4.Concrete Work

OMRON HEALTHCARE VIETNAM FACTORY PROJECT

CONSTRUCTION METHOD AND QUALITY CONTROL PLANNING For CONCRETE WORK

OBAYASHI VIETNAM CORPORATION BINH DUONG – VSIP II SITE OFFICE

2007

Project Manager

Site Manager

Building Engineer

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CONTENTS

1- GENERAL 1.1 Scope 1.2 Alteration 2- OUTLINE OF PROJECT 2.1 General parameters 2.2 Concrete parameters 3- CONCRETE MIXES 3.1 Type of concrete 3.2 Production of concrete 3.3 Transportation of concrete 4- REQUIREMENTS OF EXECUTION 4.1 Preparation of concreting 4.2 Construction joint 4.3 Concrete casting 4.4 Concrete curing 4.5 Concrete defect treatment 5- CONTROL AND SAFETY 5.1 Quality control 5.2 Safety 6- INSPECTION FORMS, PLANNING AND RECORDING FORMS 7- CONCRETE CASTING FLOW CHART

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1- GENERAL 1.1 Scope This Construction Method and Quality Control Planning shall be applied to concrete work, including all kinds of concrete made elements. Based on the design and specification, this document provides a proper procedure and management of the concrete work. 1.2 Alteration This Construction Method and Quality Control Planning may be subject to change or alter due to its revision. In that case, corrected or adjusted requirements shall prevail after its official written approval. 2- OUTLINE OF PROJECT 2.1-General parameters: * Name of the project: OMRON HEALTHCARE VIETNAM FACTORY * Location: 28 Road No. 2, VSIP II, Ben Cat Dist., Binh Duong Province. * Client: OMRON HEALTHCARE MANUFACTURING VIETNAM Co., Ltd * Design: OBAYASHI VIETNAM CORPORATION * Contractor: OBAYASHI VIETNAM CORPORATION * Construction period: June 08th 2007 to November 23rd 2007 * Land area: 38,369.1 m2 * Building area: 6,538.57 m2 2.2-Concrete parameters:

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Lean concrete quantity: Structure concrete :

3- CONCRETE MIXES 3.1 Type of concrete The table below gives the different types of concrete, which used in the various structures of building. Type of Concrete

Grade of Concrete

Minimum Compressive Strength at28 days (Cylinder strength*)

A

Normal

210 kg/cm2

All the concrete works for the structural works, unless other type of concrete is specified.

B

Normal

150 kg/cm2

Lean Concrete

Applied to

3.2 Production of concrete The concrete used to structure shall be ready mixed concrete. Concrete shall be ordered in accordance with the specified design strength, being subject to quality control as indicated herein.

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3.2.1 Supplier of ready mixed concrete: * LE PHAN CONSTRUCTION Co.,LTD -Address: 97 Nguyen Duy Vuong St., Ward 9, Dist.5 HCMC. -Tel : 84-8-8300152 -Fax : 84-8-8350449 -Capacity : .Plant No.1 : 75m3/hour .Plant No.2 : 77m3/hour -Distance from Site Omron Project: .Plant No.1, No.2 : ~ 15 km. 3.2.2 Material Type of cement

CEMENT

Portland Cement

Maker of cement

NGHI SON

COARSE AGGREGATE (Crushed stone)

Location of mining

Stone of Hoa An mining – Dong Nai

FINE AGGREGATE (sand)

Location of mining

Sand of Tan Ba – Binh Duong

Type of admixture

Water reducing

Product name

Sikament 2000AT, Plastiment 96

Maker

SIKA

　

Well Water

ADMIXTURE

MIXING WATER

3.2.3 The designed mix proportion No.

DESCRIPTION

Type A

1

Designed strength (cube)

(kg/cm2)

2

Slump

(cm)

10.0 (±2)

(kg)

341.00

(m3)

0.447

(m3)

0.838

Cement 3

Weight in 1 (m3) concrete

Fine aggregate coarse aggregate Admixture

250

(ml)

3.3 Transportation of concrete: a- Mixing trucks shall be cleaned thoroughly after completing each concrete supplying trip. Remaining hardened concrete or any foreign material inside concrete compartment must be cleaned out . b- Time of transportation from the batching plant to site shall not exceed 02 hours (otherwise truck of concrete shall be returned to the batching plant). Record of each mixing truck shall be made. c- Any segregated concrete or any defective concrete shall be rejected.

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4- REQUIREMENT OF EXECUTION 4.1 Preparation of concreting: a- General Inspection before concrete order shall be done by Obayashi engineers, The inspection shall include: + Reinforcement steel bar and anchorage, in accordance with Re-bar list and all specification in concern. + Form work, including necessary temporary stage or scaffolding for concrete casting. + Confirmation of embedded M/E devices and location. Also during concrete casting, these M/E device’s condition shall be checked by M/E sub-con staff. b- Before concreting, the moist condition shall be provided to all form work and to previous construction joint surface with water spraying. c- Before concreting, tools, equipments, electric power supply and labor shall stand by on site. d- The use of other concrete transportation means, (concrete pump, buckets, chutes) shall be planned and all these equipments shall be cleaned and sprayed with water before use. e- Top level of concrete to be cast shall be made by marking on form with nail or red adhesive tape (at interval of 1,500 ~ 2,000mm). In case of slab concrete, level shall be used for checking. 4.2 Construction joint: a- Construction joints for slab shall follow specification on structure drawings. b- The constructions joint for beams shall be located at 1/3 of span in concern; for columns, it shall be the bottom level of beams. c- The previous construction joint surface shall be cleaned and free of laitance, being roughened with wire brush before the next concrete. 4.3 Concrete casting: a- Concreting process shall be done continuously until all the planned casting finish. b- In all cases, the height of concrete drop position to concreting place shall be less than 1.5 m, otherwise a chute shall be used or intermediate height casting opening shall be made. c- The concrete shall be vibrated properly. Interval of vibration spot is about 600mm and duration of operation is about 20 seconds. d- For long and thin element, combination of vibration and tapping of form work shall be used. 4.4 Concrete curing:

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a- The new cast concrete surface shall be protected by keeping completely free of any load for at least 24 hours after the completion of concrete pouring. b- For concrete curing and marking work, entering cast area is allowed after 01 day. But concrete surface shall not be loaded with any kind of material, equipment, machine or tool until concrete curing is finished. c- In case of rain just after concreting, concrete surface shall be protected by vinyl sheets. d- The moist condition shall be kept to concrete surface by water spraying at least 2 days after casting to avoid quick hardening. 4.5 Concrete defect treatment: a- Laitance (if any) on concrete surface shall be taken out for the next concrete or for finishing work. b- After removal of form, concrete surface shall be checked. If any defect exists (honeycomb, cold joint, unusual drying out ), it shall be reported. After consulting with Obayashi engineers, it shall be repaired immediately with proper method. 5. CONTROLS AND SAFETY 5.1 Quality control a- General checking: - Before casting concrete, general checking shall be done including form work, rebar, levels and cleaning. - During casting concrete, any movement of form and re-bar shall be checked carefully. - During trowel of floor surface, the top level shall be checked at all times. b- Slump test Before casting concrete, the concrete slump must be checked and recorded. (frequency: at the same time that test cube sample is taken) c- Concrete temperature checking Before casting concrete, concrete temperature shall be checked with thermometer　and recorded. (frequency: at the same time that slump test is done) d- Sample and Compressive Test - 09 samples of concrete shall be made for each casting : .03 samples for 7-days test .03 samples for 28-days test .03 samples for extra test (For determination or prospect of the time of form & shoring removal) - Above each 03 samples shall be taken evenly from total numbers of concrete trucks. - Basically the sampling is prepared for every 150m3 of cast concrete. However, for main elements of building, concrete samples shall be taken on every concrete casting. - Sample making, curing and testing shall be done by concrete supplier with instruction of Obayashi engineers.

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- Concrete samples shall be cured in curing water tank on site until the day of test. Curing condition (water temperature, cleanliness) shall be maintained properly. The information of casting (date,building,element) must be indicated on each sample surface. - Compressive test for 7days age shall be done by concrete supplier at their laboratory. - Compressive test for 28days age and extra age shall be done by xxx - Test results and photos shall be recorded for each sample by Obayashi engineers. e- Concrete casting flow chart. (See attached) 5.2 Safety a- Material shall be put in order; safety passage shall be provided. b- Safety regulations and rules on site are applied also to concrete work c- Daily cleaning shall be done by sub-contractor to ensure the site completely clean in the area of working. 6. INSPECTION FORMS, PLANNING AND RECORDING FORMS

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7. CONCRETE CASTING FLOW CHART PLANNING SCHEDULE CONFIRMATION W/SUPPLYER

INSPECTION

FORM WORK CHECK SHEET

CONC. VOLUME ESTIMATION

RE-BAR WORK CHECK SHEET

CONC. CASTING PLAN &RECORD

APPROVAL

ORDER

DELIVERLY

SUPERVISION *FORM RE- BAR CHECK *LEVEL TROWELING CHECK *M&E SLEEVE, PIPING CHECK *SAFETY CHECK * etc.

SLUMP TEST QUALITY CHECK

TEST CUBE SAMPLING CURING

CASTING COMPRESSIVE TEST

GETTING TEST RESULT

CURING

CONC. CASTING PLAN &RECORD

CONC. CASTING PROGRESS REPORT

CONSULTING

FORM REMOVAL

CONC. SURFACE CHECKING

REPAIRING

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