or higher. His PE may make use of the Drawings in the Standard Construction Detail Manual as a guide to the design and submission of the temporary structures. The Contractor shall erect all such temporary structures in strict compliance with Professional Engineer’s plans and calculation.

1.5.7

Submission Of Proposal and Certificate Of Supervision All Works requiring the Contractor to submit his proposal for the approval of the SO Rep shall be stipulated in the Drawings and/or Specifications. The Contractor shall submit detailed structural plans and design calculations, certified by his PE to the SO Rep not later than three months from the commencement of the Works for such proposals whichever is earlier. The Contractor shall bear all consequences for late submission. The Works shall be supervised by the Contractor’s PE. Not later than two(2) weeks after completion of the Works, the Contractor’s PE shall submit a Certificate of Supervision, stating that he has carried out such supervision work and is fully satisfied that the Works have been constructed in accordance with his structural plans and design calculations as approved by the SO Rep.

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CE Spec Page 1-52 1.5.8

Excavation Piling, shoring and bracing used in trench excavation to protect persons against falling or sliding materials shall be of adequate strength. Where the trench to be excavated exceeds 1.5m and not exceeding 4m in depth, shoring shall be provided. Where the trench to be excavated exceed 4m, such protection shall be constructed in accordance with the design and drawing of a Professional Engineer.

1.5.9

Storage Of Diesel, Oil And Chemical Diesel, oil and chemical shall be stored in a designated area within a covered shed with concrete floors and collection sump to contain any leak or spillage. Such an area shall not have any outlet/opening leading to a storm water drain or sewer. A full containment bundwall should be provided around the storage area and a collection sump should be provided to collect any spillage. The contractor shall comply fully with the requirement specified in Environmental Pollution Control Act and by the other relevant authorities. The contractor shall submit the layout of the proposed diesel, oil and chemical storage areas, the design of the containment and collection sump endorsed by a PE to SO Rep for approval. The contractor shall engage licensed toxic waste contractor to collect the spillage for safe disposal and submit the receipt of disposal to SO Rep. The contractor shall be responsible for paying any fines imposed by the relevant authorities eg. Public Health Department, Drainage Department (PUB) etc. In addition, the SO Rep shall exercise his right under Clause 1.6 ”Nuisance and Irregularities” to impose charges against the contractor.

1.5.10

Provision Of Equipment, Apparatus, Devices, Etc (1)

Safety Helmets And Safety Boots The Contractor shall provide safety helmets and safety boots for use by the SO Rep and Resident Technical Officers at the Site as well as the Employer's officers visiting the Site throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract. The ownership of the safety helmets and safety boots shall be reverted back to the Contractor upon the satisfactory Substantial Completion of the Works. The requirements are as follows : (a)

Safety Helmets (i) (ii) (iii)

(b)

white colour with HDB logo in front of helmet (Colour code for HDB logo : Pantone 485) complete with canvas chin straps and sweat resisting lining comply with SS98:1987

Safety Boots (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix)

at least 24 cm in height black/brown colour with steel toe cap long-wearing of great flexibility and resilience slip proof, resistant to oil, acid and heat nail proof of excellent insulation comfortable and light comply with SS105:1987

The Contractor shall immediately replace those safety helmets and safety boots which the SO Rep considers to be not in good working condition. (2)

Torch Lights The Contractor shall provide sufficient number of torch lights on the Site at all times for use by the SO Rep, Resident Technical Officers and/or representatives from other Authorities. These torch lights shall be in good working condition and sufficiently bright enough for use.

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CE Spec Page 1-53 1.6

NUISANCE AND IRREGULARITIES

1.6.1

Nuisance And Irregularities If the Contractor is found to have committed any of the following irregularities : (a)

Omitting building materials or labour, reducing the sizes of the materials, using inferior materials; or materials constructed not according to the Specifications or Drawings;

(b)

Creating nuisance at the Site thereby causing inconvenience to the SO Rep or the public or committing similar acts (such as not complying with site safety requirements, etc) which are likely to bring the Employer into disrepute;

(c)

Non-compliance with any part of the Specifications or Drawings, or non-fulfilment of any contractual obligation,

the SO Rep reserves the right to impose on the Contractor, and the Contractor hereby fully accepts and agrees to pay without dispute or question, a charge based on prevailing guidelines set by the Employer but not exceeding $100,000.00, and for contract with a Contract Sum of less than $300,000.00, a charge not exceeding 30% of the Contract Sum per occasion as agreed compensation to the Employer for the inconvenience caused, investigation and administration expenses incurred by the Employer and for damage to the Employer's reputation and standing generally. Furthermore, the Contractor may be barred from tendering for a specified period. In addition to the above charges, the SO Rep or HDB is empowered either : (a)

to order any irregular work to be removed and made good to the satisfaction of the SO Rep or HDB at the Contractor's costs and expenses; or

(b)

in lieu of correcting work not done in accordance with the Contract, the SO Rep or HDB may allow such work to remain and shall recover any cost differences between the specified requirements and the non-compliance.

For nuisance committed on Site, the Contractor must take immediate action to cease the nuisance committed upon instruction given by the SO Rep or HDB .

SECTION 2/.....

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TECHNICAL SPECIFICATIONS

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CE Spec Page 2-1 SECTION 2

MATERIALS, WORKMANSHIP AND CONSTRUCTION IN GENERAL

2.1

MATERIALS (GENERAL) Unless otherwise stated, all materials and articles shall be of approve manufacture. They shall be obtained from manufacturers and/or suppliers approved by the SO Rep.

2.2

QUALITY OF MATERIALS AND PROVISION OF STANDARD All materials used in the construction of roads, drains, sewers, manholes etc shall be obtained from approved manufacturers. Materials and articles used shall comply with appropriate Singapore Standards (SS) published by PSB or ISO 9000 where these exist, otherwise British Standards (BS) or other specified Standards shall apply. Where a Standard specified in the Specifications has been amended or superseded, the current standard shall apply. Where British Standards are specified in the Specifications, the corresponding Singapore Standards (SS) where available shall prevail. The recommendations in the appropriate Singapore Codes of Practice (CP) shall be referred to during the construction where these are available, otherwise British Codes of Practice or other codes shall apply unless otherwise directed by the SO Rep. Where two or more alternative materials manufactured locally are proposed, the SO Rep may at his sole discretion give preference to the use of a material that is approved under ISO 9000 or any of the quality certification schemes of the PSB, such as PSB Singapore Quality Mark/Product Listing Scheme/ Certification Scheme. For the purpose of this Clause, obtain all precast concrete products such as kerbs, aeration slabs, drain units etc from ISO 9000 or PSB Singapore Quality Mark/Product Listing Scheme/Certification Scheme Suppliers.

2.3

CERTIFICATE OF COMPLIANCE WITH RESPECTIVE STANDARDS If required, obtain from the manufacturers and supply to the SO Rep the appropriate certificate of compliance with the Standard for which those materials or articles are specified to comply with.

2.4

TESTING OF MATERIALS The SO Rep may cause a sample to be taken from each consignment of materials to be tested at an SAC/SINGLAS laboratory and the results of such testing shall be accepted as final. If a sample does not conform to the required standard, the whole consignment shall be rejected and shall be removed from Site by the Contractor and charges against the Contractor under Clause 1.6 "Nuisance and Irregularities to be decided by the SO Rep shall be imposed. If for practical reasons the consignment cannot be removed from the Site, eg. material already installed, then the cost difference between the inferior/undersized/noncomplied materials and the specified materials and/or omitted labour costs based on the latest Rates shall be recouped plus the imposition of charges against the Contractor under Clause 1.6 "Nuisance and Irregularities" to be decided by the SO Rep. Also bear the cost of the final testing to be carried out by LTA, the Employer or any authority responsible for the final taking over of the completed Works; such as premix, precast concrete kerbs, dividers, etc.

2.5

EXCAVATION GENERALLY Visit and examine the Site carefully and ascertained the nature thereof and the kind of materials to be excavated, and make provision in the Contract Sum to cover for the type of materials to be excavated. Prior to commencement of excavation, the Contractor shall carry out pre-construction survey of the neighbouring properties and comply with the requirements of BCA. The Contractor shall set out the lines and structures for the inspection and approval of the SO Rep. Original ground levels shall also be taken and submitted to the SO Rep for record.

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CE Spec Page 2-2 2.5

EXCAVATION GENERALLY (CONT’D) For excavation, the Contractor shall comply fully with the relevant provisions of the Telecommunications Act 1999, the Public Utilities Act, the Workplace Safety & Health Act and the Factories Building Operations and Works of Engineering Construction Regulations 1985 or any amendment or re-enactment thereof. The Contractor shall not be allowed to make any extra claim for work or cost and expenses incurred in complying with the requirements of this clause. Excavation shall be carried out neatly in accordance with the Drawings in whatsoever material may be found, including hard rock or other hard material which requires breaking up by pneumatic drills and the excavated materials shall be used as filling if required. Any surplus excavated materials may be spread or dumped within the Site of the Works if required by the SO Rep. Alternatively, dispose off any surplus material and if so required, provide lorries for transport and make all necessary arrangements for use of an approved dumping ground and bear all costs and expenses in connection with the use thereof. Do not deposit excavated materials on private land unless written permission of both the owner and occupier of the land are submitted to the SO Rep. Unless decided by the SO Rep, surplus excavated materials shall not become the property of the Contractor and it shall not be construed that he has the right of ownership of them. Carry out excavations by any suitable methods but subject to the approval of the SO Rep. The excavated materials may temporarily during the course of the Works be tipped on either side of the excavations only where sufficient space is available without causing obstructions and shall not be tipped nearer to the excavation than a distance equal to the depth of the excavation where the soil condition is poor. The SO Rep may prescribe and limit the lengths and/or widths and/or depths of excavation to be proceeded with at one time. Excavation shall not be carried down in the first instance to a depth nearer than 150mm to formation level. The bottoming-up to formation shall be done by hand immediately in advance of placing hardcore, concrete or pipe laying unless directed otherwise by the SO Rep. Also take such steps as are necessary, in the opinion of the SO Rep, to prevent damage to the formation owing to exposure to the atmosphere and the trampling of the formation by workmen. Where, in the opinion of the SO Rep the formation is softened or spoilt, the soft or spoilt areas shall be excavated and filled with Grade 15 concrete. Cut pipe trenches to a sufficient width to receive and allow the pipes to be easily and properly jointed, but subject to the foregoing requirements, keep to the minimum practicable width. The trench width may also be reduced at or about the pipe soffit level in order to reduce the formation width. Do not construct Permanent Works in any excavation until the excavation has been approved. Form the entire excavation and leave complete and as accurate to the widths, levels, contours and slopes as possible or as otherwise directed.

2.6

EXCAVATION IN ROCK Remove any rock or boulders met with in excavation to the required depths by wedging, blasting or other means as directed. When blasting is required, obtain prior permission in writing from the SO Rep. Comply with the Local Laws and Regulations and any requirements imposed by the relevant Authorities with regard to blasting operations. The Contractor shall be required to submit the blasting proposal to the SO Rep for approval. The following information shall be required on all the blasting Works : (a) (b) (c) (d) (e) (f)

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blasting method, method statement and special techniques; vibration control and measurement; average depth, diameter and spacing of the boreholes; drilling and blasting programme; safety control measures; and over excavation and remedial measures.

CE Spec Page 2-3 2.6

EXCAVATION IN ROCK (CONT’D) Over excavation by blasting method shall not exceed 1.0 metre unless otherwise specified or directed by SO Rep. The Contractor shall make good all the over excavation to the required formation level and shape as directed by SO Rep. The cost and expense of such Works shall be borne by the Contractor. The SO Rep must be fully informed as to the steps and precautionary measures taken to safeguard the surrounding properties. Be liable for any accident, damage or injury to any person, property or thing, resulting from the use of explosives. Prior to the start of blasting operations and in the presence of the SO Rep, conduct a survey of all structures within 120m of the site where blasting is proposed, and any other structures which the SO Rep considers may be affected, in order to determine the existing or pre-blast condition of these structures. Prior to commencing blasting operations, a written report, supported by photographs where necessary, listing any existing defects in the structures, shall be submitted to the SO Rep. When blasting operation are being carried out, any road affected shall be closed to traffic and the appropriate signs erected.

2.7

ERRORS IN EXCAVATION Excavate to such depths only as shown on the Drawings or as directed. Any excavation done to a greater depth than is necessary for execution of the Works shall be filled with concrete of such proportions or with such compacted material to the required formation levels as directed. The cost and expense of such Works shall be borne by the Contractor.

2.8

RATE OF EXCAVATION AND CONSTRUCTION Arrange the work so that the rate of construction keeps pace with the rate of excavation. However, the distance over which excavation may advance ahead of the concreting and drain construction will be specified from time to time by the SO Rep.

2.9

SAFEGUARDING PROPERTIES ADJACENT TO SITE Where the Works is undertaken near or adjacent to buildings and properties and in the opinion of the SO Rep, the stability of such buildings and properties is liable to be affected as a result of the Works, arrange to have such buildings and properties inspected and record any cracks or any other defects which may be affected by the work. Every precaution shall be taken to safeguard such building or property and it shall be to the complete satisfaction of the SO Rep. When directed, excavate in such lengths of excavation as will permit the least amount to be opened at one time in order to minimize the danger of such open excavation affecting the stability of buildings or their supports. Be responsible for damage to public, private or other buildings and properties adjacent to the Site of the Works which is caused as a direct or indirect result of the Contractor's work. Should the Contractor fail to take the necessary precautions, the SO Rep may, after giving the Contractor twenty-four hours notice in writing, carry out such work as may be necessary using labour, material, Construction Equipment, implements and transport from other sources. The cost and expense of such work will be charged to the Contractor.

2.10

DEALING WITH WATER Maintain temporary diversion or damming of any existing drains, wherever necessary. Prior approval from the Drainage Department, PUB, shall be obtained before such works can commence. Any drains or watercourses so diverted shall be re-constructed to their original positions on Substantial Completion of the Works. Remove all water which may arise or be brought into the trenches or excavations and keep the level of such sub-soil or accumulated water below the bottom of any Permanent Works by the use of pumps or suitable well-point apparatus. After raising the water, at once convey it away in such a manner as not to cause any damage, nuisance or injury. All sumps or wells which may be required for the purpose of keeping the Works dry shall be sunk clear of any Permanent Works and shall be refilled after completion of the Permanent Works. Conduct the pumping operations so as to avoid undermining any part of the Works.

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CE Spec Page 2-4 2.11

APPROVAL OF EXCAVATION Report to the SO Rep when the excavations are ready to receive hardcore or lean concrete sub-base and await the inspection and approval of the SO Rep. Any hardcore or lean concrete sub-base or other work put in before the excavation has been inspected and approved shall, if so directed, be removed and new work substituted in accordance with the Specifications.

2.12

PREVENTION OF FLOATATION The structures may not be heavy enough to resist the possible uplift due to water pressure until the structure, soil cover and backfilling have been completed. Make adequate arrangement to keep the excavation dry until the structures and filling are completed or adopt other approved means of ensuring the stability of the Temporary Works or Permanent Works. Submit proposed method to the SO Rep for approval before Works commences and provide for adequate standby Construction Equipment and attendance throughout 24 hours each day. For pipelines laid in wet, waterlogged ground subject to flooding, take all necessary precautions to prevent floating or movement of pipelines whether laying, laid or under test.

2.13

REFILLING The Contractor's attention is drawn to the absolute necessity to compact the refilling by adequate consolidation and ramming. Pay particular attention to filling and ramming around and above pipes in trench to thoroughly compact the filling around structures and to the complete filling of the voids created by the withdrawal of timbering. When a trench is excavated under or near any existing work liable to be affected by subsidence of the material in the trench, or where any Permanent Works will later be constructed under, across, along, or over the line of the trench, fill the trench with Grade 15 concrete, or take such other means to prevent damage by subsidence as the SO Rep may direct. If such work is not shown on the Drawings or specified in the Specifications, any extra work so necessitated shall be paid for according to the Rates, unless, in the opinion of the SO Rep, it is necessitated by the Contractor's negligence, bad workmanship, faulty materials or lack of reasonable foresight. Maintain all refilled surfaces and be responsible for claims arising from accidents due to subsidence or inadequate maintenance. (a)

Refilling within the Service Roads, Bus Bays and Carpark/Sewer Works All concrete shall be thoroughly set before refilling is commenced. In refilling the excavation, use only unwashed sand or granite fines as fill material for the portion of excavation of drain works within the service roads, bus bays and carparks and the full excavation of sewer work trenches. Other suitable fill materials can be used for the portion of the excavation of drain works outside the service roads and carparks. In the initial refilling, carefully place the fill material on top and/or next to the Permanent Works and well pack and ram in a layer of 300mm as directed. Fill the remainder of the excavation with unwashed sand or granite fines, in layers of not more than 600mm deep or such depth as directed, each layer shall be thoroughly rammed before the next layer is placed. In all cases efficient mechanical rammers shall be employed in refilling. Refilling shall include the filling in of all voids caused by the withdrawal of timbering. During the removal of timbering from the trench withdraw the runners only to the level of the backfilling as it proceeds regularly and in layers. As timbers are lifted without exposing the face of the trench, immediately ram the filling hard into the space left by the timber. For sewer works, fill the trenches to a depth of 600mm over the pipes before the pipes are emptied of water after testing, so that any damage that may be caused by ramming can be detected. Where the sewer works are constructed within the roads, driveways or carparks, refilling of the trenches with unwashed sand or granite fines shall be taken up to the Subgrade level of the road/driveway/carpark or 500mm below the road/driveway/carpark finishing level or the proposed manhole top levels whichever is the greater.

(b)

Refilling for Roadbase Keep separate those excavated materials which are suitable for subsequent backfilling. Carefully repack selected excavated materials in place after refilling to form a compact neat surface.

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CE Spec Page 2-5 2.14

IMPORTED FILLING MATERIAL Where filling is required and suitable material from the excavations on the Site is not available, imported filling shall be used. This imported filling which must be to the approval of the SO Rep shall be good lateritic gravel or hogging, broken stone, hardcore, quarry waste or other approved material. Inform the SO Rep the source of supply of the imported filling materials.

2.15

WORKING SHAFT FOR HEADING Obtain access to tunnel or heading work from the working shafts proposed on ends of the open excavation in trench. The Contractor may seek approval from the SO Rep to open additional working shafts within the length of tunnel to facilitate the Works. Make good and refill upon completion of the Work. Provide adequate timber and protect the ends of the open trench used as tunnel or heading access.

2.16

TUNNEL EXCAVATION Engage a registered Professional Engineer to submit all proposals for excavating, timbering and constructing sewers and pipelines in tunnel and obtain the approval of the SO Rep before commencing any work. Be responsible for the safety of the timbering. Submit the design, calculation and full details of the supports and timbering to be used for approval by the SO Rep. The excavation for the tunnel shall be of sufficient size for proper execution of the construction work and all timbering shall be driven and fixed in close contact with the ground to be supported. No payment for overbreak or additional excavation shall be made and all such excavation shall be packed with concrete. Unless otherwise approved, the tunnels shall be close timbered and the timber shall be left in place on Substantial Completion of the Works. During excavation, securely fixed running boards shall be provided to the floor of the tunnel and on completion of excavation, such running boards shall be removed, the formation cleaned and dried out and a concrete sealing coat provided. The tunnel shall be driven complete between access points before commencing Permanent Works and the work shall at all times be carried out as quickly as possible so that the excavation shall remain open for the shortest possible time. The working face of the tunnel excavation shall be supported as necessary and shall be boxed up at the end of each shift when continuous working is not in progress or whenever required by the SO Rep. When work is in progress, proper access ladders shall be fixed and maintained at the tunnel access points and the tunnel lighted by electricity at not more than 110 volts. Lamps shall be provided at not more than 9 metres intervals and no flame or other naked light shall be used. Proper and adequate ventilation fans and ducts shall be provided, maintained and operated at all times. Pipes laid in heading shall be carefully bedded on Grade 30 concrete adjusted to line and level and jointed, inspected, tested and approved. After approval, the whole of the tunnel section shall be carefully and solidly packed with Grade 30 concrete.

2.17

DEWATERING OF EXCAVATION Where dewatering is approved, provide, operate and maintain to the satisfaction of the SO Rep a system of temporary drains intercepting ditches, cut off drains, sub-drains, sumps, pumps, well-points, dewatering equipment and all other things necessary for keeping the sub-soil or accumulated water out of the excavation or at a level below the bottom of any Permanent Works for such a period as the SO Rep may direct. Where ground water, irrespective of the sources, is encountered or anticipated, provide sufficient pumps to handle the ingress of water and provide and maintain in working order standby pumping units. Also arrange for night and day manning and operation of the pumps wherever necessary to ensure that at all times and weathers, the work can be proceeded with.

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CE Spec Page 2-6 2.17

DEWATERING OF EXCAVATION (CONT’D) After raising the water herein referred to, at once convey it away in such a manner as not to cause any nuisance or injury. No new or existing pipe may be used for the purpose of carrying water away from the excavations without permission in writing from the SO Rep. Make good any damage whatsoever resulting from such use of new or existing pipes or culverts. When sand, silt or mud particles are suspended and maintained in the pumped water, tanks to settle the solids shall be provided to remove the solids before discharge of the water. Site temporary works for the control of water clear of the Permanent Works, except where temporary subdrains under the Permanent Works are approved. Should the SO Rep give permission for temporary sub-drains under the Permanent Works, the pipes shall be laid with a 75mm surround of 19mm single size aggregate and the top surface of the surround shall be covered with tarred felt cloth or other approved material. Unless as directed otherwise, all temporary drains and sub-drains shall be finally sealed with concrete at intervals to the satisfaction of the SO Rep and all temporary ditches, sumps, wells etc, shall be filled and reinstated. Include in the Contract Sum for all costs and expenses for complying with this clause, irrespective of the methods adopted.

2.18

SUPPORT FOR EXISTING WORK When any excavation is carried out near, or under any existing work including buildings, services, mains, cables, and surfaces such as roads, etc., which is liable to be affected by subsidence, take necessary measures to prevent damage by subsidence, whether such existing work is shown in the Drawings or not. If it becomes essential, in the opinion of the SO Rep, to permanently divert any sewer drain, pipe, cable or other services or to reconstruct any existing building in an alternative position, such diversions and/or reconstructions shall be paid for by the Employer. Provided always that such diversions and/or reconstructions do not form part of the Works.

2.19

HARDCORE Hardcore shall be composed of approved broken stone, brick, concrete or other similar approved material, free from excessive dust, foreign matter and other impurities. It shall not contain pieces exceeding 150mm or less than 60mm gauge. Oversized hardcore shall not be considered for use unless it can be broken down to the allowable range effectively.

2.20

TIMBER All timber delivered to the Site shall be properly seasoned to moisture content not exceeding 20%, straight, sound, square cut, free from injuries, waney, edges, decay, shakes, large and dead knots, insect attack and other serious defects, and of the appropriate grade according to the Malayan Grading Rules for Sawn Hardwood Timber (current edition) as specified below : 2

(a)

All scantlings up to 400 cm in cross-section shall comply with the requirements of the grade "Merchantable".

(b)

All large structural timber above 400 cm2 in cross-section shall comply with the requirements of the grade 'Baulks & Large Squares'.

(c)

All timber for joinery and dressing used in natural state shall comply with the requirements of the grade 'Standard and Better'.

(d)

All timber for joinery and dressing which is to be painted shall comply with the requirements of the grade 'Merchantable'.

Any portion of the timber works showing signs of warps, shakes or other Defect within the Defects Liability Period shall be replaced with new works together with all other works which may be affected thereby.

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CE Spec Page 2-7 2.20

TIMBER (CONT’D) Submit sample pieces of the timber proposed to be used in the works to the SO Rep for approval. Remove from the Site immediately any timber member or component which the SO Rep does not approve. The recommendations of the Singapore CP 1 and CP 7 for use of timber shall be referred to except where they conflict with this Specifications. Where plywood is used, it shall comply with SS 1 and SS 72.

2.21

CARPENTRY AND JOINERY All timber for structural works shall be Balau, Chengal or Kapur. All timber joinery works shall be Kapur. All carpentry works shall be sawn except where specified as wrote. All exposed surfaces of joinery works shall be wrote by planing and sand-papering to an approved finish. Wrote timber shall be worked to the correct sizes and shapes as shown in the Drawings. Sizes of timber indicated in the Drawings are nominal and a maximum allowance of 2.5mm shall be permitted for each wrot face. Upon delivery all timber shall be properly stacked under cover to ensure free air circulation round all faces and to minimise warping. Take measurements for joinery works on the Site and verify it with the dimensions shown in the Drawings. When discrepancy occurs between the measurement shown in the Drawings and that taken on the Site, obtain the confirmation of the SO Rep before proceeding with the Works. Joints shall be formed in a proper workmanlike manner, well proportioned and tight fitting. Dress all exposed surfaces of joinery work. Where glued joinery work is likely to come into contact with moisture, the glue shall be waterproofed. All joinery requiring painting shall be knotted, stopped and primed before fixing. Coat the backs of all carpentry and joinery works in contact with masonry work with one coat of "Solignum" or "Presotim" or other approved preservative. Allow the preservative to be thoroughly dried before fixing of the Works. Treat all saw cuts similarly. All structural members, assemblies or framework shall be capable of sustaining with due stability and stiffness the whole dead and imposed loads without exceeding the Limits of Stresses stated in CP 1 and CP 7. The timber shall be seasoned as far as practicable to a moisture content appropriate for its particular use as spelt out in CP 1 and CP 7. Treat all timber exposed to damp conditions or in contact with ground with "Solignum" or "Creosote" or other approved wood preservative applied with brush in two coats, or be treated with approved pressurised process.

2.22

PLYWOOD Plywood shall be of the grades specified in SS 1 which in the opinion of the SO Rep is appropriate to the work and shall be as follows : Grade I

For use in the natural state. The veneer shall be free from knots, worm and beetle holes, splits, glue, stains or other defects.

Grade II

For use where subsequent painting or similar treatment is required. The veneer on the face side may have a few sound knots, occasional minor discoloration or stains and small inlay repairs.

Grade III

For use where the plywood is not normally visible. The veneer on the face may have other defects than those specified above provided that its serviceability is not affected.

Adhesives for plywood are to be one of the following types : Type 1

Phenol Formaldehyde resin adhesive classified as weather and boil proof in BS 1203 (WBP).

Type 2

Urea formaldehyde resin adhesive classified as moisture and weather resistant (WR).

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CE Spec Page 2-8 2.22

PLYWOOD (CONT’D) Unless otherwise specified, plywood for internal use shall be Grade II with Type 2 adhesive and plywood for external use shall be Grade II with Type 1 adhesive. Adequately protect all plywood used in permanent structure under damp or wet service conditions against decay and insect attack by treatment conforming to SS 72.

2.23

TIMBERING OF EXCAVATION The term "timbering" shall cover all necessary methods of support including the use of timber, concrete, steel sheet piling, steel sheeting or such materials as may be approved. If timber is used, it shall be of the species Keruing or Kempas. Provide and fix strong and sufficient timbering to support the sides and/or bottom of the excavation to the satisfaction of the SO Rep and maintain the same until the constructional work is sufficiently advanced, in the opinion of the SO Rep to permit the timbering to be withdrawn, which shall be conducted only under the personal supervision of a competent person employed by the Contractor. Carry out such timbering and shoring with due consideration to full flow or flooding conditions all to the satisfaction of the SO Rep. Submit to the SO Rep drawings and calculations showing details of the proposed timbering for approval. Where excavation exceeds a depth of 4m, engage a registered Professional Engineer to submit the design and supervise the erection of the timbering. No excavation work may start until the timbering details are approved. Where excavations for culvert, drains, sewers and manhole are required, submit the full details of the proposed timbering methods within one month from the date of the Letter of Acceptance. Failure to submit and obtain approval of details expeditiously may result in delays and the Contractor shall not be entitled to any extension of Time for Completion on this ground. Notwithstanding the approval given, the SO Rep reserves the right to instruct the Contractor to improve, alter, revise, strengthen the timbering from time to time. Be responsible for any injury to the Work and any consequential damages caused arising out of the remedy of the timbering and any advice, permission or approval given by the SO Rep relating to the relieve of timbering shall not relieve the Contractor from the responsibility specified in the Contract. The SO Rep shall have the right to order excavation and construction work to be carried out in such lengths and in such sections of the Works, as will, in his opinion, minimise the danger of such open excavation affecting the stability of any nearby structures or ground, and the Contractor shall have no claim for extra payment on this account. Shoring timbers shall be removed as the work proceeds only if their removal does not endanger existing adjacent structure. Where the SO Rep deems it dangerous to remove the shoring timbers, such timbers shall not be removed.

2.24

TIMBERING LEFT-IN The Contractor shall be paid for all timbering left in the excavation on the instruction of the SO Rep provided the timber is required to give permanent support to trench sides, services or buildings. No payment shall be made where timber has to be left in, on the instruction of the SO Rep to counter any Defect or negligence in the Contractor's execution of the Works. Only the actual quantity of timber left in shall be paid for. Payment shall not be made for labour in cutting nor for timber in ends thus cut off, nor for the disposal of additional surplus excavated materials due to the leaving in of timber.

2.25

STEEL TRENCH SHEETING Where the subsoil conditions are expected to be of a soft and unstable character in trench excavation, the normal methods of timbering will probably prove inadequate to avoid subsidence of the adjoining road surfaces and other services. The Contractor shall be responsible for all such damages as specified in the Contract. In such circumstances the Contractor shall use Steel Trench Sheeting or Sheet Steel Piling adequately supported by timber struts, walings, etc. Provide, pitch, drive and subsequently remove trench sheeting or piling in accordance with other timbering items specified in the Specifications and the terms Timber or Timbering shall also apply to Steel Trench Sheeting.

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STEEL SHEET PILING The Contractor may use steel sheet piling during the construction of the Works subject to the approval of the SO Rep. Steel sheet piles shall conform to the provisions of BS 4360 and shall be driven where required and approved or directed. Engage a registered Professional Engineer to design the layout of the piling and the overall dimensions of the excavation to suit the sheets and corners available and to give sufficient working space for the proper construction of the Works. For purposes of this Contract, it shall be clearly and definitely understood that the terms 'timber' or 'timbering' as used in any portion of the Specifications or Drawings shall be deemed to include 'Steel Sheet Piling'.

2.27

LIABILITY OF TIMBERING Approval by the SO Rep of the timbering shall not absolve the Contractor from his responsibility and the Contractor shall be responsible for making good any damage caused as a result of the timbering failing to give proper support to the sides of the excavation. Carry out the timbering to the sides of excavation for structures in such a way that there is no obstruction caused to the fixing of formwork for the walls. Remove the supporting struts and walings in stages to suit progress of concreting. If the SO Rep is not satisfied that the standard of timbering is equal to that shown on the approved Drawings or that the sides of the excavations have not been secured in a manner to render such excavations safe for working, he may, one hour after notifying the Contractor or Contractor's Representative in writing, employ other persons to alter the timbering and the cost and expense incurred for such workmen and materials employed shall be recovered from monies due or becoming due to the Contractor.

2.28

WITHDRAWAL OF TIMBERING Withdraw runners and sheets and steel sheet piles in lifts as backfilling and compaction is taking place. Any damage caused by subsidence of the excavation resulting from the careless withdrawal of support shall be the responsibility of the Contractor.

2.29

TIMBER PILING (a)

Scope of Piling Work and Valuation The value of Works completed at any stage shall be the product of the net penetration of driven piles as specified in subclause 2.29(i) "Penetration of Piles" and the rate per metre run, as described in the Rates. Unless described otherwise, such Rate shall include preliminaries, all labour, materials, Construction Equipment and its mobilisation, supply and driving of piles, excavation for piling and cutting, piles cutting, wastage and everything necessary for the execution and completion of piling work. The difference between the value of piling works completed and that as specified in the Contract as computed in the manner described in the preceding paragraph shall be adjusted as a variation to the Contract.

(b)

Construction Equipment & Experience for Driving Piles Submit together with the Tender, a schedule including full details of the Construction Equipment to be committed on the Site. A resume showing the experience of the Contractor and operators in piling work shall also be submitted.

(c)

Warranty Be responsible for the proper execution of the piling work according to the Specifications and the pile layout Drawings. Make good any damage or Defect to the super-structure resulting from Defective execution of Works at the Contractor's costs and expenses to the satisfaction of the SO Rep. The warranty period shall be one year after the completion of the superstructure.

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TIMBER PILING (CONT’D) (d)

Timber Piles Timber piles specified shall be from the HDB Materials List. Timber piles shall be 100mm x 100mm, 125mm x 125mm, 150mm x 150mm or 175mm x 175mm square sawn timber foundation piles with an allowable tolerance of 5mm, produced from the 2 species Kempas or Keruing. The safe working load shall be 8.5 N per mm in direct compressive stress and with an ultimate resistance of all piles of not less than 3 times the nominal working load. The centre line of pile shall not deviate from the straight line joining the mid points of the butt and toe by more than 25mm for any pile up to 6m in length, or 38mm for pile over 6m in length. Use only timber piles produced under the ISO 9000 or PSB Singapore Quality Mark/Product Listing Scheme/Certification Scheme Suppliers. Each batch of piles delivered to the Site shall be subjected to random sampling, for testing by an SAC accredited laboratory, in accordance with the following frequency : (i)

for every contract supply, a minimum of two tests;

(ii)

For supply up to 3,000 metre run, the first test will be carried out from any batch of piles, subsequent test will be made at each interval of 3,000 metre run, the number of test will depend on the quantity of supply but subject to a minimum of two tests for each contract as stated in (i) above.

All piles shall be pressure-treated with copper-chrome-arsenic wood preservative under a pressure of not less than 12.5 kg per cm2, with minimum depth of penetration of preservative of 25mm and with a net dry salt retention in the outermost 25mm of pile of not less than 16kg per m3. All methods of chemical treatment and testing shall be in accordance with SS 72 : 1988 or BS 4072. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each test that fails to comply with the above requirement. In the event that any test by SAC accredited laboratory resulted in failure, remove the batch of piles from which the random sampling is obtained completely from the Site. Should the Contractor negligently or wilfully transport the same batch that had failed previously to the Site again, this act shall be deemed to be an infringement and Clause 1.6 "Nuisance & Irregularities" shall apply. (e)

Steel Box Joint Join two piles by using a mild steel welded box joint 450mm long made from 4.5mm thick plate and coat with bituminous paint and approved by the SO Rep before use.

(f)

Hammer and Set for Pile Driving Use free drop hammer to drive the timber pile. The hammer weight for driving 175mm x 175mm pile shall be 1.5 tonnes, and for driving 150mm x 150mm, 125mm x 125mm or 100mm x 100mm pile shall be 1 tonne. The hammer shall drop a minimum of 1300mm. The acceptable set for the last 10 blows for 175mm x 175mm pile shall be not more than 15mm. The acceptable set for the last 10 blows for 150mm x 150mm, 125mm x 125mm or 100mm x 100mm pile shall be not more than 20mm.

(g)

Driving of Piles Drive Piles accurately in the correct locations true to line both laterally and longitudinally as indicated in the Drawings. Guide piles at the top and bottom during driving and suitably constrain them to maintain their correct position by means of guides. No piles which has been deflected from its course, or has been wrongly aligned may be forcibly brought back to correct alignment except with the written approval of the SO Rep.

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CE Spec Page 2-11 2.29

TIMBER PILING (CONT’D) (g)

Driving of Piles (Cont’d) The centre of each pile shall not deviate from its true position as shown in the Drawings by more than 25mm. Bear all additional costs of the amendment in pilecaps, ground beams, etc as designated by the SO Rep as a countermeasure to the pile eccentricities exceeding the permissible tolerance. Alternatively, the SO Rep may require extra piles to be driven at the Contractor's own cost and expense. During driving, protect the heads of all piles with the helmet of mild steel fitting closely around the pile. A 25mm thick plywood covering the head of the pile shall be contained within the helmet to separate the helmet from the head of the pile. Rigidly & securely join all piles with metal box joints. The joints shall be driven to a tight fit with the pile hammer and spiked to the section of both piles.

(h)

Piling Record Drive piles only in the presence of the SO Rep. The penetrations and sets of every pile shall be subject to the approval of the SO Rep. Record of driving for every pile shall be submitted to the SO Rep and a copy shall be kept by the Contractor on the Site. The record shall include the following items : (i) (ii) (iii) (iv) (v) (vi) (vii) (viii)

Set Temporary compression Penetration from ground level Length of pile and size of section Ground level Cut-off level to the top of pile No. of joints used Time of starting and time of completion

The method of measuring set and temporary compression shall be approved by the SO Rep. The above record shall show a series of sets and temporary compressions measured during the whole process of driving. Once the driving of a pile is commenced it shall continue until the final penetration or set is reached. (i)

Penetration of Piles The penetration of driven piles is the actual length measured from the bottom tip to the cut-off level of the driven piles. The penetration of every pile shall be recorded by the Contractor in the presence of the SO Rep. Mark the timber piles with red paint at every 300mm or other suitable interval to enable easy determination of pile penetration.

(j)

Damaged or Rejected Piles All piles which are broomed, split or damaged during handling or transportation shall be rejected. All piles damaged during driving, or driven unduly out of position, or driven out of plumb resulting in no set after driving for considerable length, where it should set based on soil data and site condition, shall also be rejected.

(k)

Compensating Piles Replace all piles driven into ground and rejected with compensating pile or piles. The position and number of compensating pile/s as decided by the SO Rep shall be such that the concentricity of the pile group is not altered. The Employer shall only pay the cost for the original number of pile/s in the pile group as shown in the Drawings.

(l)

Removal of Obstructions of Piling In the course of piling, only the removal of natural obstruction 2.5m below the ground surface shall be paid for by the Employer as an extra item based on the Contract Rates and only if the SO Rep is satisfied that the Contractor has made every effort to proceed with piling by avoiding the obstruction. Any excavation for obstruction not exceeding 2.5m, including restoring of ground surrounding the piles, and any other works necessary to complete the operation to the satisfaction of the SO Rep shall be deemed to be included in the Contract.

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TIMBER PILING (CONT’D) (m)

Cutting off of Piles Excavate and cut off the pile to the required level shown on the pile layout Drawings or otherwise directed by the SO Rep. Checking and recording of cut-off level shall be followed up immediately. In the cutting of piles, ensure that a surveyor is stationed at the Site for such work. Do not reuse any pile which has been cut off as wastage unless the waste pile length exceeds 2.5m and the cut-off head has been treated.

2.30

PAINTING (a)

Material All paints, primers and other materials shall comply with SS5, SS6, SS7, SS34, SS37, SS38, SS150, SS206 and SS345 or other relevant specifications of PSB. (i)

Enamel Gloss Paint Paint for timber and metal work shall have a synthetic enamel gloss finish with an alkyd-resin base. Where an undercoat is specified, obtain the paint from the same manufacturer whose gloss paint is approved for the particular work. A different brand shall not be used unless the SO Rep has given his consent. If more than one under-coat is specified, the undercoats shall be of different colour from each other to enable the number of coats applied to be checked. Before the following coat is applied, allow each coat at least 24 hours to dry. Carry out painting with proper paint brushes. Any other method of painting shall not be allowed unless approved by the SO Rep.

(ii)

Primers Primer for aluminium, zinc or galvanised iron shall be an approved Etching Primer with a Polyvinyl resin base and then cover with another coat of approved lead and chromate free primer with a pure linseed oil base. Thoroughly mix etching primer with the Activator before use in the ratio of 3 parts Base to 1 part Activator. Being a dual pack material, the mixture shall have a pot life of 12 hours. Carry out the painting of etching primer coat under shed or in the factory. The dried etching primer coat shall not come in contact with water and apply a coat of Red lead primer over it within two days from the date of applying the etching primer.

(iii)

Emulsion Paint All emulsion paints shall be of an approved brand with an acrylic base. Apply with a proper paint brush and not a locally made colour wash brush. If more than one coat is specified the previous coat shall be properly dried before the following coat is applied.

(iv)

Carriageway Marking Paints All paints used for carriageway marking shall be quick-drying, chlorinated rubber based and shall comply in all respects with the requirements specified in the Singapore Standard 221:1979 (UDC 667.633:625.746) for Road Marking painting. The Contractor may be required to submit to the SO Rep for his approval two cans each of five litres of the white and yellow colour paint proposed for use in the Works. If during the Time for Completion and any time period where liquidated damages are imposed under the Contract, the Contractor of his own accord decides to change the manufacturer of the above approved paint(s), he is required to submit additional samples of the new paint as afore specified. The paint samples so submitted shall be sent to an SAC accredited laboratory for testing for compliance with the Specifications and of the corresponding statement of characteristics so submitted.

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PAINTING (CONT’D) (a)

Material (Cont’d) (iv)

Carriageway Marking Paints (Cont’d) The SO Rep may direct the Contractor to change the supplier or manufacturer of the paints used in this Contract if he is satisfied that the paints used in this Contract do not comply with the Specifications and the corresponding Statement of Characteristics. Comply further with the instructions of the SO Rep all at the Contractor's own cost and expense. The SO Rep may require samples of reasonable quantity of any paint used in the Works for testing by an SAC accredited laboratory. The Contractor shall be advised of the results of the testing by the SO Rep. If the paint tested fails to meet the approved requirements on the corresponding Statement of Characteristics, then all works represented by the paint sample or the entire road or roads painted on the same day where such paint was taken for testing shall be rejected. Deliver all paints for carriageway marking to the Site ready for use. When the container for the paint is opened, the paint shall show no signs of livering or instability and be free from skin, dry sediment, and caking and shall mix readily with a paddle to a smooth homogeneous state. The paint shall meet the quantitative requirements specified in the following table: Characteristic

Requirement Minimum

Maximum

Pigment content, percentage by weight of paint

40

60

Non volatile matter, percentage by weight of paint

60

-

Viscosity, kerbs unit

70

80

Specific Gravity

1.22

Fineness of grind, microns

-

50

"No pick up" drying time, mins

-

15

70 60 50

-

Opacity (contrast ratio), percent White Yellow Red

-

Tests conducted by SAC Accredited Laboratory The properties and characteristics for all road line paints used in this Contract shall if required, be tested in accordance with the methods of testing specified in and requirements inferred from the respective standard adopted by PSB. Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

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Test Non volatile matter Colour Flexibility and Adhesion (Bend Test) Scratch resistance Condition in container Skimming properties Specific gravity Dilution stability Brushing properties Spraying properties Viscosity (Stormer viscosimeter) Fineness of grind Pigment content Opacity (contrast ratio) "No pick-up" drying time Resistance to bleeding Abrasion resistance

Method of Test (Refer to SS 5) Part 6 Part 10 Part 12 Part 13 Part 16 Part 17 Part 19 Part 20 Part 21 Part 22 Part 23A Part 24 Part 26 Part 29 Part 39 Part 40 Part 41

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PAINTING (CONT'D) (b)

Certificate Submit a certified 'STATEMENT OF CHARACTERISTICS FOR CARRIAGEWAY MARKING PAINTS' on the prescribed Form as produced in Appendix A2. This statement shall be completed by the paint manufacturer whose paint the Contractor proposes to use in the Works. This statement shall be used to make periodic assessment of the Contractor's paints as sampled from time to time and is for the strict confidential use of the SO Rep and the information in the Statement would not be revealed by the SO Rep but shall serve and assist in identifying and testing the paint samples taken during the execution of the Works.

(c)

Equipment Mechanisation in all aspects of painting of road line and carriageway markings is compulsory under the Contract. It shall be a prerequisite for the Contractor to own and make available the following equipments for use under the Contract : (i)

Carriageway Marking Machines The apparatus shall be self propelled and constructed so as to apply or spray paint under pressure in continuous uniformity to dimensions of the markings. It shall be equipped with the devices for agitation of the paint while in operation. All parts of the apparatus which come into contact with the paint shall be so constructed as to be easily cleaned and maintained. The apparatus shall be capable of adjustment to provide a uniform spray wet film thickness of between 200 to 500 microns and in this respect shall be automatically self drive and be capable of travelling at uniform speed. It shall be mobile and manoeuvrable to the extent that straight lines can be followed and regular curves can be prescribed in a true arc. The apparatus shall have the capacity of selection of either automatic or manual skip marking operations preferably to four preset programmes. The apparatus shall also be capable of marking line widths varying from 100mm to 600mm with extended facilities of applying paint to symbolic signs and messages using templates. The marking apparatus shall also be equipped with devices capable of applying glass beads balloting in such a manner that the balloting are dispersed almost instantly upon the freshly painted surface at a rate of 0.72 kg per litre of paint or at the recommended rate of the paint manufacturer. The balloting depositor shall be synchronised with the cut off of the paint application control. The balloting shall be applied with sufficient velocity to ensure retention in the surface of the paint.

(ii)

Roadline Erasing Machine The apparatus shall be mechanically propelled and be able to erase road lines uniformly in the cold state.

(iii)

Flow Cups and Wet Films Gauges All painting machines shall be provided with approved flow cups (ISO flow cups or equivalent) for measuring the consistency of viscosity of the paint used and wet film gauges (Ericksen type 333 or equivalent) with a measuring range of 0 to 600 microns having an accuracy of 25 microns for the determination of the wet film thickness of paint laid. Also supply six aluminium plates 200mm x 200mm of 15 gauge for the purpose of the testing of the thickness of the road line paint.

(d)

Mode of Operation All road line paintings and carriageway markings which include pedestrian crossing, box junctions, continuous broken lines, numerals, bus zones, arrows, letterings, etc shall be fully mechanised and drawn or spray painted by road line painting machine. On no account shall the paint be applied by brushes to road lines and markings and in the event that such lines and markings are so drawn, such work shall be rejected. Painting of other traffic appurtenances and road related facilities may unless otherwise directed by the SO Rep be carried out by brushes. Under such circumstances the workmanship shall be of the highest standard and care shall be exercised to produce a smooth and uniform coat of paint.

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PAINTING (CONT'D) (e)

Weather Conditions (i)

No painting shall be done on surfaces which are wet or damp from rain, dew or any other causes until they have been properly dried.

(ii)

Prepare all surfaces before the application of paints. Preparation shall have the following meaning for the surfaces indicated : Preparation (1)

On new concrete or plastered surfaces to receive cement paint or emulsion paint : Prepare by washing down with soap (if necessary) to remove dirt, grease and other adhering materials. Rinse off with clean water and allow to dry thoroughly.

(2)

On existing painted plastered or concrete surfaces to receive cement paint or emulsion paint : Prepare by removing all nails etc., scraping thoroughly and brushing briskly with a stiff brush to remove efflorescence and flaking materials. Where necessary wash down with soap to remove dirt, grease and rinse off with clean water and allow to dry thoroughly. Make good areas of defective plaster or concrete and fill up cracks and holes with approved filler.

(3)

New metal surfaces to receive paint : Prepare by scraping and removing all rust and mill scales by sand paper and rub down with emery cloth.

(4)

Existing painted metal surface to receive primer coat and paint : Prepare by burning down all existing paint, thoroughly wash off the surface with soap and rinse with clean water. Allow it to dry thoroughly and rub down with emery cloth.

(5)

Existing painted surface to receive paint only : Prepare by rubbing down with sand paper to remove flaky old paints, and rinse surface thoroughly with water and allow to dry thoroughly.

(6)

Painting of road line and carriageway markings : Prepare by sweeping off all dust, grit and foreign matter on the road surface with stiff brushes. Mark out to the required dimensions and alignment for directional arrows, box junctions, bus zones continuous or broken lines, lettering, etc. before the application of the paint.

(f)

Wet Film Thickness Supply all paints for carriageway marking ready mixed by the manufacturer and no thinning with any materials to the already mixed paints shall be permitted. Apply all paints for carriageway marking by apparatus approved by the SO Rep to a wet film thickness of 375 microns (plus or minus 50 microns). The SO Rep may request the Contractor to mark measurements with respect to the thickness of wet paint film by measuring with the appropriate gauge. For this purpose, supply at least six pieces of clean aluminium gauge No. 15 plates each of size 200mm by 200mm. The marking apparatus with set settings shall run over one plate and the wet film thickness measured expeditiously.

(g)

Colour Scheme The colour schemes for any work and the various coats to be applied shall be determined by the SO Rep.

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PAINTING (CONT'D) (h)

(i)

Adulteration (i)

Under no circumstances shall any oil or spirit be added to paint. All oil or spirit found in the possession of any painter or the presence on Site of any tins, drums, kegs or other containers marked with the name of a brand or material or manufacturer different from those which the SO Rep has selected to be used, as a receptacle for brushes, as paint kettles, etc. shall be deemed as evidence of adulteration.

(ii)

At any one time during the actual painting, the SO Rep shall have the right to take samples of paint, or scrap or chip off actual painted work for the purpose of laboratory testing. Paint which is found to be adulterated, or different from the original sample as tested, shall be dealt with under the provisions of Clause 1.6 "Nuisance & Irregularities". Erase off and clean all the rejected paint work applied up to that time and to repaint same.

(iii)

Before any paint is applied, the prepared surfaces shall be inspected and approved by the SO Rep.

(iv)

After a coat has been applied the succeeding coat shall not be applied until the work has similarly been inspected and approved and not before 24 hours have lapsed after the first application.

Durability of Paintwork The visibility of road lines and carriageway markings shall not be decreased by more than 50% at any time after the initial painting or repainting. Provide everything necessary to maintain all paintworks during the Defects Liability Period. For road lines and carriageway markings, repaint the entire work when the paintworks failed to meet the above requirement and at the end of the Defects Liability Period. In this respect, the decision of the Superintending Officer on the 50% visibility requirement shall be final. For other painted items of structures, provide everything necessary and repaint every and all such items with 1 coat of approved paints at the end of the Defects Liability Period. Satisfactorily attend to all Defect such as rust, chipped or dented surfaces, etc. prior to repainting. In this respect, arrange a joint site meeting with the SO Rep before any remedial work is carried out, and comply with all requirements as directed.

2.31

REFLECTORISED THERMOPLASTIC ROAD MARKING (a)

General Where reflectorised thermoplastic road marking is indicated on the Drawings or where directed by the SO Rep, the road shall be prepared and the prime coat and reflectorised thermoplastic road marking supplied and applied in the manner as specified. On receipt of instructions from the SO Rep, proceed promptly with such work on receipt of such instructions. Carry out the Works continuously and complete within such time as specified allowing only for unavoidable lost time because of any inclement weather during the course of the Works.

(b)

Material Specifications (i)

Thermoplastic Material The thermoplastic material to be used under this Specifications shall comply with the British Standard BS 3262:1982 - "Hot Applied Thermoplastic Road Marking Materials". The material shall be able to resist damage caused by the spillage of petroleum on the road. The material shall be tough, durable, elastic and of heavy duty, formulated to adhere excellently on pavements of all descriptions and to provide superior resistance to abrasion. The material shall be able to withstand the ravages of traffic impacts, staining and flaking.

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REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (b)

Material Specifications (Cont’d) (i)

Thermoplastic Material (Cont’d) The thermoplastic material shall be so manufactured to be applied by extrusion onto the pavement in molten form with glass beads mixed in and also dropped into the material immediately after it is applied. Reflectorization with solid glass beads of a suitable grading shall be used to improve the visibility of road markings at night. The proportion and grading of glass beads shall be in accordance with subclause 2.31(b)(vi) "Solid Glass Beads" specified hereunder and shall be correctly sprayed to achieve the specified retroreflection throughout its lifetime.

(ii)

Aggregate The aggregate shall consist of light coloured silica and, calcite, quartz and calcined flint.

(iii)

Pigment White material shall be of titanium dioxide complying with the requirements of type A (anatese) or type R (rutile) of BS 1851. Yellow material shall consist of sufficient yellow pigment of lead chromate of sufficient heat stability when heated to temperature of 200 degrees Centigrade to substitute part or all of the titanium dioxide.

(iv)

Extender Extender shall be in whiting (calcium carbonate prepared from natural chalk) complying with BS 1795.

(v)

Binder Binder shall consist of synthetic hydrocarbon resin plasticized with mineral oil.

(vi)

Solid Glass Beads The reflectorization shall be done by solid glass bead, of which the following classes are appropriate for use : Class

Application

A

Incorporation in thermoplastic road marking compounds

B

Surface applied for thermoplastic road marking compounds and pavement marking paints

The solid glass bead shall be made from soda glass and not less than 70% by mass shall be of transparent glass, reasonably spherical and free from flaws. Class A glass beads shall conform to the following requirements of BS 6088 with respect to particle size distribution, roundness and defect :

Sieve

1.18 mm 1.18 mm 850 m 425 m

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% Retained

Minimum % spherical beads by mass tested in accordance with Appendix C of BS 3262

0 to 3 0 to 3 0 to 10 90 to 100

) ) ) )

70

Maximum % of defective beads as tested in accordance with Appendix D of BS 3262

30

CE Spec Page 2-18 2.31

REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (b)

Material Specifications (Cont’d) (vi)

Solid Glass Beads (Cont’d) Class B glass beads shall conform to the following requirements of BS 6088 with respect to particle size distributions, roundness and defect :

Sieve

% Retained

Minimum % spherical beads by mass tested in accordance with Appendix C of BS 3262

0 to 5 5 to 20 30 to 75 10 to 30 0 to 315

) ) ) ) )

Maximum % of defective beads as tested in accordance with Appendix D of BS 3262

(m) 850 600 300 180 Below 180

20

80

The solid glass beads may be applied by either gravity feed or air assisted feed and may have a moisture proof coating or a flotation coating. The solid glass bead used shall be of the chemical composition given in the tables below : Chemical Composition

Requirement

Silicon dioxide

Si02

Calcium oxide Magnesium oxide Sodium oxide

Ca0 Mg0 Na20

) ) )

) ) together not less than 8% )

Potassium oxide Aluminium oxide Ferric oxide

K20 Al203 Fe203

) ) )

) ) together not more than 18% )

not less than 70%

The proportion of the constituents of the mixed materials shall comply with the following requirements :

Item

Constituents

Percentage by Mass of Total Mixture Minimum

Maximum

1

Binder (resin and oil)

18

22

2

Solid glass beads

20+

-

3

Aggregate, pigment extender, and solid glass beads*

78

82

* where specified. + 20% shall be maintained even in the case of material to which solid glass beads are to be applied by pressure application.

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REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (b)

Material Specifications (Cont’d) (vi)

Solid Glass Beads (Cont’d) The grading or the combined aggregates, pigment, extender and solid glass beads as found on analysis shall comply with the following requirements : Sieve Size 2.80mm 600 microns

(c)

Percentage by mass passing 100 75 - 95

Equipment Specification Mechanisation in all aspects of painting of road line and carriageway markings is compulsory under this Contract. It shall be a pre-requisite for the Contractor to own and make available the following equipment for use under the Contract : (i)

Carriageway Marking Machines The equipment shall be self propelled and constructed so as to apply thermoplastic roadmarking using screed method, or where the roadmarking thickness required are of 1.5mm only, spray thermoplastic can be applied. It shall be equipped with devices to provide uniform heating, continuous mixing and agitation of the material with balloting beads while in operation. The equipment shall be capable of adjustment to ensure continuous uniformity in the dimensions of the stripe. It shall be mobile and manoeuvrable to the extent that straight lines can be prescribed in a true arc. It shall provide a means of clearly cutting off square stripe ends upon the installed line. The finished lines shall have well-defined edges and free of wariness. Provide a special melting kettle for heating, melting and mixing of the thermoplastic material. The kettle shall be equipped with a correct thermometer so as to provide positive temperature control and prevent overheating of the thermoplastic material. Heated thermal oil jacket may be utilised to keep the thermoplastic material at constant temperature. When the spray method is employed, the traverse speed of the equipment shall be between five to seven kph. In this case, a self contained preheater unit shall be provided. The heating shall be by oil jacket and thermostatically controlled. A transport trailer unit towable easily by a land rover or equivalent vehicle shall be provided for the transportation of the spray machine from site to site. The trailer shall be twin-ram and of tiltable deck raised and lowered by a screw lever device without any wheel housing to interfere with a machine having side mounted equipment. The equipment shall also be equipped with devices capable of applying solid glass beads ballotini in such a manner that the ballotini are dispersed upon the freshly painted surface. The ballotini depositor shall be synchronised with the cut off of the paint application control. The ballotini shall be applied at a sufficient rate to ensure retention in the surface of the paint. For the case of a glass bead spray gun, the rate of glass bead dispersion shall be up to 7 kg per minute. All parts of the equipment which come into contact with the paint shall be so constructed as to be easily cleaned and maintained. Ensure that the equipment is properly cleaned or maintained at all times.

(ii)

Roadline Erasing Machine The apparatus shall be mechanically propelled and be able to erase road lines uniformly in the cold state.

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REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (c)

Equipment Specification (Cont’d) (iii)

Retroreflectometer For Measuring Retroreflectives Of Roadmarking It is essential that the Contractor provides at least two (2) units of retroreflectometer for use in this Contract. The instrument shall be robust, simple and quick to operate, weighing not more than 10kg and portable (preferably having dimensions not more than 500mm x 210mm x 210mm) and be operated by one-operator. It shall be easily connected to a 24 Volt carbattery or a suitable generator for power supply and shall have digital readout in mcd/lx.m2. The measuring area of the instrument shall be of a maximum width of 100mm for each reading taken. The measuring geometry shall be as follows : Entrance Angle Observer Angle

: 86.5% : -85%

The lamp used shall be a single 12 volt 100W halogen/quartz Iodide lamp which shall be easily replaceable without tools. The instrument shall be internally zeroed and calibrated; ie. it shall have a built in zero and reference standard and when in normal use shall be capable of setting to zero and calibrating to 600 (six hundred) mcd/lx.m2. (iv)

Deep Frame Micrometer For Measuring Thickness Of Roadmarking It is essential that the Contractor provide two units of approved deep frame micrometer with an anvil area of at least 10mm2 and an accuracy of 0.01mm for use in measuring the Works.

(d)

Method Specifications For Application Of Thermoplastic Roadmarking (i)

Preparation of Site An approved adhesive primer coat at the rate of 220 g per m2 shall be provided on old polished surfaces of bituminous pavements, existing road markings and on concrete before the markings are applied to ensure optimum adhesion. The thermoplastic material shall not be laid over loose detritus, mud or extraneous matter or over old flaking markings of road line paint or thermoplastic material. The road surface shall be clean and absolutely dry before markings are placed over. The surface shall be swept by a handsweeper, and any damp spot or grease stain shall be burned off with a gas burner. In events whereby existing road lines and markings are out of alignment with the new thermoplastic lines and markings, erase off such existing road lines and markings using Roadline Erasing Machine.

(ii)

To avoid discoloration and embrittlement of the material due to heating at a temperature in excess of that laid by the manufacturer, the thermoplastic material shall be heated in sufficient quantities in a heater fitted with a mechanical stirrer. Once molten, the material shall be laid on expeditiously. It shall not remain in a molten state for more than 6 hours for hydrocarbon resins and shall not at any time be heated above the manufacturer's declared safe heating temperature.

(iii)

Laying Of Thermoplastic Materials The application of the material to the road shall be by machines using the screed and/or spray method. Equip the machine with various sizes of shoes or to employ a range of machines that would enable him to mark the required lines in one pass. The materials shall be laid within the temperature range specified by the manufacturer and not exceeding 180 degrees Centigrade. The thermoplastic markings shall be uniform in texture and thickness and free from blisters, bubbles and streaks. The finished lines shall be sharp and free of ragged edges. Proper templates shall be used for marking of arrows and letterings. The thermoplastic material shall be applied at the specified thickness excluding surface applied solid glass beads or otherwise specified.

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CE Spec Page 2-21 2.31

REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (d)

Method Specifications For Application Of Thermoplastic Roadmarking (Cont’d) (iii)

Laying Of Thermoplastic Materials (Cont’d) Prepare the road surface thoroughly to ensure satisfactory adhesion of the thermoplastic material. The road surface shall be free from moisture and loose particles. The application of the material shall take place when the road temperature is lower than 40 degrees Centigrade and the relative humidity of the air not greater than 85%.

(iv)

Reflectorization By Surface Application The material shall have minimum 20% (by weight) of ballotini beads incorporated in the thermoplastic as specified in sub clause 2.31(b)(vi) "Solid Glass Beads". To achieve immediate reflection, a further quantity of glass beads shall be sprayed onto the hot material at the time of application. The beads shall be applied by pneumatically "fired" drop-on or by gravity at the rate of approximately 300 50 g per m2, immediately after the thermoplastic material has been deposited on the road but before it has hardened. The retroreflectorization of the thermoplastic roadmarking shall be measured in the field by the retroreflectometer as in subclause 2.31(c)(iii) "Retroreflectometer For Measuring Retroreflectives of Roadmarking". Measurements shall be done at suitable time when traffic density is lowest and with proper signing as specified in subclause 1.5.1 "Site Safety Measures".

(v)

Thickness The material shall be laid to the specified thickness of 1.5mm/3.0mm. When the film thickness is specified as 1.5mm/3.0mm, the minimum thickness of thermoplastic lines, as viewed from a lateral cross section, shall be not less than 1.5mm/3.0mm at the edge and centre. These measurement shall be taken as an average through any one metre section of the line. The minimum thickness specified are exclusive of surface applied solid glass beads. The method of thickness measurement shall be in accordance with Appendix B of BS 3262:1981.

(e)

Performance Specification and Related Test Methods All material properties and their related test methods shall as far as possible conform to BS 3262:1981 unless otherwise stated or approved by the SO Rep. Generally the material shall be easy to apply, has high brightness, very short overdriving time and very low dirt attack. In order for the material to be considered it shall have the following properties : (i)

Colour Luminance When tested in accordance with BS 3262:1981 Appendix D, the luminance factor of white shall not be less than 70 (as delivered) while that for yellow shall not be less than 80 (as delivered).

(ii)

Density The density of the thermoplastic material shall not be less than 1.65 kg per litre.

(iii)

Softening Point When tested by the Ring and Ball method in connection with Appendix C of BS 4692, the softening point shall be greater than 80 degrees Centigrade.

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REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (e)

Performance Specification and Related Test Methods (Cont’d) (iv)

Heat Stability When tested in accordance with Appendix E of BS 3262:1981, the decrease in luminance factor of the white and yellow material as measured in accordance with Appendix D shall not be more than 5.

(v)

Flow Resistance A cone made and tested in accordance with Appendix F BS 3262:1981 shall not slump by more than 25%.

(vi)

Resistance to Calcium Chloride The material when immersed in a strong solution of calcium chloride for a period of 4 weeks will remain completely unaffected.

(vii)

Viscosity The material shall possess the following characteristics - solid at 20 degrees Centigrade, thick fluid at 170 degrees Centigrade.

(viii)

Abrasive Resistance The material shall possess excellent wear-resistance properties. The wear resistance shall be measured on a Taber Abraser Type 503 standard abrasion tester using H-22 calibrate wheels in accordance with Appendix K of BS 3262:1981. The loss in weight of the test panel after 200 revolutions shall not exceed 0.5g.

(ix)

Skid Resistance When tested in accordance with Appendix G, BS3262:1981 skid resistance of the newly placed road marking or any roadmarking that is still within the Defects Liability Period shall not be less than 45.

(x)

Degree Of Erosion When the material applied in accordance with the Specifications, is tested in accordance with Appendix M of BS 3262:1981, the total wear index for the test area on each stripe shall not exceed 30 at each of the regular inspection intervals.

(xi)

Reflectivity Measure the reflectivity by the retroreflectometer as specified in subclauses 2.31(c)(iii) "Retroreflectometer For Measuring Retroreflectives Of Roadmarking" and 2.31(d)(iv) "Reflectorization By Surface Application" immediately after the thermoplastic roadmarking has hardened. Four measurements are to be taken at representative locations. The average of the ten readings in any one measurement shall achieve :

CE12/S2.DOC(22) oym(151211) DPD

(a)

For white roadmarking

:

retroreflection reading not less than 300 mcd/lx.m2

(b)

For yellow roadmarking and other colours

:

retroreflection reading not less than 200 mcd/lx.m2

CE Spec Page 2-23 2.31

REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (e)

Performance Specification and Related Test Methods (Cont’d) (xii)

Thickness Of Material Laid Measure the thickness of the thermoplastic laid by a deep frame micrometer. Carry out measurements immediately after the thermoplastic roadmarking has hardened. 10 measurements are to be taken at representative locations. For each measurement at a selected location, 3 samples' mean of 4 readings are taken by the deep frame micrometer to make up one measurement. The 3 samples are to be taken from positions at least 3 metres apart. The average of the 3 samples' mean forming one measurement shall not be less than the thickness specified in subclause 2.31(d)(v) "Thickness" and as shown in the Drawings.

(xiii)

Non-Compliance Of Thickness And Reflectivity If the thickness or reflectivity is found to be below the values specified, grind away the surface of the portions represented by the sample readings and then apply thermoplastic material and glass beads to bring the thickness to 1.5/3mm and the reflectivity to at least the minimum required values.

(f)

Shape and Spacing Of Roadmarking For new road surfaces, ensure that the surface be sufficiently clean and dry before the application of the thermoplastic material. The Contractor shall be responsible for erasing the old roadmarkings and the resetting of the whole intersection and marking of the lines to the required widths and dimensions as shown in the Drawings or as directed where existing markings have faded or have run out of alignment. All markings shall be laid in accordance with the Drawings.

(g)

Guarantee Of Material Quality Guarantee the thermoplastic road marking material furnished and installed under the Specifications against failure due to poor adhesion resulting from defective materials or method of application for a period of twelve (12) months in conjunction with the Defects Liability Period.

(h)

Test Samples And Testing For Content Of Material Present the proposed grading of the glass beads, and aggregates; and samples of the following materials intended for use under the Specifications to an approved Highway Authority Material and Research Laboratory for test. The Authority testing the material may be the same country where the product is manufactured. Details of testing requirements and the test methods shall conform to BS 3262:1981 Appendices A to M or of a method and standard acceptable to the SO Rep. Submit latest test reports of the samples to the SO Rep for consideration. If materials presented under this subclause are accepted, they shall be the standard by which materials actually applied under the Contract are compared with.

(i)

Samples To Be Supplied At The Start Of Time For Completion Supply 2 no. of white roadmarking and 2 no. of yellow roadmarking properly laid on 30mm x 150mm aluminium sheets before the commencement date for the Time for Completion. The thermoplastic roadmarking materials shall be of 3mm thickness. The tone of colour agreed upon by the SO Rep for the samples shall be used as the standard tone for all the Works. The SO Rep reserves the right to request for another supply of these same number of samples if he feels that the tone of colour has inevitably changed.

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CE Spec Page 2-24 2.31

REFLECTORISED THERMOPLASTIC ROAD MARKING (CONT’D) (j)

Information Of Product To Be Supplied By Manufacturer Obtain from the manufacturer the following information of the thermoplastic material proposed for use for the Works : (i) (ii) (iii) (iv)

Maximum safe heating temperature of the material. Temperature range of application for screed laying. Flash point of the material. Composition of the mixture.

The foregoing information shall be provided to the SO Rep one week before the start of the laying operation. (k)

Protection Of New Road Marking Make arrangements for the protection of new marking until such time as the material has `set-up' sufficiently to resist being damaged by traffic. Replace all materials laid and subsequently rendered unfit by the action of traffic or other road users.

2.32

WATER FOR THE WORKS Obtain all water to be used for making mortar or concrete or for other purposes from the PUB mains. Make provisions for such storage tanks, temporary connections, etc as may be required and for moving such tanks to keep them sufficiently adjacent to the part or parts of the Works in progress. Arrange for the supply of water to the Works and for paying all charges.

2.33

CEMENT All cement used in the Works shall be of approved local manufacture except otherwise permitted by the SO Rep. Where cement is specified it shall comply with SS 26 and BS 12. With each delivery the Contractor may be required to send to the SO Rep a memorandum of the quantity delivered and the manufacturer's test certificate. Unless otherwise specified, the compressive strength test shall be used to determine the strength of cement.

2.34

CEMENT STORE Provide on the Site a building or shed to be used exclusively for the purpose of storing the cement. This building or shed shall be dry inside and closed to entry of water, have thoroughly dry floors and walls, be well lighted and ventilated and be capable of holding at least one month's supply of cement and at least sufficient cement for two week's supply shall always be kept in the shed. So far as is practicable keep different consignments of cement separately. Use cement in the order in which it has been delivered to the Site on a first in first out basis and the method of storage shall be arranged to facilitate this requirement. Keep cement in the store until it is actually required for use on the Works and any cement temporarily placed near the mixer or elsewhere, after removal from the store, shall be adequately protected by approved means. Cement shall not be kept in a temporary store except in so far as is necessary to allow for efficient organisation of the mixing plant. If the Contractor proposes to use cement delivered in bulk obtain the prior approval of the SO Rep as to the method of delivery and storage. If the Contractor refuses to accept the cement delivered to the Site by the supplier on the instruction of the SO Rep but instead accepts the cement from another supplier, the SO Rep shall impose charges against the Contractor in accordance with the provisions as spelt out in Clause 1.6 "Nuisance & Irregularities".

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CE Spec Page 2-25 2.35

CEMENT TESTING The SO Rep and his representative shall have access to the cement store at all reasonable hours and shall be furnished with the means of identifying the several consignments of cement. Cement shall comply with SS 26 and BS 4550. The manufacturer's approved test certificate shall normally be accepted as proof of compliance with the Specifications.

2.36

AGGREGATES (a)

The materials used as aggregates shall be chemically inert, strong, hard, durable and free from clay lumps and organic and other impurities. All materials and grading of aggregates shall comply with SS 31, SS 73, SS 74, BS 812, BS 882, 1201 and tested in accordance with the requirements of SS 73 and BS 812.

(b)

Grading Of Fine Aggregates The grading of the aggregate, when based on sieve analysis as described in SS 31, SS 73, SS 74, BS 812, 882 and 1201 shall be within the limits of one of the grading zones given in Table 2.2, except that a total tolerance of up to five percent may be applied to the percentage given in bracket. For crushed stones, the permissible limit is increased to 20 per cent. The fine aggregates shall be described as fine aggregates of the grading zone into which it falls, eg. SS 31, Grading Zone One.

(c)

Grading Of Coarse Aggregates The grading of coarse aggregate, carried out in accordance with the procedure detailed in SS 31, SS 73, BS 882, 1201 and BS 812 shall be within the following limits of Table 2.1 :

TABLE 2.1 - COARSE AGGREGATES Percentage by weight passing BS Sieves

Nominal size of graded aggregate BS 410 Test Sieve

Nominal size of single-sized aggregates

1½ in to 3/16 in (38mm to 5mm)

3/4 in to 3/16 in (19mm to 5mm)

½ in to 3/16 in (13mm to 5mm)

2½ in (64 mm)

1½ in (38 mm)

3/4 in (19 mm)

1/2 in (13 mm)

3/8 in (10 mm)

in

mm

3

76.20

100

-

-

100

-

-

-

-

2½

63.50

-

-

-

85 - 100

100

-

-

-

1½

38.10

95 - 100

100

-

0 - 30

85 - 100

100

-

-

3/4

19.00

30 - 70

95 - 100

100

0-5

0 - 20

85 - 100

100

-

½

12.70

-

-

90 - 100

-

-

-

85 - 100

100

3/8

9.52

10 - 35

25 - 55

40 - 85

-

0-5

0 - 20

0 - 45

85 - 100

3/16

4.76

0-5

0 - 10

0 - 10

-

-

0- 5

0 - 10

0 - 20

No.

mm

7

2.36

-

-

-

-

-

-

-

0-5

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CE Spec Page 2-26 2.36

AGGREGATES (CONT’D) (c)

Grading Of Coarse Aggregates (Cont’d) TABLE 2.2 - FINE AGGREGATES BS 410 Test Sieve

Percentage by weight passing BS Sieves Grading Zone 1

Grading Zone 2

Grading Zone 3

Grading Zone 4

in

mm

3/8

9.52

100

100

100

100

3/16

4.76

90 - 100

90 - 100

90 - 100

(95) - 100

No.

mm

7

2.36

60 - (95)

(75) - 100

(85) - 100

(95) - 100

14

1.18

30 - (70)

(55) - 90

(75) - 100

(90) - 100

15 - 34

35 - 59

60 - 79

80 - 100

Microns 25

600

52

300

5 - (20)

(8) - (30)

(12) - (40)

(15) - 50

100

150

0 - (10)

0 - (10)

0 - (10)

0 - 15

Store the fine and coarse aggregates separately and in such a manner that segregation of the various size particles shall not occur, form the stockpiles on a platform of weak concrete, timber or similar approved hard standing and keep aggregates clean and free from foreign substances. 2.37

SAMPLES OF AGGREGATES Methods of sampling and testing of aggregates shall comply with SS 73 and BS 812. If required submit samples of the aggregates to the SO Rep at least two weeks before the Contractor begins to deliver materials to the Site. Materials shall not be delivered until samples have been approved. Samples of fine aggregates, each of about 0.015 cu m shall be submitted in air tight containers and samples of coarse aggregate each of about 0.030 cu m shall be submitted in suitable containers. Label all samples plainly with descriptions of the material and source of supply. Furnish additional samples as directed. Test sieves shall comply with SS 74 and BS 410.

2.38

CEMENT MORTAR Cement mortar for general purposes shall consist of one volume of Portland Cement to three volumes of fine aggregates unless otherwise specified or as directed by the SO Rep. Testing of cement mortar shall comply with BS 4551. Thoroughly mix the materials in a dry state either by hand on a close jointed wooden platform or in a mechanical mixer of an approved type and sufficient water shall then be added and the whole mixed to a mortar of even and proper consistency. The proper consistency is that when moisture is excluded under a slight pressure, the mortar binds together into a solid lump. Use mortar immediately after it has been prepared and on no account shall it be used after it has commenced to set.

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CE Spec Page 2-27 2.39

CONCRETE Unless otherwise stated, concrete mix refers to "designed mix". In designed mixes, the strength shall be the main criterion specified, with compliance to minimum and maximum cement content, and maximum water/cement ratio. The workability of the mix shall be such that the measured slump shall not deviate from the agreed value by more than + 25mm or one third of the value, whichever is greater, or Clause 16.6 of BS 5328. Mix design shall be based on a target mean strength not less than the specified characteristic strength plus 7 N per mm2. The Contractor shall design the mix and shall be responsible to ensure that the mix supplied will give the required properties including strength. Unless otherwise specified for protection against aggressive soil conditions, designed concrete mixes shall comply with the specifications in the Table below : Specifications For Designed Concrete Mix Grade

55

50

45

40

35

30

25

20

15

Minimum crushing strength N per mm2 at 7 days

37

34

30

27

24

20

17

14

9

Characteristic strength N per mm2 at 28 days

55

50

45

40

35

30

25

20

15

Minimum cement content in kg per m3 of fully compacted concrete

475

425

375

350

350

325

300

270

205

Maximum cement content in kg per m3 of fully compacted concrete

550

550

550

550

550

550

550

550

550

Maximum water/cement ratio

0.4

0.45

0.45

0.5

0.5

0.5

0.55

0.6

0.7

Design of the mix shall ensure no segregation, no excessive bleeding and ability to achieve specified surface finish. Segregation and bleeding shall be determined by visual inspection. "Nominal mix" may be used in place of "designed mix" provided :  the works are of minor nature or involving a small quantity of concrete. the approval of the SO Rep is given.  the strength of the concrete is still the responsibility of the Contractor. 

The Contractor may adopt the prescribed nominal mix and preparation of ingredients as shown in the table below : Nominal Mix For Use In Minor Works Or Involving Small Quantity Of Concrete Class of Concrete

Grade 30 Grade 25 Grade 20 Grade 15

Nominal Volumetric Proportions

1:1:2 1:1.5:3 1:2:4 1:3:6

kg

Volume of Fine Aggregates m3

Volume of Coarse Aggregates (19mm to 5mm) m3

(a)

(b)

(c)

7 Days

28 Days

50 50 50 50

0.035 0.050 0.070 0.105

0.07 0.100 0.140 0.210

20 17 14 9

30 25 20 15

Weight of Cement

Minimum Crushing Strength N per mm2

Basing on : (a) (b) (c)

Cement of bulk density 1450 kg per m3. Semi-dry sand (30% voids) of bulk density 1600 kg per m3. Coarse aggregate (45% voids) of bulk density 1400 kg per m3.

The whole of the concrete shall be dense, compact and thoroughly homogeneous. It shall be placed in foundations, walls, floors, slabs, moulds or shuttering after mixing as soon as practicable and no concrete shall be placed without being thoroughly tamped and compacted. Complete all tamping well before the initial setting of the cement commences. The SO Rep reserves the right to instruct the Contractor to modify, alter and improve the concrete mix from time to time during the progress of the Works.

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CE Spec Page 2-28 2.39

CONCRETE (CONT’D) Keep the fine and coarse aggregates separately until actually mixed in the hopper of the concrete mixer, which shall be of the batch or other approved type. Mix each batch for a sufficient period to produce a mixture of even and proper consistency. Immediately after mixing, convey the concrete to the place of final deposit as rapidly as possible by methods which will prevent the segregation, loss or contamination of any of the ingredients. In all cases place the concrete and compact within 20 minutes of the addition of water to the mix. Any concrete left unplaced after this time or showing any indication of drying out or taking its initial set shall be immediately rejected and removed from the Works. Transport the concrete in clean metal buckets, barrows, dumpers or trucks and obtain the written approval of the SO Rep before any method involving the use of concrete pumps, placers, pipelines, chutes or spouts may be used. For transporting concrete by means of chutes, segregation should be minimised by providing a downpipe at the end of the chute. Chutes shall be of metal or metal-lined, preferably round-bottomed, and large enough to guard against overflow. Slopes shall not be flatter than 1 to 3 or steeper than 1 to 2 for ordinary mixes. The SO Rep may allow the use of steeper slopes for stiff mixes. Hand mixing shall be allowed only for small quantities of concrete and subject to the mixing being satisfactorily performed and approved by the SO Rep and to the addition of 10% extra cement. Adjust the proportions of water and aggregates according to the moisture content of the aggregate. Add only sufficient water to the cement and aggregates during mixing to produce a concrete having sufficient workability to enable it to be well consolidated, to be worked into the corners of the shuttering and around the reinforcement and to have the specified strength. When a suitable amount of water has been determined, maintain the resulting consistency throughout the Works and conduct tests from time to time to ensure consistency. The method of determining the consistency of concrete shall either be by slump test or by the compactor tests as defined in SS 78 and BS 1881. Supply all labour and materials necessary to carry out the tests as directed. All concrete which has too high a water content shall be rejected straightaway. No concrete shall be re-mixed after it has once become partially set or hardened but shall be rejected and removed from the Works.

2.40

DEPOSITING AND COMPACTING CONCRETE Do not tip the concrete from a height of more than 2 m but lowered in chutes or skips. It shall be placed in regular courses, in layers of not more than 250mm thick, punned down, beaten and neatly levelled to a smooth surface. It shall not be covered up until passed. When the Works is interrupted, the surface of the unfinished concrete shall be thoroughly cleaned, watered, coated with cement grout and covered with a layer of cement mortar, at least 10mm thick, immediately before further concrete is added and whenever practicable, wooden battens shall be inserted in the unfinished concrete and withdrawn to form a continuous key for further concrete, both in horizontal and vertical joints. At all junctions between new and existing concrete work, clean, roughen, coat and spread with at least 10mm thick of cement mortar to the surface of the existing concrete; immediately before the new concrete is deposited. No concrete shall be placed unless the SO Rep has inspected the receiving surfaces and is satisfied with the conditions for concreting. Concrete shall be normally compacted by means of approved immersion vibrators of minimum 5000 cycles per minute or otherwise well rammed between and around the steel reinforcement by hand rammers to ensure compactness and to avoid air-holes, or voids and to produce smooth surfaces, free from honey combs. Remove any water accumulating on the surface of newly placed concrete by approved means and place no further concrete thereon until such water is removed. Take great care to prevent the displacement, bending or deformation of the steel before, during or after concreting. Insert all reinforcement members in position before concreting and they shall be temporarily held, fixed, tied or wired securely in position.

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CE Spec Page 2-29 2.41

PROTECTION AND CURING OF CONCRETE Allow no load of any kind, however light, on concrete which has not properly matured. Do not allow walking on or laying of planks on concrete until it has been properly matured and ready to carry load. Allow a period of 24 hours between the laying of the concrete foundation and the laying of pipes or kerbstones before backfilling. After being placed in position, all fresh concrete shall be protected from rain, sun and drying wind, and shall not be subjected to any vibrational disturbance other than that arising from compacting. The exposed surfaces of concrete, other than concrete foundation and haunching for kerbstones and pipes, shall be cured with an appropriate curing compound as approved by the SO Rep. The curing compound shall be applied by mechanical sprayer and comply strictly with the manufacturers' instruction. If the curing compound is exposed to rain or water within 4 hours from the time the application is completed, the Contractor shall re-apply the area affected with appropriate curing compound again. The curing compound shall not be used in concrete containing Portland Blast Furnace Cement or Sulphate - Resisting Cement. In such instance, other appropriate curing method shall be adopted.

2.42

CONCRETING AGAINST SURFACE OF EXCAVATION Place concrete only against surfaces of excavation when the receiving surfaces are clean, firm and free from any accumulation of water. Should the receiving surfaces deteriorate as a result of the Contractor's delay in placing concrete, the Contractor shall, as directed, cut the loose material and top-up with compacted firm material or lean concrete. Unless otherwise specified, concrete sealing to foundations shall be 75mm Grade 15 concrete. Wherever in the opinion of the SO Rep that ground conditions permit, the timbering shall be removed before concreting and the concrete placed in the walls for the full width from the shuttering to the face of the excavation in one operation. The Contractor's attention is drawn to the desirability of keeping the working space or overbreak to a minimum in all cases. Where concreting in one width is called for by the SO Rep, payment for any extra concrete involved will be priced at the Rates and the appropriate item for rough shuttering will be omitted.

2.43

CONCRETING THROUGH WATER Concreting shall not be deposited under water without the prior consent of the SO Rep. Submit details of the proposed method of placing concrete through water for the approval of the SO Rep. Design a concrete mix for this purpose with a high workability of approximately 150mm slump and an increased cement content of 25%.

2.44

FINISH OF CONCRETE Upon removal of the shuttering and with approval of the SO Rep, make good honeycombed surfaces immediately by a method approved by the SO Rep and superficial water and air holes shall be filled in. Unless instructed to the contrary, rub down the face of exposed concrete placed against shuttering with a carborundum stone immediately upon removal of the shuttering to remove fins or other irregularities. Float the face of concrete for which shuttering is not provided (other than slabs) to give a finish equal to that of the rubbed down face where shuttering is provided. No cement wash, mortar or paint may be applied to any concrete surface without the permission of the SO Rep. Generally concrete finishes as struck from the shuttering are required. Lay all floors, slabs and inverts to the required depths, thickness, inclinations and curvatures shown on the detail Drawings. The falls shall be even so that no pockets occur and the concrete well rammed, consolidated and formed to a true and even slope by means of wooden screeds and straight edges, and immediately thereafter be floated over with a wooden float, any hollows or rough places unavoidably left after screeding being filled up with fine concrete. Subsequently and just before setting, finish off the concrete to a smooth and even surface with metal floats, unless otherwise directed by the SO Rep. Do not lay concrete floors and inverts in two courses, except where specified or by special permission of the SO Rep in writing. Where screeds are required or approved, key and roughen the structural concrete to ensure proper bond. First class plane surfaces free from ripples, hollows, air holes or exposed aggregate is required.

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CE Spec Page 2-30 2.45

CONCRETE ADDITIVE Suitable additives may be used in concrete only with the approval of the SO Rep. Apply the concrete additives as approved in accordance to the manufacturer's recommendation and instructions. When directed by the SO Rep, carry out verification on the suitability of concrete additives by trial mixes and laboratory tests.

2.46

PREMIX AND READY-MIX CONCRETE If the Contractor wishes to use ready-mix concrete, obtain prior approval from the SO Rep who will, inter alia, require to be satisfied that the proposed supplier will adhere to the requirement specified in the Specifications and that the quality and control of the mix are satisfactory and comply with SS EN 206 and BS 5328. The SO Rep shall have access during all working hours of the ready-mix plant. The ready-mix concrete shall comply in all respects with the specified requirements for concrete. The concrete shall comply in all respects with the specified requirements for concrete and the Contractor shall arrange and pay for the making of all the requisite tests. Transport premix concrete only in continuous mixing lorries of an approved design and type. Transport the concrete dry and the water shall be added to the mix only after arrival at the Site and immediately before placing. Transport ready-mixed concrete only in continuous mixing lorries complying with the manufacturer's operating standard. Appropriate retarder when used shall be subject to the approval of the SO Rep. No additional water shall be added to the ready-mixed concrete.

2.47

TESTING OF CONCRETE CUBES The methods of sampling and testing concrete shall comply with BS 78, BS 1881 and BS 5328. Provide a minimum of 4 numbers of standard metal moulds. No concreting Works shall be allowed to commence unless the required number of moulds is present at the Site. No extension of the Time for Completion shall be allowed for stoppage of work due to the Contractor's failure to comply with this requirement. On each concreting day, for every 20 cubic metres or part thereof of each grade of concrete, at least one test shall be taken. At least 4 cubes shall be cast for each test. Two cubes shall be tested at 7 days and the remaining two cubes shall be tested at 28 days for compliance of the specified concrete strength. Testing for Grade 15 Concrete is not required unless directed by SO Rep. Compliance of the specified concrete strength shall be judged by tests made on cubes at an age of 7 days and 28 days respectively. Two test cubes shall be made for each test at the age required. The cube strength shall be calculated from the maximum load sustained by the cube at failure. The appropriate strength requirement shall be considered to be satisfied if : (i)

the average of the two cubes is not less than the specified minimum crushing strength; and

(ii)

the difference of the two cube strength is less than 15% of the average crushing strength.

The test cubes shall be cured in accordance with SS 78, BS 1881 and BS 5328. Concrete shall be placed in standard steel mould in layers approximately 50mm deep and each layer compacted by using a steel bar 300mm long weighing 1.8 kg and having a ramming face of 25mm square. The number of strokes per layer shall not be less than 35 for 100mm cubes or as per SS requirements. The cubes shall be tested at the HDB’s Engineering Materials Laboratory or other approved accredited testing laboratory with equivalent or better testing facilities, auto-capturing and computerized monitoring system with analysis capabilities. The Contractor shall submit the information pertaining to the proposed laboratory to SO Rep for approval. All contract information and test results shall be uploaded to EPTC e-cube website. The Contractor shall provide lockable humid boxes of adequate size to store all the test cubes for the specified period. The humid boxes shall be placed in a covered area and maintained at a relative humidity of above 95%. The keys to such curing facility shall be exclusively held in custody by a person designated by the SO Rep. The Contractor shall provide lockable humid boxes of adequate size to store all test cubes for the specified period. The humid boxes shall be placed in a covered area and maintained at a relative humidity of above 95%. The keys to such curing facility shall be exclusively held in custody by a person designated by the SO Rep. The test cubes to be tested at HDB’s Engineering Materials Laboratory shall be collected by the SO Rep from the designated site at regular interval. The SO Rep shall inform Contractor of the designated collection site and the Contractor shall deliver cubes to the designated collection site on the day of collection.

CE12/S2.DOC(30) oym(151211) DPD

CE Spec Page 2-31 2.47

TESTING OF CONCRETE CUBES (CONT'D) The Contractor shall provide all necessary assistance to hand over the cubes to the HDB’s appointed contractor for the collection of cubes. The Contractor shall provide facilities to enable the identification of test cubes by radio frequency or similar means. The Contractor shall provide at least one web-based radio frequency identification (RFID) reader capable of reading the RFID tags on the concrete cube from a minimum distance of at least 40 mm. The reader must be able to read all 125kHz RFID tags, including tags starting with hex codes of '2800' and ‘2868’. The Contractor shall include the appropriate interfacing software to a web-based controller. The Contractor shall logon to a website of the Employer to register the concrete cube data and tag IDs using the RFID reader. The registration of cube data and tag IDs shall be done within the same casting day. The appropriate RFID tags shall be placed at the corner of the cubes while the cubes are still fresh. The top surface of the RFID tag shall be level with the concrete cube surface. The Contractor shall protect the RFID tags on the concrete cube while demoulding. For damage or loss of RFID tag, the Contractor shall be charged the replacement cost based on the Employer's purchase price The Employer shall deduct the charges payable by the Contractor from any monies due or becoming due to the Contractor or recover the same from the Contractor as a debt due by the Contractor to the Employer.

2.48

FAILURE OF TEST ON CONCRETE TEST CUBES For each batch of concrete, make two test cubes for each test at 7 days and 28 days respectively. The crushing strength to be achieved shall be as specified in Clause 2.39 "Concrete". Notwithstanding that the test on the 7 days cubes pass the strength as specified in Clause 2.39 "Concrete", the test on the 28 days cubes shall still be required to be carried out. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each test that fails to attain the required crushing strength at 28 days as specified in Clause 2.47 "Testing Of Concrete Cubes". The SO Rep may also require that part of the Works represented by the cubes that has failed, be taken down or cut and replaced to comply with the Specifications or that additional measures shall be provided to make the Works secure.

2.49

CONCRETE WALLS Concrete walls generally shall be constructed in alternate bays not exceeding 7m in length. The height of any lift of concrete shall not exceed 2.5m unless otherwise permitted by the SO Rep. Walls shall be truly vertical and all surfaces which are exposed to view or to liquids finished to a smooth surface.

2.50

SHUTTERING All shuttering or formwork shall comply with Singapore Standard CP 23 and shall be, in every respect, rigidly constructed of approved material and shall be true to the shape and dimensions as shown in the Drawings. Timber used for formwork shall be medium hardwood, machined dressed to a uniform thickness. The timber shall be well seasoned, free from loose knots and, unless otherwise approved, wrought on all faces. Where plywood is to be used, it shall be Phenolic film faced plywood complying with SS1 and cut to size from sheets at least 12mm thick. The Contractor shall provide an appropriate formwork system that produces concrete surfaces with good off-form finish requiring no plastering or skimming. However, if the off-form finish is unsatisfactory, the SO Rep reserves the right to instruct the Contractor to carry out plastering and skimming work to achieve the required finish as specified. The form face in contact with concrete shall be free from dirt, adhering grout, projecting nails, splits and other Defect. Formwork shall be coated with an approved form oil which is compatible with the required finish. Such oil shall be insoluble in water, non-staining, not injurious to concrete and shall not become flaky or be removed by rain or wash water. Diesel oil and liquids which retard the setting of concrete shall not be used. The same approved type of form oil shall be used for all work. The application of the form oil shall be such that no reinforcement is coated by the oil and there shall be no accumulation of the oil on the formwork. Close all joints tightly and prevent all leakage of liquid cement from the concrete. All formwork shall be inspected and approved by the SO Rep before any concreting operation is commenced but this shall in no way affect, vary or relieve the Contractor of his responsibilities under the Contract.

CE12/S2.DOC(31) oym(151211) DPD

CE Spec Page 2-32 2.51

STRIKING OF SHUTTERING Striking or removing shuttering shall not begin until the concrete is matured to sufficient strength to carry its own weight plus any constructional or designed loads likely to come upon it, and this work shall be conducted only under the personal supervision of a competent foreman. After striking of formwork, any honeycombed surface and defective or damaged concrete work arising from improper work procedures shall be immediately made good, as, directed by the SO Rep. Any remedial measures carried out without the knowledge and approval of the SO Rep shall be liable for rejection and re-execution. All holes formed by tie bolts shall be filled with cement mortar. The minimum period before striking of the formwork for ordinary Portland Cement concrete shall be in accordance with the following : Type of Formwork All vertical or side formwork Soffit formwork to slabs and beams Props to slabs and beams Props to cantilever slabs and cantilever beams

2.52

Minimum Period Before Striking 12 hours 3 days 14 days 21days

Remarks The period shall commence from the time of last pour of concrete. After striking of formwork, props shall be immediately put up to support the structure.

RE-CONSTRUCTION OF FAULTY WORK Remove and reconstruct any structural member of work which gives evidence before or after removal of the shuttering that the concrete was of faulty quality at the time of deposition or was not properly deposited and rammed in the shuttering or gives evidence that any member of the reinforcement was omitted, incorrectly placed, or displaced by any agency or cause or which gives evidence of any Defect, fault or injury from any cause whatsoever which might prejudicially alter the strength and durability of the construction.

2.53

STEEL REINFORCEMENT Obtain steel reinforcement from local manufacturer or other manufacturers as may be approved in writing by the SO Rep and comply with SS 2, SS 18, SS 32, BS 4449, BS 4461, BS 4482 and BS 4483 wherever applicable. All reinforcement shall be free from scale and all loose rust. It shall not be coated with any grease, oil, paint or adhering earth that may impair the bond between the concrete and reinforcement.

2.54

TESTING OF STEEL Whenever required by the SO Rep, arrange for the manufacturer to supply direct to the SO Rep a test certificate stating the process of manufacture and the results of each of the mechanical tests applicable to the description of the material purchased, the chemical analysis and all as specified in the relevant Standards. Alternatively, the SO Rep may require that the steel elements be tested according to BS 4360. If the representative samples fail to achieve the minimum value specified, the batch represented shall be rejected and the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each such failure.

2.55

BENDING, PLACING AND FIXING REINFORCEMENT BARS The number, size, form and position of each steel bar, tie, link, stirrup or other member of the reinforcement shall be in exact accordance with the approved Drawings. Nothing shall be allowed to interfere with the disposition of any member of the reinforcement and special precaution shall be taken that it is not only correctly placed but made to keep its correct place during the placing and setting of the concrete.

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CE Spec Page 2-33 2.55

BENDING, PLACING AND FIXING REINFORCEMENT BARS (CONT'D) The ties of links connecting longitudinal bars in columns shall be taut so that the main bars shall be properly braced in all directions. Bend reinforcement bars by machine or other approved means producing a gradual and even motion. Bend bars cold unless the SO Rep shall approve bars of over 25mm in size being bent hot. Bars bent hot shall not be heated beyond cherry-red colour and after bending allowed to cool slowly without quenching. Bars depending on cold-working for their strength shall always be bent cold. Where it is necessary to reshape steel previously bent, this shall only be done with the approval of the SO Rep and each bar shall be inspected for sign of fracture. Bends shall comply with the dimensions given in the bending schedule. Dimensions of bent bars and internal dimensions of binders and the like shall not exceed the dimensions given on the bar schedule or elsewhere, and shall not be more than half per cent shorter than the specified dimensions. The internal radii of bends shall not be less than twice the size of the bar unless described to the contrary. The internal radii of the bends at corners or binders or the like shall be half the size of the bar embraced by the binder. For the purpose of this requirement the size of a bar shall mean the diameter of plain round bar or wire, or twice the diameter of one of the composing bars of a twin twisted bar, or one-and-a-half times the nominal dimensions of the side of a twisted square bar. Where steel fabric is required as reinforcement, carefully and accurately bend to the required shape when cold, either with a bending machine or edge block. All bending shall be done before the fabric is laid in position and no heating or welding shall be allowed. Carefully straighten steel fabric if they come in rolls. No piece of steel, wood or any foreign material whatsoever shall be employed on the bottom board, or against the side board of the shuttering to keep the reinforcement bars in position. The length of lap joints shall be not less than forty times the diameter of the steel member unless otherwise permitted by the SO Rep. Hooks shall have a diameter of curvature of at least four times the diameter of the member and shall be bent to a semi-circular form with a straight and measuring in length at least four times the diameter of the member. Wherever shown on the Drawings all free ends of bars shall be hooked as above and all joints in the length of bars shall be lapped and laps shall be at points of minimum stress. Maintain the vertical distances required between successive layers of bars in beams of similar members by the provision of mild steel spacer bars inserted at such intervals that the main bars do not perceptibly sag between adjacent spacer bars. Immediately before concreting, examine the reinforcement for accuracy of placing and cleanliness and corrected if necessary. No concreting shall commence until the SO Rep has inspected the reinforcement in position and until his approval has been obtained. Reinforcement projecting from work being concreted or already concreted shall not be bent out of its correct position for any reason unless approved and shall be protected from deformation or other damage. Provide and maintain the cover of concrete to the reinforcement as described in the Drawings and within a tolerance of 3mm by means of distance pieces of plastic spacers or cement mortar.

2.56

FIXING FABRIC REINFORCEMENT Securely and accurately tie fabric reinforcement which shall comply with SS 32 and fix in position in accordance with the general requirements for fixing bar requirement. All fabric shall be "lapped" and the minimum lap allowed in the case of rectangular mesh fabric shall be : 450mm overlap of the longitudinal wires, 75mm overlap of the transverse wires.

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CE Spec Page 2-34 2.56

FIXING FABRIC REINFORCEMENT (CONT'D) With square mesh fabric the minimum lap allowed shall be : 300mm overlap of the longitudinal wires, 300mm overlap of the transverse wires. In all types of fabric the lap provided shall be sufficient to develop the full strength of the material. Allow for all cutting to waste.

2.57

CONSTRUCTION JOINT Construction joints shall be of an approved shape and shall be vertical or horizontal, as required and except that in an inclined member, the joint shall be at right angle to the axis of the member. Provide in the positions shown on the Drawings or as directed. Key by the use of battens placed in the concrete and subsequently remove. Before placing new concrete against concrete that has already set, clean and roughen the face of old concrete and remove loose aggregate therefrom. Immediately before placing the new concrete, wet the face thoroughly and apply a coating of neat cement grout thereto. Ram the new concrete well against the prepared face before the grout sets.

2.58

BRICKS Bricks shall be at the best of their respective kinds, sound, hard, squarely made, well burnt throughout, regular in size and shape, with good faces and clean arrises and free from lime, chalk, pebbles, shells or other Defect. They shall be of the standard size and conform to SS 103 and BS 3921. Obtain all common bricks from the HDB Brick Factory unless otherwise permitted by the SO Rep. They shall not be removed away from the Site without written permission by the SO Rep. The crushing strength of bricks shall not be less than 27.5 KN per m2.

2.59

BRICKWORK GENERALLY Lay each brick after being immersed in water as far as practicable or wetted in full and close joints of cement mortar in its bed, ends and sides in one operation, each course being subsequently flushed and finished solid without damage to the external faces of the work. In no case shall a brick be laid dry or with insufficiently filled joints and afterwards flushed in. At least every fourth course shall be laid fair and smooth to line and joints shall not exceed 6mm in thickness and shall be neatly finished on the face with flat or flushing joints. Transport bricks carefully in carts or lorries and stack and remove all broken bricks from the Site without delay. Press every brick firmly into position, the surplus mortar being lightly struck off flush with a trowel or pointed. Wet the top of any work left unfinished immediately before re-starting. Keep all faces of brickwork clean. Fill bed and vertical joints of brickwork solid with mortar and no vertical joint allowed to be flushed up from the top, but each joint filled up as the bricks are laid. All Works found not complying strictly with this requirement shall be taken down and rebuilt. Maintain vertical joints in alternate courses in vertical lines. No work shall be carried up to a height greater than 1 m above the level of adjacent work. The style of brickwork in vertical walls shall be English Bond unless otherwise specified. The height of four courses of bricks laid in mortar shall not exceed by more than 25mm the height of the same brick laid dry. Where the work is curved on plan, crop the bricks when necessary to ensure that they break joint correctly.

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CE Spec Page 2-35 2.60

CONCRETE PIPES Concrete pipes, bends and channels for sewers, manholes and culverts shall be obtained from an approved manufacturer and shall be made from Portland Cement and the pipes shall preferably be spun reinforced concrete pipes. If permitted by the SO Rep, pipe may have collar joints when socketed pipes are unobtainable. Socketed pipes shall have the sockets cast with the barrel of the pipe. The sewer pipes shall comply with the requirements of the Water Reclamation (Network) Department, PUB, and also comply with SS 183 wherever applicable. Unless otherwise permitted, use only concrete pipes and fittings with spigot and socket rubber ring joints or similar approved for sewers. They shall be of the required class and be tested and certified satisfactory by PSB or Water Reclamation (Network) Department, PUB. Unless otherwise specified, such as limestone aggregate or using PVC lining, all concrete pipes shall be thickwall reinforced concrete pipe using Ordinary Portland Cement all in accordance with the Standard Specifications and tests of Water Reclamation (Network) Department, PUB. The Contractor's attention is drawn to the requirement that all Clauses laid down in the current Standard specifications for Sewerage Works published by the Water Reclamation (Network) Department, PUB, shall also be complied with.

2.61

REINFORCED CONCRETE PIPES OF DIAMETER 300MM TO 825MM FOR SEWERAGE WORK All sewers using reinforced concrete pipes and are of nominal internal diameter between 300mm and 825mm shall comply with the following requirements : (a)

thickwall reinforced concrete pipe using Ordinary Portland Cement and with an extra internal wall thickness of 38mm over the normal cover to reinforcement, as provided for in the approved standard of manufacture;

(b)

the extra wall thickness of 38mm shall be added monolithically to the internal surface of the pipe barrel; and

(c)

comply with the specifications of Water Reclamation (Network) Department, PUB.

2.62

VITRIFIED CLAY PIPES

2.62.1

Vitrified Clay Pipes And Joints (a)

Vitrified clay pipes and fittings shall comply with either European Standard EN 295: 1991, Australian Standard AS 1741: 1991 or other Equivalent Standard.

(b)

All pipes shall be sampled and tested to the requirements of the relevant Standards. PSB Test Report or Certificate of conformity. Type-tested pipes by other local/overseas test laboratories accredited with PSB are also acceptable.

(c)

All pipes and its joints must be watertight. Rubber sealing ring and other jointing materials used in the joint assemblies shall comply with the requirements as specified in the relevant Standards.

(d)

The chemical resistance, hydraulic roughness, abrasion resistance and shear resistance of all pipes and fittings shall be tested and comply with the requirements as specified in the relevant Standards.

(e)

Dimension Requirements Vitrified clay pipes shall have minimum bores as follows : Nominal Size (mm)

200

225

250

300

400

500

600

700

800

Minimum Bore(mm)*

195

219

244

293

390

487

585

682

780

* Note: Other nominal sizes greater than nominal size 200mm may be manufactured to comply with this standard, providing that the minimum permissible bore is not more than 2.5% less than the nominal size, rounded to the nearest mm. CE12/S2.DOC(35) oym(151211) DPD

CE Spec Page 2-36 2.62.1

Vitrified Clay Pipes And Joints (Cont’d) (f)

Marking Requirements (i)

All pipes manufactured and supplied shall have the following marks indented on the exterior of the barrel :     

(ii)

2.62.2

The manufacturer's name Date of manufacture Nominal bore size of pipe Standard Reference Crushing Strength in kN/m

All pipes and fittings shall be from only one manufacturer. The Contractor shall forward the manufacturer's signed certificate stating that the pipes and fittings comply with the relevant standard and the results of all tests to the SO Rep.

Vitrified Clay Pipes And Joints For Trenchless Construction The following sets out the requirements for flexibly jointed vitrified clay pipes for construction by trenchless installation technique including pipe jacking. (a)

Strength Requirements (i)

(b)

Vitrified clay pipes shall have minimum crushing strength as follows : Nominal Size (mm)

200

225

250

300

400

500

600

700

800

Strength (kN/m)

48

54

60

72

80

80

96

112

129

(ii)

The manufacturer shall declare the design jacking load.

(iii)

All pipes or pipe sections shall be sampled after any grinding or cutting of ends and tested to the requirements of the relevant Standards.

(iv)

When tested in accordance with EN 293-3:1991, the deviation from squareness measured at the pipe ends shall be not greater than 1mm.

Jointing Sleeves The joints of the vitrified clay pipes shall be of the double spigot type that are suitable for direct jacking or microtunnelling. The jointing sleeves shall be made of Type 316 stainless steel.

(c)

Rubber Rings The rubber sealing rings and other jointing materials used in the joint assemblies shall comply with the requirements as specified in the relevant Standards.

(d)

Buffer Rings The buffer ring shall be made of standard flooring grade chipboard sheets.

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CE Spec Page 2-37 2.62.3

Vitrified Clay Pipes And Joints In Open-Cut Method Of Construction The following sets out the requirements for flexibly jointed vitrified clay pipes for installation by open-cut method of construction. (a)

Strength Requirements (i)

2.62.4

2.63

Vitrified clay pipes shall have minimum crushing strength as follows : Nominal Size (mm)

200

225

250

300

400

500

600

700

800

Strength (kN/m)

32

36

40

48

64

80

80

84

96

(ii)

All pipes or pipe sections shall be sampled after any grinding or cutting of ends and tested to the requirements of the relevant Standards.

(iii)

Pipes shall meet the tolerance for squareness at ends of pipes as specified in EN 295:1991. This is fixed at 6mm for pipes up to and including nominal diameter 300mm and then at 2% of nominal diameter for larger sizes.

Flexible Joint To Vitrified Clay Pipe (a)

Flexible joints to stoneware pipes shall be of the rubber ring or polyester type of a design and form approved by the SO Rep.

(b)

The joints shall be of a type to remain completely watertight while accommodating a deflection of 5E in any direction.

(c)

Where polyester joints or polyester/rubber ring joints are supplied the formed polyester must be securely bonded to the stoneware and pipes having damaged or loose polyester rings or socket packings shall be rejected.

PITCH FIBRE PIPE Pitch-Fibre pipes shall be of an approved type and manufacture conforming in all respects with BS 2760. The joints shall be of a design to permit flexibility and movement without leakage.

2.64

CAST IRON PIPE (a)

Unless otherwise specified cast-iron pipes and specials and cast (spun) iron pipes shall comply with BS 4622 and shall be Class "B". Flanged pipe fittings and flanges shall also comply with BS 4622 Class "B". The expression "cast-iron" also embraces spun iron where applicable.

(b)

Joints to cast iron pipes unless otherwise indicated shall be "screwed gland", "bolted gland" or a proprietary rubber ring joint "Tyton" or other approved.

2.65

STEEL PIPES

2.65.1

Sizes And Lengths Of Steel Pipe (a)

The diameters described are the finished internal diameter of the linings, and the steel pipes, joints, flexible joints, etc, shall all be made to such dimensions as to suit the required finished internal diameter. A tolerance of plus or minus 3 mm will be allowed in the finished lining thickness. The tolerance for the finished internal diameter shall not exceed plus or minus 1% of the nominal diameter of the pipe.

(b)

The pipe lengths stated are effective lengths when laid and the Contractor shall allow in his Contract Sum for the additional length of pipe required to form the joints.

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CE Spec Page 2-38 2.65.2

2.65.3

Thickness Of Steel (a)

The thickness of steel plate to be used in manufacturing the pipes is stated in the Drawings.

(b)

In the even of the plate thickness stated not being available, the Contractor shall allow in his Contract Sum for supplying the nearest available thicker plate section.

Steel For Pipe And Special The steel for the pipes and specials shall be manufactured by the open-hearth or electric process, acid or basic and shall conform to and be tested in accordance with BS 534.

2.65.4

2.65.5

2.65.6

Testing Of Steel Pipes (a)

All pipes and specials shall be hydraulically tested after manufacture (ie. without the lining or coating) as described in BS 534 in the presence of the SO Rep to a test pressure of 200 metres load of water.

(b)

Where specials and fittings are of a shape or size on which it is not practicable to apply the hydraulic test the SO Rep may give approval to an alternative method of test such as the paraffin test.

(c)

The Contractor shall bear the cost and expense for all the tests specified.

Lining Of Steel Pipes (a)

All the pipes and specials shall after the removal from the inner surfaces of all rust, loose seals, oil, grease or other foreign matter and thorough cleansing, be lined with concrete or other materials as specified and shall be in accordance with the current BS 534. It shall be terminated as near to the ends of the pipes and specials as will allow for effective jointing without damage to the lining.

(b)

Great care must be taken to avoid overstressing the lining at any stage of manufacture, handling or during delivery and storage and linings showing hollow, drumming sections or with cracks, other than surface cracks which can be shown not to penetrate more than 6mm below the surface will not be accepted. All pipes above 900mm diameter shall be clearly marked "Top" and "Bottom" as soon as the pipe is lined.

External Coating Of Steel Pipes The external coating shall be as described hereunder:(i)

All pipes and specials shall be cleaned over the whole of their external surface by sand or grit blasting, acid pickling or mechanical wire brushing in order to remove all millscales, rust, paint, grease and loose dirt.

(ii)

Within two hours of cleaning, the dry clean surface shall receive one cold application of approved bitumen primer by brush or spray application over the whole external surface.

(iii)

When the primer is dry and within 5 days of its application, the pipes shall be coated to within 75mm of each and with a continuous coating of not less than 2.4mm thickness of hot applied coal-tar enamel by pouring onto the primed pipes as they are mechanically rotated. The temperature of the enamel as it flows onto the pipes shall be between 225C and 250C but the temperature of the enamel in the melter is not to exceed 260C. Any melt which has been overheated shall be immediately removed from the rolling rig and discarded.

(iv)

Simultaneously with the pouring of the hot enamel 150mm wide coal-tar saturated felt reinforced with glass fibres at 6mm spacing outer wrap shall be spirally wrapped with 6-12mm overlap on to the exterior of the exterior of the hot coating, on the rotating pipes, so as to firmly adhere to it.

(v)

The primer and enamel shall meet American Water Works Association Specification C:203:1962 which is for plasticised coal-tar base materials.

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CE Spec Page 2-39 2.65.7

2.65.8

2.66

2.67

2.68

Joints To Steel Pipes (a)

Expansion and welded joints are to be made in accordance with the Drawings although changes may be proposed by the Contractor and such changes must be approved in writing by the SO Rep before manufacture commences.

(b)

The flexible joints are to be of an approved form similar to Viking Johnson Couplings. Details of the type of joints are subject to the approval of the SO Rep.

Protection During Transit And Storage Of Steel Pipe (a)

The coated pipes shall be lime washed and provided with sufficient protection such as straw roping to prevent any damage during transit or storage. The ends of all pipes and specials shall be covered with caps or discs of an approved pattern to prevent damage to the pipe ends, joints and lining.

(b)

The unprotected surfaces of all pipes and specials after lining (eg pipe ends, joints, etc.) shall be protected from corrosion during storage by the application of Shell "Ensis" or other approved temporary coating.

GASKETS FOR FLANGED PIPE (a)

Gaskets for flanged pipes shall comply with the requirements of BS 2494 and BS 3063.

(b)

They shall be "full face" Class "D" 3mm thick.

BOLTS, NUTS AND WASGERS FOR FLANGED PIPE JOINT (a)

Bolts, nuts and washers for flanged pipe joints shall be in accordance with BS 4190 and BS 4320.

(b)

Where flange bolts are to be installed and buried under ground the bolts, nuts and washers shall be non-ferrous or metal coated to prevent any corrosion.

UPVC PIPES Unplasticized polyvinyl chloride (UPVC) pipes and fittings shall be of an approved type and manufacture complying with the requirements of the Water Reclamation (Network) Department, PUB. They shall conform to SS 272, BS 4660, BS 5481 and the relevant Australian Standards where applicable.

2.69

ORDER OF SEWER PIPES, FITTINGS AND MANHOLE PARTS For the construction of sewers, place order for the supply of all the required pipes and manhole parts within 7 days from the date of the Letter of Acceptance and shall notify the SO Rep of this in writing. The order shall stipulate the specified times of delivery to the Site after all the necessary tests required by PSB or Water Reclamation (Network) Department, PUB. If no such order is made, the SO Rep may place on behalf of the Contractor the necessary order to a supplier decided and approved by the SO Rep. Bear all costs and expenses involved in such an order and these shall be paid to the supplier by deducting from monies due or becoming due to the Contractor.

2.70

PIPE LAYING Carefully brush all pipes inside and visually test for soundness before being laid. Lay the pipes to true inverts, straight lines and falls, each pipe being separately bonded between sight rails and bearing evenly upon the solid ground or concrete for its full length. Where pipes are to be laid in rock cutting, take the excavation down to 100mm below bed level and take great care to ensure that there are no projecting pieces of rock on which the pipe will ride. Make up the bed to its true line and level by refilling with either 100mm of consolidated, selected material from the excavation, well rammed and watered if necessary or with 100mm of compacted sand or with 100mm of Grade 15 concrete as directed.

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CE Spec Page 2-40 2.70

PIPE LAYING (CONT’D) Where pipes are to be supported on a bed of concrete or surrounded with concrete, provide rectangular blocks composed of concrete made in approved moulds at least 14 days before use and approved hardwood folding wedges. Provide two blocks for each pipe set and bond into the correct level on the formation bottom and lay the pipe on them properly centred and socketed. Two hardwood folding wedges of a width equal to the width of the concrete block shall then be inserted between the body of the pipe and the block and shall be driven together until the pipe is brought to the exact level required. Blocks and wedges shall then be left undisturbed while the pipes are being jointed and the concrete surround is being placed in position. Ensure that all blocks and wedges are of sufficient size and strength to prevent settlement of the pipes and make good any settlement.

2.71

JOINTING CAST IRON PIPE In general for all types of joint, thoroughly clean the pipe joint and jointing ring or material of dirt and grease before any jointing commences. The pipes shall be properly supported, bedded and lined up before the joint is set up and made. Make bolted gland, screwed gland and similar types of flexible patent joint in accordance with the manufacture's instructions. Clean the joint rings, lubricate with the manufacturer recommended material and accurately position it. Firmly push or jack home the joint and where screwed or bolted glands are involved steadily and evenly tighten the glands all round. No lead caulked joints shall be permitted. Carefully clean the flanged joints, centre and line up with only 3mm allowed for the gasket between the faces of the flange. The flanged gasket shall be carefully positioned and held by the flanged bolts.

2.72

JOINTING STEEL PIPES (a)

Welded pipe joints shall be made by means of the metal welding process in compliance with the general requirements for this process laid down in BS 1856.

(b)

The jointing of pipes and specials shall be done with the pipes and specials laid in their final positions. Their positions shall be so adjusted in preparation for welding that the clearance between pipe barrel and jointing sleeve does not exceed 3mm.

(c)

If tack welds are used they shall be limited in number and positioned evenly throughout the circumference of the joint. The length of each tack weld shall not be less than 40mm.

(d)

The section size of the tack welds shall be similar to that of the root run to be deposited in the joint. The extremities of tack welds shall be chipped or ground to facilitate the proper fusion with subsequent disposition if they are to be incorporated in the initial root run. A whipping technique shall be employed at the end of the run on each tack weld and all other electrode changes to prevent craters.

(e)

The main welds shall be fillet welds and the leg of each weld shall not be less than the thickness of the steel plate being welded.

(f)

Steel pipes above 825mm diameter shall be welded both internally and externally.

(g)

Welding shall not be performed where, in the opinion of the SO Rep, the weld would be subject to excessive cooling rates and welded joints shall not be disturbed until thoroughly cooled.

(h)

Welds shall be free from undercut, porosity, cracking, zones of incomplete fusion, inadequate root penetration, or any other defect listed in BS 499, Section 6 and the Appendix. Porosity, slag inclusion of any other foreign body shall not exceed 1.6mm in any dimension nor shall there be more than six such inclusions of this maximum size per square inch of weld metal, nor shall the 2 combined areas or any numbers of defects exceed 0.02mm of weld metal.

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2.73

JOINTING STEEL PIPES (CONT’D) (i)

Cut lengths shall be jointed by the use of welded butt straps or flexible joints. Wherever necessary the external and internal lining shall be made good as specified after completion and acceptance of the joint. When butt straps are used they shall be welded both internally and externally.

(j)

Short tubes may be provided on the side of the pipes to form an access for welding leads during pipe laying. These access tubes shall be sealed off by welding sockets into the tubes.

JOINTING CONCRETE PIPES Push well home each concrete pipe with the rubber ring accurately positioned on the spigot into the socket of the previously laid pipe by means of uniformly applied pressure with the aid of a jack or similar appliance. Use roll on rubber rings and they shall be lubricated before making the joint using soft soap, water or other approved lubricant supplied by the manufacturer. The manufacturer's instruction shall be deemed to form part of this Specifications. Lay the PVC lined concrete pipes and join as specified above except that all necessary precautions shall be taken to protect and safeguard the PVC lining from any damage during pipe laying. After the pipes have been laid, jointed and approved by the SO Rep, "Thermo Weld" the cover flaps of the PVC lining across the pipe joints, according to the manufacturer's instruction and this shall be carried out in conjunction with the pipe laying progress. Where the lined pipes enter the manholes and other structures, seal the PVC lining by the welding of approved preformed cover fillets or angles forming returns to the arrises built into the in-situ concrete work. The manufacturer's instructions for jointing and thermo-welding the joints shall be deemed to form part of this Specifications. The manufacturer shall submit to the SO Rep for approval, the methods for field testing the PVC lining and thermo-welded joints for flaws, burnt surfaces, pin holes etc. Employ approved methods for the complete testing of the lining, jointing and welding throughout the line.

2.74

FRACTURE OF PIPES In the event of pipes being fractured after being, to all appearances, properly laid, whether due to imperfect beds having been formed or the material for refilling having been improperly selected or due to any other cause, the Contractor shall be responsible and shall be called upon to replace such defective pipes, if such Defect appears before the expiry of the Defects Liability Period. Immediately remove and replace any pipe or length of pipes found to be defective and remake all leaking joints.

2.75

PRECAST CONCRETE DRAIN CHANNELS, KERBS, DIVIDERS, ETC Precast concrete drain channels, kerbs, road channels (gutters) and dividers shall be constructed in accordance with the Drawings and shall comply with the requirements as regards to strength of concrete, water absorption, rate of wear, finish and size, where applicable with BS 7263 and/or SS 214. Obtain precast concrete units from ISO 9000 or PSB Singapore Quality Mark/Product Listing Scheme/ Certification Scheme Suppliers only. Lay precast concrete drain channels, kerbs, road channels (gutters) and dividers, true to line and level in accordance with the Drawings. 0.5% of the total number of precast units to be used for the Works subject to a minimum of three numbers of precast units shall be selected at random by the SO Rep for water absorption tests by a competent Authority whilst the Works is in progress. The SO Rep shall exercise his rights under clause 1.6 Nuisance and Irregularities to impose charges against the Contractor for every test that exceeds the average absorption rate as stated below. For each water absorption test, three test pieces shall be used for determining the average increase in weight by water absorption. When tested for water absorption, the average increase in weight by absorption of water in the first 30 minutes shall not exceed 3% of the dry weight of the three test pieces for all precast concrete channels, kerbs, etc. These tests shall be in addition to those to be carried out by either LTA or the SO Rep prior to taking over of the completed Works before the expiry of the Defects Liability Period. Comply with the final decision made by LTA or the SO Rep in respect of any test carried out by them.

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PRECAST CONCRETE SLABS Precast concrete slabs for footpaths, etc shall comply with the requirements of BS 7263, whenever applicable. Submit the details of the supply of this item to the SO Rep for approval.

2.77

TRAFFIC SIGNS, CONES, BARRIERS AND LAMPS The following shall comply with the requirements of LTA, subject to the approval of the SO Rep : (a)

Traffic Sign All warning, regulatory and information signs shall be made of aluminium sheeting. The sheeting shall be 2.03 mm thick of SWG No. 14 and the materials for the sheeting shall comply with the relevant specification of BS 873 and BS 1470. The reflective sheeting adhered to the aluminium plate shall be diamond grade. It shall consist of spherial lens elements embedded in transparent plastic having a smooth, flat outer surface. The material of the reflective sheeting shall comply with the relevant specification and be tested according to ATM D4956. The thickness of the reflective sheeting inclusive of adhesive shall be in the range of 5.5 mils to 6.5 mils. All warning, regulatory and information signs shall be supported/fixed on to galvanised square hollow section, tripod stand or plate support as shown in the Drawings. All mild steel pipe frames shall consist of 25 mm internal diameter medium grade mild steel pipe vertically and horizontally. All tripod stands shall consist of 19 mm internal diameter medium grade galvanised iron pipes all round. The information plate supports shall consist of 50 mm internal diameter medium grade galvanised iron pipes all round. The weight of the warning and regulatory signs together with the support shall not be less than 15 kg.

(b)

Cones The traffic cones shall conform to all the relevant clauses and parts of the latest BS 873. All cones shall be conical in shape and hollow. The opening at the top shall be manufactured to accommodate the blinker's adaptor. The sleeve of the cone shall be made of replaceable retro reflective sheet of BS 873 : Part 6 Class/material or better with the HDB logo printed on three sides or two sides if space does not allow. The cones shall be made of medium density polyethylene with additional stabiliser or pigmented poly-vinyl chloride. Each cone shall have a minimum weight of 4.40 kg and the minimum thickness shall be 3 mm. The cones shall be sufficiently stable that they remain upright and not creep or topple under normal traffic condition. Ballast shall not be used. The cones shall not overturn when it is tilted up to an angle of 49 degrees away from its vertical axis. The cones shall also have excellent impact performance and shall be sufficiently flexible for the cone to recover its shape after distoration at normal temperature or after being knocked over by any vehicle. The cones shall be stackable.

(c)

Barriers (i)

Plastic Barriers The plastic barrier board shall be rectangular in shape. The board shall be stiffened by fixing flat metal bars to the top and bottom edges of the board. The barrier shall be moulded with flexible toggle fixing to fit the barrier stands. The board shall be made of high density polyethylene. The minimum wall thickness of the board shall be 3.5 mm and the minimum weight per metre run of the board shall be 1.8 kg per metre run.

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TRAFFIC SIGNS, CONES, BARRIERS AND LAMPS (CONT'D) (c)

Barriers (Cont'd) (i)

Plastic Barriers (Cont'd) The stand shall not overturn when it is tilted up to an angle of 46 degrees from its vertical axis. The stand shall have drainage holes at its base to prevent water collecting there. Provision shall be made to accommodate the toggles of barrier and blinker. There shall be a locking device to prevent the easy removal of the barrier board from the stand. The materials for the stand shall be medium density polyethylene with additional stabiliser. The minimum wall thickness of the stand shall be 3mm and the minimum weight of the stand shall be 18.8 kg. The materials for the stand shall have a minimum tensile strength of 15 N 2 per m .

(ii)

Barrier Fencing Barrier fencing is a continuous plastic mesh which may serve as an alternative for close barricading. The plastic mesh shall only be used by fixing securely to stable supports and the gaps between these support should be not more than 6.0 m. Barrier fencing is used to exclude pedestrians from a worksite and for the containment of workers. If it is erected parallel and adjacent to traffic, a separate delineation with a line of traffic cone shall be provided between the plastic mesh and the traffic. The colour of the mesh shall be high visibility orange or red. The material shall be re-usable, high durability, non-fading and UV resistance plastic.

(iii)

Longitudinal Safety Barrier The type of barriers may be required for the protection of traffic, the works as well as the workers in long term stationary works. They may also be used to separate opposing traffic. Suitable treatment of the ends of such barriers shall be taken to minimise risks associated with end-on collisions. The longitudinal safety barriers are a continuous close barricading formed by interconnection of individual portable units that are made of concrete, steel or polyethylene reinforced with steel. The performance of the safety barrier system shall be fully tested to meet the recommended structural adequacy, occupant risk and vehicle trajectory criteria set forth in the National Cooperative Highway Research Programme (NCHRP) Report 350 for Test Level 2. Test reports shall be provided by the manufacturer for verification by SO Rep. Only safety barrier system satisfying the required performance criteria shall be used for the protection purpose.

(d)

Lamps (i)

Flashing Lamps All low and high intensity flashing lamps shall comply with BS 3143:1985 and the Australian Standard AS 1165-1982 on traffic hazard warning lamps. The flashing lamp shall have a luminous intensity integrated over flash duration of not less than 2 cd.sec (minimum photometric performance) for low intensity type and not less than 50 cd.sec for higher intensity type as in AS 1165 (cd stands for candela). The rate of flashing shall not be less than 60 pulsations per minute. The requirements of the light output of flashing lamps shall apply within an elliptical cone bounded by : (a)

Directions 5 degrees above and below an axis normal to the surface of the geometric centre of the light emitting face in the vertical plane containing the axis.

(b)

Directions 7.5 degrees on either side of the axis normal to the surface of the geometric centre of the light emitting face in the horizontal plane containing the axis.

The flashing lamp shall be provided with photoelectric control so that the flashing lamps shall operate when the horizontal illuminance is less than 100 lux and shall cut off when the horizontal illuminance is exceeding 1800 lux.

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TRAFFIC SIGNS, CONES, BARRIERS AND LAMPS (CONT'D) (d)

Lamps (Cont'd) (i)

Flashing Lamps (Cont'd) The flashing lamp shall be resistant to corrosion or be suitably treated to prevent corrosion and shall be weatherproofed. The flashing lamp shall be provided for swivelling the lens 360 degrees and shall be designed so that the rotation will not damage any wiring or components. The flashing lamp shall be designed so as to facilitate easy replacement of the batteries and lamp. The flashing lamp shall be clearly and indelibly marked as tested to BS or AS Standards. The battery shall be designed to operate the lamp for at least 200 hours and of which the output during this period shall not drop below 50% of its initial lamp output. The flashing lamp shall also pass the impact test as detailed in BS 3143 Appendix A. Also submit test reports by independent testing authority on the flashing tested to BS 3143 or AS 1165 and the Specifications, as and when required. Use low intensity flashing lamps for all barricading and cone tapering area. In residential areas use low intensity flashing lamps at warning signs and regulatory signs instead of high intensity flashing lamps. They may be switched on to static mode if the flashing light is posing a problem to residents. Use high intensity flashing lamps for all warning signs and first regulatory signs only. They shall be used along all other roads but not for private residential minor roads. Ensure that : (a)

the flashing lamps are mounted between 1.0m and 1.2m above the road surface.

(b)

the flashing lamps of directional type are aimed at centre of on-coming traffic at about 100 to 200m away.

(c)

The orientation of the lamp are checked to ensure correct aiming and alignment is maintained.

Check all flashing lamps daily to ensure that they are functioning properly. Replace any blown lamps or weak batteries and also ensure that the flashing lamps are cleaned daily and after rain so that dust and dirt do not accumulate on the surface of the lens. (ii)

Rotating Lamps All portable amber rotating lamps shall comply to BS 3143:Part 4 and the Australian Standard AS 1165 on traffic hazards warning lamps. The rate of flashing shall be between 120 and 150 flashes per minute. The power requirement for the rotating lamp shall be of 12V and have a minimum wattage of 50 watts. The bulb shall be of halogen type. The material for the lens shall be of polycarbonate material. Use portable amber rotating lamps for all cases in lane diversion, road diversion, bends, crests and all other roads except for private residential minor roads. Unless otherwise indicated, they shall generally be placed at the first warning sign and the last regulatory sign. The rotating lamp shall be operational at all times (24 hours). To replace with static mode high intensity warning lamps if the rotating mode is posing a problem to residents. For longer duration work, the AC current type of portable amber rotating lamps may be used. However, the lamps shall meet all the requirements of the DC current type. On the safety aspect, the requirement of PowerGrid shall be met and approval from PowerGrid shall be obtained before they are allowed to be used on the Site.

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HOT DIPPED GALVANISED GRATINGS All galvanised gratings shall be zinc coated by the hot-dip galvanising process in accordance with SS 117 or BS 729 Part 1. Batches of galvanised gratings delivered to the Site shall be accompanied by a certification letter or copy of invoice from the firm at which they are galvanised. The word 'gratings' used in this Clause shall also be deemed to include the frames and their miscellaneous components. Submit the details of the galvanising to the SO Rep for approval. All gratings shall be thoroughly removed of all welding slags prior to galvanising. Galvanised gratings found having welding slags remaining on them shall be rejected and all such items shall be immediately removed from the Site. The galvanised gratings shall be tested for their zinc mass coating. The testing shall be performed at an SAC accredited laboratory using magnetic or electronic thickness measuring devices. 2% of the total number of gratings delivered to the Site subject to a minimum of three numbers of gratings shall be selected for testing. The mass of zinc coating tested shall be carried out at regular points of not less than 32 no. total on the surface of all the steel angles and flats of the grating. The results of the tests at every point for one grating shall be averaged to determine the average zinc coating weight of the grating. The mass of zinc coating on each grating shall comply with the following average coating mass : Thickness of Steel 5mm thick and over Under 5mm, but not less than 2mm Under 2mm

Average Coating 2 Mass g per m 610 410 350

Minimum Permissible 2 Value g per m 580 390 330

Gratings which fail to achieve the requirements specified above shall be dealt with as follows :

2.79

(a)

The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for any grating the zinc coating mass of which is less than the average coating mass but greater than the minimum permissible value.

(b)

The batch of galvanised gratings having any one of the representative samples failing to achieve the minimum permissible value shall be rejected and the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each such failure. Batches of rejected gratings may be sent for re-galvanising and may be accepted if tests show that they comply with the requirements of the zinc mass coating.

GEOTEXTILE (a)

General Where indicated in the Drawings or as directed, the type of geotextile specified shall be laid strictly in the manner required and also in accordance with the manufacturer's instructions. Generally woven or non-woven type geotextile may be used for road construction and other civil engineering construction. Use non-woven type geotextile for sub-soil drainage unless otherwise specified. The geotextile shall be composed of one or a combination of the following polymers. (i) (ii) (iii)

polypropylene polyethylene polyamide

Other polymers may be used subject to approval by the SO Rep. (b)

Protection The geotextile shall be properly sealed when delivered to the Site. Ensure that it is well protected against direct sunlight and contamination by chemical solutions while in storage. Only minimum exposure to weathering in the course of laying is permitted. Geotextile with stain markings shall be rejected.

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GEOTEXTILE (CONT’D) (c)

Testings Random samples of the geotextile shall be selected for testing for its mechanical and hydraulic properties to be carried out by an SAC accredited laboratory when required. The batch of geotextile fabric from which failed samples are taken shall be rejected and taken out of the Site immediately. In addition to the rejection, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

(d)

Method of Testings Geotextiles shall be tested for its properties in accordance with ASTM unless otherwise specified. The following tests shall be carried out when required by the SO Rep : (i) (ii) (iii) (iv) (v) (vi)

Load vs strain characteristic Curve (ASTM D1682) Grab Tensile Test (ASTM D1682) Trapezoidal Tear Test (ASTM D2263-68) Mullen Burst Test (ASTM D751-73) Water Permeability Test Pore-Size Distribution Curve

The Contractor shall be required to bear the cost and expense for sampling and testing when required by the SO Rep. 2.80

MANHOLE COVER AND FRAME The manhole covers and frames shall be of cast iron machined type and of approved size, weight and pattern. The heavy duty type shall be used in roadways and paved areas. Manhole covers and frames shall comply with SS 30 and BS 497 and be of the standard type and size specified by the Water Reclamation (Network) Department, PUB, Drainage, or LTA and shall be in accordance with the Drawings. The cover and frame shall be cast from a mixture of cast iron scrap and a suitable grade of pig iron. The mixture of the resultant metal shall be such as to provide a strong grey structure free from chill. The cover and frame shall be free from air, sand holes and cold shuts. They shall be neatly dressed and carefully fettled. All casting shall be free from voids, whether due to shrinkage, gas inclusion or other causes. Supply manhole covers and frames coated with a black bituminous composition. They shall be well fitting, flush at the top and shall not rock. Where required, the cover and frame shall be tested in accordance with SS 30.

2.81

STEP-IRONS Step-irons shall be of malleable cast iron and complying with BS 1247 and shall be used only under the direction of the SO Rep.

2.82

HAND-RAILING All mild steel pipes used for handrailing shall be bare steel light tubes of 40mm nominal bore conforming to BS 1387 and SS 17:1970. All mild steel tubes and flats shall conform to BS 15 or SS 104. Provide on the Site a building or shed which shall be dry and close to entry of water. The floors and walls shall be dry and the building or shed shall be well lit and ventilated. Before painting, bring the handrailing into the building or shed and clean with a wire brush to remove all rust and mill scale. Paint the handrailing with one coat of approved priming paint or as specified. Allow the paint to dry completely before it is removed from the shed or building for erection.

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HAND-RAILING (CONT’D) After erection, paint the handrailing with two undercoat of approved oil base paint and one finishing coat of approved oil base paint or as specified. Provide all the necessary items to carry out painting of one additional finishing coat of approved oil base paint before the expiry of the Defects Liability Period. Attend to all Defect such as rust, chipped or dented surfaces prior to the repainting.

2.83

SAFETY CHAINS Safety chains shall be made of aluminium alloy HE 30 FT.

2.84

LADDERS Ladders shall be made of aluminium alloy HE 30 FT and of approved design complying with BS 1474 and BS 2037 unless otherwise specified. The ladder rungs shall be at 300mm centres and stringers 380/450mm apart. Strong support stays shall be provided on both sides of the ladder at not more than 2.5m centres.

2.85

BAKAU PILES Bakau piles shall be of an approved species, good, sound, straight with fresh uninjured bark and of reasonably uniform size throughout. They shall be supplied in minimum 4.0m length, measured after the heads have been squared and the undersized ends cut off. They shall not be less than 80mm in diameter at the larger end and not less than 55mm in diameter at the smaller end, including the thickness of bark. Such measurements shall not be done over knobs and protuberances. The permissible deviation of the axis of the pile from the straight joining the centres of the two ends shall not be more than 25mm. All bakau piles shall be inspected and approved by the SO Rep before being used. Bakau piles that have been rejected shall be removed from the Site immediately. When the piles need to be joined, such joints shall be made of mild steel collars of 300mm long. The steel collar joint shall be divided into 2 equal sections, each with different diameters. The internal diameter of the mild steel collar for the top 150 mm section shall be 70mm and for the lower 150 mm section shall be 90 mm, with a diaphragm plate welded at the connection. The minimum thickness of the mild steel collar and the diaphragm shall be 1.8mm with joints fully welded and coated with tar or bituminous paint approved by the SO Rep. Prior to the commencement of the bakau piling work, the Contractor shall submit to the SO Rep a design sketch duly endorsed by the Contractor's PE to show the full details of the mild steel collar joint including the type and size of the welding. A sample of the collar joint made to the Professional Engineer's design shall also be submitted for the approval of the SO Rep before it is used on the Site for the bakau piling work. Bakau piles shall be joined with such mild steel collar firmly wedged with the axis of the top pile properly aligned to coincide with the driven pile. Unless specified otherwise, the Contractor shall provide all the bakau piles driven to the numbers and lengths according to the Specifications and Drawings. The Contract Sum shall be adjusted for the net quantities actually provided in the Works.

2.86

BAKAU PILING Where indicated on the Drawings, bakau piles as specified and of approved lengths shall be driven plumb and in approved positions to the full length of the piles or to refusal or otherwise directed by the SO Rep. Piling shall be carried out by experienced operators and shall be in accordance with the instructions of the SO Rep. The piles shall be driven with a piling frame with a drop hammer of approved weight of not less than 200 kg to a final set of 200mm for the last 10 blows from a drop of 1.0m to 1.5m height. Wherever required by the SO Rep, drive piles at required set with number of blows and the weight of hammer determined and the bearing capacity of the piles assessed. The SO Rep may call for test piles to be driven in different sections of the excavations to determine the stability of the ground below the formation level and hence the approved requirements of piles. Extract and replace or else duplicate all incorrectly or badly driven piles and piles damaged during driving.

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BAKAU PILING (CONT’D) On completion of bakau piling saw off all pile heads to the required level and trim the excavation around the pile heads. When directed by the SO Rep, the Contractor shall carry out simple load tests to determine the bearing capacity of the driven pile, as directed all at the Contractor's own cost and expense.

2.87

SOIL MIXTURE FOR WATER CATCHMENT AND NON-WATER CATCHMENT AREA Soil mixture shall consists of 3 parts of top soil to one part of sludge for non-water catchment areas. All topsoil shall be of good quality, free from rubbish, roots, stumps, subsoil or other extraneous matter, be friable and porous in texture. Sludge shall only be used in non water catchment areas. Sludge shall be dry, solid and well treated type from approved sources. The use of sludge for turfing and other work shall comply with Water Reclamation (Network) Department, PUB's instructions and recommendations on the prevention of smell and flies problems : (a)

Immediately use sludge delivered to Site meant for the turfing works.

(b)

Evenly cover sludge stockpiled on the Site with a layer of lime and cover over with a layer of topsoil.

(c)

After planting of turf no additional spreading of sludge or soil on the turfed area shall be allowed.

For water catchment areas, soil conditioner shall be used instead of sludge. Soil conditioner shall be peat, cocopeat, organic compost; or other approved fibrous organic matters suitable for mixing with soil to make a friable growing medium for planting. The soil mixture shall be three parts of topsoil with one part of sludge for non water catchment areas or 3 3 parts of topsoil with 1 part of soil conditioner and 1 kg per m of compound fertilizer NPKMg (15:15:6:4) for water catchment areas. Provide and spread the required amount of top soil for such turfing and tree planting works. 2.88

PLANT SOIL In the event that the Contractor is unable to obtain the necessary top soil of the quality acceptable to the SO Rep from any source, subject to the approval of the SO Rep, plant soil may be provided as a substitute for top soil. Provide, mix and use the plant soil for the Works. Manufacture the plant soil by mixing 4 parts of sub-soil, 2 parts of unwashed sand and 1 part of treated sludge for non water catchment areas to achieve a thorough and homogenous mix relatively free of lumpy material. In water catchment areas, the one part of sludge shall be substituted by one part of soil conditioner and 1 kg per m3 of compound fertilizer NPK Mg (15:15:6:4). The mixing may be carried out by spreading the various components on the ground in layers and ploughing and mixing them using appropriate machinery or by using a mixer or by any other process. The resulting plant soil shall be relatively free of lumpy material and shall have the following range of composition by weight : Sand Clay Organic Matter (a)

40% to 70% 10% to 25% 2% to 5%

Sub-Soil The clay content of the sub-soil which is the soil strata found just below the top soil layer, shall not be greater than 45%. Only approved sub-soil shall be utilised for the production of the plant soil.

(b)

Unwashed Sand Provide the unwashed sand required for the manufacture of plant soil. The unwashed sand to be used shall be free of any debris, stones or other foreign material. The unwashed sand delivered to the Site shall be rejected it if fails to meet this requirement and shall be immediately removed from the Site. Neatly store all acceptable unwashed sand on the Site prior to their use.

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PLANT SOIL (CONT’D) (c)

Treated Sludge Provide the treated sludge required for the manufacture of plant-soil. Collect the treated sludge as and when required from any of the following treatment works as directed. The treatment works are : (i) (ii) (iii) (iv) (v)

Bedok Wastewater Treatment Plant Serangoon Sludge Treatment Works Ulu Pandan Sewage Treatment Works Kranji Sewage Treatment Works Seletar Sewage Treatment Works

Collect, transport and store the treated sludge properly. Bear all costs and expenses incurred in this respect, including any charge levied by PUB for the collection of the treated sludge. Neatly store the treated sludge within a demarcated area on the Site prior to their use. Treated sludge shall only be used in non water catchment areas. In water catchment areas, use approved soil conditioner and compound fertilizer in its place. Before proceeding with the manufacture of plant soil the Contractor shall first carry out a trial mix using the approved sub-soil, unwashed sand and sludge. Three samples of the trial mix shall be analysed for its physical composition to ascertain if the composition of the final mix falls within the range of composition specified above. Mixes that do not conform to the Specifications shall have their mix proportion modified to achieve an acceptable composition. 2.89

TURFING Provide a layer of minimum 125mm thickness of approved soil mixture evenly spread over the Site or as directed by the SO Rep, followed by the planting of fresh turves. Sludge can be omitted for heavily built up and pedestrianised across areas such as neighbourhood and town centres and eating houses and compound fertilizers substituted. All turves supplied by the Contractor shall be of healthy and vigorous stock of approved type and quality. The turfing shall be cut square and approximately 0.2m x 0.2m (0.04 sq m) in area, and the sod, a minimum 25mm thickness. All turves supplied shall be free from weeds especially Mimosa Pudica. Submit for approval a sample of the grass whenever an area is to be turfed. Plant the approved turf promptly on arrival to avoid desiccation. The type of grass used for turfing shall be any one of the following species : (a) (b) (c)

Cow Grass (Axonopus Compressus) Serangoon Grass (Digitaria Didactyla) Manila Grass (Zoysia Japonia)

Lay turves abutting unless otherwise directed, with a tolerance of 10mm  5mm between adjoining turves. Roll each sod with a suitable garden roller. On slopes steeper than 1 in 2, peg down each sod properly. The turfing shall on completion present a uniform appearance. Establish the turves in 3 months from the date of planting by means of : (a) (b) (c) (d)

Watering at regular intervals Weeding regularly Replacing badly growing or unsatisfactory turves immediately Applying fertilizer and cutting the grass once every two weeks.

Thereafter, apply compound fertilizer once every 3 months. The compound fertilizer shall be of approved type and the application rate shall be 10 g to 15 g per m2.

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TURFING (CONT’D) All earth slopes when specified to be closed turfed shall be carried out as soon as possible in order to ensure rapid growth of protective grass. Provide and fix the turves promptly after laying the top soil in order to prevent erosion thereof due to wet weather or other causes. Make good any loss of unprotected or inadequately protected top soil. When the level of the completed turfing Works is undulating or uneven, the turfed areas, except for those on steep slopes, shall be properly rolled out with a garden roller or other approved means. The turfing shall give a uniform even surface on completion.

2.90

MAINTENANCE OF TURVES The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services as specified hereunder, to the turfing Works, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this clause). Throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract and during the Maintenance Period, maintain the turves by cutting and removing dead turves and weeds once every two weeks and replacing with new stock. Before commencing necessary grass cutting, manually remove all weeds and undesirable vegetation growing in the turfed areas. Close cut grass as short as possible following the general contours of the ground. The stock or blade of the grass after each cutting shall not stand higher than 20mm above the ground level. Approved mechanical cutters of various capacities to suit site conditions shall be utilised to cut the grass. Remove all cut grass from the Site. Cut back the edges of all sidetables and other turfed areas adjoining roadways, footpaths, kerbs, dividers and concrete paved areas to proper straight lines or curves as the case may be, and trim thereafter to produce a neat and tidy appearance. Carry out this work immediately after the grass in the area has been cut or manually weed out and clear. Cut and manually weed out and clear grass growing in the joints of footpaths, scupper drains, etc. If the Contractor fails to maintain the turves, the Employer shall have the right to engage its own workmen or other contractors to carry out such work and the cost incurred shall be recovered from the Contractor. In addition, the SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor.

2.91

SAFETY MEASURES FOR GRASS-CUTTING MACHINES (a)

Take every safety precaution to eliminate danger to the workmen, the general public and the property of others.

(b)

Install all grass-cutting machines used with suitable protective guards of steel or other approved materials to eliminate splinters and flung-off objects from causing damage. Under no circumstances shall the protective guards be removed from machines in operation.

(c)

The Contractor shall not use open blade rotary machine. Hand held rotary grass cutters shall be of the nylon cord type.

(d)

The grass-cutter shall wear safety boots, goggles, helmets and safety vest. When these safety requirements are not complied with, the Contractor's foreman or the SO Rep shall instruct the grass-cutter to stop work.

(e)

Keep the public away from the grass-cutter and erect a signboard on the Site with the wordings "DANGER", KEEP OFF, Grass Cutting Works In Progress".

CE12/S2.DOC(50) oym(151211) DPD

CE Spec Page 2-51 2.92

TREE PLANTING WITHIN ROAD SIDETABLES Tree planting reserve shall consist of a 1000mm deep trough of loamy soil throughout. Loamy soil shall be considered to be within the following range of composition of Sand, Silt and Clay. Sand Silt Clay

: : :

30% to 60% 10% to 70% 0% to 30%

Testing of the soil composition at the rate of 1 test for every 200m of sidetable subject to a minimum of 2 tests are to be carried out at an approved laboratory. The Test shall comply with the relevant specification of BS 1377. Where the existing soil does not conform to the above requirement, replace the existing soil with loamy soil. Samples of the loamy soil may be required by the SO Rep for testing at an approved laboratory. Provide all the necessary Construction Equipment, tools, instruments and materials for carrying out the tests including the provision of all necessary transportation of test materials, samples, etc. (i)

(ii)

(iii)

Setting Out (a)

The Contractor shall set out the Works in accordance with the Drawings or as directed by the SO Rep.

(b)

Location of trees and palms shall be laid out and pegged by the Contractor on the Site to be inspected by the SO Rep before commencement of the Works.

Hole For Planting (a)

All holes shall be inspected and approved by the SO Rep before backfill of soil mixture. All excavated and unwanted materials shall be carted away.

(b)

Holes for the planting of instant tree shall be 1.50m x 1.50m x 1.0m deep, unless otherwise specified. Holes for the planting of palms shall be 1.0m x 1.0m x 1.0m deep, unless otherwise specified.

Soil Mixture Used All topsoil shall be of approved quality, free from rubbish, roots, stumps, subsoil or any extraneous matter, be friable and porous in texture. Unwashed sand shall be free of any debris, stones or other foreign material. Soil conditioner shall have at least 50% organic matter, NPK of 1%: 2%: 1% and a pH value of between 6 to 8. The Contractor shall provide a laboratory test report to the SO Rep for approval before using the soil conditioner. All planting holes shall be backfilled with 3: 1 topsoil, soil conditioner and 1 kg per m3 of granular fertilizer NPK (15:15:6:4) or 4:2:1 subsoil, unwashed sand and soil conditioner with 1kg per m3 of granular fertilizer NPK (15:15:6:4) well mixed to a level 250mm higher than the adjacent ground level at the time of filling. The subsoil is defined as the strata found below the topsoil layer.

(iv)

Purchase Of Trees The Contractor shall purchase the trees/palms from private nurseries. All costs of purchasing, transplanting and maintenance of trees shall be included in the Contract Sum.

(v)

Plant Quality Unless otherwise specified, the plant quality of plants purchased from private nurseries shall comply with the following specifications:

CE12/S2.DOC(51) oym(151211) DPD

(a)

All trees/palms delivered to the Site shall be of the specified size, free of pests and diseases and undamaged. The trees shall be approved by the SO Rep before planting.

(b)

The SO Rep shall reserve the right to reject unhealthy, damaged, diseased, infested trees during the entire Time for Completion and Defects Liability Period.

CE Spec Page 2-52 2.92

TREE PLANTING WITHIN ROAD SIDETABLES (CONT’D) (v)

Plant Quality (Cont’d) (c)

The Contractor shall immediately remove and replace all rejected trees/palms at his own cost and expense.

(d)

The plant size shall be measured on the day of planting at the Site in accordance with the Drawings or as directed by the SO Rep in writing.

(e)

All trees/palms shall posses the natural characteristics and growth habit typical of its variety and species to the satisfaction of SO Rep.

(f)

All trees/palms where required under the Contract shall comply with the descriptions and requirements specified hereunder : Instant Trees All instant trees shall have a minimum of 2 m clear and upright straight trunk of 0.3m girth (measured at 0.5m height from the collar of the trunk) with at least three (3) branches of minimum girth 0.08m each and 1.0m in length each. They shall have a minimum rootball dimension of 750mm diameter x 600mm deep. Singled-Stemmed Palms All palms shall have a single trunk of minimum 1.5m height or as specified and measured from the collar to the tip of the youngest frond. Clustered Palms All clustered palms shall have a minimum of 5 suckers per clump clustered together and shall have a minimum of 3 main stems of minimum clear trunk height of 1.2m measured from the root collar to the base of the leaf sheath or otherwise described for each species.

(vi)

(vii)

Plant Protection (a)

All plant materials shall be carefully protected and if necessary wrapped in the nursery during lifting, awaiting transportation, and unloading and during storage on the Site. No plant shall be left on the Site unplanted for more than two (2) days.

(b)

Any evidence of unsatisfactory protection to roots, stems, branches and leaves will result in the trees being rejected.

(c)

The Contractor shall handle the plant in such a manner so that the ball of earth surrounding the roots is not broken. This shall be firmly held by plastic or other wrappings. All plastic and other imperishable wrappings shall be removed before planting. Trees shall be planted with the ground level at the same level as the soil mark on the stem. Water all trees thoroughly immediately after planting.

Stakes, Ties, Tree Guards And Collar Protectors Stakes shall be stout, straight, of good quality, properly treated with approved wood preservative, and approved by the SO Rep. They shall be of a diameter of at least 40 mm and at least 1.50m long for trees. Alternatively, the stakes can be of galvanised GI pipes of diameter 25.4 mm and approximate length of 2.5m or 3.0m approved by the SO Rep. They shall be firmly driven into the ground by using a mechanical device to be approved by the SO Rep and suitable ties and pads are to be supplied and fixed for each tree. Tree guards shall consist of 4 numbers of 50mm x 50mm x 1.50m poles vertically driven into the ground to a depth of 0.50m and 8 numbers of 25mm x 50mm horizontal poles of 1000mm or 1500mm length as directed. All poles of the tree guards are to be fixed with screws and nuts. The timber used shall be approved by the SO Rep and painted with paint, the colour and quality of which shall be approved by the SO Rep. Tree collar protectors are to be provided for all trees. A protector is made of a PVC tube of length 200mm and diameter 100mm and thickness 2 mm with a slit cut along the full length of the tube.

CE12/S2.DOC(52) oym(151211) DPD

CE Spec Page 2-53 2.92

TREE PLANTING WITHIN ROAD SIDETABLES (CONT’D) (viii)

Watering Of Trees Immediately after planting, the Contractor shall water the trees and continue to water them at least once a day for at least 10 continuous days, or until the trees are well established and need no further daily watering. The Contractor shall also water the trees at any time during the Defects Liability Period whenever directed by the SO Rep at the Contractor's cost and expense. The source of water shall be approved by the SO Rep.

(ix)

Weeding Weeding shall be carried out using garden forks approved by SO Rep. The Contractor shall loosen the soil with the garden fork around and under the weeds and thereafter remove the loosened weeds by hand.

(x)

Fertilising For ornamental instant trees, fertilizer NPK Mg (12:12:17:2) shall be inserted at a rate of 0.5kg per 250mm girth into holes 300mm deep and at 500mm apart along the dripline. For other instant trees, the details of fertilising shall be submitted to the SO Rep for approval.

(xi)

Trimming The Contractor shall provide only trained workmen or those experienced in pruning work. The Contractor shall ensure that his workmen completely and explicitly comply with the instructions of the SO Rep regarding pruning Works required, in particular, the height, length and number of tree branches to be pruned or trimmed and the final height of tree to be pollarded. A vertical clearance of 6m for tree branches is required for trees planted on the roadside table and a vertical clearance of 4.5m for tree branches at the centre divider. For horizontal clearance, the Contractor shall ensure that there is no tree branches obstructing road users. As for street lighting, a clearance of 2m both horizontally and vertically around the lamps are required. The Contractor shall provide each of his pruning team with a measuring pole approved by the SO Rep to measure and show to the SO Rep that the final height of tree pruning height complies with the instructions of the SO Rep. Trees shall be trimmed as directed by the SO Rep including performing and providing the following : (a) (b) (c) (d) (e) (f)

(xii)

Trim and removed extra leader Trim and remove all side branches from the main trunk measured 3.0m from the ground for trees along footpaths and roadside. Trim and remove all dead, broken, diseased and unwanted branches/shoots. Trim and remove overlapping branches rubbing each other. Remove and clear from site all trimmed vegetation. Paint all cut surfaces exceeding 25mm with 2 coats of anti-fungus wound sealant

Pest Control For vegetative stage of trees, the top and bottom of the tree leaves shall be thoroughly sprayed with approved pesticides. Re-spraying shall be done if it rains within 6 hours after spraying. Approved pesticides are : Dimethoate Deltamethrin White Summer Oil Abate 1% sand granules Benomyl Captan Thiram Terrazole Copper Fungicide (Metalic Copper) Mancozeb Captafol Omite Tenac (sticker)

CE12/S2.DOC(53) oym(151211) DPD

40% EC 1.25% EC 80% EC 50% EC 50% UP 50% UP 24% EC 50% 80% WP 39% EC 30% WP

CE Spec Page 2-54 2.92

TREE PLANTING WITHIN ROAD SIDETABLES (CONT’D) (xiii)

Maintenance Of Roadside Trees The Contractor shall allow in the Contract Sum for all cost and expense for providing maintenance services, as specified hereunder, to the tree/palm Works, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works as certified by the Superintending Officer. Planted trees/palms shall be maintained by adjusting tree tie, adjusting tripod support including providing and / or performing the following maintenance work or other reasonable work. OPERATION Weeding Watering Pest Control Fertilizing Pruning Adjusting tree ties and supporters

2.93

FREQUENCY Monthly Daily Monthly Monthly Monthly Monthly

) ) and/ or to be carried out ) as directed by the SO ) Rep ) )

Replace / repair of damaged/missing supporters / collars for trees

As directed by SO Rep.

Replace unhealthy, damaged, diseased or infested trees

As directed by SO Rep.

PLANTING OF INSTANT TREES IN CARPARKS (a)

Transplanting of Existing Trees (Instant Trees) Purchase Instant Trees from the Nurseries. Arrange to transplant such trees from the Nurseries to the proposed work. The cost of the whole transplanting operation including the purchase of the trees shall be included in the Contract Sum.

(b)

Transplanting Requirements and Procedures Transplanting of existing trees shall be carried out as follows : (i)

Branch Pruning Prune branches or pollard the tree as directed and paint all cuts with fungicidal sealant.

(ii)

Rootballs All trees to be transplanted shall have an earth rootball of a minimum diameter or a size as specified by the SO Rep. This shall be done by excavating a trench about 0.5m deep around the tree at an appropriate distance. Cut all protruding roots and paint with fungicidal sealant. Transplant excavated trees within the same working day unless otherwise directed.

(iii)

Tree Pits To avoid delay, make ready the new pit for the tree transplant before the tree is brought to the planting site. Pit shall be at least 0.5m wider and 0.25m deeper than the rootball to allow for incorporation of topsoil surrounding the roots. The minimum tree pit dimensions shall be 1.5m x 1.5m x 1.0m. All planting holes for instant trees shall be backfilled with good quality approved soil mixture to a level 250mm higher than the adjacent ground level at the time of filling. Tripod shall be provided to keep it firmly in place, if required.

(iv)

Tree Guards Provide tree guards to Instant trees planted as specified.

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CE Spec Page 2-55 2.93

PLANTING OF INSTANT TREES IN CARPARKS (CONT’D) (b)

Transplanting Requirements and Procedures (Cont’d) (v)

Lifting and Transporting Lift the tree by motor crane or other lifting machinery of appropriate capacity. Take every precaution including wrapping rootball securely by moistened canvas and angle bar frame or other approved materials to prevent damage to the rootball during the loading and transporting of the tree to the work Site.

(vi)

(c)

Before unloading the tree into position, measure the depth and diameter of the rootball and made the necessary adjustment to the pit. Set and orientate the tree in the hole, adjust the depth and plant to a depth corresponding to its former depth with minimum delay. Firmly consolidate the backfilling to eliminate air pockets under and around the roots.

Fertilising of Instant Trees Apply fertilizer NPK Mg (12:12:17:2) at a rate of 0.5 kg per 250 mm girth into holes 300mm deep and 500mm apart along the dripline. Carry out the first fertilising at the end of 6 months after planting. Thereafter, carry out fertilising twice in the next 6 months.

(d)

Maintenance of Instant Trees The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services, as specified hereunder, to the instant tree Works, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works, as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this subclause). Maintain planted instant trees by carrying out the following works : Operation

Frequency

Watering

(i)

Daily watering for the 1st month.

(ii)

Thereafter, water on alternate days for the 2nd month.

(iii)

Thereafter, water once a week for the 3rd month.

(iv)

Thereafter, water when necessary or as directed by the SO Rep until the end of the Maintenance Period.

In addition, make good all damaged tree guards during the Maintenance Period. 2.94

LANDSCAPING OF PEDESTRIAN OVERHEAD BRIDGE The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services, as specified hereunder, to the planting Works for the pedestrian overhead bridge, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works, as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this clause). Plants for the pedestrian overhead bridge shall be of selected/approved stocks and shall be obtained from the Contractor's own source, transported to the Site and planted according to the Drawings or as directed. Comply with the current requirements of planting of shrubs/palms/creepers etc as laid down by NParks. The standards of the planting and maintenance of the plants may be obtained from NParks. Ensure that the plants are established and grown to reasonable size at the end of the Maintenance Period before handing over to NParks for their maintenance. The planting scheme shall strictly comply with their requirements.

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CE Spec Page 2-56 2.94

LANDSCAPING OF PEDESTRIAN OVERHEAD BRIDGE (CONT’D) The planting and maintenance of the shrubs/palms/creepers shall conform to the following requirements : (a)

Soil Mixture for Planting Excavate holes for planting as indicated in the planting scheme Drawings or as directed. Backfill all planting holes beneath the staircases/ramps, around bridge columns and the entire planting trough along the prestressed concrete beams with approved soil mixture. For planting holes, carry out the backfilling to levels not exceeding 250mm higher than the adjacent ground level at time of filling.

(b)

Planting of Shrubs/Palms/Creepers Handle the plants in such a manner that the ball of earth surrounding the roots is not broken. This shall be firmly held by plastic or other wrapping. Remove all plastic and other imperishable wrappings before planting. Plant with ground level at the same level as the soil mark on the stem. Water all plants thoroughly immediately after planting.

(c)

Watering Use 10 litres of water per m2 for watering the plants. Additional watering may be required as and when directed. Carry out watering by using rubber hose fitted with an adjustable spraying head/gun to wet the soil thoroughly.

(d)

Soil-Loosening Spike the weeding area to a depth of 100mm using a garden fork.

(e)

Weeding Weed the landscaped area using hand trowel or weeding hoe.

(f)

Fertilising (i)

Palms Broadcast fertiliser NPK Mg (15:15:6:4) at a rate of 375 g per palm within the weeding circle 120mm away from stem.

(ii)

Landscaped Area Broadcast Fertiliser NPK Mg (12:12:17:2) at 50 g per m2 as directed.

(iii)

Climber/Creeper Spray approved foliar fertiliser as directed.

(g)

Pest Control Spray approved pesticides immediately after the infestation is spotted until the infestation is controlled.

(h)

Maintenance Maintain planted shrubs/palms/creepers by carrying out the following works : Operation

CE12/S2.DOC(56) oym(151211) DPD

Frequency

Watering

(1) (2) (3) (4)

Daily watering for the 1st month. Thereafter, water on alternate days for the 2nd month Thereafter, water once a week for the 3rd month Thereafter, water only as directed until the end of the Maintenance Period

Soil Loosening

Monthly till the end of the Maintenance Period

Weeding

Monthly till the end of the Maintenance Period

CE Spec Page 2-57 2.95

PRECAST R.C. AERATION SLABS (a)

General Where indicated in the Drawings or as directed, precast R.C. aeration slabs shall be manufactured and laid in the manner as specified. Submit details of the R.C. aeration slabs to the SO Rep for approval. 75mm thick aeration slabs shall be used in the carparks while 100mm thick aeration slabs shall be used in the lorry parks. The details of the slabs shall comply strictly with that shown in the Drawings. For purpose of identification, there shall be different types of slab arrangement used for the car and lorry parks. Locations of a particular type of slab arrangement to be adopted in each car or lorry park shall be as shown in the Drawings. The number of slabs per lot for each type of arrangement shall be as shown in the Drawings.

(b)

Singapore Quality Mark/Product Listing Scheme Certification Scheme/ISO 9000 Obtain the precast R.C. aeration slabs only from suppliers licensed under ISO 9000 or PSB Singapore Quality Mark/Product Listing Scheme/Certification Scheme.

(c)

Laying of Aeration Slabs Roll the crusher run base to a level to allow the granite fines layer to be laid. The finished surface level of the slabs after laying shall follow the gradient of the surface of the adjacent premix and the straight edges of the slabs when formed shall be true to line and level. Inspect each slab for stability after laying. If rocking takes place, remove from position and regrade the granite fines to achieve the desired result.

(d)

Turfing between Aeration Slabs Fill the gaps between the slabs with approved good quality top soil to a level 10mm below the top surface of the aeration slabs. Tear or Cut the turves to a size slightly wider than the gaps and close plant into position followed by light tamping with a piece of timber. Do not use excessive pressure produced by heavy objects. Watering of the turf just planted shall immediately be followed up. Mix top soil with sludge to a proportion of 3:1.

(e)

Watering of Turves Water the turves and trees at least twice daily once they are planted in position or otherwise directed. This process shall continue for a period of not less than one month or until such length of time when the plants have taken roots and show signs of growth. Convey water through a hose connected to a tapped supply or where this is not available in the vicinity, from water tanks of sufficient capacity and direct towards the gaps and voids where turves are planted or at the pits where the trees are planted, at a distance not more than 150mm away to avoid splashing.

(f)

Water Absorption Tests Select random samples of the precast RC aeration slabs for water absorption tests to be carried out by an SAC accredited laboratory. The maximum average rates of water absorption (%) calculated on the dry weight of three test pieces per sample shall not exceed 3% at 30 minutes. 0.5% of the total number of slabs from the stockpile subject to a minimum of three numbers of slabs shall be taken for water absorption test. Break the selected slabs to be tested into three test pieces each before transporting them to the laboratory.

(g)

Failure of Water Absorption Tests The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for every sample of aeration slab whose average water absorption exceeds 3% at 30 minutes,

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CE Spec Page 2-58 2.95

PRECAST R.C. AERATION SLABS (CONT'D) (h)

Transverse Strength Tests Samples of RC aeration slabs at a rate of up to three pieces for every 1,000 pieces shall be selected for transverse strength test performed in the manner as described in BS 7263 and in an SAC accredited laboratory. For the purpose of this test, the supporting rollers shall be spaced at 500mm apart for the 75mm slabs and 635mm apart for the 100mm slabs and the slabs when subjected to a centrally placed vertical load shall not fail at a value of 40 KN and 48 KN for the 75mm and 100mm thick aeration slabs respectively. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each sample that fails to comply with the above test requirement. Each batch of slabs represented by the three sample whose combined average results fail to attain 40 KN or 48 KN for the 75mm and 100mm thick aeration slabs respectively may be accepted only at the sole discretion of the SO Rep after he has considered the degree of failure and other related circumstances.

(i)

Maintenance The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services, as specified hereunder, to the Precast RC Aeration Slabs and turfing Works, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works, as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this subclauses). Keep a schedule of completion date of work done in each and every car and lorry park and return to the Site so as to carry out the necessary maintenance work of regular trimming, deweeding, tending and watering the turves and plant at least once a month throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract and the Maintenance Period. Maintain all the aeration slabs in proper conditions once they have been laid. Keep a schedule of completion dates and return to the Site at least once a month throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract and the Maintenance Period to inspect and ensure that the slabs are stable and do not rock under the loads of vehicles. Replace any slab found cracked or chipped to an extent which is unsatisfactory.

2.96

PRECAST BG SLABS (a)

General Manufacture precast B.G. slabs as indicated in the Drawings or where directed by the SO Rep and in accordance to the requirement of BS 7263 or SS 214 whenever applicable. Random samples of 3 for every order of 1000 precast B.G. slabs are to be taken for carrying out Water Absorption Test and Transverse Strength Test as specified in BS 7263 or SS 214 at an SAC accredited laboratory subject to a minimum of 3 numbers. The maximum average rate of water absorption (%) calculated on the dry weight of three test pieces per sample shall not exceed 3% at 30 minutes. For the Transverse strength test, the supporting rollers shall be spaced at 450mm apart and the slabs when subjected to a centrally placed vertical load shall not fail at a value of 19 KN. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each sample that fails to comply with the above test requirement.

(b)

Laying of B.G. Slabs Inspect each B.G. slabs for stability after laying. If rocking takes place, remove it from position and regrade and compact the base to achieve the desired result.

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CE Spec Page 2-59 2.96

PRECAST BG SLABS (CONT'D) (c)

Turfing between B.G. Slabs Fill the gaps between the slabs with approved soil mixture to a level 10mm below the top surface of the B.G. Slabs. Cut or tear turves to a size slightly wider than the gaps and close planted into position and then tamping lightly with a piece of timber. Excessive pressure produced by heavy objects shall not be allowed. Follow up immediately with watering of the turf just planted.

(d)

Watering of Turves Water the turves at least twice daily once they are planted in position or otherwise directed. Continue watering for a period of not less than one month or until such length of time when the plants have taken roots and show signs of growth. Convey water through a hose connected to a tapped supply or where this is not available in the vicinity, from water tanks of sufficient capacity and direct towards the gaps and voids where turves are planted, at a distance not more than 150mm away to avoid splashing.

(e)

Maintenance The Contractor shall allow in the Contract Sum for all costs and expenses for providing maintenance services, as specified hereunder, to the Precast B.G. Slabs and turfing Works, for a period of one year commencing from the Date of Substantial Completion for the Works or phase or sub-phase of the Works, as certified by the Superintending Officer (hereinafter referred to as the "Maintenance Period" for the purposes of this subclause). Keep a schedule of completion date of work done and return to the Site so as to carry out the necessary maintenance work of regular trimming, deweeding, tending and watering the turves and plant at least once a month throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract and the Maintenance Period. Maintain all B.G. slabs in proper condition once they have been laid. Ensure that the slabs are stable and do not rock throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract and Maintenance Period. Replace any slab found cracked or chipped to an extent which is unsatisfactory.

2.97

TESTING OF PREMIX The quality and standard of premix for the road and carparks shall be in accordance with the Clause and subclauses on premix bituminous surfacing. Should the bitumen content of the premix or the grading of aggregate fall outside the specified limits, the premix shall be rejected. In these circumstances, the Contractor shall be required to accept the corrective measures including compensation by additional layer of premix or the payment of fines as maintenance fees as directed by the SO Rep or LTA who shall be the final authority for the road.

2.98

TAKING OVER BY LTA AND THE EMPLOYER All materials used for the roads and carparks such as concrete kerbs, channels, concrete pipes, etc are to conform to the standard requirements of LTA and the SO Rep in strength, hydraulic, bearing, grading, absorption tests, for taking over purposes.

2.99

LTA'S OR THE SO REP'S REQUIREMENTS The Contractor's particular attention is drawn to all tests required by LTA or the SO Rep for premix and such concrete precast units as roadside kerbs, dividers, road base and sub-base etc. Samples shall be extracted from the Works actually incorporated for analysis to ensure compliance with the Specifications. Provide the necessary labour in extracting the samples as requested by the SO Rep. Make good and patch up all cavities caused by the removal of these samples.

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CE Spec Page 2-60 2.99

LTA'S OR THE SO REP'S REQUIREMENTS (CONT'D) The number of test samples shall conform to LTA requirements or the relevant SS or BS. For service roads and carparks to be taken over by the HDB, the number of samples for final testing shall comply with the following : Rate of Sampling

Minimum Number

Kerbs

1 sample for every 120m length

Two

Premix

1 sample for every 550m2 of carpark

Two

1 sample for every 450m2 of service road/driveway

Two

1 sample for every 350m2

Two

Precast Footpath Slabs

Where any of the tests carried out by LTA or the SO Rep fails to pass the requirements, the decision taken by them shall be final irrespective of whether the same samples had been passed by other Authorities or not. The Contractor shall either : (a)

replace the sections of the rejected works as indicated by LTA or the SO Rep with the approved ones, or

(b)

pay to LTA or the Employer the sum of money determined by the LTA or SO Rep according to the degree of failure.

The SO Rep shall determine whether item (a) or (b) of the above is to be adopted and reserves the right to set off such bills and expenses against monies due or becoming due to the Contractor. 2.100

LTA'S ROAD TESTING REQUIREMENT 1.

The Contractor shall engage the services of SAC/SINGLAS laboratories for plant, material, labour and transport needed for cutting of samples and to carry out testing of the cut samples and shall be responsible for the supervision of the cutting of samples and reinstatement after extraction.

2.

Prior to road testing, the Contractor shall submit the following to the SO Rep for his approval and subsequent submission to LTA: (a)

A copy of coloured site plan showing the road/roads to be tested and the location where samples would be extracted. (i)

For premix, cut sample to be obtained from pavement at every 50m on each carriageway.

(ii)

For rigid pavement (concrete), cut sample to be obtained at every 50m3 of concrete on each carriageway.

(iii)

For precast kerbs, 3 test kerbs shall be taken at random for every 2000 units or less.

A minimum of 3 samples is required on each type of pavement and kerb of the road Works. The test results endorsed by a PE are to be submitted to the SO Rep..

CE12/S2.DOC(60) oym(151211) DPD

(b)

Name of the SAC/SINGLAS laboratory

(c)

Name of Supplier of premix

(d)

Date of premix and concrete laid on site

(e)

Type of premix and concrete mix laid on site

(f)

Thickness of premix and concrete laid on site

(g)

Date and Time of sample cutting.

CE Spec Page 2-61 2.100

LTA'S ROAD TESTING REQUIREMENT (CONT'D) 3.

The following Tests are to be carried out : 3.1

Water absorption test for precast kerb -

3.2

3.3

4.

5.

To conform to the requirements and criteria for acceptance specified in Section 9.18.8 of LTA Materials & Workmanship Specification.

Compressive strength test for concrete (core strength) -

the compressive strength of a core shall be prepared and tested in accordance with BS 1881.

-

to conform to the requirements and criteria for acceptance specified in Table 9.5 of Section 9.9.7 of the LTA Materials & Workmanship Specification.

Aggregate gradations and bitumen contents of Wearing Course and Asphaltic Base Course -

to conform to the requirements and criteria for acceptance specified in the following Sections of LTA Materials & Workmanship Specification :

-

Graded Granite Aggregates - Section 13.3.2.3(f), (g) & (h)

-

Aggregate Grading Requirement - Section 13.3.3.2 Table 13.17

-

Requirement for Bitumen - Section 13.3.3.2 Table 13.17

The following are to be submitted together with the test results : 4.1

A record of the thickness of wearing course, base course and sub-base measured at the locations where the samples are extracted.

4.2

Photographs showing the samples at each location during extraction.

4.3

Photographs showing the road after reinstatement.

4.4

Test results be endorsed by the SAC/SINGLAS Laboratory supervisor and a PE.

4.5

For road test for Asphaltic Concrete Mixes, the accredited laboratory certified by the PSB has to compute the Deduction Factor (a factor used to determine whether the asphaltic concrete used falls within the acceptable limit) and reflect it in the individual sample test result and provide a summary of computation of laboratory test results for all the samples.

The LTA's road testing requirement is applicable for roads designed to LTA standard under Section 18 of the Streets Work Act and in addition to other testing requirements specified in the Specifications.

SECTION 3/.....

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CE Spec Page 3-1 SECTION 3

CONSTRUCTION AND WORKMANSHIP FOR ROADS AND DRAINS

3.1

SEQUENCE OF CONSTRUCTION Commence construction of the road work with the excavation for and construction of stormwater drains commencing at their outfalls. Excavation for and construction of roads shall not commence until the construction of stormwater drains is sufficiently advanced in the opinion of the SO Rep to permit free drainage of the road formation.

3.2

GENERAL REQUIREMENTS OF DRAINAGE DEPARTMENT, PUB The Contractor's attention is drawn to the following general requirements of Drainage Department, PUB, failure to comply with these requirements may render him liable to prosecution under the Water Pollution Control and Drainage Act : (a)

The execution of any work shall not change, disrupt, fill, block or disturb the existing overland flow or the existing system of drains unless an alternative approved drainage system has been provided and permission for use has been given by the Drainage Department, PUB.

(b)

Close turf all earth slopes adjacent to any drain.

(c)

Obstruction of any kind shall not be placed, laid or erected within drainage reserves and drains both of which shall remain accessible at all times.

(d)

No temporary structures such as cofferdams, crossings, stagings, etc shall be constructed in or over an existing drain without the prior approval of the Drainage Department, PUB.

(e)

Remove any temporary structures if approved within the drainage reserve immediately on Substantial Completion.

(f)

Bunds of stockpiled earth from trench work shall not be longer than 10m long and gaps of at least 1 m wide shall be provided between the bunds to allow the free flow of surface runoff.

(g)

Material from any stockpile shall not be allowed to fall or be washed into drain. Adequate preventive measures, including the provision of proper and stable barricades or screens where necessary, shall be provided.

(h)

Scupper inlets shall not be blocked by excavated or stockpiled material.

(i)

Drains shall not be covered without the approval of the Drainage Department, PUB.

(j)

Report any damage to existing drains arising out of any work immediately to the Drainage Department, PUB. Any obstruction to flow arising from the damage shall be immediately and completely cleared, and repair & reconstruct the damaged drain to the requirement of the Drainage Department, PUB.

(k)

Reclamation work, earthwork, roadwork, development work or any other construction work shall not be carried out unless a system of temporary lined perimeter cut-off drains and silt traps or other approved alternative measures are provided to prevent overflowing of surface runoff and silt from the work Site to the drains and adjacent premises.

(l)

Desilt and maintain regularly all temporary lined perimeter cut-off drains and silt traps to ensure that the discharge from the silt trap is free of silt.

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CE Spec Page 3-2 3.3

ADDITIONAL REQUIREMENTS OF DRAINAGE DEPARTMENT, PUB Ensure and take all necessary precautions and actions for preventing silt from being washed into drains and canals and comply with the following requirements strictly : (a)

Treatment Of Silt-laden Water Ensure that silt-laden water is not discharged directly or by pumping into drains or canals. Channel the silt-laden water to silt traps, sedimentation tanks or other measures for removal of silt before discharging into drains or canals.

(b)

(c)

Provision Of Silt Traps And Perimeter Cut-Off Drains (i)

Provide silt traps, perimeter cut-off drains and other facilities to ensure that earth, silt, mud, etc are not discharged into drains or canals. Details of these facilities shall be duly designed and endorsed by a Professional Engineer. Construct these facilities before the commencement of the Works.

(ii)

Desilt silt traps, perimeter cut-off drains and other facilities and maintain at least once a week or more often if necessary to effectively prevent the discharge of silt from the work Site.

Protection Of Exposed Earth Surfaces Carry out close turfing promptly to prevent soil erosion at the Site. Plant all exposed earth surfaces not affected by construction activities with turfing on an immediate basis. Where necessary to prevent soil erosion effectively, carry out progressive turfing on the Site. In cases where turfing is not practical or not effective in protecting exposed earth surfaces which are left bare and undisturbed for more than one month, protect such surfaces from soil erosion by spraying with bitumen based emulsion or other effective methods to be approved by the SO Rep. Notwithstanding the approval of the SO Rep, ensure that the methods are effective in the prevention of soil erosion.

(d)

(e)

Excavated Material (i)

Cart away all surplus excavated materials to own disposal ground immediately. The surplus excavated material shall not be stockpiled on the Site.

(ii)

Earth materials stockpiled on the Site for construction Works shall be within properly contained areas and covered to prevent the earth from washing into drains or canals. The locations for stockpiling the earth shall be subject to approval by the SO Rep. Notwithstanding the approval of the SO Rep, the Contractor shall ensure that earth is not washed into drains or canals.

(iii)

Only carry out trench excavation work as the rate of construction keeps pace with the rate of excavation.

Treatment Of Mud Slurry Ensure that mud slurry from drilling, tunnelling, diaphragm wall construction and jet grouting, etc. is not discharged into drains or canals.

3.4

EXCAVATION Carry out the excavation in accordance with Clauses 2.5 to 2.8 (inclusive) of the Specifications.

3.5

PIPE CONDUIT DRAINS Excavation of trenches shall be to straight lines and gradients required for the pipes and beds as specified. The trench bottom shall be of sufficient width to allow adequate working space but beyond these requirements, the width shall be kept to a minimum.

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CE Spec Page 3-3 3.5

PIPE CONDUIT DRAINS (CONT'D) Maintain the setting out of sufficient length of pipe lines in advance of pipe laying and carry out such exploratory excavation as may be necessary. For lengths of pipelines, which are curved in plan, the curve shall be obtained by deflecting the pipes at each joint. Set the inverts of the drains by wooden pegs with the help of boning rod or other means at regular intervals of not more than 5 metres. Thoroughly compact the bedding for the pipes and lay the pipes evenly on the barrel at the required level. There shall be no hollows, voids or foreign material under the pipe. Take particular care to ensure that proper bedding is obtained at either side of the pipe joints. When concrete bed foundation is specified it shall consists of concrete or reinforced concrete as shown in details on the Drawings. In all cases, well ram or vibrate and work the concrete under and around the pipes. No concrete shall be placed around the pipes until the pipe joints have been inspected and approved. At approximately every four pipes or 6 metre length whichever is the lesser interval, form a joint in the concrete bed or surround by vertically shuttering the bed or surround with 25mm thick fibreboard, timber or other approved material. The shuttering material shall be left in to form a permanent joint. Where the concrete bed is required to be reinforced all reinforcement shall stop on either side of the joint. At every point of loading, or unloading, handle pipes or castings by approved lifting tackle. Do not unload by roll down planks or any other form of inclined ramp unless the consent of the SO Rep has been obtained. Carefully stacked pipes on the Site with timber packings under and between the pipes. Where pipes are stacked, the height shall not exceed 2m. All pipes shall be carefully brushed out inside and shall be tested for soundness before being laid. Lay the pipes separately to true inverts, straight lines and falls, each pipe being separately boned between sight rails and bearing evenly upon the solid ground or concrete for its full length. Where pipes are laid without a concrete bed, cut holes in the bottom of the trench of such size and depth so as to allow the joints to be properly made and the barrel of the pipe to bear evenly on the solid ground for its full length. Where pipes are to be laid on rock formation, take the excavation down to 100mm below bed level and take great care to ensure that there are no projecting pieces of rock on which the pipe will ride. Make up the bed to its true line and level and refill with either 100mm of consolidated, selected material from the excavations, well rammed, and watered if necessary or with 100mm of grade 15 concrete as directed by the SO Rep. Ensure that all blocks and wedges are of sufficient size and strength to prevent settlement of the pipes. Push home each well positioned concrete pipe with rebated joint into the previously laid pipe by means of uniformly applied pressure. Then carry out jointing by filling the opening at the joint with cement mortar and finish off flush. Gauge mortar for jointing pipes and precast concrete units in the proportions of one part of cement to three parts of sand. Mix cement mortar in small quantities sufficiently only for 30 minutes work and do not remix or work up again after setting or hardening; any mortar that has become set or hard shall be rejected and removed from the Works. In the event of pipes being fractured after being to all appearances properly laid whether due to imperfect beds having been formed or the material for refilling having been improperly selected or to any other cause, the Contractor in every instance, shall be held responsible and shall be called upon to replace such defective pipes, if such Defect appears before the expiry of the Defects Liability Period.

CE12/S3.DOC(3) oym(151211) DPD

CE Spec Page 3-4 3.6

CULVERTS AND PROTECTIVE COATING TO INNER WALL Construct pipe culverts of precast reinforced concrete pipes as specified herein all in accordance with the Drawings. Lay and joint pipes as described in Clauses 2.70 "Pipe Laying" and 2.73 "Jointing Concrete Pipes". Where box culverts are to be cast-in-situ reinforced concrete, Construct them in accordance with Clause 2.39 "Concrete" and to the approval of the SO Rep. For box culverts within the road reserve to be handed over to LTA for maintenance, protective coating to inner walls of the culverts is required. The protective coating shall contain Alkylalkoxy silane component. When the concrete has been properly cured, the water repellent but vapour permeable coating shall be applied to its surface. The protective coatings shall be capable of resisting the ingress of water and aggressive atmosphere influences including chloride ions, carbon dioxide and sulphur dioxide in accordance with the specification and as directed by the SO Rep. When applied outside shelter, the protective coating shall have resistance against heat and ultra violet ray. The Contractor shall submit details of all proprietary materials for the protective coating to the Client for acceptance. The Contractor shall submit proven track record and relevant test data of the proposed material used in any country with weather condition that is similar to Singapore. The proposed material shall comply with this specification. All approved proprietary materials shall be used strictly in accordance with the manufacturers' recommendations. Protective coating used shall comply with the following standards : BS

Date

Title

3177

1959(1995)

Method for determining the permeability to water vapour of flexible sheet materials used for packaging.

3900:Part C5

1992

Method of test for paints.

EN 2431

1995

Ethylene-propylene rubber (EPM / EPDM). Hardness 80 IRHD.

EN 24624

1993

Paints and Varnishes Pull off test.

ASTM

Date

Title

D4138`

1982

Standard method of measurement of dry film thickness of protective coating systems by destructive means.

E96-94

"Water Vapour Transmission of Materials".

The Contractor shall submit the testing reports when directed by the SO Rep. All the cost and expense incurred in testing shall be borne by the Contractor.

3.7

BACKFILLING FOR CULVERTS When backfilling the excavation after the completion of the culvert, carefully place the quarry dust, in layers of not more than 600mm deep; each layer shall be thoroughly rammed and watered to achieve adequate compaction and consolidation. Note carefully that proper backfilling of trenches shall be required and measures shall be taken as may be necessary to enforce compliance with this Clause. Maintain all backfilled surfaces including existing roads until they are completely reinstated.

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CE Spec Page 3-5 3.8

FILL ADJACENT TO BRIDGE ABUTMENTS, CULVERTS AND RETAINING WALLS Before backfilling, place a filter drain against weepholes in all structures. The filter drain shall consist of clean, hard and durable broken stones or hardcore. The large stones shall be placed adjacent to the weepholes and the smaller particles behind and above the larger particles. Extend the length of the filter drain horizontally throughout the whole width of the structures or as shown in the Drawings. Unless otherwise stated, it shall have a width of 300mm and shall vertically cover the weephole by at least 300mm. Place granular material adjacent to all structures in accordance with Table 3.1. Other approved materials may be used as backfill outside the limits as specified in the same Table. Table 3.1 Fill Adjacent To Abutments, Culverts And Retaining Walls Structure Bridge abutment & wingwalls

Minimum Width Of Granular Fill Material 2.0 m

Culvert wingwalls

H/3

Retaining walls

H/3

Barrels of box culverts

H/3

Barrels of pipe culverts

H where H = height of structure

Place backfill in horizontal layers of thickness appropriate to the compacting plant used. Compact backfill with care to the required density but avoid excessive compaction. For framed structures, bringing fill at both ends of the structure up simultaneously and equally, with the difference in levels of fills at both ends limited to 600mm. No fill shall be placed against concrete structures within 21 days after placing the concrete unless the Contractor has provided sufficient supports to the walls to the approval of the SO Rep. The supply, filling and compaction of the granular material shall form part of the Contract and the Contractor shall allow for such Works in the Contract Sum.

3.9

COFFERDAMS Any proposal for cofferdams shall not be implemented without the prior written approval of the SO Rep. The proposal shall include the method of construction, materials used, width, height, length and location of the cofferdams.

3.10

PREPARATION OF ROAD FORMATION Where the bearing capacity of the soil is determined by the SO Rep as adequate and where the road is in cut, carry out excavations to the required levels as required by the thickness of construction and the levels of the finished road. Excavate the formation to the required level of the camber or cross-fall shown for the finished road and trim to an even surface. Thoroughly roll the formation with 10 tonne rollers or similar equipment until thoroughly compacted. Where the road is on previously filled ground or where excavation has to be carried deeper than normal formation level on account of weakness in the subsoil as may be shown on the Drawings or determined by the SO Rep during the progress of the work, bring up the formation to the correct level with filling as specified in Clause 5.5 "Filling Generally". Properly compact such filling up to formation level by rolling successively with compaction equipments as detailed in Clause 5.9 "Compaction" and bring to proper shape and camber as is the case of the formation where the road is in cut.

CE12/S3.DOC(5) oym(151211) DPD

CE Spec Page 3-6 3.10

PREPARATION OF ROAD FORMATION (CONT'D) Trim off all high spots and reconsolidate the section. Should any depressions appear in the formation during compaction, fill in, level and compact with material as specified, before crusher run laying can commence. The SO Rep may require fill materials to be tested by an SAC accredited laboratory in accordance with BS 1377 to determine its maximum dry density and optimum moisture content for compaction. One test will be conducted to determine the maximum dry density and optimum moisture content for each class of material to be compacted. Maintain the moisture content of the in-situ material during compaction as close to the optimum moisture content as possible. If necessary, this shall be adjusted by wetting or drying on the Site to enable the required in-situ field densities of the fill material to be obtained consistently. Following the compaction process, carry out in-situ field density tests in accordance with BS 1377:1990 Test No. 15(A) (Sand Replacement Method) or Test No. 15(F) (Water Displacement Method). The in-situ field density may also be determined using nuclear density meters. At least one in-situ field test shall be made for every 300 m2 of surface area of each compacted layer. Obtain the following in-situ field densities of compacted materials given as percentage of the maximum dry density derived from BS 1377 Test No. 13 (4.5kg rammer) : (a)

Within 500mm of formation level (sub-grade or foundation) - 95% of maximum dry density

(b)

From 500mm below formation level - 90% of maximum dry density

The Contractor may choose to establish by site trials the relationship among the in-situ material for compaction, compaction plant used, thickness for each layer, and compacting effort in terms of number of passes. If so established and agreed by the SO Rep the Contractor shall allow the same compaction arrangement for each and every subsequent layers in compaction. However, the SO Rep may at any time carry out in-situ field density tests to determine whether the degree of compaction is satisfactory. The agreed compaction arrangement as mentioned above shall be adjusted when the compaction is found inadequate.

3.11

SUB-GRADE OF CARRIAGEWAY (a)

Sub-grade Formation In addition to Clause 3.10 "Preparation Of Road Formation", trim the finished level of sub-grade along the road centre-line and finish to the lines, grades and cross-sections as shown on the Drawings. On straight lengths of roads, trim the sub-grade to a cross-fall as shown in the Drawings on each side of the road's centre-line. Where the alignment is curved the cross-fall of the sub-grade shall be the same as that of the pavement on both super-elevations and transitions. Trim the sub-grade so that the level does not vary more than 25mm above or 50mm below the levels shown on the Drawings.

(b)

Sub-grade Material Fill material for the last 500mm of the sub-grade shall be the best selected material which shall have a soaked CBR (California Bearing Ratio) value of not less than the value shown on the Drawings or the Specifications or given by the SO Rep in writing. In cut or natural ground where the soaked CBR value of the last 500mm of sub-grade material is less than the required minimum value and if directed in writing, remove 500mm of this material and replace it with an approved selected fill material which conforms to the minimum value required at the Contractor's cost and expense. Compact the last 500mm of the sub-grade material in layers not exceeding 150mm to the required density given below.

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CE Spec Page 3-7 3.11

SUB-GRADE OF CARRIAGEWAY (CONT'D) (c)

Compaction Of Sub-Grade Carry out compaction of the sub-grade by mechanical means using the approved type of compaction equipment such as smooth-wheel roller, tamping roller, pneumatic typed roller and vibrating smooth drum roller, to the required density as specified in Clause 5.9 "Compaction". For undisturbed natural ground, compaction shall be the required dry density for a depth of not less than 200mm. Compact the last 500mm layer of sub-grade material below the level of the granite base course to a density as shown in the Drawings or the Specifications. The location of the samples and the field measurement of the dry density of the compacted material shall be carried out in-situ with a standard instrument approved by the SO Rep. At the time of compaction of each layer, adjust the moisture content of the material by spraying water uniformly or allowing the material to dry out sufficiently to obtain the required compaction. No base course material shall be laid on the carriageway until the sub-grade has been approved by the SO Rep. Any material laid on the sub-grade before the sub-grade has been approved by the SO Rep shall be removed from the Site, if directed by the SO Rep. The location where test is required shall be determined and approved by the SO Rep. The laboratory test shall be carried out at an SAC accredited laboratory. During construction, the SO Rep may take samples from the compacted sub-grade for CBR tests, the location of which shall be determined by the SO Rep depending on the uniformity of the soil type encountered. The number of samples to be taken shall be at a rate of one sample for every 2 50m of carriageway or 500 m of carpark area subject to a minimum of 3 samples. However, if the soaked CBR values fail to achieve the standard required, further tests shall be carried out.

(d)

Improved Sub-grade Course Of Carriageway No sub-grade material or granite base material shall be laid on the carriageway until the sub-grade has been approved by the SO Rep for the laying of the improved sub-grade or base course materials. Unless specified otherwise, the thickness of the base and sub-base course shown in the Drawings shall be the compacted thickness.

3.12

CONCRETE HAUNCHED UPVC SCUPPER DRAINS Concrete haunch 250mm diameter upvc pipe to SS272 (with no joint) and lay within the side-tables to the details shown on the Drawings. Provide drop inlets to the details shown in the Drawings and the connection to the scupper pipes/drains neatly joint in cement mortar.

3.13

ROADSIDE KERBS, CHANNELS, ETC All precast concrete roadside kerb channels (gutters), dividers and drain channels shall comply with BS 7263 and/or SS 214:1979. Set the kerbs, dividers etc in cement mortar on a bed of concrete and haunched with concrete all as shown on the Drawings. Great care shall be taken to ensure the trueness of the line and level of the kerbs. Trim, cut or cast end units squarely to suit required dimensions. The composite and other drain channels shall conform entirely to the shape and dimensions shown in the Drawings. All joints between kerb units shall be pointed in 1:3 cement-sand mortar and of a uniform thickness of 20mm unless site condition requires otherwise. Cast the kerbs to the necessary radii to suit sharp curves on plan and the required proportion shall have shaped insets to suit the entrances to scupper drains.

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CE Spec Page 3-8 3.14

CRUSHER RUN BASE COURSE Crusher run material shall consist of hard, clean, durable, and angular aggregate with a nominal size of 100mm and maximum size of not more than 125mm. If the required compacted depth of the base course exceeds 150mm, construct the base in two or more layers of approximately equal thickness compacted and blinded as specified or indicated in the Drawings. The maximum compacted thickness of any layer shall not exceed 150mm irrespective of the type of compacting equipment employed. Mechanically spread the crushed granite or by any other means approved by the SO Rep to a uniform thickness. Roll each layer of the crushed granite base course with a smooth steel wheeled roller of at least 10 tonnes until a uniform surface is attained. Spread 20mm granite aggregate and brush into the surface voids and rolling shall continue until a smooth and uniform surface is attained and there is no movement in the crushed granite layers. Begin rolling at the sides and progress gradually towards the centre parallel to the longitudinal axis of the road, with a uniform over-lap of each succeeding trip of the roller. Make good irregularities of the compacted crusher run layer before the next course is laid. Blind the surface of each layer with granite dust or an approved blinding material. Brush these blinding materials into the interstices of the granite base course and water with a watering cart. Roll and water the whole surface sweep and roll repeatedly until all the interstices in the granite base course have been filled and the granite base course forms a dense and compact layer. On completion the surface of the base course shall present a smooth and compact appearance, true to levels and camber or cross-fall and shall be sufficiently water-bound to withstand traffic.

3.15

PLANT MIXED CRUSHED GRANITE AGGREGATE BASE COURSE All crushed granite base course shall consist of graded crushed, clean and hard angular aggregate. The grading of the materials is as shown in Table 3.2 below : Table 3.2 Grading Requirements For Plant Mixed Crushed Granite Base Course BS Sieve Size 50 38.0 19.0 9.5 4.8 2.4 425 75

mm mm mm mm mm mm m m

% Passing (by weight) 100 95 to 60 to 40 to 25 to 15 to 6 to 0 to

100 80 60 45 35 18 10

Mix the aggregates at a mixing plant by continuous mixing using a pug-mill mixer, or batch type mixing using a revolving blade, rotary pan, or rotary tilting drum mixer. The plant shall be in sound mechanical condition and shall consistently produce a uniform mixture or aggregates and water at optimum moisture content or at a moisture content as directed by the SO Rep. To achieve the desired grading, the use of any sand, granite dust or approved filler such as laterite, the quality of such materials and the amount to be added into the mixing plant shall be subject to the approval of the SO Rep. Water used for mixing shall be clean and substantially free from detrimental impurities such as oil, salts, acids, alkali and vegetable substance. The method of loading and unloading of material shall be such that segregation shall be minimised. Remove from the Site material which does not comply with the Specifications.

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CE Spec Page 3-9 3.15

PLANT MIXED CRUSHED GRANITE AGGREGATE BASE COURSE (CONT'D) During delivery, cover the material with canvas, or other approved material to prevent loss of moisture during transport. Vehicles used for delivery of material to the hoppers of spreading machines shall have bodies or discharge equipment which shall enable the load to be discharged direct into hopper without spillage and in such a way that segregation shall be minimised. The Contractor is required to furnish information on the following : (a) (b) (c) (d)

Date and time of loading The name of the supplier The registered number of the vehicle The nature and source of the material

The record book shall be kept by the SO Rep on the Site. Spreading of the pavement material shall not commence without the prior consent of the SO Rep. Complete spreading within 3 hours of the time of loading the delivery vehicle. Spread the whole of the mixture by an approved self propelled mechanical spreader with an automatic tamping device. Each layer shall be spread in an uniform layer not exceeding 200mm consolidated thick. After the final rolling which shall be carried out with a self propelled steel-wheeled roller of at least 12 tonnes in weight, the whole surface shall then be allowed to "cure" by opening the carriageway to traffic for a period of at least two weeks or longer if required by the SO Rep. When used in a pavement which is not to carry a bituminous surfacing, that portion of the material which will pass a 425 m sieve shall have the following properties : Liquid Limit Plasticity Index Linear Shrinkage -

not more than 25% not more than 6% not more than 3%

The sand equivalent of the material passing the 4.8mm sieve shall not be less than 30. When used in a pavement which is to carry a bituminous surfacing, the portion of the material which will pass a 425 m sieve shall have the following properties : Liquid Limit Plasticity Index Linear Shrinkage -

3.16

not more than 35% between 4 and 9% between 2 and 4%

PREMIX BITUMINOUS SURFACING (a)

General Where indicated in the Drawings or where directed, lay the road with hot Asphalt Premix Surfacing to a consolidated thickness of either 25mm, 50mm or thicker as shown in the Drawings and as detailed below. The Works under these clause and sub-clauses shall include the following : (i)

Sweeping and brushing surface prior to applying tack coats or asphalt surfacing.

(ii)

Supply and application of suitable tack coats wherever required.

(iii)

Supply and unloading of hot mix asphalt paving mixes as directed.

(iv)

Supply, lay by mechanical spreader/finisher, and rolling and finishing of hot mix asphalt paving mixes.

On receipt of instructions from the SO Rep, the Contractor shall proceed promptly with such work within 48 hours. Carry out the Works continuously and complete within such time as is specified by the SO Rep, having due regard to the output capacity of the Contractor's mixing plant and allowing for unavoidable lost time because of any inclement weather during the course of such Works.

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CE Spec Page 3-10 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (b)

Materials All bitumen supplied shall comply with SS 84 and SS 85 and shall be approved type asphaltic bitumen of either 60/70 penetration and/or 80/100 penetration, as directed by the SO Rep (measured at 25C in both cases). All bitumen shall be straight-run bitumen prepared only by the refining of asphaltic-base petroleum and such refining shall not involve the "cracking process". No mineral matter other than that naturally contained in such bitumen shall be present. The bitumen shall be of uniform quality, free from water and shall not foam when heated to 175C. When required by the SO Rep, submit all necessary information on the country of origin of all bitumen supplied, and the price paid for such bitumen, all at the Contractor's cost and expense prior to its use in the Works. Test for the properties of bitumen shall be carried out whenever required in accordance with the methods set out in SS 86. Mineral Filler shall consist of crushed rock fines, Portland Cement to SS 26 and/or granite fines of appropriate grading. At least 85% of cement filler shall pass BS Sieve No. 200 and the filler shall be thoroughly dry and shall be free from organic matter and clay particles. Fine Aggregate shall consist of approved clean well-graded granite fines produced in a secondary crushing plant, or approved clean natural sand properly washed free from all impurities. Fine aggregate shall be taken as materials mainly passing a BS Sieve 4.76mm and retained on BS Sieve No. 200. Coarse Aggregate shall consist of clean, well-graded, angular, crushed granite of approved quality free from dust, dirt, and/or deleterious materials, and free from excess of flat, elongated or weathered pieces. Coarse aggregate shall be taken as material mainly retained on BS Sieve 4.76mm.

(c)

Rollers Rolling equipment shall, consist of steel wheel and pneumatic type rollers. Steel Wheel Rollers shall be of the following types unless otherwise approved by the SO Rep: (i) (ii)

three-wheel rollers of 10 to 12 tonnes in weight. two-axle tandem rollers of 8 to 12 tonnes in weight.

These rollers shall, under working conditions, develop a compression in the rear-wheels of 44 N per mm to 59 N per mm of roll width. Rollers shall be in good working condition and be free from backlash, faulty steering mechanism, or worn parts. Rollers shall be equipped with adjustable scrappers to keep the rollers clean and with efficient means of keeping the wheels wet to prevent mixes from sticking to the rolls. Rollers shall also be free of flat areas, openings or projections which will mar the surface of the pavement. Pneumatic Tyre Rollers shall be self-propelled or towed type, single or double-axle, having an effective rolling width of not less than 1.2 metres. The rollers shall be equipped with smooth-thread pneumatic tyres of equal size and diameter. The wheels of the roller shall be so spaced that two passes of a single-axle roller or one pass of a two-axle roller shall accomplish one complete coverage equal to the rolling width of the machine. There shall be a minimum of 7mm over-lap of the tracking wheels of a double axle roller. The wheels shall not wobble. The roller shall be uniform for all wheels. Pneumatic-tyred rollers shall be constructed with ample ballast space to provide an operating weight per tyre of between 54 to 76 N per mm of tyre track width. The total operating weight of the roller may be varied by the SO Rep. The towing vehicle for towed-typed rollers shall be equipped with smooth-thread pneumatic tyres. (d)

Preparation of Area to be Paved The area to be paved shall be true to line and grade, having a dry and properly prepared surface prior to the start of paving operations. It shall be brushed until the stone aggregate surfaces are exposed and the whole area shall be swept free of all excess granite dust or blinding material and other loose chippings or foreign material. Patch or correct all depressions and other irregularities to the complete satisfaction of the SO Rep.

CE12/S3.DOC(10) oym(151211) DPD

CE Spec Page 3-11 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (d)

Preparation of Area to be Paved (Cont’d) Apply a tack coat complying with SS 85 on the prepared crushed stone base before the Hot Asphalt premix surfacing is laid. The rate of application of the tack coat shall be 0.55 litre per m2. Paint the surface of kerbs, gutters, vertical faces of existing pavements and all structures in actual contact with the asphalt mixes with a thin uniform coating of approved bituminous emulsion complying with SS 85 to provide a closed bonded watertight joint.

(e)

Tack Coat Supply and lay a suitable tack coat of cationic emulsion of 40% bitumen content as directed, to any surface, prior to the spreading of the asphalt thereon, and after such surface has been thoroughly cleaned and dried. Apply the bitumen emulsion by means of an approved type of mechanical sprayer only, and at the specified rate of application uniformly. Remove any excess or unevenly distributed bitumen from the road surface. The bitumen emulsion shall be allowed a period of 10 minutes "to break" before laying premix over it.

(f)

Asphalt Mixing & Delivery Furnish the SO Rep in advance with full details of all asphalt mixing plant to be used, including average output capacity, type, age, maintenance facilities and all other relevant particulars whenever required by the SO Rep. The mixing plant to be used shall have an output capacity of not less than 50 tonnes per hour. The appropriate mix required for each work shall be in accordance with the Table of Mix as specified in subclause 3.16(n) "Table of Mixes" of the Specifications. Wherever considered advisable, the SO Rep may vary the specified proportions of coarse and fine aggregate within a range of 10% and there shall be no cost adjustment to the Contract Sum. The SO Rep may vary the percentage of filler to be used, within a range of 2% and there shall be no cost adjustment to the Contract Sum. The SO Rep may likewise vary the percentage of bitumen to be used, whereupon the price paid for the work shall be adjusted by him in accordance with the change in bitumen content ordered, based only on the nett purchase price paid by the Contractor for the bitumen being used. If this price is greater than the ruling nett purchase price of bitumen at the time of the variation, then the latter price shall be adopted for the purpose of calculating the value of any such variation. Thoroughly dry all aggregate of the requisite sizes and grading and feed at a temperature of 149C to 190C into a mechanical mixer of approved type. Install an accurate registering pyrometer at a suitable point at the discharge end of the drier with a registering device so located as to indicate clearly the temperature of the coarse and fine aggregate when discharged. Heat the bitumen in an approved type boiler, to a temperature of 136C to 163C, and thereafter add, together with the required proportion of filler, to the coarse and fine aggregate, and all ingredients thoroughly and effectively mixed together until complete coating of all aggregate and filler with the bitumen has been achieved. The SO Rep shall have access at all times to the asphalt mixing plant and shall at liberty take such samples of materials as considered necessary from time to time to verify the proper operation thereof. It is particularly important to avoid excessive heating of the bitumen binder as this will lead to hardening of the binder and result in a shortening of the useful life of the pavement. In all cases keep temperatures as low as is consistent with proper mixing and laying.

CE12/S3.DOC(11) oym(151211) DPD

CE Spec Page 3-12 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (f)

Asphalt Mixing & Delivery (Cont’d) Discharge the asphalt, after proper mixing, from the mixer direct into a tipping truck, for transportation to the work Site. The temperatures of the mix on arrival at the work Site shall not be less than 121C. Cover asphalt in transit when required, with suitable canvas cover to minimise heat loss. When required, provide an adequate number of accurate thermometers for checking the temperature. Vehicles used for transporting the asphalt shall be thoroughly cleaned, free of all foreign materials immediately prior to loading with asphalt. The use of dirty or otherwise unsatisfactory vehicles shall render the load(s) of asphalt liable to rejection.

(g)

Spreading and Finishing Furnish the SO Rep in advance with full details of the mechanical spreader/finisher to be used whenever required by the SO Rep. The mechanical self-propelled spreader/finisher shall be capable of laying an asphalt carpet of not less than three metre width, unless otherwise permitted, and of being operated at varying rates of travel consistent with the rate of delivery and the type of asphalt mixture to be laid. On arrival at the Site, tip the asphalt mix into the hopper of the mechanical self-propelled spreader/finisher and thereupon spread, level, tamp and finish to correct profile, camber or crossfall, without causing segregation, dragging, burning or other surface Defect or irregularities. Follow the SO Rep instructions on the rate of travel of such machine at all times. Operate the spreader at a uniform rate of travel and feed the mixer to the spreader at such a rate as to permit continuous laying, in so far as the supply and site conditions allow. The spreader/finisher shall not operate on any type of side forms, but shall employ mechanical devices to adjust the grade and confine the edges of the asphalt to true lines. Immediately after laying, and before rolling, check the surface with a straight edge of not less than 3.0 m and a spirit level (both to be supplied by Contractor when required) to determine the proper crossfall or camber required. Correct all irregularities and Defect in alignment, grade, texture, etc in an approved manner. The surface, after final rolling, when tested with a straight edge 3.0 m long placed parallel to the centre line of the carriageway shall show no depression greater than 9mm. Carry out preliminary rolling with steel wheel rollers of the type approved by the SO Rep as soon as the asphalt mix has cooled sufficiently to support such roller without lateral flow of the mix. Carry out finishing rolling with an 8 to 12 tonnes tandem roller or other suitable type of roller acceptable to the SO Rep, as soon as practicable after the preliminary rolling, and proceed until no further compaction of the asphalt can be obtained. All rolling shall proceed at a sufficiently slow speed so as to avoid pushing or shoving of the asphalt carpet. The rollers shall not remain stationary on the warm asphalt carpet for any appreciable length of time. Do not use oil on the wheels of any roller to prevent adhesion of asphalt. Protect sections of newly compacted asphalt carpet from traffic for at least six hours, or until properly hardened by cooling. The requirements of the SO Rep in this matter shall be final. Clean all manholes, kerbs, channels and other projections against which the asphalt mix is to be laid, and apply a thin coating of bitumen emulsion applied prior to the laying of the asphalt. Carefully tamp the mixture around and against all projections by means of mechanical tampers and the finished surface left flush, or, if required, up to a maximum of 3mm above such projection. Where existing manholes are lower than the new premixed surface, provide wooden frames to demarcate its position during the process of the laying and premix, so that the manhole can be raised subsequently by the respective service departments.

(h)

Laying Hot Asphalt Premix Lay all asphalt premix against a timber batten laid and pegged into the stone base along the longitudinal joint if it is not laid against a kerb, gutter or against a paving. The battens shall be of a thickness not less than the specified compacted thickness of the asphalt paving. Immediately cut back all joints both longitudinal and transverse squarely prior to laying of further asphalt in contact with such joints.

CE12/S3.DOC(12) oym(151211) DPD

CE Spec Page 3-13 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (i)

Compaction of Asphalt Premix General At least two rollers shall be required at all times and as many additional rollers as necessary to provide specified pavement density. When plant production exceeds 75 tonnes per hour, at least one additional roller shall be required for each additional 50 tonnes or fraction thereof. During rolling, keep the roller wheels moist with only sufficient water to avoid picking up the material. After the longitudinal joints and edges have been compacted, start rolling longitudinally at the sides and gradually progress towards the centre of the pavement, except on super-elevated curves, begin rolling on the low side and progress to the high side. There shall be over-lapping on successive trips by at least one-half the width on tandem rollers and uniformly lapping each preceding track or covering the entire surface with the rear wheels where three-wheel rollers are used. The rollers shall move at a slow but uniform speed (not exceeding five kilometres per hour) with the drive roller wheel nearest the paver. The line of rolling shall not be suddenly changed or the direction or rolling suddenly reversed, thereby displacing the mix. If rolling causes displacement of the materials, the affected areas shall be loosened at once and restored to the original grade of the loose material before being re-rolled. Heavy equipment or rollers shall not be allowed to stand on the finished surface until it has thoroughly cooled. Rolling of the mix shall consist of six separate operations in the following order : (i) (ii) (iii) (iv) (v) (vi)

transverse joints; longitudinal joints; edges; initial or breakdown rolling; second rolling; finish rolling

The edges shall not be exposed for more than fifteen minutes without being rolled. Particular attention shall be given to the construction of transverse and longitudinal joints in both base and wearing courses. Transverse Joints Carefully construct transverse Joints in both base and wearing course and thoroughly compact to provide a smooth riding surface over these joints in the pavement. If the joint is formed with a bulkhead, such as a board, to provide a straight line and vertical face, the joint face need not be trimmed before fresh material is placed against it to complete the joint. If a bulkhead is not used to form the joint and the roller is permitted to roll over the end of the new material, locate the line of joint at the back of the rounded edge a sufficient distance to provide a true surface and crosssection. Paint the joint with a thin coat of asphalt before fresh material is placed against it. To obtain thorough compaction tightly crowd the joint against its vertical face. Continue rolling until a thoroughly compacted neat joint is obtained. Longitudinal Joints Roll longitudinal joints directly behind the paving operation. The first lane placed shall be true to line and grade and have a vertical face. Tightly crowd the material being placed in the abutting lane against the vertical face of the previously placed lane. Position the machine such that in spreading, the material overlaps the edge of the lane previously placed by 25mm to 50mm and is sufficiently high to allow for compaction. Before rolling, carefully move the material over-lapping the joint by brooming onto the surface of the unrolled lane. When rolling is accomplished with a three-wheel roller, shift over into the previously placed lane so that no more than 150mm of the rear roller wheel rides on the edge of the fine material left by brooming. Continue rolling until a thoroughly compacted, neat joint is obtained. If only tandem rollers are used they shall be similarly operated to complete the joint. When the abutting lane is not placed on the same day or the joint is distorted during the day's work by traffic or by other means, carefully trim the edge of the lane to line and paint with a tack coat of bitumen before the abutting lane is placed.

CE12/S3.DOC(13) oym(151211) DPD

CE Spec Page 3-14 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (j)

Density, Thickness and Surface Requirements The completed pavement shall have a density equal to or greater than 95% of a laboratory specimen made in the proportions of the approved job-mix formula and the Marshall test when required. Carefully control both density and thickness during construction and ensure they comply with the approved plans, Drawings and the Specifications. The checking of compacted thickness shall be carried out by the SO Rep by cutting test holes after he is fully satisfied that the asphalt layer has been fully compacted. As a guide each test hole shall be cut at 60 metres interval along each carriageway. Each test hole shall be 150mm diameter and the average thickness of four readings shall be taken as the depth of the asphalt at the test hole. Provide all the necessary labour and Construction Equipment for carrying out both density and thickness tests including the reinstatement of the test holes. Carry out tests for the densities of the asphalt base course and wearing course if required, using an Automatic Asphalt Density Recorder or any other method which the SO Rep may approve. The decision on whether or not the asphalt laid has been compacted to the required density shall be made by the SO Rep based on the above tests and his decision shall be final. If the tests carried out by the SO Rep show that the asphalt surface has not been compacted to the required density the Contractor shall immediately continue to roll the asphalt layer until the SO Rep is satisfied that the required density has been obtained. In addition to the use of a straight edge to check the asphalt surface finish, when necessary, also use a `Rolling Straight edge' to check for any surface irregularity. The decision of the SO Rep on whether or not the asphalt surface has been finished to the regularity required shall be final. Take immediate steps to rectify Defect as directed by the SO Rep.

(k)

Sampling & Testing Samples of asphalt premix shall be taken as, when and where considered necessary, by the SO Rep and testing shall, as far as practicable, be in accordance with SS 86 and BS 598. The number of samples required to be tested shall be one sample for every 550m2 of carpark/450m2 of roadway subject to a minimum of two samples. Extract all test samples of 150mm diameter by coring method. The sampling and testing processes shall be conducted by an SAC accredited laboratory. Where test results are unsatisfactory, the SO Rep may condemn all the asphalt represented by such unsatisfactory sample(s). The Contractor or the Contractor's Representative may be present during the carrying out of any tests, provided he has given one day's clear notice, on each occasion, of such intention. The Contractor shall be responsible for the immediate reinstatement of all cored holes on the road surface where samples have been extracted for testing purposes. Clean the cored holes and dry before backfilling with hot asphalt premix which shall be kept at the required temperature. Properly compact all reinstated cored holes in layers to achieve perfect match between the old and new surfaces.

(l)

Extraction Test (i)

Grading Analysis All aggregates shall be well graded to conform to the proportions specified in the various sieves and the grading curve of the mix shall fall within the approved design envelope bounded curves demarcating the maximum and minimum limits. Any grading falling outside these limits shall be considered as having failed the test and the premix so represented by the sample shall be rejected. The Contractor shall be required to accept the corrective measures including the payment of fees or charges as required by the SO Rep or LTA.

CE12/S3.DOC(14) oym(151211) DPD

CE Spec Page 3-15 3.16

PREMIX BITUMINOUS SURFACING (CONT'D) (l)

Extraction Test (Cont’d) (ii)

Bitumen Content The percentage (%) of soluble bitumen in the mix of any sample shall not be less than the minimum percentage specified. Where any of the test samples fail to comply with the requirement as specified, all the asphalt surfacing represented by such unsatisfactory samples shall be rejected, and the Contractor shall be charged according to the Maintenance Fees imposed by the SO Rep or LTA. Where the bitumen content of any sample exceeds the maximum percentage specified, the entire premix represented by the samples tests shall be rejected and similar Maintenance Fees as specified shall also be imposed. The average percentage of soluble bitumen of all the samples tested shall also be not less than the average percentage specified. Similar Maintenance Fees as specified shall be imposed for failure to comply.

(m)

Marshall Test Result of all Marshall tests of the premix samples if required, shall comply strictly with the undermentioned critical limits : (i)

Marshall stability (KN) - not less than 7.1 KN

(ii)

Flow value - not more than 4.05mm

(iii)

Voids in mix (%) : 3 to 5

(iv)

Percentage of aggregate voids filled with bitumen binder - 75 to 82

As a guide, for the purpose of carrying out Marshall Tests, a set of minimum number of three samples shall be taken for each 150 linear metre of each carriageway or part thereof of premix laid. The samples shall be taken from positions as directed. Samples for Marshall Tests if required, shall be taken in conjunction with Grading Analysis and Bitumen Test or taken separately as directed. (n)

Table Of Mixes Mix the premix bitumen in the proportions as shown on the attached Table of Mixes.

(o)

Reinstatement Of Test Holes Immediately reinstate all holes on the road surface where samples have been extracted for testing purposes.

CE12/S3.DOC(15) oym(151211) DPD

CE Spec Page 3-16 TABLE OF MIXES Mix Classification Type of Mix

W1 & W2

W3 & W4

W5 & W6

B1 & B2

20mm Wearing Course

25mm - 40mm Wearing Course (Type "C")

50mm Wearing Course (Type "A")

Base or Binder Course (Type "B")

15mm to 20mm

25mm to 45mm

45mm to 64mm

50mm to 100mm

10mm

20mm

25mm

38mm

Thickness of course (vary) Max size of stone aggregate used Sieve size Passing

Total Percentage Passing Including Filler

% Soluble Bitumen (by weight of total mix) 60/70 penetration ) 80/100 penetration )

100 95 to 100 84 to 92 65 to 82 48 to 62 35 to 50 22 to 35 12 to 19 3 to 8

100 95 to 100 76 to 90 54 to 70 39 to 55 27 to 41 15 to 22 3 to 8

100 95 to 100 70 to 83 50 to 65 29 to 44 15 to 24 3 to 8

100 90 to 100 65 to 82 39 to 55 22 to 32 3 to 8

50 mm 38 mm 25 mm 19 mm 13 mm 9.5 mm 6.4 mm 3.2 mm 1.2 mm (BS 14) 0.3 mm (BS 52) 0.075 mm (BS 200) Mix

Min

Max

Mix

Min

Max

Mix

Min

Max

Mix

Min

Max

W1 W1

5.5 5.5

6.5 6.5

W3 W4

5.5 5.5

6.5 6.5

W5 W6

5.5 5.5

6.5 6.5

B1 B2

4.5 4.5

6.0 6.0

Overall requirements : % graded coarse aggregates retained on 3.2mm BS Sieve (by wt of total aggregate & filler)

31

42

52

57

% graded fine aggregates passing 3.2mm BS Sieve but retained on 0.075 (BS 200) Sieve (by wt of total aggregate & filler)

63

52

43

39

% mineral filler passing BS 200 Sieve (by wt of total aggregate & filler)

6

6

5

4

% Soluble Bitumen by weight of total mix

6

6

6

5

CE12/S3.DOC(16) oym(151211) DPD

CE Spec Page 3-17 TABLE OF MIXES Mix Classification

AI-IIIb

AI-IVa

AI-IVb

AI-IVc

AI-IId

AI-IIe

AI-IIId

AI-IIIe

AI-A

AI-B

Type of Mix

Wearing Course

Wearing Course

Wearing Course

Wearing Course

Base Course

Base Course

Base Course

Base Course

Skip Gradation

Skip Gradation

Thickness of Course (vary)

25mm to 45mm

20mm to 45mm

25mm to 45mm

45mm to 64mm

45mm to 64mm

50mm to 100mm

45mm to 75mm

50mm to 100mm

25mm to 45mm

50mm to 100mm

20mm

13mm

20mm

25mm

25mm

38mm

25mm

38mm

20mm

38mm

100 95 to 100 50 to 70 30 to 50 5 to 25 2 to 10

100 95 to 100 60 to 80 30 to 50 20 to 40 5 to 25 1 to 10

Max size of stone aggregate used

Sieve Size Passing 50 mm 38 mm 25 mm 19 mm 13 mm 9.5 mm 4.75 mm 2.36 mm 600 m 300 m 150 m 75 m % Soluble Bitumen (60/70 Penetration Grade)* (% by weight of total mix)

Total Percentage passing including filler 100 75 to 100 60 to 85 35 to 55 20 to 35 10 to 22 6 to 16 4 to 12 2 to 8

100 80 to 100 55 to 75 35 to 50 18 to 29 13 to 23 8 to 16 4 to 10

100 80 to 100 70 to 90 50 to 70 35 to 50 18 to 29 13 to 23 8 to 16 4 to 10

100 83 to 100 62 to 78 50 to 65 35 to 50 19 to 30 13 to 23 7 to 15 0 to 8

100 70 to 100 35 to 60 15 to 35 5 to 20 0 to 4

100 70 to 100 50 to 80 25 to 50 10 to 30 5 to 20 0 to 4

100 75 to 100 61 to 82 47 to 68 32 to 48 20 to 35 5 to 20 3 to 12 2 to 8 0 to 4

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

Min

Max

4.5

5.5

4.5

5.5

4.5

5.5

4.5

5.5

3.5

5.0

3.5

5.0

3.5

5.0

3.5

5.0

4.5

5.5

4.5

5.5

* When required 80/100 Penetration Grade Bitumen shall be used instead of 60/70 Penetration Grade Bitumen at the Contractor's own cost and expense. No Claims for extra payment shall be allowed for using 80/100 Penetration Grade Bitumen.

CE12/S3.DOC(17) oym(151211) DPD

100 75 to 100 60 to 85 50 to 71 40 to 60 30 to 47 20 to 35 5 to 20 3 to 12 2 to 8 0 to 4

CE Spec Page 3-18 TABLE OF MIXES Road Mixes Mix Classification

WSS

Type of Mix Thickness of Course

W3

Wearing Course

B1

W5

Binder Course

W5B

Wearing Course

15 to 25 mm

30 to 50 mm

50 to 100 mm

45 to 65 mm

45 to 65 mm

50 to 80 mm

19 mm

10 mm

19 mm

35 mm

25mm

19 mm

25 mm

50 mm

-

-

-

-

-

-

-

37.5 mm

-

-

-

100

-

-

-

25 mm

-

-

-

95 to 100

100

-

100

19 mm

100

-

100

84 to 92

95 to 100

100

89 to 97

13.2 mm

80 to 90

-

90 to 100

65 to 82

76 to 90

85 to 95

73 to 83

9.5 mm

63 to 77

100

-

-

-

-

-

6.3 mm

-

90 to 100

70 to 83

48 to 62

54 to 70

58 to 68

50 to 60

3.35 mm

-

65 to 82

50 to 65

35 to 50

39 to 55

40 to 50

40 to 50

2.36 mm

46 to 56

-

-

-

-

-

-

1.18 mm

-

39 to 55

29 to 44

27 to 41

27 to 41

21 to 31

25 to 35

600 m

16 to 26

-

-

-

-

-

-

300 m

-

22 to 32

15 to 24

15 to 22

15 to 22

11 to 17

13 to 16

212 m

8 to 18

-

-

-

-

-

-

75 m

6.5 to 10.5

3 to 8

3 to 8

3 to 8

3 to 8

4 to 8

4 to 8

5  0.5

6  0.5

6  0.5

5  0.5

5.5  0.5

5  0.5

4.8  0.5

% Soluble Bitumen (60/70 Penetration Grade) (% by Wt of Total Mix) Void in Mix

3.0 to 5.0

*When required 80/100 Penetration Grade Bitumen shall be used instead of 60/70 Penetration Grade Bitumen at the Contractor's own cost and expense. No Claims for extra payment shall be allowed for using 80/100 Penetration Grade Bitumen.

CE12/S3.DOC(18) oym(151211) DPD

W3B

50 to 75 mm

Max. Size of Stone (BS) Passing

W1

4.5 to 6.5

CE Spec Page 3-19 3.17

INTERLOCKING CONCRETE PAVING BLOCKS (a)

General The concrete blocks shall comply with the requirements of BS 6717:Part 1, unless otherwise specified. The interlocking concrete paving blocks shall be precast, vibrocompacted blocks. The maximum dimensional deviations from the standard work sizes for the paving blocks, measured in accordance with BS 6717 : Part I or SS 76M, shall be as follows : Length Width Thickness

: : :

2mm 2mm 3mm

Any pigment used shall comply with BS 1014. (b)

Sampling And Testing For Compressive Strength A total of 16 concrete blocks shall be tested for each 550m2 of interlocking concrete pavement. The average compressive strength of the paving blocks, tested in accordance with BS 6717 or SS 76M, shall not be less than 49N per mm2, and the crushing strength of any individual block shall be not less than 40N per mm2.

(c)

Failure Of Test On Compressive Strength The SO Rep shall exercise his rights under Clause 1.6 "Nuisance & Irregularities" to impose charges against the Contractor for : (i) (ii)

each batch of 16 concrete blocks for which the average compressive strength is less than 49N per mm2; or each individual block of which the compressive strength is less than 40N per mm2.

In addition, the consignment represented by the test sample shall be accepted only at the sole discretion of the SO Rep, after he has considered the degree of failure and other related circumstances. Any consignment rejected by the SO Rep shall be removed from the Site immediately. (d)

Sampling And Checking Of Surface Layer Thickness In Composite Concrete Paving Blocks Coloured concrete paving blocks formed by the addition of pigments may be either homogeneous or non-homogeneous in colour. Non-homogeneous coloured concrete paving blocks are considered as composite concrete paving blocks. In composite concrete paving blocks, the coloured surface layer shall be formed as an integral part of the block and shall not be less than 5mm thick. A total of 5 composite concrete blocks shall be checked for surface layer thickness compliance for 2 each 550m of interlocking composite concrete pavement. The checking shall be carried out at an SAC accredited laboratory. Each concrete block to be checked shall be cut neatly at the mid-span of the length of the composite concrete block, cutting of the blocks shall only be carried out at the accredited laboratory. The average surface layer thickness of each composite block shall be derived from the measured thickness at the left edge, middle and right edge of the surface layer thickness on the cross-sectional face of the cut-off block. The thickness shall be measured by a caliper. The measured thickness shall be to the nearest 0.1mm accuracy. The Contractor shall ensure that the cut samples are collected back from the accredited laboratory and returned to HDB for verification. These cut samples shall be kept at the site office and only disposed off at the sole discretion of the SO Rep.

CE12/S3.DOC(19) oym(151211) DPD

CE Spec Page 3-20 3.17

INTERLOCKING CONCRETE PAVING BLOCKS (CONT'D) (e)

Failure To Comply With The Minimum Surface Layer Thickness Requirement In Composite Concrete Paving Blocks The SO Rep shall exercise its right under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for each composite concrete block for which the average surface layer thickness is less than 5mm. In addition, the consignment represented by the samples checked for surface layer thickness compliances shall be accepted only at the sole discretion of the SO Rep, after he has considered the degree of failure and other related circumstances. Any consignment rejected by the SO Rep shall be removed from the Site immediately.

(f)

Marking Before laying, divide the paving blocks into consignments designated for each area of not more than 550m2. A sample of 16 blocks shall be taken from each such consignment. In the case of composite concrete paving blocks, an additional 5 blocks shall be taken from each such assignment. Clearly mark the sample at the time of sampling in such a way that the consignments represented by the sample are clearly defined.

(g)

Inspection Before commencing the placing of the sand bedding course and the laying of units, the sub-base shall be inspected and approved by the SO Rep.

(h)

Edge Restraints Provide adequate edge restraint along the perimeter of all paving in the form of integral kerb and gutter, concrete kerb or edge strip or established structure. The face of the edge restraint, where it abuts paving units, shall be vertical down to the sub-base.

(i)

Bedding Sand (i)

Material Bedding sand shall be a well-graded sand passing a 4.75mm sieve and suited for concrete manufacture. The grading limits are : A.S. Sieve 9.52 mm 4.75 mm 2.36 mm 1.18 mm 600 m 300 m 150 m 75 m

% Passing 100 95 to 100 80 to 100 50 to 85 25 to 60 10 to 30 5 to 15 0 to 10

The bedding sand shall be free of deleterious soluble salts or other contaminants likely to cause efflorescence or lead to reduced skid resistance. (ii)

Moisture Content The sand shall be of uniform moisture content when spread and shall be protected against rain when stockpiled on the Site prior to spreading.

(iii)

Spreading Bedding Sand Spread the sand bedding loose and in a uniform layer. Determine the precise depth in the field prior to spreading. Screed the sand bedding in a loose condition to the nominated design profile and levels plus the necessary surcharge to achieve a uniformly thick layer, following compaction to the thickness specified in the Drawings.

CE12/S3.DOC(20) oym(151211) DPD

CE Spec Page 3-21 3.17

INTERLOCKING CONCRETE PAVING BLOCKS (CONT'D) (i)

Bedding Sand (Cont'd) (iv)

Screeding Of Bedding Sand Carefully maintain the spread sand in a loose condition and protect against precompaction both prior to and following screeding. Loosen any precompacted sand or screeded sand left overnight before further paving units are placed. Lightly screed sand in a loose condition to the predetermined depth only, slightly ahead of the laying of the paving units. Under no circumstances shall the sand be screeded in advance of the laying face to an extent to which paving will not be completed on that day. Protect screeded sand against accidental precompaction including compaction by rain or dew. Remove any screeded sand which is precompacted prior to laying of units and bring back to profile in loose condition.

(j)

Laying Of Paving Units (i)

General Place paving units on the uncompacted screeded sand bedding to the nominated laying pattern, care being taken to maintain the specified bond throughout the job. Place paving units to achieve a positive gap of 3mm between the units. Under no circumstances shall units be allowed to touch nor should the gap between units exceed 5 mm. Correctly place all joints to suit the laying pattern and bond. The first row shall abut an edge restraint with a gap of 2 to 4 mm and shall be laid at a suitable angle to the edge restraint to achieve the required visual orientation of paving units in the completed pavement. In each row all full units shall be laid first. Cut closure units and fit subsequently. Such closure units shall consist of not less than 25% of a full unit. Units may be cut using a mechanical or hydraulic guillotine, bolster, or by power sawing. Except where it is necessary to correct any minor variations occurring in the laying bond hammer the paving units into position. Where adjustment of position is necessary take care to avoid premature compaction of the sand bedding. Any foot or barrow traffic shall use boards overlaying paving to prevent disturbance of units prior to mechanical compaction. No other construction traffic shall be allowed on the pavement at this stage of construction.

(ii)

Compaction After laying the paving units they shall be compacted to achieve consolidation of the sand bedding and brought to design levels and profiles by not less than two and preferably three passes of a suitable plate compactor. The compactor shall be a high-frequency, low-amplitude mechanical flat plate vibrator having a plate area sufficient to cover a minimum of 12 paving units. Compaction shall proceed as closely as possible following laying and prior to the acceptance of any traffic. Compaction shall not be attempted, however, within one metre of the laying face. Compaction shall continue until lipping has been eliminated between adjoining units. Joints shall then be filled and compacted as hereinafter described. All Works to within one metre of the laying face shall be left fully compacted at the completion of each day's laying.

(iii)

Damaged Units Immediately remove and replace any units which are structurally damaged during compaction.

CE12/S3.DOC(21) oym(151211) DPD

CE Spec Page 3-22 3.17

INTERLOCKING CONCRETE PAVING BLOCKS (CONT'D) (j)

Laying Of Paving Units (Cont’d) (iv)

Filling Joints As soon as practical after compaction, and in any case prior to the termination of work on that day and prior to the acceptance of construction traffic, spread sand for joint-filling over the pavement. The joint-filling sand shall conform to the following grading limits : A.S. Sieve

% Passing

2.36 1.18 600 300 150 75

100 90 to 100 60 to 90 30 to 60 15 to 30 10 to 20

mm mm m m m m

and shall be as dry as possible prior to spreading and brooming into the joints. At least one pass of the vibrating-plate compactor is necessary to achieve compaction of the jointingfilling sand. After the first pass joints shall be checked for adequacy of filling and any shortfall shall be made good prior to a further pass of the compactor. (v)

Pavement Preloading Where directed by the SO Rep the pavement shall receive not less than 5 and up to 10 passes of a pneumatic-tyred roller having a gross weight not less than 10 tonnes.

(vi)

Excess Sand Excess surface sand shall be removed by brooming prior to handing over the pavement.

(vii)

Tolerance To Design Profile All surfaces and pavement structures shall be true to line and levels, grades, thicknesses and cross sections shown on the Drawings. Finish all pavements to lines and levels to ensure positive drainage at all drainage outlets and channels.

3.18

CLAY PAVERS (TYPE PB) FOR FLEXIBLE PAVEMENT (a)

General The clay pavers (Type PB) shall comply with requirements of BS 6677 Part 1, unless otherwise specified. The maximum and minimum value for the overall measurement of 24 clay pavers (for commonly available work sizes) shall be as follows : Work Size (in mm)

Maximum

Minimum

Length

215 210 200

5216 5095 4852

5104 4985 4748

Width

105 102.5 100

2555 2494 2433

2485 2426 2367

Thickness

65 50

1594 1226

1526 1174

Other work sizes may be used if permitted by the SO Rep.

CE12/S3.DOC(22) oym(151211) DPD

CE Spec Page 3-23 3.18

CLAY PAVERS (TYPE PB) FOR FLEXIBLE PAVEMENT (CONT’D) (b)

Sampling And Testing For Transverse Breaking Load 2

A total of 10 clay pavers shall be tested for each 200 m of clay pavers used for flexible pavement. The mean transverse breaking load of 10 clay pavers shall be not less than 7 kN and the transverse breaking load of each clay paver shall be not less than 4 kN. (c)

Failure Of Test On Transverse Breaking Load The SO Rep shall exercise his rights under Clause 1.6 "Nuisance and Irregularities" to impose charges against the Contractor for : (i)

Each batch of 10 clay pavers for which the mean transverse breaking load is less than 7 kN, or

(ii)

each individual paver of which the transverse breaking load is less than 4 kN.

In addition, the consignment represented by the test sample may be accepted only at the sole discretion of the SO Rep, after he has considered the degree of failure and other related circumstances. Any consignment rejected by the SO Rep shall be removed from the Site immediately. (d)

Sampling, Testing And Failure Criteria For Wet Skid Resistance 2

A total of 5 clay pavers shall be tested for each 200m of clay pavers used for flexible pavement. The Mean Wet Skid Resistance of the 5 clay pavers shall not be less than 60. The SO Rep shall exercise his rights under Clause 1.6 "Nuisance And Irregularities" to impose charges against the Contractor for each batch of 5 clay pavers whose mean wet skid resistance fails to attain the above criteria. In addition, the consignment represented by the samples may be accepted only at the sole discretion of the SO Rep, after he has considered the degree of failure and other related circumstances. Any consignment rejected by the SO Rep shall be removed from the Site immediately. (e)

Marking Before laying, divide the pavers into consignment designated for each area of not more than 200 2 m for Transverse Breaking Load Test and Wet Skid Resistance Test. A sample of 15 pavers shall be taken from each such consignment. Clearly mark the sample at the time of sampling in such a way that the consignments represented by the sample are clearly defined.

(f)

Laying of Interlocking Clay Paving Blocks The method for the laying of clay pavers shall comply with the requirements as specified in subclause 3.17 (g) to subclause 3.17 (j) inclusive for interlocking concrete paving blocks.

(g)

Colours and laying patterns The Contractor shall submit workshop drawings to the SO Rep showing the range of colours and laying patterns of the clay pavers for selection and approval. The SO Rep reserves the right to change the colours and laying patterns and his decision shall be final.

3.19

CONCRETE FOOTPATH The paving slabs shall be properly bedded on a layer 25mm thick of unwashed sand and 100mm thick hardcore well compacted and special care shall be taken to ensure that the earth formation of the footpath is fully compacted and free from any vegetable matter or roots before footpath construction is commenced. Footpaths shall be laid true to the lines and levels of the roadside kerbs or divider and shall be given a slight fall as shown on the Drawings transversely towards the carriageway. For cast-in-situ concrete footpath panels of approximately 3m length shall be cast. The surface of each panel shall be floated smooth with a wooden float or similar appliance. Provide Construction/Contraction joints at the intervals between panels.

CE12/S3.DOC(23) oym(151211) DPD

CE Spec Page 3-24 3.20

BUS BAYS AND SHELTERS Construct all bus bays shown in the Drawings to proper lines and levels, in reinforced concrete. Complete construction of bus bays before the carriageway base course metalling is commenced and protect the edges of the concrete slabs during carriageway construction. Make good any damage to such concrete to the satisfaction of the SO Rep. Roll the bed for the bus bay with a 10 tonne roller to the satisfaction of the SO Rep before receiving crushed granite 100mm thick and blinded. Install all bus shelters adjacent to the bus bays as shown in the Drawings.

3.21

TRAFFIC AND ROAD DIRECTIONAL SIGNS The design, fabrication and installation of traffic signs and road directional signs shall comply with the following general requirements and the LTA general guidelines laid down in the SIGNS MANUAL INFORMATION SIGNS, prepared by the Traffic Management Department, LTA, and/or revised LTA guidelines on materials, support, letter types, colour codes, sign legibility, dimension etc. as and when applicable. Fabricate the signs with aluminium sheeting of thickness No. 14 SWG. The reflective sheeting shall be diamond grade consisting of prismatic lens that are formed in a transparent synthetic resin and sealed or other approved equivalent to LTA standard for all traffic and Road Directional Signs; The reflective sheeting shall be durable and remain sharp during its expected service life under local weather conditions. Submit a test report on the reflective sheeting from an SAC accredited laboratory and/or from the manufacturer and/or any other independent laboratory approved by the SO Rep together with the Tender and/or as and when required by the SO Rep. The test shall conform with ASTM D4956-90 for diamond grade and the report shall carry technical information on the reflectivity factors' durability of the reflective surface; and adhesive, corrosion and abrasion resistance, colour tests etc. and any other technical information outlined in the LTA general guidelines and/or required by the SO Rep. The diamond grade reflective sheeting shall be guaranteed by the supplier and/or the Contractor against any Defect such as discolouring, peeling, cracking, shrinking or any other apparent or latent Defect for a period of seven years commencing from the Date of Substantial Completion. Generally, joints shall not be permitted for aluminium sheeting and reflective sheeting. Where the size of the sign requires joints, they shall be positioned horizontally at the dividing line between the legends or as directed by the SO Rep. Joints of reflective sheeting shall coincide with those of aluminium sheeting and the joints shall be rivetted. Use only round block script letters and numerals in all the traffic and road directional signs. The letter size and word spacing shall conform to the LTA standard and/or Specifications and/or Drawings and/or specified by the SO Rep. Support the signs either by 80mm diameter GI pipe or 125mm x 125mm x 6mm SHS supports and embedded in concrete foundations, all in accordance with the LTA standard and/or Specifications and/or Drawings and/or specified by the SO Rep. Give the supports one coat of red lead primer undercoat and two finishing coats of enamel paint.

3.22

VEHICULAR IMPACT GUARDRAILS Erect the guardrail to the alignment specified in the Drawings or as directed by the SO Rep. Connect the adjacent rails by lap joints and the erection of the guardrail shall proceed in the direction of traffic flow to avoid vehicles striking rail ends. The nominal thickness of base metal for guardrails shall be 3.0mm formed into corrugated cross-section of width 300mm minimum and trough depth 75mm conforming to the requirement of AASHTO:M180-74. When simply supported over a span of 3.54 metres with its traffic face uppermost, the mid-point deflection of the rail shall not exceed 75mm under a concentrated load of 1000 kg at mid-span. The mechanical properties of the base metals for the rails shall conform to the following : Minimum yield point Minimum tensile strength Elongation

CE12/S3.DOC(24) oym(151211) DPD

-

345N per mm2 483N per mm2 50mm, maximum 12%

CE Spec Page 3-25 3.22

VEHICULAR IMPACT GUARDRAILS (CONT’D) All fabricated rails shall be hot-dip galvanised at shop in accordance with BS 729 and shaped in the workshop in standard length and assembled on the Site by galvanised oval shoulder button headed bolts and nuts of 16mm nominal diameter. All guardrail posts and spacers, unless otherwise specified shall be Mild Steel Channels or Steel Hollow Sections.

3.23

ILLUMINATED SIGNBOARDS (i)

Materials and Workmanship All materials used in the manufacture of the signboards shall be new and of the required quality, correct dimensions, sizes and gauges as approved by the SO Rep and free from any Defect or damage on completion of the fabrication, assembly and delivery of the signboards. If any of the materials used is found to be defective or below the acceptable standard, the SO Rep may instruct the Contractor to cease all work and replace those materials with proper and suitable materials in accordance with the specifications or conform to British Standards or equivalent PSB Standards. The Contractor shall submit details of the components used for the proper fabrication and fixing of the various components and parts of the signboards to the SO Rep for his approval before the Works are carried out.

(ii)

Electrical Installation The Contractor shall employ a licensed electrical worker of the appropriate grade to carry out the Works. A licensed electrical worker shall mean a qualified competent person to perform electrical works under the Electrical Workers and Contractors Licensing Act 1974. The electrical installation shall comply with all regulations issued by PowerGrid. All parts of the installation shall where applicable, be to the complete satisfaction of the SO Rep, PowerGrid, all Government Authorities and Fire Officers and shall be in strict accordance with all bye-laws, rules and regulations of such Authorities.

(iii)

Bolts and Nuts All galvanised bolts and nuts for fixing signboards shall be provided with galvanised washers.

(iv)

Painting to Metal Surfaces Apply one coat approved lead and chromate free primer to the surfaces of mild steel angles, hollow sections, brackets, weldings, nuts and bolts, etc. All primed metal surfaces shall be finished with two coats of approved paint.

(v)

Fluorescent Luminaries The signboard luminaries shall be fluorescent luminaries with: (a)

1200mm - 36W tubes and 600mm - 18W tubes All luminaries shall be pre-wired and completed with tubes, power factor corrected electronic ballasts and lampholders. The Contractor shall provide and wire the luminaries to a termination block within the signage box for termination purpose. Where applicable, the fluorescent luminaries shall comply with the following Standards :

CE12/S3.DOC(25) oym(151211) DPD

(1) (2)

IEC 81 : 1984 IEC 400 : 1991

(3)

IEC 928 : 1995

(4)

IEC 929 : 1994

Tubular fluorescent lamp for general lighting service. Lampholders for tubular fluorescent lamps and starterholders. Auxiliaries for lamps - A.C. supplied electronics ballasts for tubular fluorescent lamps. General and safety requirements. A.C. supplied electronic ballasts for tubular fluorescent lamps. Performance requirements.

CE Spec Page 3-26 3.23

ILLUMINATED SIGNBOARDS (CONT’D) (v)

Fluorescent Luminaries (Cont’d) (b)

Ballasts supplied shall be suitable for local use and separate ballasts shall be provided for each lamp. The ballasts shall have a protection features to cut off the supply if it sense a faulty fluorescent tube and restart automatically when the faulty tube is replaced.

(c)

Fluorescent tubes installed shall be 'Philips' (Daylight), or other approved, of 26mm nominal diameter type with lamp wattage of 36W and/or 18W. All tubes shall have to pass batch tests conducted by PSB.

(vi)

Wiring and Electrical Accessories The wirings from the termination block in the illuminated signboards shall be 2 x 1.5mm2 PVC/PVC completed with 2.5mm2 PVC earth run in 20mm diameter Class 4 G.I. conduits including accessories and terminated at the weather proof termination box. The termination box shall be of steel construction not less than 2mm thickness and protected against corrosion by hot dip galvanizing internally and externally. The termination box shall be provided with the following wiring and electrical accessories:

(vii)

(a)

a 25 Amp 440V cut-off with provision of looping in of two numbers of phase, neutral and earth conductors and looping out of one number of phase, neutral and earth conductors of 2 up to 25mm and a 5 Amp HRC fuse as shown in the Drawings.

(b)

internal wiring of minimum size of 2 x 1.5mm2 PVC/PVC complete with 2.5mm2 PVC (green) earth connecting the cut-off to the luminaries.

(c)

brass compression glands for armoured PVC insulated cables, complete with brass locknuts, earth tags, earthing tap and shroud.

Bonding All exposed conductive parts shall be effectively bonded to the circuit protective conductor.

(viii)

Electrical Testing & Completion Certificate Upon completion of the Works, the Contractor's licensed electrical workers of the technician grade shall test the installation to ensure that it complies with PowerGrid requirements and CP5:1988. The Contractor shall furnish all data in the Electrical Testing & Completion Certificate as shown in Appendix A3 and attached the single-line diagram to the SO Rep.

3.24

WORKS ON ROADS (a)

Works On Roads With Speed Limit Below 70 Km Per Hour For any Works on roads with speed limit below 70 kph, the Contractor shall provide adequate signboards, blinker lights, cones, etc, in accordance with LTA Code of Practice For Temporary Traffic Control. The Contractor shall be deemed to have considered and allowed for all costs and expenses for the temporary precautions and measures in the Contract Sum.

(b)

Works On Roads With Speed Limit 70 Km Per Hour And Above For any Works on roads with speed limit 70 kph and above, the Contractor shall provide adequate signboards, blinker lights, cones, etc, in accordance with LTA Code of Practice For Temporary Traffic Control. The Contractor shall note that he is required to provide a collison attenuator or truck mounted attenuator (TMA) attached/fitted/mounted onto an appropriate shadow vehicle with the necessary equipment for traffic control and road safety in accordance with LTA Code of Practice For Temporary Traffic Control. The TMA provided shall comply with LTA specification and requirements. The Contractor shall be deemed to have considered and allowed for all costs and expenses for the temporary precautions and measures in the Contract Sum.

(c)

CE12/S3.DOC(26) oym(151211) DPD

For road openings on public streets, the Contractor shall comply with LTA Code of Practice For Road - Opening Works. The Contractor shall be deemed to have considered and allowed for all costs and expenses.

CE Spec Page 3-27 3.25

SEALANT USED FOR EXPANSION JOINT IN RIGID PAVEMENT (a)

General Expansion joints shall be of an approved shape and be provided in the positions as shown in the Drawings or as directed. Suitable joint filler material is placed between the pavement slabs to allow the slabs to expand and contract. Joints shall be sealed using appropriate joint sealant.

(b)

Joint Sealant (i)

Type of Sealant The type of sealant used shall be cold applied, fuel resistant. Cold applied sealant capable of accommodating high movement.

(ii)

Requirements The sealant shall comply with the British Standard BS 5212 : 1990 "Cold applied joint sealant systems for concrete pavements" Type F. Cold applied, high duty pavement sealant shall possess the following properties :

CE12/S3.DOC(27) oym(151211) DPD

Form

:

Two part compound Base compound - viscous liquid Curing agent - liquid

Colour

:

Black

Movement accommodation Factor (BS 6093)

:

Butt joints 25%

Physical or Chemical change :

Chemical cure

Setting time

:

After 16 to 24 hours, sealant will be tacked free and accepted traffic. Full cure and maximum hardness are attained in approximately 3 to 4 days at 25C.

Application temperature

:

To avoid unacceptably prolonged cure time, do do not apply to temperatures below 5C.

Hardness shore 'A' at 25C

:

12 to 17

Chemical resistance to Occasional spillage

:

Dilute acids Mild alkalis Petrol Aviation fuels Diesel fuels Synthetic oils Mineral oils Hydraulic fluids Kerosene

Solid content

:

100%

Density

:

1.36 kg per litre

Flash point

:

Over 65C

Flammability

:

Burns but does not readily support combustion

-

resistant resistant resistant resistant resistant resistant resistant resistant resistant

CE Spec Page 3-28 3.25

SEALANT USED FOR EXPANSION JOINT IN RIGID PAVEMENT (CONT'D) (c)

Method for application of sealant (i)

Joint Preparation Joint sealing slots shall be accurately formed and shall be dry, clean and sound. All grease, water and dust shall be removed from the joint before applying the primer. Ensure that any expansion joint filler is tightly packed in the joint and at the required depth to provide the seal dimensions specified.

(ii)

Priming Primers shall be applied only to sealant contact surfaces which must be clean, dry, sound and free of contaminants. Prime joint sealing slot surface with appropriate prime for the type of sealant approved by the SO Rep. Allow primer to air dry prior to applying sealant. Drying time also depends on the type of primer used and ambient temperature. The surface shall be touch dry. The approved sealant shall be applied within the time period after priming before the primer film has completely reacted. Primed surfaces not sealed with sealant within the required time period shall be re-primed before applying sealant.

(iii)

Application of sealant Dried primer is free of any residue and prepared joints are free of any foreign matter or contaminations. Apply sealant into the sealing slot so that the finished level of the seal is recessed below the trafficked surface as specified.

(d)

Information of product to be supplied by manufacturer Obtain from the manufacturer the following information of the sealant/primer proposed for use for the Works : Maximum safe heating temperature of the material. Temperature range of application. Flash point of sealant and primer. Composition of the mixture. Type of primer required. Application instructions. Health and Safety Data Sheets on sealant and primer for additional information concerning usage, handling precautions, first aid procedures, warranty including shelf life. The foregoing information shall be provided to the SO Rep one week before the start of the sealant application.

3.26

PRECAST CONCRETE PERFORATED INTERLOCKING PAVING SLABS Where precast concrete perforated interlocking paving slabs are included in the Works, the Contractor shall comply with the requirements for sand bedding preparation and laying as specified in clause 3.17 'Interlocking Concrete Paving Blocks" including all subclauses under it. The colour of the interlocking paving slabs shall be decided by the SO Rep. For sampling and testing of the interlocking paving slabs, the Contractor shall comply with the following : (a)

Sampling and Testing (i)

Transverse Strength Test The transverse strength for each paving slab shall not be less than 19kN. Samples of paving slabs at a rate of 3 paving slabs for every 1,000 paving slabs delivered to the Site, shall be selected for transverse strength test to be performed in the manner as described in BS 7263 and in an SAC accredited laboratory. If the overall quantity of paving slabs in the Works is less than 1,000 pieces, a minimum of 3 numbers of paving slabs shall be chosen for the transverse strength test.

CE12/S3.DOC(28) oym(151211) DPD

CE Spec Page 3-29 3.26

PRECAST CONCRETE PERFORATED INTERLOCKING PAVING SLABS (CONT'D) (a)

Sampling and Testing (Cont'd) (ii)

Water Absorption Test The maximum average rate of water absorption test (%) calculated on the dry weight of 3 test pieces per paving slab shall not exceed 3% at 30 minutes. 5 numbers of paving slabs for every 1,000 paving slabs delivered to the Site, shall be selected for water absorption test to be performed in the manner as described in BS 7263 and in a SAC accredited laboratory. If the overall quantity of paving slabs in the Works is less than 1,000 pieces, a minimum of 5 numbers of paving slabs shall be chosen for the water absorption test.

(iii)

Surface Layer Thickness in Composite Paving Slabs Coloured concrete paving slabs formed by the addition of pigments may either be homogenous or non-homogenous. Non-homogenous coloured paving slabs are considered as composite paving slabs. The coloured surface layer of each composite paving slab shall be formed as an integral part of the paving slab and shall not be less than 12mm thick. For every 550m2 of interlocking composite paving slabs laid on the Site, 5 numbers of paving slabs shall be checked for surface layer thickness. If the overall quantity of paving slabs in the Works is less than 550 m2, a minimum of 5 numbers of paving slabs shall be chosen for checking on surface layer thickness. The checking shall be conducted in a SAC accredited laboratory. Each paving slab shall be cut neatly at mid-span of its length. Cutting the paving slab shall only be carried out in the accredited laboratory. The average surface layer thickness of each composite paving slab shall be derived from the measured thickness at the left, middle and right edges of the surface layer thickness on the cross-sectional face of the cut-off paving slab. The thickness shall be measured to the nearest 0.1mm accuracy. The Contractor shall ensure that the cut samples are collected back from the SAC accredited laboratory and returned to HDB for verification. These cut samples shall be kept at the site office and disposed off only at the sole discretion of the SO Rep.

The SO Rep shall exercise his rights under Clause 1.6 ‘Nuisance and Irregularities’ of Standard Specifications to impose charges against the Contractor for each sample that fails to comply with the above test requirements. Each consignment of slabs represented by the sample testing may be accepted only at the sole discretion of the SO Rep after he has considered the degree of failure and other related circumstances. Any consignment rejected by the SO Rep shall be removed from the site immediately.

SECTION 4/.....

CE12/S3.DOC(29) oym(151211) DPD

CE Spec Page 4-1 SECTION 4

CONSTRUCTION AND WORKMANSHIP FOR SEWERS

4.1

ADDITIONAL WATER RECLAMATION (NETWORK) DEPARTMENT, PUB’S REQUIREMENTS FOR SEWERS AND MANHOLES Use approved flexible joints thickwall concrete pipes and vitrified clay pipes with flexible joints in accordance with the current Standard Specification and tests of the Water Reclamation (Network) Department, PUB. Comply with the clauses laid down in the current "Standard Specification for Sewerage Works" published by Water Reclamation (Network) Department, PUB. The Standard specification may be obtained from the Water Reclamation (Network) Department, PUB.

4.2

EXCAVATION AND REFILLING Carry out the excavation in accordance with Clauses 2.5 to 2.14 (inclusive) of the Specifications. Carefully excavate and install timbering in accordance with the Drawings in such a manner that the toes of the runners are always at least 150mm below the bottom of the excavation. Where necessary in order to keep the road open to vehicular and foot traffic, cart away excavated material from the trench as may be necessary so to keep the road open. Should any of the sewer trenches be excavated to a greater depth than is necessary for the proper execution of the Works, fill in the part over-excavated with Grade 15 concrete or other approved hard material.

4.3

TIMBERING OF EXCAVATION Brace all excavation adequately and securely with suitable timber using the methods indicated in the Drawings where necessary or otherwise approved by the SO Rep. Notwithstanding the approval given, the SO Rep shall, where necessary, instruct the Contractor to improve, alter or strengthen the timbering from time to time. The Contractor shall be responsible for any injury to the Works and any consequential damages caused and any permission given by the SO Rep shall not relieve the Contractor from this responsibility. In the particular case of timber to be left in trenches the class of timbering shall be approved by the SO Rep and this timber shall be cut off only after backfilling is completed, as indicated in the Drawings. Take every precaution against slips and falls or other disturbances to both the temporary and permanent work in the excavations. If however any slips, falls etc should occur, at once make good the same including all surface restoration all to the satisfaction of the SO Rep. If any slip or fall disturbs or weakens any foundation or support of the Works or to existing structures mains etc or cause a space to be left outside the new work itself or causes excessive surface cracks to appear in the ground surrounding the excavation, execute such additional works or take such additional precautions as the SO Rep may require in consequence thereof and fill up the space so caused with concrete if necessary, as the SO Rep may direct. The Contractor shall be fully responsible for the reinstatement or repair to the disturbances or damages caused.

4.4

PILING OF FOUNDATIONS Where bakau piles are indicated in the Drawings, they shall be of approved lengths and driven straight and in approved positions and to the full length of the piles or to the required set as determined by the SO Rep and any pile not correctly driven shall be duplicated. Where other types of piles are indicated in the Drawings, they shall be installed in the approved manner. Where horizontal bakau rollers are specified they shall be laid horizontally in the bottom of the excavations to correct gradients in approved positions.

CE12/S4.DOC(1) oym(151211) DPD

CE Spec Page 4-2 4.5

SEWER FOUNDATION Lay pipes and concrete in every instance on an even and solid foundation. The pipes shall be laid evenly on the barrel at the required level. Hollows, voids or foreign material under the pipe shall not be allowed. Complete the bedding to the correct profile as shown in the Drawings. Provide all sections of the sewer with either hard filling, concrete base with/without piling as specified. However, should the SO Rep decide to change the type of foundation after the close of the Tender, such change shall constitute a variation to the contract and shall be valued in accordance with the Contract provisions.

4.6

SEALING COAT Where indicated in the Drawings and immediately after a sufficient length of trench has been bakau piled and/or passed by the SO Rep, lay a seal coat of Grade 15 concrete, 75mm thick across the complete width of the trench, including filling with concrete to the temporary drainage channel. Finish the seal coat neatly such that the bakau pile heads, if any, are left projecting 25mm.

4.7

CONCRETE BED FOUNDATION The concrete bed formation for the sewer pipes shall consist of a concrete foundation using Grade 30 concrete as shown in the Drawings according to the different Type Sections.

4.8

GRANOLITHIC CONCRETE Granolithic concrete shall consist of one part of Portland Cement, two parts of fine aggregate and three parts of 10mm granite chippings free from dust. In all other respects it shall comply with the remainder of the Specifications for concrete.

4.9

PIPE LAYING Lay pipes for sewers true to line and grade as shown in the Drawings and all in accordance with Clause 2.70 "Pipe Laying".

4.10

CLEARING PIPELINES OF OBSTRUCTION After testing the pipelines as specified and at a time to be directed by the SO Rep, inspect the interior of the pipelines to ascertain that the pipes are entirely clear of obstruction and that the invert is smooth. The outside diameter of the ends of the plug shall not be smaller than the diameter of the pipe through which it is to be passed by 25mm and its length shall not be less than its diameter. The SO Rep may not instruct for this test until he is satisfied that the lengths concerned are complete and ready for operation. Remove any obstruction in the pipelines and make good any unevenness of the invert. If, as a result of the removal of any obstruction, the SO Rep considers that any damage may have been caused to the pipelines, the Contractor shall be required to re-test again the length of such pipelines. Should such re-test prove unsatisfactory, amend the work and carry out such further tests as required by the SO Rep.

CE12/S4.DOC(2) oym(151211) DPD

CE Spec Page 4-3 4.11

TESTING OF GRAVITY SEWERS (i)

(ii)

General (a)

All gravity sewers of 600 mm or less in diameter shall be tested by filling with water to an internal pressure of 1.5 metre head of water above the invert of the pipe at the highest end of the pipeline.

(b)

Testing shall be carried out for the whole length of the pipeline between manholes and before the pipeline is concreted and covered. The Contractor shall bear the cost and expense for the testing of gravity sewers to comply with the requirements of PUB.

Testing Procedure (a)

(iii)

Ensure that the following equipment is available : (i)

A plug of appropriate size to be fitted at the downstream end of the pipeline.

(ii)

A measuring cylinder to measure the actual loss of water.

(iii)

A 90 degree elbow bend and vertical pipe of equal diameter to be fitted at the highest end of the pipeline. For minor sewers, the elbow bend and the vertical pipe shall be of the same diameter of the sewer. For main sewers, the minimum diameter of the elbow bend and vertical pipe shall be 225mm although the same diameter as that of the pipeline is always preferable.

(b)

Ensure that the pipeline is properly anchored.

(c)

Fit the plug at the downstream end of the pipeline and the elbow bend with the vertical pipe at the highest end of the pipeline.

(d)

Fill the pipeline with water through the vertical pipe up to its brim making sure that there are no pocket of trapped air.

(e)

Ensure that the pipeline is completely filled with water by allowing the water to drain away at the downstream end and topping up with water again to the brim of the vertical pipe.

(f)

Allow the pipeline to stand for a minimum of 2 hours for absorption and topping up as necessary before carrying out the water test.

(g)

Test the pipeline at the required head of 1.5 metres head of water. Top up the vertical pipe using the measuring cylinder at intervals of 5 minutes and noting the quantity of water needed to maintain the test head over a period of 30 min.

(h)

On completion of the test, remove the plug at the end of the pipeline and observe the water level at the vertical pipe to ensure that the level drops freely and the water in the pipeline drains away.

Acceptance Criteria (a)

The pipeline shall not be accepted until they have withstood the required pressure head of 1.5 metres head of water for 30 minutes without loss of water in excess of 1.5 litres for 100m length of pipe for each 300mm in diameter.

(b)

Formula to calculate permissible loss of water for 30 minutes is as follows : Permissible Loss (ml) = Diameter of Pipe (mm) X Effective Length of Pipeline (m) X 1500ml 300 (mm) 100 (m)

Gravity sewer of 600 mm and above in diameter need not be hydraulically tested. They shall be inspected by Closed-Circuit Television (CCTV) inspection or for man-entry sewers, manual inspection shall be carried out. The Contractor shall make appropriate arrangements to install the CCTV and keep proper records of the sewer inspection. The Contractor shall bear the cost and expense for the CCTV and man-entry inspection in accordance with the requirements of PUB. Do not cover the pipes until they have been inspected and passed.

CE12/S4.DOC(3) oym(151211) DPD

CE Spec Page 4-4 4.12

BUILT-IN PIPES At all points where pipes are built into concrete walls or floors, take great care that the joint is watertight. If found to be otherwise, cut away and replace the concrete to make a watertight joint to the satisfaction of the SO Rep.

4.13

JUNCTIONS AND CONNECTIONS The junctions where provided shall be securely stoppered, such temporary stopper being secured with cement mortar.

4.14

CONCRETE AROUND PIPES After each length of pipes has been tested and passed, bed haunch and surround the pipes with concrete as shown in the Drawings. At approximately every four pipes or 6m whichever is the lesser interval, form a joint in concrete bed or surround by vertically shuttering the bed or surround with 25mm thick fibre board, timber or other approved material. Leave the shuttering material in to form a permanent joint. Where the concrete bed is required to be reinforced, stop all reinforcement on either side of the joint. The whole of the concrete shall be thoroughly set before any work of refilling is commenced.

4.15

TUMBLING BAYS AND BACKDROPS Where required, construct tumbling bays and backdrops in accordance with the details of the approved Drawings. Use special spigot and socket junctions in the junction between the two lines of pipes. For backdrops and tumbling bays above 300mm diameter the junction shall be cast iron to approved dimensions and shape. Lay the tumbling bays or backdrop pipes on a concrete foundation and completely encase in concrete surround as shown in the Drawings. Where indicated in the Drawings, build tumbling bay pipes into the walls of the manhole by cutting a neat hole sufficient for building in the pipes and finish flush with the inside of the manhole and neatly splay on the outside to form a watertight joint.

4.16

BRICK MANHOLES Where detailed, build brick manholes in positions shown and in accordance with details in the Drawings. Construct the brickwall in accordance with Clauses 2.58 "Bricks" and 2.59 "Brickwork Generally". Set the reinforced concrete slabs covering the chambers of the manhole and joint in cement mortar as specified to form watertight joints. Form channels and benching to the concrete floors of the manholes as detailed in Grade 30 concrete as specified and render in cement mortar 20mm thick. Build ends of pipes into the walls of the manholes and finish off in cement mortar. Set manhole covers and frames in cement mortar and covers left flush with the road surface or the finished ground level. Flush point internal and external joints of brick manholes in 1:3 cement mortar and finish off to a smooth surface.

CE12/S4.DOC(4) oym(151211) DPD

CE Spec Page 4-5 4.17

PRECAST CONCRETE MANHOLES Where indicated, precast reinforced concrete ring manholes shall be built in the positions shown in the Drawings. Submit details of the supply of this item to the SO Rep for approval. Set the rings forming the chambers of the manholes on a reinforced concrete foundation comprising a base of concrete and a built-up section, sufficient to completely build in the ends of the pipes. Construct the base, benching and pointing of all precast and in-situ concrete manholes in Ordinary Portland Cement, unless otherwise directed. Form the benching at the soffit level of the out-going sewer pipe rising by 75mm to the manhole walls. Form curves and junction benchings to a radius in the centre line of the channel not less than one and a half times the diameter of this pipe. Set the reinforced concrete slabs covering the chambers and the shafts of the manholes in 1:3 cement mortar to form watertight joints. Form channels and benching to the concrete floors of concrete manholes in Ordinary Portland Cement concrete. Set manhole covers and frames as specified in Clause 2.80 "Manhole Cover And Frame" in cement mortar and surrounded with concrete and covers left flush with the road surface or the finished ground level.

4.18

CLEANING OF SEWERS Thoroughly clean all sewers to the requirements of Water Reclamation (Network) Department, PUB before final inspection prior to acceptance. Throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract, when required by the SO Rep, provide without charge one number aluminium ladder, two numbers powerful lamp of at least six cells, two pairs of keys for lifting manhole covers and one number spirit level, two numbers mirrors all to the approval of the SO Rep.

4.19

INSPECTION AND APPROVAL OF SEWERS BY WATER RECLAMATION (NETWORK) DEPARTMENT, PUB Before their acceptance, thoroughly clean the sewers and made ready for inspections by the SO Rep and by the Water Reclamation (Network) Department, PUB's representative. No sewer or part of a sewer may be put into use until a final inspection has been carried out and the sewers and manholes found to be satisfactory. Provide and install all the necessary plugs to the manholes before the sewers are put into use and remove the plugs when the lines are to be in use all to the requirements and satisfaction of the SO Rep and Water Reclamation (Network) Department, PUB. The Works shall only be certified satisfactory when both the SO Rep and the Water Reclamation (Network) Department, PUB have approved all the sewers and manholes.

4.20

CONNECTION OF HOUSE DRAIN TO SEWER MANHOLE No final connections may be made from the house drain/s to a sewer manhole until the sewer has been passed as satisfactory, after a final inspection has been carried out.

4.21

CONNECTION OF SEWERS TO EXISTING MANHOLE All sewer connection to existing manholes shall be included in the Contract, unless otherwise indicated in the Drawings.

CE12/S4.DOC(5) oym(151211) DPD

CE Spec Page 4-6 4.22

PIPE JACKING (a)

(b)

CE12/S4.DOC(6) oym(151211) DPD

General (i)

Where specified in the Drawings, sections of the sewer shall be laid by pipe jacking.

(ii)

Submit details of Construction Equipment, materials and the method of construction to perform and complete the work for approval by the SO Rep before commencing these operations. Approval by the SO Rep shall not relieve the Contractor of his sole responsibility for the efficacy, reliability, soundness of the method employed in completing the work in a satisfactory manner.

(iii)

The general soil profile along the route of the sewer shall be given in the borelogs, for the Contractor's information only. The Employer accepts no responsibility for the accuracy, reliability or completeness of this information. The Contractor shall satisfy himself as to the soil conditions along the pipe jacking route and carry out additional soil investigations at his own cost and expense.

(iv)

In general, the soil is usually of an unstable nature and the ground water table is usually high. Maintain stable soil conditions at the jacking face to prevent loss of ground above the jacking operation and movement of the surrounding earth. The methods of maintaining face stability and preventing ground movement and subsidence shall be by means of compressed air or other plenum methods where fluid slurry or earth pressure is applied-to the tunnel face. Alternatively, stabilise unstable ground ahead of the jacking face by the injection of suitable chemicals. Methods which require dewatering of the ground and methods which may lead to significant ground loss shall not be accepted. Submit soil stabilization method to the SO Rep for approval.

(v)

Monitor movement or settlement of structures, utilities and pavement during the jacking operation and report to the SO Rep. If movement or settlement occurs which, in the opinion of the SO Rep may cause damage, take immediate action to prevent further movement, settlement or damage. Repair any damage and restore structures or pavements to the satisfaction of the SO Rep.

(vi)

Inspect the location and familiarise himself with the conditions under which the work shall be performed and with all necessary details as to the orderly execution of the work. The omission of any details shall not relieve the Contractor's full responsibility for the satisfactory installation of the work in its entirety. No monetary or other claims made by the Contractor on the grounds of want of knowledge shall be entertained by the Employer.

Materials (i)

The pipes for jacking operation shall be precast reinforced concrete pipes. The pipes shall be manufactured by a centrifugal or other equivalent process to be approved by the SO Rep. Design, manufacture and factory testing of the pipes and specials shall be to SS 183 or BS 5911 or AS 1342 or other acceptable standard. The clear cover of concrete over steel reinforcement shall not be less than 50mm.

(ii)

All pipes shall be manufactured with two sets of grout holes. Each set shall consist of three grout holes spaced at 120 degrees on centres circumferentially located at the quarter points from either end of the pipe.

(iii)

The precast reinforced concrete pipes shall be sufficiently reinforced with steel to withstand all stresses induced by handling, jacking, earth and water pressures and all working loads at the depths at which they are to be used without cracking, spalling or distortion. The pipes shall be of at least strength Class `H'. A load factor of not larger than 1.5 shall be used in the calculations to determine the strength of the pipes required. The strength of the pipes shall be tested by the three edge bearing test. When subjected to the design load in such a test, the maximum crack width developed on the pipe shall not exceed 0.25mm.

(iv)

Submit full details of his proposals for the pipes, giving detailed drawings showing sizes, reinforcement and type of joints, calculations, together with the name of the proposed manufacturer, the place of manufacture, and the manufacturing processes to the SO Rep for approval. All workmanship and materials used in the manufacture shall be subject to the approval of the SO Rep who shall from time to time be permitted to inspect materials at source and the manufacturing processes in the factory.

CE Spec Page 4-7 4.22

PIPE JACKING (CONT'D) (b)

(c)

CE12/S4.DOC(7) oym(151211) DPD

Materials (Cont'd) (v)

The pipes shall be sufficiently matured before they are used in the construction of the Works. Handle the pipes with extreme care to prevent the edges of the pipes from chipping. Repaired pipes shall not be allowed for use in the Contract. The SO Rep may reject any pipes he considers not suitable for the Works and these rejected pipes shall be removed from the Site immediately. After factory testing and before despatch, every pipe and special shall be marked in accordance with the Standard used. In addition, each pipe shall be marked with a number corresponding with the order of manufacture. Test certificates from the manufacturers or other relevant authority shall be submitted to the SO Rep.

(vi)

Where steel shield is utilised during the jacking operation, bolt this steel shield to or by other approved means jointed to the first piece of pipe which is being jacked.

(vii)

Use a jacking ring. The jacking ring may be either of steel or concrete construction and shall be used at all times when a pipe is being jacked. This jacking ring shall allow the jacking pressure to be distributed evenly around the wall of the pipe.

(viii)

Use a jacking frame during all operations. The jacking frame shall be designed to distribute the stresses from the jacks evenly to the jacking ring.

Jacking Operations (i)

The Contractor shall be fully responsible for the materials, Construction Equipment and facilities required in conjunction with jacking the reinforced concrete pipe.

(ii)

Before starting work, submit to the SO Rep for approval, a detailed schedule of the entire jacking operation. Approval of such schedule shall not relieve the Contractor of his responsibility to provide a fully satisfactory installation. Provide together with his submission, evidence that he has successfully completed a jacking installation using procedures similar to those proposed.

(iii)

Where the Contractor proposes to use compressed air, his proposal shall comply with the requirements of the specifications for "Working in Compressed Air" and "Work in Compressed Air".

(iv)

Where chemical stabilization of soil is used, pressure inject a chemical grout into the soil over and ahead of the pipe jacking to stabilise the soil. The chemical grout used shall have a demonstrated history of success for stabilizing soils similar to that through which the pipe is to be jacked.

(v)

Where a mechanical shield is used, provide proof that the particular model of shield has been used successfully in soils similar to that on the Site. The crew for the operation of the shield shall be specialists, with experience in the use of that particular type of machine.

(vi)

After the jacking operation has begun, work continuously (24 hours per day) until the complete length of jacked pipe is installed.

(vii)

Jack the pipes into place true to line and level. The maximum tolerance allowable in the displacement of the centreline of the laid pipe from the designed centreline is 50mm in the horizontal plane and 25mm in the vertical plane but there shall be no backfall at any point. Any pipe which is not laid in its correct position shall be removed and relaid or adjusted to obtain its correct position.

(viii)

There shall be provision to prevent the relative movement between pipes at the joints by the use of steel gaiters or other approved methods during jacking operation. Provide a packing piece of compressible material at each joint to be securely held before the pipes are lowered into the thrust pit. Submit details of proposals to the SO Rep for approval.

(ix)

Furnish and install and remove to the extent required, thrust blocks or whatever provisions that may be required for backing up the jacks employed in driving the pipe forward. Equip the jacking pit with steel rails or beams embedded in concrete. Use these rails or beams for placement and alignment of each pipe during the jacking operation.

CE Spec Page 4-8 4.22

PIPE JACKING (CONT'D) (c)

(d)

4.23

Jacking Operations (Cont’d) (x)

The Contractor shall be responsible for the design and construction of the jacking and receiving pits, thrusting wall, installation of jacking equipment, sheeting, bracing, etc, and for the efficient execution of the jacking operation. Submit full details of the proposals, including Construction Equipment, shield machine, equipment, operating procedures, jacking pit and intermediate jacking stations etc, for approval by the SO Rep before construction. However, approval by the SO Rep and review of the plans shall not relieve the Contractor from his responsibility to provide a safe and satisfactory jacking pit.

(xi)

Monitor closely the progress of the jacking operation. Daily site records of thrusting pressures and the line and level measurements shall be properly maintained and shall be made available to the SO Rep at all times.

(xii)

Ensure that the completed tunnels are watertight. If leakage occurs before Substantial Completion or during the Defects Liability Period, carry out any remedial work that may be necessary to make the Works watertight.

Cement Grouting (i)

Prevent the occurrence of voids outside the pipe and if they occur, fill them with cement grout.

(ii)

Immediately following the jacking operation, pressure grout the jacked section to fill all voids existing outside of the pipe. Grouting shall be from the interior of the pipe through grouting holes as specified.

(iii)

Provide systems of standard pipe, fittings, hose, and special grouting outlets embedded in the pipe walls. Ensure that all parts of the system are maintained free from dirt. Carefully force grout composed of cement, sand and other approved compound and water under pressure into the grouting connections at the invert and proceed until grout begins to flow from upper connections. Make connections to these holes and continue the operation to completion.

(iv)

Apparatus for mixing and placing grout shall be of a type approved by the SO Rep and shall be capable of mixing effectively and stirring the grout and then forcing it into the grout connections in a continuous uninterrupted flow.

(v)

After grouting is completed, maintain pressure by means of stop cocks, or other suitable devices until the grout has set sufficiently. After the grout is set, completely fill grout holes with dense concrete and finish neatly without evidence of voids or projections.

(vi)

For pipes with PVC or HDPE linings, carry out grouting and ensure that the pipeline is watertight before proceeding with the jointing of the linings of the pipes and the patching of the lining over the filled grout holes

JOINTING COLLARS FOR JACKED-IN-PLACE REINFORCED CONCRETE SEWER PIPES Where steel collars are used for pipe joints, it shall be made of austenitic stainless steel of Type 316 with minimum chrome content of 17% and minimum nickel content of 8%. The jointing collar shall be of the dimensions and thickness in accordance with the Water Reclamation (Network) Department, PUB's requirements.

SECTION 5/..... CE12/S4.DOC(8) oym(151211) DPD

CE Spec Page 5-1 SECTION 5

CONSTRUCTION AND WORKMANSHIP FOR EARTHWORKS

5.1

DEFINITION AND CLASSIFICATION OF EARTHWORKS MATERIALS The following definitions of earthworks materials shall apply to this Section including all clauses and subclauses under it : (a)

'Top Soil' shall mean the top layer of soil that can support vegetation.

(b)

'Approved Material' shall comprise those that are acceptable in accordance with the Contract for use in the Works and those which are capable of being compacted in the manner specified in Clause 5.9 "Compaction" to form a stable fill.

(c)

'Unsuitable Material' shall mean those other than the Approved Material and shall include : (i)

material from swamps;

(ii)

peat, logs, stumps and perishable material;

(iii)

material susceptible to spontaneous combustion;

(iv)

soil of liquid limit exceeding 70 and/or plasticity index exceeding 35;

(v)

material having an in-situ moisture content greater than the maximum permitted for such materials in the Contract, unless otherwise permitted by the SO Rep.

(d)

'Rock' shall mean hard material whose geological nature is to be regarded as such and individual boulders exceeding 0.20 cu m in size or other masses of hard material which necessitate the use of blasting or approved pneumatic tools for their removal.

(e)

'Special Filling Material' shall mean "Approved Material" as defined in the foregoing definition but shall all pass a 75 mm BS sieve. The fraction passing a 75m BS sieve shall have the following characteristics : (i)

Liquid limit not exceeding 35;

(ii)

Plasticity index not exceeding 12;

(iii)

Coefficient of uniformity shall be greater than 10;

(iv)

The percentage passing 75m BS sieve shall be less than 20% by weight.

(f)

'Cohesive Soil' shall include clays with up to 20% of gravel and having a moisture content not less than the value of the plastic limit minus 4.

(g)

'Well-Graded Granular And Dry Cohesive Soils' shall include clays containing more than 20% of gravel and/or having a moisture content less than the value of plastic limit minus 4, well-graded sands and gravels with a uniformity coefficient exceeding 10.

(h)

'Uniformly-Graded Material' shall include sands and gravels with a uniformity coefficient of 10 or less, and all silts. Any soil containing 80% or more of material in the particle size range from 60m to 2m shall be regarded as silt for this purpose.

CE12/S5.DOC(1) oym(151211) DPD

CE Spec Page 5-2 5.2

EARTHWORKS GENERALLY Carry out all earthworks in such a manner as to prevent erosion or slips, limit working faces to safe slopes and height, and ensure that all surfaces have at all times sufficient gradients to enable them to shed water without causing erosion. At the end of each day, all surfaces shall be left with no area that can retain water. If necessary, provide and maintain temporary and approved surface or subsurface drainage system to ensure minimum delay in work progress due to wet weather. Alternatively, adequate means, such as covering all surfaces with polythene paper, shall be provided and maintained. Provide and maintain all necessary temporary access roads and divert and reinstate permanent drainage system. Submit the proposed alignments and levels of temporary access roads to the SO Rep for approval prior to their construction. Provide all temporary roads with drainage ditches over full length. The Contractor is required to take out a Temporary Occupation Licence (TOL) and pay TOL fees for the use of State Land for erection of site offices and other temporary facilities within the Site contract boundary of earthworks.

5.3

CUTTINGS INCLUDING SLOPES Unless otherwise specified or shown in the Drawings, neatly round the top edges of all cuttings to the dimensions shown in the Drawings or as directed by the SO Rep. Unless otherwise specified or shown in the Drawings, slopes to cuttings shall conform with the following : Table 5.1 Material

Allowable Slopes In Cutting Slope (Horizontal Distance To Vertical Rise)

Sand

Two to One to Five to One

2 : 1 to 5 : 1

Loose gravel or clay

Two to One

2:1

Loam, shale or similar soft Rock

One to One

1:1

Rock with clay seams

Three-quarter to One

¾:1

Jointed Laminated or soft Rock

One-half to One

½:1

Massive Rock

One-quarter to One

¼:1

Where the location of unsuitable soil is shown in the Drawings or specified to be removed, the Contractor shall remove such unsuitable soil. Where the SO Rep re-determines the slopes, the Contractor shall not be entitled to any claim whatsoever or to adjustment to the Contract Sum except where such redetermination of slopes by the SO Rep results in a difference in work quantities, either addition or omission, which shall constitute a variation to the Contract. In all cuttings, whether in earth or Rock, undulations in the general plane of the slope shall not be permitted. The SO Rep may direct that any overhanging, loose or unstable material, whether outside or behind the specified slope, be removed. Any additional cost so involved shall be paid as a variation to the Contract. Arrange the excavation such that the working areas are adequately drained throughout the Time for Completion and any time period where liquidated damages are imposed under the Contract.

CE12/S5.DOC(2) oym(151211) DPD

CE Spec Page 5-3 5.4

FOUNDATION FOR FILLS Embankment construction shall include the preparation and compaction to the degree as specified under Clause 5.9 "Compaction" of the areas upon which embankments are to be placed, the placing and compacting of Approved Material within areas from which Unsuitable Material has been removed as specified hereunder, and the placing and compacting of embankment material in holes, pits, and other depressions within the foundation area. Unless otherwise specified, clear the natural ground over which filling is to be placed of all loose boulders, grass, topsoil, bushes, trees, roots and other vegetation. If the SO Rep considers that any underlying material is unstable or unsuitable, he may direct it to be removed and replaced with Approved Material, the cost of which shall be valued in accordance with the Contract provisions and be borne by the Employer. Remove any overhanging Rock ledges or caves within the foundation area before the placing of fill commences. Where ground water or extensive seepage are encountered in the foundation area, and no special drainage arrangements are shown in the Drawings, the SO Rep may direct that suitable pipe drains be installed in the fill area, or that deep open drains be excavated clear of the fill. All these drainage Works shall form part of the Contract and the Contractor shall not be entitled to any extra claim. The construction of any section of a fill shall not commence until the foundation for that section has been approved by the SO Rep.

5.5

FILLING GENERALLY Carry out filling in layers compatible with the compaction plants used. End tipping of fill shall be allowed provided the end tipped material is compacted to the requirements as specified in Clause 5.9 "Compaction". When the state of the weather is such that, in the opinion of the SO Rep, it would adversely affect the placing of specially compacted fill, all such work shall be stopped. Remove and replace all filling material, whether placed and/or compacted or awaiting placing and/or compaction which, in the opinion of the SO Rep does not comply with the Specifications or has been damaged by weather or in any other way.

5.6

HILLSIDE FILLS Where an embankment is to be constructed on a hillside, or where the natural surface falls away at the toe of the fill at a slope steeper than one vertical to four horizontal, cut a horizontal bench to support the toe. The minimum width of the bench shall be equal to one third of the vertical height of the fill (measured from the toe) provided that the width shall not be more than 3.70m nor less than 600mm. Material excavated in benching may be used in fills, if it has satisfied the requirement of Approved Material as afore defined. Where embankments are to be constructed on hillsides or on the slopes of existing embankments, or where embankments are to be constructed in part-widths, cut the existing slope, if it exceeds one vertical to four horizontal, in the form of horizontal terrace over the full area to be covered by new fill. As each layer of new embankment is constructed, step the existing slope in successive terraces, each at least 600mm in width and progressively cut the terraces as the embankment is placed. Recompact materials thus excavated as part of the new embankment material. No adjustment shall be made to the Contract Sum for material removed in the construction of benches and terraces, which shall be regarded as part of the earthworks in the Contract. If, in preparing hillsides, the Contractor removes material outside the limits specified in this Clause in order to facilitate his operations, no adjustment to the Contract Sum shall be made for the removal of this extra material, and the Contractor shall be required to make good at his own cost and expense any scars created by him.

CE12/S5.DOC(3) oym(151211) DPD

CE Spec Page 5-4 5.7

PLACING FILLS IN EMBANKMENTS Construct embankments in even horizontal layers over the full width, laid in thickness appropriate to the compaction plant used and compacted to satisfy the requirement specified in Clause 5.9 "Compaction". At all times maintain the embankments with a sufficient camber and a surface sufficiently even to enable surface water to drain readily from them. If the material deposited as fill subsequently reaches a condition such that it cannot be compacted in accordance with the requirements of the Contract, the Contractor shall be required either : (a)

make good by removing the material off the embankment either to tip or elsewhere until it is in a suitable physical condition for re-use, and replacing it with suitable materials; or

(b)

make good the material by mechanical or chemical means to improve its stability; or

(c)

cease work on the material until its physical condition is again such that it can be compacted as specified in the Contract.

Rock material shall be broken down to dimensions not exceeding the compacted thickness of the layer in which it is placed. Rock material shall be well distributed in layers extending the full width of the fill, and sufficient fine material shall be placed around the larger material as it is deposited to fill the voids and produce a dense compact fill. Where insufficient fine material is present to fill the voids, additional fine material shall be obtained from the Contractor's own sources. Unless otherwise specified or shown in the Drawings, the top edges of embankments shall be neatly rounded to the dimensions shown in the Drawings or as directed by the SO Rep. Such work shall be deemed to have been included as part of the earthworks in the Contract.

5.8

FILL SLOPES The slope faces of embankments or other fill areas shall be formed by overfilling, cutting back and trimming neatly to the desired profile. Unless otherwise specified or shown in the Drawings, the slopes shall conform to the following : Table 5.2 Material

Allowable Slopes In Cutting Slope (Horizontal Distance To Vertical Rise)

Sand loam, soft clay and loose sand

Between Two to One and Five to One

2 : 1 and 5:1

Ordinary earth

Two to One

2:1

Rock

One and One-quarter to One

1¼ : 1

Rock filling - hand pitched

One to One

1:1

Where the SO Rep re-determines a slope, the Contractor shall not be entitled to claim whatsoever or to adjustment to the Contract Sum except where such re-determination of slopes by the SO Rep results in a difference in work quantities, either addition or omission, which shall constitute a variation to the Contract. When completed, the average planes of the slopes of embankments shall conform to those determined by the SO Rep or as specified in the Drawings.

CE12/S5.DOC(4) oym(151211) DPD

CE Spec Page 5-5 5.9

COMPACTION All materials shall be compacted in layers as soon as practicable after deposition. The thickness of each layer shall be compatible with the compaction plant used and shall be agreed by the SO Rep. Table 5.3 may be used as a guide for the Contractor in establishing compaction arrangement. However site trials shall be carried out to ensure that the density requirement is achieved. The Contractor shall allow in the Contract Sum for all costs and expenses incurred in executing compaction by whichever method he has adopted and any subsequent alteration as directed. The various types of compaction plants, and their compacting capabilities, are shown in Table 5.3. The definitions and requirements associated with the Table are given below : (a)

"Number of passes" shall mean the number of times that each point on the surface of the layer being compacted has been traversed by the compaction plant (or struck in the case of power rammers or dropping weight compactors). The effective width of a pneumatic-tyred roller, for this purpose, is the sum of the widths of the individual wheel tracks together with the sum of the spacing between the wheel tracks provided that each spacing does not exceed 225mm. When the spacing exceeds 225mm the effective width shall be taken as the sum of the width of the individual wheel tracks only.

(b)

The force per 100mm width shall mean the total weight on the roll divided by the total roll width. Where a smooth-wheeled roller has more than one axle the machine shall be assessed on the basis of the axle giving the highest value of force per 100mm width.

(c)

Wheel load shall mean the total weight of the roller divided by number of wheels.

(d)

Vibratory rollers shall mean self propelled or towed rollers having means of applying mechanical vibration to one or more rolls.

(e)

(i)

The requirements for vibratory rollers shall be based on the use of the lowest gear on a self propelled machine and a towing speed of 1800 to 2400m/hour for a towed machine. If higher gears or speeds are used an increased number of passes shall be provided in proportion to the increase in speed of travel.

(ii)

Vibratory rollers operating without their vibration mechanism in use shall be classified as smooth-wheeled rollers.

(iii)

Vibratory rollers shall only be operated with their vibration mechanism operating at the frequency of vibration recommended by the manufacturers. All such rollers shall be equipped with a device automatically indicating the frequency at which the mechanism is operating.

Vibrating-plate compactors or machines having a base-plate to which is attached a source of vibration consisting of one or two eccentrically-weighted shafts. (i)

The static pressure under the plate of a vibrating-plate compactor shall be calculated by dividing the total weight of the machine in working order by the area in contact with compacted material.

(ii)

Vibrating-plate compactors shall be operated at the frequency of vibration recommended by the manufacturer. They shall normally be operated at travelling speeds of less than 900m per hour but, if higher speeds are necessary, the number of passes shall be increased in proportion to the increase in speed of travel.

(f)

Vibro-tampers shall mean machines in which an engine-driven reciprocating mechanism acts on a Spring system, through which oscillations are set up in a base-plate.

(g)

Power rammers shall mean machines which are actuated by explosions in an internal combustion cylinder, each explosion being controlled manually by the operator.

CE12/S5.DOC(5) oym(151211) DPD

CE Spec Page 5-6 5.9

COMPACTION (CONT'D) The depth of compacted layer shall mean the height by which an embankment is raised by each successive compacted layer. Where combinations of different types of categories of compaction plant are used, the compaction requirements shall be as follows : (a)

the depth of layer shall be that for the type of compaction plant requiring the least depth of layer; and

(b)

the number of passes shall be that for the type of compaction plant requiring the greatest number of passes.

However, where the Contractor uses a lighter type of compaction plant to provide some preliminary compaction only to assist the use of heavier compaction plant, this shall be disregarded in assessing the above requirements.

CE12/S5.DOC(6) oym(151211) DPD

CE Spec Page 5-7 Table 5.3 Compaction Requirements Cohesive Soil Type Of Compaction Plant

Category

Smoothwheeled roller

Force per 100mm width in kN

Grid-roller

Force per 100mm width in kN

2.1 to 2.6 2.61 to 5.2 More than 5.2

2.6 to 5.2 5.3 to 7.8 More than 7.8 Pneumatic tyred roller

125 125 150

8 6 4

125 125 150

10 8 8

125 10* 125 8* Unsuitable

150 150 150

10 8 4

Unsuitable 125 12 150 12

150 10 Unsuitable Unsuitable

125 150 175 225 300 350 400 450

6 5 4 4 4 4 4 4

Unsuitable Unsuitable 125 12 125 10 125 10 150 8 150 8 175 6

150 10* Unsuitable Unsuitable Unsuitable Unsuitable Unsuitable Unsuitable Unsuitable

Force per 100mm width in kN 0.25 to 0.45 0.46 to 0.70 0.71 to 1.25 1.26 to 1.75 1.76 to 2.3 2.31 to 2.8 2.81 to 3.5 3.51 to 4.2 4.21 to 4.9

Vibratory plate compactor

Min no of passes

Uniformly-Graded Materials Max depth Min no. of of compacted passes layer (mm)

Wheel Load in tonnes : 1 to 1.5 1.5 to 2 2 to 2.5 2.5 to 4 4 to 6 6 to 8 8 to 12 More than 12

Vibratory roller

Max depth of compacted layer (mm)

Well-Graded Granular And Dry Cohesive Soils Max depth of Min no of compacted passes layer (mm)

Unsuitable Unsuitable 100 12 125 8 150 4 175 4 200 4 225 4 250 4

75 75 125 150 150 175 200 225 250

16 12 12 8 4 4 4 4 4

150 150 150 200 225 250 275 300 300

16 12 6 10* 12* 10* 8* 8* 8*

Unsuitable Unsuitable Unsuitable 100 150 200

6 6 6

Unsuitable 75 10 75 6 125 6 150 5 200 5

75 100 150 150 200 250

6 6 6 4 4 4

100 125 200

3 3 3

100 125 150

3 3 3

150 200 225

3 3 3

150 275

4 8

150 275

6 12

Static pressure under base plate 2 in kN per mm 8.6 to 10.3 10.3 to 12.1 12.1 to 13.8 13.8 to 17.2 17.2 to 20.7 More than 20.7

Vibrotamper

Mass Kilogramme

Power rammer

Mass Kilogramme

50 to 65 65 to 75 More than 75

100 More than 500

Unsuitable Unsuitable

For items marked with * the rollers shall be towed by track laying tractors. Self propelled rollers are unsuitable.

SECTION 6/..... CE12/S5.DOC(7) oym(151211) DPD

CE Spec Page 6-1

SECTION 6 LIST OF APPENDICES

Appendix

A1

Instruction On Work Injury Compensation Policy

A2

Statement Of Characteristics For Carriageway Marking Paints

A3

Electrical Testing & Completion Certificate

CE12/S6.DOC(1) oym(151211) DPD

CE Spec Page 6-2 APPENDIX A1

INSTRUCTION ON WORK INJURY COMPENSATION POLICY

1.

The Policy shall be issued in the prescribed form produced in Appendix A1 (please do not re-type).

2.

The Policy shall include the following requirements : (a)

The Insured shall be "(Name of Contractor to insert) as Contractor and all his sub-contractors, and the Housing & Development Board as Principal FTRR & I".

(b)

The period of insurance shall commence from the date the site is handed over to the Contractor and shall end upon expiry of the Defects Liability Period under the Contract.

CE12/S6.DOC(2) oym(151211) DPD

CE Spec Page 6-3 APPENDIX A1

Policy No. : Insurer's Company Stamp :

WORK INJURY COMPENSATION POLICY

CE12/S6.DOC(3) oym(151211) DPD

CE Spec Page 6-4 APPENDIX A1 Policy No. : Insurer's Company Stamp :

WORK INJURY COMPENSATION POLICY WHEREAS the Insured carrying on the Business described in the SCHEDULE and no other for the purpose of this insurance by an application which shall be the basis of this contract and is deemed to be incorporated herein has applied to the Insurer for the insurance hereinafter contained and has paid or agreed to pay the Premium stated in the SCHEDULE as consideration for such insurance. NOW THIS POLICY WITNESSETH that if any employee in the Insured's employment shall sustain personal injury by accident or disease caused during the Period of Insurance and arising out of and in the course of his employment by the Insured in the Business, the Insurer will subject to the terms exceptions conditions and warranties, and any memorandum if applicable, contained herein or endorsed hereon (all of which are hereinafter collectively referred to as the Terms of this Policy) indemnify the Insured against all sums for which the Insured shall be liable to pay compensation either under the Legislation or at Common Law, and will in addition pay all costs and expenses incurred by the Insured with the written consent of the Insurer. In the event of the death of the Insured the Insurer will indemnify the Insured's legal personal representatives in accordance with the Terms of this Policy in respect of liability incurred by the Insured provided that such personal representatives shall as though they were the Insured observe comply fulfil and be subject to the Terms of this Policy in so far as they can apply. PROVIDED ALWAYS that in the event of any change in the Legislation or the substitution by other Legislation therefor this policy shall remain in force and the Insurer reserves the right to charge additional premium therefor.

JURISDICTION 1.

This Policy shall be governed by the laws of the Republic of Singapore.

2.

The indemnity under this Policy shall not apply in respect of judgements which are not in the first instance delivered by or obtained from a court of tribunal of competent jurisdiction within the Republic of Singapore.

AVOIDANCE OF CERTAIN TERMS AND RIGHT OF RECOVERY Nothing in this Policy or any endorsement hereon shall affect : (a)

the right of any person entitled to indemnity under this Policy; or

(b)

the right of any other person to recover compensation,

under or by virtue of the Legislation. BUT the Insured shall repay to the Insurer all sums paid by the Insurer which the Insurer would not have been liable to pay but for the Legislation.

CE12/S6.DOC(4) oym(151211) DPD

CE Spec Page 6-5 APPENDIX A1 Policy No. : Insurer's Company Stamp :

EXCEPTIONS The Insurer shall not be liable in respect of :

(a)

any employee of the Insured who is not a "employee" within the meaning of the Legislation unless such employee of the Insured is covered under this Policy by virtue of Clauses 11 and 12 of the Conditions;

(b)

any injury by accident or disease attributable to war hostilities (whether war be declared or not) invasion act of foreign enemies rebellion revolution insurrection or military or usurped power or civil war;

(c)

any liability of whatsoever nature directly or indirectly caused by or contributed to by or arising from : (i)

ionising radiations or contamination by radioactivity from any nuclear fuel or from any nuclear waste from the combustion of nuclear fuel radio-active toxic explosive or other hazardous properties of any explosive nuclear assembly or nuclear component

(ii)

pressure waves caused by aircraft or other aerial devices travelling at sonic or supersonic speeds

(d)

any injury to any employee of the Insured resulting from an accident if it is proved that the injury to the employee is directly attributable to the employee having been at the time thereof under the influence of alcohol or a drug not prescribed by a medical practitioner unless the Insured is liable under the Legislation;

(e)

any incapacity or death resulting from a deliberate self-injury or the deliberate aggravation of an accidental injury.

CONDITIONS 1.

This Policy and the SCHEDULE shall be read together as one contract and any word or expression to which a specific meaning has been attached in any part of this Policy or the SCHEDULE shall bear such specific meaning wherever it may appear.

2.

In so far as it is not prohibited by the Legislation the Insured shall at all times observe, comply and fulfil the Terms of this Policy.

3.

The truth of the statements and answers in the application shall be conditions precedent to any liability of the Insurer to make any payment under this Policy and shall be the basis of this contract.

4.

Every notice or communication to be given or made under this Policy shall be delivered in writing to the Insurer.

5.

The Insured shall take all reasonable precautions to prevent accidents and disease to the Insured's employee and shall comply with all statutory obligations and requirements.

CE12/S6.DOC(5) oym(151211) DPD

CE Spec Page 6-6 APPENDIX A1 Policy No. : Insurer's Company Stamp : 6.

(a)

In the event of the occurrence of any accident/occupational disease that may give rise to a claim under this Policy, the Insured shall give notice of the occurrence in accordance with the time limits set out by Legislation to the Insurer with full particulars. If the notice period is not stipulated by legislation for a particular occurrence then notice of the occurrence shall be given to the Insurer within 10 days of the Insured having knowledge of the same.

(b)

Every letter claim writ summons and process shall be notified or forwarded to the Insurer immediately on receipt. Notice shall also be given to the Insurer immediately the Insured shall have knowledge of any impending prosecution inquest or fatal inquiry in connection with any such accident or disease.

7.

No admission offer promise or payment shall be made by or on behalf of the Insured without the written consent of the Insurer. The Insurer shall be entitled if it so desires to take over and conduct in the Insured's name the defence or settlement of any claim or to prosecute in the Insured's name for its own benefit any claim for indemnity or damages or otherwise and shall have full discretion in the conduct of any proceedings and in the settlement of any claim and the Insured shall give such information and assistance as the Insurer may require.

8.

The Insurer may cancel this Policy by giving thirty (30) days' notice by registered letter to the Insured at his last known address and in such event the Insurer will return to the Insured the premium paid less the actual premium payable for the period during which the Policy had been in force subject to a minimum premium # payment of $ by the Insured. This Policy may be cancelled at any time by the Insured by giving seven (7) days' written notice to the Insurer and provided no claim has arisen during the period which the Policy had been in force the Insured # shall be entitled to a return of premium subject to a minimum premium payment of $ by the Insured and subject to any adjustment of premium required by the terms or conditions of this Policy. The Insurer shall notify the Principal Housing & Development Board before the cancellation of this Policy.

9.

This Policy shall cover all *

's insurance

obligations with regard to Work Injury Compensation stated in the Contract between the Principal Housing & Development

Board

and

*

. 10.

(i)

In the event of any employee employed by the within Insured or by the Insured's Contractors as referred to in (ii) hereon or any dependant of such employee, bringing or making a claim under any Work Injury Compensation Act for the time being in force in Singapore or at Common Law against the Principal Housing & Development Board for personal injury or disease sustained whilst at work on any Contract covered by this Policy which the Insured may be carrying out for the Principal Housing & Development Board the Insurer will indemnify the said Principal Housing & Development Board against such claim and any costs charges and expenses in respect thereof. Provided always that the Insurer shall be entitled to have the sole conduct and control of all proceedings connected with claims covered by this. Nothing herein shall be construed as affecting the Insured's right to recover damages in any other way under the said Legislation.

(ii)

The indemnity herein granted is intended to cover the legal liability of the Insured to employees in the employment of contractors performing work for the Insured while engaged in the business and occupation in respect of which the Policy is granted but only so far as regards claims under any Work Injury Compensation Act for the time being in force in Singapore or at Common Law.

*Name of Contractor to be inserted # To be filled in by Insurer

CE12/S6.DOC(6) oym(151211) DPD

CE Spec Page 6-7 APPENDIX A1 Policy No. : Insurer's Company Stamp : 11.

In consideration of premium being paid in respect of employees of the Insured in an Occupation described in the Schedule it is hereby agreed that the Insurer will not in the event of any accident or disease arising out of and in the course of their employment by the Insured in the Business raise the defence that such employee is not a person employed by way of manual labour within the meaning of the Legislation.

12.

In consideration of premium being paid in respect of employees of the Insured in an Occupation described in the Schedule it is hereby agreed that the Policy is extended to indemnify the Insured in respect of the Insured's liability at common law for any accident or disease arising out of and in the course of their employment by the Insured in the Business.

13.

All disputes or differences under this Policy shall be referred to Arbitration in accordance with the Arbitration Act (Chapter 10) or any statutory re-enactment thereof. The making of an Award by an Arbitrator or Arbitrators as hereinbefore specified shall be a condition precedent to any right of action against the Insurer.

14.

At any time after the happening of any accident or disease giving rise to a claim or series of claims under this Policy the Insurer may pay to the Insured the full amount of the Insurer's liability and relinquish the conduct of any claim defence or proceedings and the Insurer shall not be responsible for any damage loss or liability alleged to have been caused to the Insured in consequence of any alleged act or omission of the Insurer in connection with such claim defence or proceedings or of the Insurer relinquishing such conduct nor shall the Insurer be liable for any costs or expenses whatsoever incurred by the Insured or any claimant or other person after the Insurer shall have relinquished such conduct. INTERPRETATION

1.

ALL references to "Legislation" in this Policy shall mean the Work Injury Compensation Act (Cap 354), amendments and re-enactments thereof and any regulations made thereunder.

2.

Words used in the Policy shall have the same meanings as that defined in the Legislation. WARRANTY

The Insured warrants that in the event of any failure by him to comply with any of the Terms of this Policy, he shall repay to the Insurer all sums paid by the Insurer which the Insurer would not have been liable to pay but for the Legislation. PREMIUM WARRANTY CLAUSE 1.

Notwithstanding anything herein contained but subject to clause 2 hereof, it is hereby agreed and declared that if the period of insurance is 60 days or more, any premium due must be paid and actually received in full by the Insurer (or the intermediary through whom this Policy was effected) within 60 days of the inception date of the respective coverage under the Policy, Renewal Certificate or Cover Note or effective date of each Endorsement, if any, issued under the Policy, Renewal Certificate or Cover Note.

2.

In the event that any premium due is not paid and actually received in full by the Insurer (or the intermediary through whom this Policy was effected) within the 60-day period referred to above, then:(a) (b) (c)

3.

the respective cover under the Policy, Renewal Certificate, Cover Note or Endorsement is automatically terminated immediately after the expiry of the said 60-day period; the automatic termination of the respective cover shall be without prejudice to any liability incurred within the said 60-day period; and the Insurer shall be entitled to a pro-rata time on risk premium for the respective coverage subject to a minimum of $25.00.

If the Period of Insurance is less than 60 days, any premium due must be paid and actually received in full by the Insurer (or the intermediary through whom this Policy was effected) within the Period of Insurance.

CE12/S6.DOC(7) oym(151211) DPD

CE Spec Page 6-8

APPENDIX A2

STATEMENT OF CHARACTERISTICS FOR CARRIAGEWAY MARKING PAINTS

To :

Director HDB HDB Hub 480 Lorong 6 Toa Payoh Singapore 310480

CONFIDENTIAL

Dear Sir

The following are the characteristics of the designated sample of carriageway marking paint submitted by :

M/s _________________________________________ to M/s __________________________________________ (Paint Manufacturer) (Name of Contractor) of ______________________________________________________________ to be used under this contract. (Address)

1.

Manufacturer's Code No. :

2.

Colour : White / Yellow

3.

Type : Chlorinated Rubber Based or _________________________________________________ (specify)

4.

Weight per litre ____________ kg per litre for both colours

5.

Drying time : (a) (b)

________________

No pick up

____________ minutes for both colours

Hard Dry

____________ minutes for both colours

6.

Viscosity (as ready for spraying application) _____________ kerbs for both colours

7.

Percentage of pigment in paint ____________ for both colours

8.

Pigment volume concentration ____________ for both colours

9.

Percentage of vehicle in paint ____________ for both colours

10.

Percentage of non-volatile in vehicle _____________________________

11.

State chemical nature of non-volatile vehicle : ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________

12.

Recommended rate of application of paint on a road line 100mm wide __________ linear kilometres per litre of paint

CE12/S6.DOC(8) oym(151211) DPD

CE Spec Page 6-9 APPENDIX A2

White Paint 13.

(a)

Nature of pigment

(b)

Weight of above pigment per litre of finished paint

(c)

Recommended solvent for

Yellow Paint

(i)

Thinning : __________% of

____________________________________

(ii)

Cleaning

______________________________________

I, _____________________________________, ___________________________________________ (Name of Officer) (Designation in Company)

of ________________________________________________________________________________________ (Manufacturing Firm)

certify the above to be true. This statement of paint characteristics is submitted for

___________________________________________________________________________________________ (Name of Contractor)

_____________________________ (Seal of Company)

CE12/S6.DOC(9) oym(151211) DPD

________________________ (Signature)

________________ (Date)

CE Spec Page 6-10 APPENDIX A3

ELECTRICAL TESTING & COMPLETION CERTIFICATE

To:

The Superintending Officer's Representative Housing & Development Board

Illuminated Signboards For _______________________________________________________________________ _____________________________________________________________________________________________ in the Name of :

______________________________________________________

I _____________________________________, a licensed electrical worker and authorised small installation tester hereby certify that the abovementioned has been inspected and tested by me in accordance with the Singapore Standard CP 5 1988: Code of Practice for Wiring of Electrical Equipment of Buildings, and that to the best of my knowledge and belief the abovementioned complies with the Singapore Standard CP 5 1988 and other relevant Regulations. The said has been tested on ___________________________. Description

Brand/Model/Supplier

Quantity

Lamp (18 W) Lamp (36 W) Ballasts Polarity Check Satisfactory

:

Yes/No

Approved Method of Installation

:

Yes/No

All Lamp Circuit Functional

:

Yes/No

___________________________________________ Signature of Electrical Worker

__________________________________ Date

Name of Electrical Worker : ____________________________

PowerGrid License No : _______________________

Rubber Stamp of Licensed Electrical Contractor : __________________________

PowerGrid License No : 3/_____________________

End/...

CE12/S6.DOC(10) oym(151211) DPD