Method Statement for Masonry Works

Bujagali Energy Limited Bujagali Hydro-Electric Power Project

Salini Costruttori Concrete Hollow Blocks Work Method Statement

SUMMARY

1. AIM OF THE DOCUMENT AND FIELD OF APPLICATION 2. REFERENCE DOCUMENT 3. PURPOSE AND DESCRIPTION OF THE HOLLOW CONCRETE BLOCK WORKS 4. RSPOSIBILITIES 5. EQUIPMENT 6. PERMANENT MATERIALS 7. OPERATIVE METHODS AND WORKING PHASES 8. PLANNING OF THE WORKS 9. SAFETY MEASURES 10. ENVIRONMENTAL ASPECTS

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Bujagali Energy Limited Bujagali Hydro-Electric Power Project

Salini Costruttori Concrete Hollow Blocks Work Method Statement

1. AIM OF THE DOCUMENT AND FIELD OF APPLICATION The present Method Statement establishes the type of construction methods and techniques carried out during the phase of work concerning the masonry blocks placing, floor screed and wall plastering works, in order to meet the contract requirements. The present document is applicable to all the permanent works which involve the above operations within the construction of the Bujagali Hydro-electric Power Project. 2. REFERENCE DOCUMENTS Quality Control Plan Construction SA-D-GE-QA-1002 Project Procedures SA-D-GE-QA-1003 BS 5628-1 : 19992 on use of masonry FI-D-GE-SP-0011 Technical Specification for Concrete, Reinforcement and Formworks 3. PURPOSE AND DESCRIPTION OF THE MASONRY SCREED AND PLASTERING WORKS

BLOCK , FLOOR

The purpose of: • The masonry block works is to provide external and internal partition/wall within the floor area for the intended purposes. Concrete Hollow Blocks produced on site to approved standards are mainly used. The partitions/walls are basically cladding and non load bearing structures. • The floor screed is to provide level, even and strong surface in some cases meeting special requirements. The screed shown here is for equipment rooms such as in Level 1081 of all units in the Power House. • The wall plastering is to provide even surface for application of paint where shown on the drawing 4. RESPONSIBILITIES The responsibilities for the implementation of the present Method Statement are assigned as follows: Project Manager :

He has the responsibility to approve this document. He cooperates with the Construction Manager, the Technical Services Manager and the Quality Control Manager to establish proposal of non conformity treatment and approves it.

Construction Manager :

He makes sure that the production activities are in line with the present Method Statements and all Inspection and Testing plans, he allocates all the resources needed for their implementation. He informs the Quality Control Manager and the Technical Services Manager about the non conformities found by himself or his collaborators. He cooperates to establish the proper treatment of the non conformities.

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Bujagali Energy Limited Bujagali Hydro-Electric Power Project

Technical Services Manager:

Salini Costruttori Concrete Hollow Blocks Work Method Statement

He cooperates with the Quality Control Manager to draft the Quality Control Procedures giving all the required technical support. He organizes the Quality Control activities on Site regarding the laboratory and the survey. He prepares and distributes the method statements. He is also responsible for the distribution of any technical documents needed for the execution of the work. He cooperates with the Project Manager, with the Construction Manager, and with the Quality Control Manager to establish the proposal of non conformity treatments.

Chief Laboratory Technician:

He performs the laboratory mix proportions of the mortar used for Hollow Concrete Block works.

Quality Control Manager:

He drafts the quality procedures and checks their implementation involving in these activities all the relevant site organization. He coordinates the registration of the non conformities and the actions necessary to solve them. He is responsible for the acceptance of the permanent material described in the paragraph 6. He checks the conformity of the incoming permanent material with the specifications and fills the relevant fields of the incoming permanent material form.

5. EQUIPMENT • Masonry Hand Tools • Wheel Barrow or Dumper • Scaffolding • 3 to 4 meter long straight edges • Small vibrator 6. PERMANENT MATERIAL The Quality Requirements of the Permanent materials used in the construction of the block works are described below: • • • • •

Cement: OPC CEM I 42.5 N conform to EN 197-1 (for mortar) Aggregate ( sand for mortar) Hollow Concrete Blocks (conforming to BS 5628-1:1992) Mortar (Designation iii of BS 5628-1:1992) Mortar for screed

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• • •

Salini Costruttori Concrete Hollow Blocks Work Method Statement

Mortar for plastering Peneseal FH for concrete surface hardening and curing Sika Latex

7. OPERATIVE METHODS AND WORKING PHASES i) Masonry Block Works using Concrete Hollow Blocks a. Marking of the line of the block and openings is done on the floor as per the dimensions indicated on the relevant drawing. These markings must be checked and confirmed by the Quality Control Inspector. b. Plastic sheet (200mm wide DPC) laid along the of block line where indicated on the drawing with 2 anchor bars (dia. 12mm, 1 to 1.5 meter long) inserted in the floor along the line of the block at the specified spacing. c. Mortar (20-40mm thick) laid for two guiding HCBs to true grade and alignment. With similar application of mortar, intermediate HCBs are placed following the string line between the two guiding blocks with constant check of level using the spirit level. The holes where the vertical bars are passing through are filled with mortar. d. The above phase (c) is repeated for each course/layer of HCB. e. Horizontal bar (12mm dia. rebar full length of the block work and inserted at one end to the adjoining concrete column/structure) is placed where indicated on the drawing. Introduction of intermediate beams for wall heights exceeding 3.5 meters is foreseen. f. Maximum number of courses to be laid in a day not to exceed 6 courses or 1.5 meters height. g. Curing to be done as required. ii) Floor Screed a. The floor area is roughened or bush hammered and cleaned properly making it free from dust, grease, oil or any other dirt. b. Fix BRC mesh to the floor using nails(2.5 mm wire forming mesh) c. Apply Sika Latex for bondage (Sika to water ratio of 1: 2) d. Place special mortar {Heavy Duty Floor Finish(HDFF)} and vibrate using the small vibrator and finish the floor surface to survey level with the cross fall shown on the drawing (min. 0.04%) e. Apply Peneseal FH (one litre for 5m2 area) immediately following the finishing operation of the mortar screed i.e as soon as the surface is firm enough to walk on before hairline or temperature cracking begins. The entire surface is kept wet with Peneseal FH for 30 minutes. Peneseal FH helps for curing and hardening the concrete surface and thereby increase its density, abrasion resistance and durability.

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Salini Costruttori Concrete Hollow Blocks Work Method Statement

iii)Wall Plastering a. Protruding or excess mortar removed from the surface and the wall well wetted. b. First stage application of mortar (Type BW) or rendering done on the whole surface intended for plastering in order to make the surface rough enough to receive second stage application of mortar as filler. c. Second stage filler mortar (Type BW) is applied to required thickness to obtain an even surface. d. Then the third stage plastering or fine finishing is made using the special mortar (Type BW1) with cement and sieved fine sand in the ratio of 1:1. This is applicable for internal and external walls; however it can be substituted by the use of gypsum for internal walls only. e. Curing shall be carried out as required 8. PLANING OF THE WORKS All masonry works are expected to be completed: • By end of 2010 in the PH rooms. • By August 2010 in the Switchyard Control Building • By October 2010 in the Erection Bay Control Building • By June 2011 in the Workshop/Store Building • By April 2012 in the Guard Houses and Visitor Center

9. SAFETY MEASURES The risk analysis and the description of the safety measures to be considered to carry out the works under safe conditions and complying with the legal requirements are described in the document SA-D-GE-RA-1126-0

10. ENVIRONMENTAL ASPECTS The analysis of the environmental aspects involved in the block works has been carried out. Production of HCB aspects, operation and working phases do not show any significant environmental aspects. Environmental management measures will be carried out on site during the above mentioned activities, according to the document SA-D-GE-EA-1014.

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P R O D U C T ICS PE N ETRON I NTE R NATIONAL

D A T A

S H E E T

45 Research Way, Suite 203 East Setauket, NY 11733 +1(631) 941-9700

[email protected]

PENESEAL FH DESCRIPTION Peneseal FH is a transparent, chemically reactive, water-based sealer that penetrates concrete and masonry building materials, protecting, preserving and strengthening them permanently by: Curing: Peneseal FH controls hairline and temperature cracking on new concrete when applied to properly placed, structurally sound, freshly finished concrete. Peneseal FH will uniformly cure the concrete through a combined chemical/moisture retention reaction so vital to the complete hydration process. Sealing: Peneseal FH penetrates deep into the concrete forming a chemical reaction that locks the pores from within, providing a deep permanent seal on all types of concrete surfaces. Hardening: Peneseal FH solidifies the component parts of the concrete, increasing the density, toughness and hardness and substantially increasing the abrasion resistance and durability of the concrete surface. Smooth steel troweled surfaces develop a marble-like finish and sheen. Peneseal FH treated concrete has been compressively tested 38% harder after 30 days than fully cured, untreated concrete. Dustproofing: Peneseal FH chemically reacts with the salts in the concrete, densifying the surface, greatly reducing release of concrete dust through the surface pores. Neutralizing Alkali: As the Peneseal FH progressively penetrates the concrete; it neutralizes the alkali forcing them to the surface where they can be washed away during the application. The deep alkali and efflorescence are locked in reducing the leaching of alkali to the surface. Bonding: When properly applied, Peneseal FH prepares the treated surface for paints, caulking compounds, adhesives and floor coverings by eliminating the surface concrete salts that are so detrimental to proper bonding. Peneseal FH is coatable and compatible with any type of covering when standard surface preparation guidelines are followed. Treatment Results: A single application of Peneseal FH helps cure and seal concrete and masonry, rendering them highly resistant to oils, greases, and other surface contaminants. The component parts of the concrete are solidified into a solid mass, which toughens, hardens and increases the density. The surface alkali is neutralized and efflorescence and the leaching of lime and alkali are stopped. Treatable Materials: Concrete, heavyweight concrete block, mortar, plaster, stucco, terrazzo, exposed aggregate, and any sand, aggregate, cement combination. PACKAGING 5 gallon (19 l) pails, 55 gallon (208 l) drums and 275 gallon (1041 l) containers. T H E P E N E T R O N SYS T E M

Coverage: Approximately 200 square feet per gallon (5m²/l). Coverage depends on the temperature and porosity of the concrete. Storage Life: Indefinite. Agitate bucket or drum before using. Do Not Allow to Freeze! DIRECTIONS FOR USE Methods of Application: Spray or pour and broom to saturate the surface. Tools Needed: Low-pressure sprayer, soft bristle broom, squeegee, and water hose. Surface Preparation: Remove surface dust, dirt and contamination by sweeping all areas to be treated with a fine bristle broom or scrub brush. Hose off with water and let dry. Remove all form oil and breaking compound residue from areas where forms have recently been removed. Peneseal FH can be applied to damp surfaces as long as all puddled areas are swept away so that the Peneseal FH is not diluted before it is able to penetrate the surface. For New Concrete: Step 1. Apply Peneseal FH immediately following the finishing operation as soon as the surface is firm enough to walk on before hairline or temperature cracking begins. Keep the entire surface wet with Peneseal FH for 30 minutes. Step 2. As the Peneseal FH becomes slippery underfoot, lightly mist the surface with water. This will keep the material in solution providing maximum penetration. Do not allow the Peneseal FH to dry on the surface. Step 3. As the Peneseal FH again becomes slippery underfoot, thoroughly flush the entire surface with water and squeegee the surface completely dry to remove all surface alkali or Peneseal FH residue. On exterior broom finished surfaces, no flushing is required, but any remaining Peneseal FH must be squeegeed or broomed from the surface after 30-40 minutes. For Old Concrete (all cured surfaces): Step 1. Saturate the surface with Peneseal FH so that the entire surface is wet with Peneseal FH for 30 minutes. Mist with water if necessary to keep material from drying on the surface. Step 2 (Option 1). If after 30-40 minutes the majority of the Peneseal FH has been absorbed into the surface, broom or squeegee any excess material from all low spots and puddles so that all remaining Peneseal FH totally removed from the surface. Porous surfaces way require an additional application of Peneseal FH to achieve maximum protection.* Step 2 (Option 2). If after 30-40 minutes the majority of the Peneseal FH is still on the surface, wait until it becomes slippery underfoot, then thoroughly flush the entire surface with clear water and squeegee completely dry to remove all Peneseal FH residue. TOTA L C O N C R E T E P R OT E CT I O N

P R O D U C T

D A T A

S H E E T

PENESEAL FH TECHNICAL DATA Applicable Standards: ♦ Abrasion: ASTM C 779 - 32.7% increase in abrasion resistance. ♦ Bonding: ASTM D3359 -17% increase in epoxy adhesion. No change for polyurethane adhesion. ♦ Curing: 94% greater moisture retention during the initial critical 24 hour curing period as compared to untreated samples. ♦ Hardening: ASTM c 39 - 40% increase in compressive strength 7 days; 38% increase at 28 days over untreated samples. ASTM C 805 - Schmidt hammer - 13.3% increase in impact resistance. Permeability: The seepage rate using a 7 foot (213 cm) head of water on a 4.91 square inch (31.7cm²) area treated with Peneseal FH was 0.022cc per hour. Weathering: ASTMG2381 - ultra-violet light and water spray exposure had no adverse effect on Peneseal FH treated samples. Thinners: None required. Clean all equipment with water only. Number of Applications Required: One application is typically required. An additional application may be required on porous substrates to achieve maximum performance. Duration of Effectiveness: Permanent. The concrete becomes harder and better sealed the older it becomes. Time Requirement for Curing, Sealing and Hardening: 60-90 days. Unlike surface coatings that wear away with use, Peneseal FH seals the concrete from within by permanently locking the pores, thus making the concrete itself the penetration barrier. This process is essentially complete within 90 days, but may continue at a much slower rate for up to one year. Color: Clear. Peneseal FH will not change the natural appearance of the masonry or concrete. Where alkali, lime and other impurities are forced to the surface and the natural appearance is to be preserved, all treated surfaces must be flushed clean with clear water according to the manufacturer’s instructions. Sheen: On smooth steel troweled concrete surfaces a natural wax-like sheen will appear between 6 and 12 months after treatment. This sheen is caused by the hardening and sealing effects of the Peneseal FH as well as abrasion from cleaning and use of the floor. As a permanent part of the concrete surface, the sheen will last the lifetime of the surface with proper cleaning and maintenance. Application Temperature Limits: 100°F, 40ºF (40°C, 5°C). At low temperatures completely protect new concrete from freezing for a period of six days. The reaction of the Peneseal FH will also be slowed during colder temperatures. T H E P E N E T R O N SYS T E M

Drying Time: 1-3 hours. The surface can be used as soon as the application is complete and the surface is again dry to the touch. Newly placed concrete requires the normal hardening period. Painting or Covering Preparation: Old concrete - allow 3-7 days before applying paint or coverings. New concrete allow 30 days for proper curing. Internal Makeup: Non-toxic, non-combustible, non-flammable. Not harmful to lungs or hands. Complies with all V.O.C. and U.S.D.A. regulations. Limitations: Do not apply Peneseal FH in the following cases: ♦ To seal lightweight block or other extremely porous masonry that contains actual holes and air pockets. ♦ When temperature falls to below 40ºF (5ºC). ♦ To areas previously treated with curing or sealing agents, unless these coatings have been removed by chemical or mechanical means. NOTE: Avoid use on glazed and finished surfaces such as glass, aluminum, etc. In case of contact, flush immediately with water. AVAILABILITY AND COST Peneseal FH manufactured exclusively by ICS Penetron International Ltd. is distributed throughout the United States direct to the job-site or through regional factory warehouses and is competitively priced. For specific price information contact ICS Penetron International Ltd. MAINTENANCE Floors: Wash or wet mop with neutral or high pH detergent. Walls: Flush with water. TECHNICAL SERVICES Technical information and assistance can be obtained from ICS Penetron International Ltd. WARRANTY ICS PENETRON INTERNATIONAL LTD. warrants that the products manufactured by it shall be free from material defects and will conform to formulation standards and contain all components in their proper proportion. Should any of the products be proven defective, the liability to ICS PENETRON INTERNATIONAL LTD. shall be limited to replacement of the material proven to be defective and shall in no case be liable otherwise or for incidental or consequential damages. ICS PENETRON INTERNATIONAL LTD. makes no warranty as to merchantability or fitness for a particular purpose and this warranty is in lieu of all other warranties expressed or implied. User shall determine the suitability of the product for his intended use and assume all risks and liability in connection therewith. TOTA L C O N C R E T E P R OT E CT I O N