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英文版道路施工组织设计method statements for road construction


METHOD STATEMENTS FOR ROAD CONSTRUCTION

1. Earth Works ...........................................................................................2 2. Drainage Works .....................................................................................3 3. Cement Stabilized Gravel - Road Sub-base material............................4 4. Cement Improved Graded Crushed Stone Road Base ..........................6 5. Asphalt Concrete Works........................................................................8 6. Dense Bitumen Macadam (DBM) Works ...........................................11 7. Cement Concrete .................................................................................14 8. RE WALL WORKS ............................................................................18 I. Introduction....................................................................................18 II. Handling Reinforced Earth Materials...........................................20 III. Construction Procedures .............................................................21

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1. Earth Works
Work under this chapter mainly includes obtaining approved materials from in and out of the road corridor, transporting to site, spreading, grading to required slope and compacting to meet the requirement as specified in the Technical Specification.

1. Excavation
Excavation shall be carried out by 2~3 no. excavators from top to bottom in a stepped manner. The excavated materials shall be transported by dump trucks to designated dumping sites. Work shall be undertaken in sections which should be of adequate sizes to allow for economic operations.

2. Selection of Construction Equipment for Earth and Rock Works
Based on our experiences, construction equipment of all kinds shall be selected as follows: Excavator: 3 No. (Capacity per bucket: 1.0~2.0m3) excavators shall be delivered into site for excavation. Dump trucks: 10 sets dump trucks shall be delivered to site for transport of earth and rocks. This plant/equipment may be adjusted according to workload.

3. Filling a. Transport
Design for transport shall be made in accordance with earthwork construction scheme. Transportation shall be carried out by 12~18 m3 dump trucks. During transportation, entrance to and exit from working place of heavy vehicles shall be supervised by specially-assigned personnel to avoid any damages to constructed fills or existing road network.

b. Spreading
During spreading, the actual moisture content of fills shall be maintained within the specified/optimum moisture content. Spreading operation shall be carried out in two stages: first stage, grading fills unloaded from dump trucks by graders; second stage, compacting fills by rollers.

c. Compaction
Construction technical parameters (including roller tonnage, traveling velocity, dynamic stress, vibrating frequency and rolling times etc.) shall be obtained from an approved trial section.

Notes:
Rolling from light to heavy, the transition shall be determined by the results of a trial section; The adjacent two rolling operations shall have a lapping width of at least 15cm; Spread fills shall be compacted in time during shift. In case of rains, at end of each shift, spread fills shall be compacted to prevent surface water or rain water from infiltrating; In case of abruptly bad/wet weather , spread fills, which can’t be compacted in time, shall be leveled and be sealed through compaction on the top to reduce infiltration of water and covered with impermeable membrane. When commencing the next stage of operation, such
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fills shall be scarified for drying in the sun up to the required moisture content and then be re-spread and re-compacted. 1). Machinery with operators a) b) c) d) e) f) g) Excavator – 3 No. Motor graders – 2 No. 12 Ton steel vibrating rollers – 2 No. 8 Ton tyred pneumatic rollers – 2 No. 5000L water bousers – 2 No. Transport for stabilizer-dump trucks - 10No. Assorted tools

2). Manpower / Personnel a) Engineer – 1 b) Foreman – 1 c) Surveyor – 1 d) Chairmen – 3 e) Laborers – 15 No.

Any necessary adjustments will be done on sites as the situation demands.

2. Drainage Works
Drainage works in this project will entail culverts of various sizes and open drains as will be instructed by the Engineer, side drains, mitre-drains and stone pitching or lining channels where instructed. These will be carried out as per Engineer’s Instructions and Design and in accordance with specifications. **** will have an independent team for drainage structures work to be headed by an experienced foreman so that drainage works will precede earthworks where necessary or alongside it depending on the kind of drainage works involved. **** has concrete mobile mixers and towed mixers, which will be available for these works. Where culverts are to be done with insitu concrete formwork shall consist of a combination of balloons and marine plywood. All stages of work shall be approved by the Engineer before the contract proceeds with the next stage. i.e. The Engineer shall approve each of the following stages setting out-excavation-bed preparation-formwork-reinforcement-base casting-balloon-formwork-reinforcement-concrete-formwork & balloon removal-concrete strength-loading etc 1). Machinery with operators

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a) b) c) d) e) f) g) h)

Excavators – 1 No. Motor graders – 1 No. 12 Ton steel vibrating rollers – 1 No. Transport for stabilizer-dump trucks - 2No. Mobile truck mixers – 2 No. Vibrators – 2 No. Balloons – 2 No. Assorted tools

2). Manpower / Personnel a) Engineer – 1 b) Foreman – 1 c) Surveyor – 1 d) Chairmen – 1 e) Laborers – 10 No.

Any necessary adjustments will be done on sites as the situation demands.

3. Cement Stabilized Gravel - Road Sub-base material
1. Introduction: This Method Statement describes the works operation to under take the spreading of Cement and stabilization of sub base, specifically for Section A of the project. It covers all the works in connection with the exploitation, hauling, dumping and processing of natural gravel material for cement stabilization. The entire process shall be done in adherence to contract requirements. In particular the requirements of the specifications and road design manual part III will be observed. 2. Methodology and Procedure: A trial section, approximately 100m will be done following the procedure below to establish the vital parameters to be adopted for the actual operations thereafter. Actual stabilization will be undertaken in sections of 150m length. It its estimated that such lengths will be processed within 2-4hrs. This time estimate is taken from the moment the cement bags are opened to the completion of compaction. Once the formation layer is placed and approved, material for sub-base will be dumped immediately thereafter to protect the formation from damage. All necessary reference pegs for levels and offsets shall already be in place. The approved material will be dumped at intervals to achieve the required final thickness and spread.
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In the case of material form borrow pits with large chunks of boulders, pre-processing by adequate passes of the sheep foot roller and grader will be made to breakdown the material into workable form. The final surface will be compacted lightly. The day before the actual stabilization, pre-levelling and pre-watering will be done .the actual activity of stabilization will commence with dumping of cement bags at spacing determined to achieve required percent of cement stabilization based on laboratory tests. The bags will then be opened. Cement will be spread using the grader blade and hand brooming. The gravel material will then be scarified by grader. Hand brooms will be used in areas where mechanical operation is difficult. Dry mixing will be done by one pass of the pulvimixer. Water will then be applied from water bowsers. The second and possibly third pass of the pulvimixer will then follow. The quantity of water required shall be guided by the properties of the material as obtained from laboratory test, accordingly calculated to suit the section length, width &thickness and material density. The experience of the personnel executing the works will be of great value in this operation. It is estimated that 60% of the total water for this operation will be applied at the pre-watering stage on the day before stabilization. This will reduce the likelihood of cement being washed due to excessive application of water. Immediately after the second of third pass of the pulvimixer, 2 No. passes of the sheep foot roller will be used for primary bottom compaction 3 passes of the smooth steel roller for top compaction will then follow according to the results of the trial section. The grader shall cut the final level and the pneumatic tyred roller shall continue to roll till mechanically stable crack free surface is obtained. Final level shall then be checked and the layer is finally tested to determine its acceptance as per section 2 of general specifications. Curing shall then follow as per specified or as will otherwise be directed by the Resident Engineer. 3. Resources for Execution: a) Materials Natural material form borrow pit complying with clause 1203(c) of the General Specification and approved by the Engineer for Sub base. Cement will be ordinary Portland cement 42.5 complying with the requirements of section 2 of the standard specification Curing material will be one of the options as in Clause 1409 of the General Specification and 1409 of the Special Specification, as will be agreed with Resident Engineer. b) Plant Bulldozer – 1 No This machine will be used for stockpiling material at borrow pits Tipper – 5 No Tippers will be used to haul material from barrow pits to designated section ready to receive sub base material.
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Wheel loader – 1 No Will be used for loading sub base material at the borrow pit Motor Grader -2 No Water Thanker 18,000 litres – 2No Bomag 213 Steel Roller (13 ton)-1N0 Pneumatic Roller (16 ton)-1No Self Propelled Pulvimixer-1 No The above machines will be used for processing and compaction of the sub base. The other machines will be as follows Prime Mover + Trailer – 1No (For Cement) Water Pump 4’’-1 No

c) Senior Supervision personnel Projects Manager Projects Engineer Consultant Materials Engineer Superintendent of works Site Engineer Quality Control Materials Engineer d) Labour Foremen Operators Drivers Head men Un skilled labourers Watchmen

2 No - 8 No - 8No - 2No - 15No - 3No

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4. Cement Improved Graded Crushed Stone Road Base
1. Materials The first step for the programme of the construction of the GCS road base will be the establishment of the material sources that will comply with the specifications and approved by the Engineer. The specified materials are ordinary Portland cement and graded crushed stone size 0/30. The amount of the cement to be used is between 1 – 2% by weight and the actual amount will be established by laboratory tests and field trials and will be subject to Engineers’ approval. Cement will be stored either in weather proof silos (bulk supply) or stores (50 kg bags supply). 2. Mixing
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We shall use stationary batching plant for mixing the aggregates and cement. The mixing plant is fitted with electronic controls that will ensure that the materials introduced in the mixing plant by conveyors will be as predetermined by the laboratory and site trials and approved by the Engineer. The capacity of the batching plant is 75 m3/hr and shall target a daily production of 500 m3. 3. Transportation The mixed materials shall be transported from the batching plant to the laying site using 20 Ton dump trucks. Adequate numbers will be provided to ensure continuous supply of both treated and untreated materials. 4. Laying The laying of the treated materials will be done using a mechanical paver. Our paver is capable of laying an eight (8) metre width and is also fitted with electronic level sensors to ensure accurate thickness control. The thickness of the road base layer is 250 mm while the maximum allowable thickness of laying is 180 mm. We shall therefore construct the base in two equal layers of 125 mm. a. Compaction Compaction will be done using approved vibrating and kneumatic rollers to produce a pavement compacted to 95% MDD and free from ridges, compaction planes, surface irregularities or segregation and within acceptable tolerances. All care will be taken to ensure that the whole operation from the time of cement introduction to rolling completion does not exceed two hours. b. Protection And Curing The completed layer will initially be kept continuously dump by lightly spraying with water until all quality control parameters are checked and approved by the Engineer. The layer will then be covered by approved polythene sheeting properly secured over the whole width of the treated layer. The curing period shall be a minimum of seven days before the primer is applied. No traffic will be allowed on the completed layer except the watering bousers. c. Resources To achieve the above stated method statement the following resources will be deployed:Personnel a) Site Engineer – 1 No. b) Surveyor – 1 No. c) Chain men - 3 No. d) Foremen – 2 No. e) General Labour - 10 No.

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Equipment with operators a) Batching Plant - 1 No. b) 20 Ton Trucks - 15 No. c) Vibrating Rollers - 2 No. d) Kneumatic roller - 1 No. e) Water tanks (bousers) - 2 No. f) Paver - 1 No.

5. Asphalt Concrete Works
1. Introduction This method Statement describes the operations and procedures to undertake works on asphalt concrete. It covers all the works in connection with the production of constituent aggregates mixing, laying and compaction for the road pavement. The operation shall be done in accordance with the contract requirements. In particular the requirements of the standard and Special Specifications will be observed. A trial section of 100m will be undertaken before the commencement of the actual works 2. Methodology and Procedure The operation shall commence with careful selection, crushing and testing of suitable stone for strength parameters (LAA, ACV, FI and CR), durability (SSS) and bitumen affinity. Upon confirmation of the suitability of the stone source and its quality, as well as the bitumen to be used, mix designs shall be done in accordance with the requirements of clause 1603B and 1604B of the special specification for approval by the supervisor, Routine testing for grading shall then be carried out on the material, correctly sampled from daily production and thereafter from the stockpiles as deemed necessary. The approved aggregates will be hauled to stockpiles adjacent to the asphalt plant. The asphalt plant will be calibrated prior to use. A dry mix of the selected blend of aggregates will be run through the plant. The resultant product will be tested in the laboratory to ascertain the calibration. A trial mix with bitumen will then be done based on a selected mix for the dry run using appropriate bitumen contents. Asphalt concrete will be mixed at the batching asphalt plant. The various aggregate sizes that have been approved will be weighed in the relevant proportions determined from the selected blend, through the hoppers. A pre-determined percentage of heated bitumen will be pumped into the plant so achieve the required bitumen content of the mix. The combination of materials shall be mixed further with heating at the right temperature in accordance with the specification to produce homogenous asphalt concrete. After loading the trucks will be driven to the tarpaulin yard via the weigh bridge to be covered tightly with canvas for protection from adverse conditions of dust, rain etc and to maintain desired temperatures. The AC shall be laid onto the surface of approved and cleaned dense bitumen macadam. Water will be
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sprayed on the surface by a water bowser then broomed and left to dry. In case of immediate laying, a compressor will be used for drying the surface. The corridor within which the AC is to be laid will be set out and marked using white paint. A tack coat of K160 will be applied on the DBM just before laying of the AC if considered necessary. The road deviation adjacent to the area of works will be watered to abate dust. Ramps shall be constructed for the trucks to access the road corridor to ensure the embankment and other completed layers are not disturbed. The material shall be laid by paver. The depth shall be preset to specified thickness using a wooden plank of similar thickness at the start. Trucks shall queue in front of the paver and will be reversed in turns to tip into the hopper of the paver. Once an adequate quantity is tipped into the hopper the temperature will be checked to ensure compliance with the specifications. The material will be sampled for testing and analysis at the laboratory for Marshall Requirements, extraction of binder and aggregate grading. The material will be mixed further by the auger of the paver. Tipping shall be slow and gentle to avoid segregation. The material will then be laid in one layer of 60mm thick to obtain a final 50mm thick layer after compaction. Initial compaction will be provided by the paver itself .The compaction factor for the paver is about 80% and is adequate to provide stable slope at the asphalt concrete edges to support roller weight without undue movement. The slope will be compacted using and rammers, Dip sticks will be used to check the layer thickness by dipping regularly into the laid material. Necessary adjustments will be made to the paver to correct the layer thickness during the operation. Laying operations shall only commence once several tippers/trailers have queued in front of the paver to avoid stoppage of paver operations that could result in rippling effect .the entire width shall be laid at once. Compaction shall commence with the pneumatic tyre roller followed by the smooth steel vibratory roller. Four passes of both rollers will be used for a start, to be adjusted accordingly once compaction results are obtained. The rolling shall overlap at the joint. The Bomag BW120 roller will be used for compaction at the central joint. The temperature of the material shall be checked again at the completion of compaction for compliance with the specifications. The slope (camber/crossfall) of the final surface shall be checked using a straight steel edge. Cores will be cut from the trial section to determine the density of the compacted material and also confirm thickness laid, refusal density, voids at refusal, stability and flow. The holes will be filled with hot asphalt the following day after application of tack coat and rammed manually to levels exceeding the surrounding slightly. 3. Resources for Execution a) Materials

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Asphalt Concrete from the asphalt plant complying with Clause 1603B and 1604B of the standard specification and approved by the Engineer. b) Plant Asphalt Plant – 1 No (100 ton/hr) Production of Asphalt Concrete material using aggregate and bitumen Tippers (20 Ton) - 10No Tipper trucks will be used to haul aggregate material from the crusher stockpile Water Tanker (18,000 litres ) – 1 No Cleaning the DBM surface and watering deviation if /where necessary and filling of rollers Tractor drawn Mechanical Broom – 1No Cleaning the surface of DBM Compressor – 1No Drying the washed and broomed surface of DBM in the case of prompt laying Vibratory Smooth Steel Roller (9 ton) – 2 No Pneumatic Roller (7 wheels each 5 ton max) – 1No Compaction Paver-1No Laying of Asphalt Concerte Water Pumps – 1No Fill up the water bowser c) Senior Supervision personnel Consultant Material Engineer Site Manager Assistant Site Manager Superintendent of works Quality Control Materials Engineer Laboratory field team ( on-field ,sampling and testing ) Laboratory team (lab testing and analysis ) d) Labour Foremen Operators Drivers Head men Unskilled Labourers Watchmen

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2 No 11No 33No 2No 10No 6 No

4. Daily Asphalt Production
Our target for daily production will be 900 tons per day. between 10.00 pm and completed before 5.00 am. The mix will be laid and compacted

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5. Personnel & Equipment The above method will involve the following input;
1). Personnel a) b) c) d) e) Engineer – 1 No. Foreman – 2 No. (one at plant another at site) Surveyor – 1 No. Chainman – 3 No. Laborers – 15 No.

2). Equipment with operators a) b) c) d) e) f) g) 20 Ton tippers – 15 No. 10 Ton steel vibrating roller – 2 No. Pneumatic 8 Ton rollers – 2 No. Asphalt Paver – 1 No. Asphalt premix plant of effective production capacity of 100 tons/hr – 1 No. Bitumen distributor – 1 No. Mechanical broom – 1 No.

6. Dense Bitumen Macadam (DBM) Works
1. Introduction This method Statement describes the operations and procedures to undertake works on Dense Bitumen Macadam. It covers all the works in connection with the production of constituent aggregates mixing, laying and compaction for the road pavement. The operation shall be done in accordance with the contract requirements. In particular the requirements of the standard and Special Specifications will be observed. A trial section of 100m will be undertaken before the commencement of the actual works 2. Methodology and Procedure The operation shall commence with careful selection, crushing and testing of suitable stone for strength parameters (LAA, ACV, FI and CR), durability (SSS) and bitumen affinity. Upon confirmation of the suitability of the stone source and its quality, as well as the bitumen to be used, mix designs shall be done in accordance with the requirements of clause 1603B and 1604B of the special specification for approval by the supervisor, Routine testing for grading shall then be carried out on the material, correctly sampled form daily production and thereafter form the stockpiles as deemed necessary. The approved aggregates will be hauled to stockpiles adjacent to the asphalt plant. The asphalt plant will be calibrated prior to use. A dry mix of the selected blend of aggregates will be run through the plant. The resultant product will be tested in the laboratory to ascertain the calibration.
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A trial mix with bitumen will then be done based on a selected mix form the dry run using appropriate bitumen contents . Dense Bitumen Macadam will be mixed at batching asphalt plant. The various aggregate sizes that have been approved will be weighed in the relevant proportions determined form the selected blend, through the hoppers. A pre-determined percentage of heated bitumen will be pumped into the plant so achieve the required bitumen content of the mix. The combination of materials shall be mixed further with hearting at the right temperature in accordance with the specification to produce homogenous Macadam. The Macadam shall then be stored in the plant silo awaiting loading onto the tippers. After loading the trucks will be driven to the tarpaulin yard via the weigh bridge to be covered tightly with canvas for protection form adverse conditions of dust, rain etc and to maintain desired temperatures. The DBM shall be laid onto the surface of approved primed graded crushed stone. The primed surface of the GCS shall be cleaned and dried prior to laying of DBM. The corridor within which the DBM is to be laid will be set out and marked by pegs. A white line will be drawn by paint with the help of strings to define the extents of this corridor. The pegs shall be driven at every chainage. A tack coat of K160 will be applied lightly just before laying of the DBM where considered necessary. The road deviation adjacent to the area of works will be watered to abate dust. Ramps shall be constructed for the trucks to access the road corridor to ensure the embankment and other completed layers are not disturbed. The material shall be laid by pavers working in echelon. The trucks shall queue in front of the pavers and will be reversed in turns to tip into the hopper of the pavers. Once an adequate quantity is tipped into the hoppers, the temperature will be checked to ensure compliance with the specifications. The material will be sampled for testing and analysis at the laboratory for Marshall requirements, extraction of binder and aggregate grading. The material will be mixed further by the auger of the pavers. Tipping shall be slow and gentle to avoid segregation. The material will then be laid in one layer of 150mm thick and initial compaction provided by the pavers. The compaction factor from the pavers is about 80% and is adequate to provide stable slope at the macadam edges to support roller weight without undue movement. The slopes will be compacted use of hand rammers. A dip stick will be used to check the layer thickness by dipping regularly into the laid material. Necessary adjustments will be made to the pavers to correct the layer thickness during the operation. Laying operations shall only commence once several tippers/trailers have queued in front of the paver to avoid stoppage of paver operations that could result in ripple effects or surface distortions. Compaction shall commence with the pneumatic tyre roller followed by the smooth steel vibratory roller. Four passes of both rollers will be used for a start, to be adjusted accordingly once compaction results are obtained. The rolling shall overlap at the joint. The temperature of the material shall be checked again at the completion of compaction for compliance with the specifications. The slope (camber/crossfall) of the final surface shall be checked
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using a straight steel edge. Cores will be cut from the trial section to determine the density of the compacted material and also confirm thickness laid, refusal density, voids at refusal, stability and flow. The holes will be filled with hot DBM the following day after application of tack coat and rammed manually to levels exceeding the surrounding slightly. 3. Resources for Execution a) Materials Dense Bitumen Macadam from the asphalt plant complying with Clause 1603B and 1604B of the standard specification and approved by the supervisor. b) Plant Asphalt Plant – 1 No (100 ton/hr) Production of Asphalt Concrete material using aggregate and bitumen Tippers (20 Ton) - 10No Tipper trucks will be used to haul aggregate material from the crusher stockpile and also DBM from the asphalt plant to the road. Water Tanker (18,000 litres ) – 1 No Cleaning the graded crushed stone surface and watering deviation if /where necessary and filling of rollers Tractor drawn Mechanical Broom – 1No Cleaning the graded crushed stone surface Vibratory Smooth Steel Roller (9 ton) – 2 No Compaction Pneumatic Roller (7 wheels each 5 ton max) – 1No Paver-1No Laying of Dense Bitumen Macadam Water Pumps – 1No Fill up the water bowser c) Senior Supervision personnel Consultant Material Engineer Site Manager Assistant Site Manager Superintendent of works Quality Control Materials Engineer Laboratory field team ( on-field ,sampling and testing ) Laboratory team (lab testing and analysis ) d) Labour Foremen

- 2 No
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Operators Drivers Head men Unskilled Labourers Watchmen

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11No 33No 2No 10No 6 No

7. Cement Concrete
1. Introduction
The starting point for cement concrete works will be the identification of materials that meet the required specifications and establishment of the batching plants. This will be followed by determination of (design/job mixes) material proportions to be applied to the different classes of concrete. The materials will then be mixed, transported, placed and compacted in the appropriate locations to give a strong and durable component of the permanent works. All bulk material shall be stock piled at our Mlolongo-Katani site, JKIA camp site, Globe Cinema roundabout, Museum Hill or at Aristocrat Quarry. Cement may be stocked by the various engaged manufacturers in stores clearly identified and reserved for this project only. Materials will be regularly transported from this bulk storage to satellite stores in various work sections. Cement shall be stored in both silos and bags. The various classes of concrete required under this contract include concrete classes 15, 20, 25, 30, 35, 40 (N/mm2) Annexure for detailed methodology on concrete on bridges and related structures including RE walls will be provided as soon as geotechnical investigations are completed and our bridge engineers come in and discuss details on the bridge and other structures designs. To achieve the foregoing, the following steps will be followed:

2. Material

Sources

a. Course aggregates
We shall establish a crushing plant at Mlolongo-Katani. The area has geological features that produce adequate quantity of rock that produces strong and clean aggregates. There are other operational quarries in the area that are producing aggregates for the construction industry. The rocks will be crushed and separated to different sizes using appropriate sieves on the crushing plant. Before our crushing plant is established and operational, we intend to buy any required aggregates from the existing quarries. The aggregates will be analyzed to ascertain that they comply with all specifications before any orders are placed. We shall also minimize the number
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of suppliers to avoid frequent analysis. Details of our crushing plant are provided in the asphalt section above.

b. Fine Aggregates
Fine aggregates will either be river sand, crushed sand or a combination of river and crushed sand. Tests will be undertaken for compliance with specifications. River sand will be supplied from Kajiado and Machakos, whereas crushed sand shall be from our Katani quarry.

c. Cement
Ordinary Portland cement will be obtained from the local cement manufacturers, whose product has been approved by the Kenya Bureau of Standards. Any additional tests will be undertaken as instructed by the Engineer.

d. Water
We shall get clean water from the mains supplying Nairobi City. Applications for connections and metering will be submitted to the relevant Authority.

e. Steel Reinforcement
The initial requirements will be met from the local market after testing and approval by the Engineer. However, most of the steel will be imported after compliance certificates are received from the manufacturers and approved by the Engineer.

f. Formwork /Falsework
The formwork for the reinforced concrete structures shall be manufactured to produce or to give the specified finishes. The formworks for the different structures will be constructed using the materials outlined below. All formwork for insitu concrete will be subject to approval by the supervision team on site whereas formwork for all precast concrete the contractor shall prepare and submit shop drawings for approval before commencing any concreting works. All imported form for precast works in bridges and other structures will be submitted to Engineer for approval before delivery to site. 1. Foundations We shall use 18 mm thick weather proof plywood in conjunction with 50 mm diameter steel pipes. 2. Columns & Copings Manufactured steel sheet formwork shall be used. 3. Abutments 18 mm thick weather proof plywood with 50mm diameter steel pipes. 4. Super structures Prestressed precast Girders:

Manufactured steel sheets shall be used.
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Box beam: be used.

A combination of weather proof plywood and steel sheet will

All false works shall be 50 mm Diameter steel pipes. Before the commencement of manufacturing or fabrications, the necessary designs shall be submitted to the Engineer for approval. Fabrication locations will be as indicated in our camp site establishment proposal (i.e. at Globe Cinema roundabout and Museum Hill).

3. Mixing Materials
Before production of concrete for permanent works, design and job mixes/trial mix will be made to determine the optimum combination of materials to produce a specific class of concrete. Full production will commence upon the approval of the job/trial mix. We shall establish two batching plants of 50 and 75m3 per hour capacity. The 50m3 capacity is already operational at site camp B located at JKIA. This unit will be used mainly for production of small precast units like road kerbs, channels and paving slabs. The plant will also be used for production of concrete that may be required before the installation of the 75m3 per hour plant. Aggregates will be hauled generally at night by trucks from material sites to plant locations either at camp site B or Globe Cinema Roundabout. Due to the limited space available at Globe Cinema, the stock piled materials will be for two to three days consumption. The batching plants are fitted with automatic controls. Once the design mix has been approved, automatic controls will be set to give the mix. The different sizes of aggregates will be fed mechanically into the bins, which will then discharge the required quantities to the mixing drum. The combined materials will be mixed in the drum until a homogeneous mixture is attained.

4. Transportation of the Ready Mix
The mixed materials shall be discharged from the mixing drum to mobile transit mixers of 6m3 capacity. Care will be taken to take into account the time taken from the batching plant to the pouring point. In the event of traffic congestion challenges, admixtures, retarders, plasticizers etc may be introduced with the approval of the Engineer.

5. Placing of Concrete
When the ready mix reaches the site, it will be transported to the required point using either crane mounted bucket or pumping equipment. The bucket will be used for foundations while pumping method will be appropriate for super structures. All the necessary care will be taken to avoid any segregation.

6. Compaction

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The concrete shall be compacted by 35 mm or 50 mm mechanical immersion poker vibrators. The placed layer shall be fully compacted before proceeding to the next layer. Electric/diesel vibrators of various diameter sizes as approved by the Engineer will be used.

7. Surface Finish The finishing of concrete surface shall be as specified or instructed. taken for the exposed surfaces to ensure aesthetic finishes. 8. Curing

Extra care will be

Curing of concrete will commence immediately after the initial setting. Water retaining sheets, hessian cloth or use of curing compounds will be considered and submitted to the Engineer for approval before application. The frequency of watering or curing compound application per day and the total curing duration shall depend on weather conditions, the specification and Engineers instructions.

9. Joints
Shop drawings for contraction or expansion joints will be prepared and submitted for approval. All joint sealant materials shall be approved by the Engineer before importation.

10. Resources The above method will involve the following input for each operation
1.) Personnel a) b) c) d) e) f) g) h) Engineer – 2 No. Foreman – 5 No. Surveyor – 2 No. Chainman – 3 No. Mason – 5 No. Carpenter - 20 No. Steel fixers – 10 No. Laborers – 65 No.

2.) Equipment with operators a) b) c) d) e) f) g) Batching plant (50m3/h) in JKIA – 1 No. Batching plant (75m3/h) Globe Cinema Roundabout – 1 No. Transit mixers (6m3/h) – 5 No. Concrete pump – 2 No. Vibrator – 10 No. Tower crane – 2 No. Steel cutting machine – 2 No.
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h) i) j) k) l)

Steel bending machine – 2 No. Generator (720KW) – 1 No. Generator (25KW) – 1 No. Dump trucks – 5 No. Shovel – 3 No.

8. RE WALL WORKS I. Introduction
Reinforced Earth wall is a composite material formed by the association of a frictional soil and reinforcing strips. In concept, it is like reinforced concrete; that is, Reinforced Earth wall is an economical means of improving the mechanical properties of a basic material, earth, by reinforcing it with another, steel. The reinforcing strips resist stresses produced within the soil mass; stresses are transferred to the strips via friction. A Reinforced Earth wall structure constructed using this material is the "reinforced volume". Concrete panels are used at the face of the reinforced volume to prevent erosion of the backfill and to provide an attractive, finished appearance. 1. Responsibilities It is the Contractor’s responsibility to complete construction in strict accordance with the Plans, Specifications, and Contract Documents. To assist the Contractor in this regard, the contractor provides proposed erection procedures in this method statement. Nothing in this document is intended to relieve the Contractor of the responsibility of complying with all safety standards and construction procedures, including fall protection, at the job site. 2. Components Reinforced Earth wall structures consist of the following: Concrete Leveling Pad A cast-in-place or pre-cast un-reinforced concrete leveling pad serves as a smooth, level surface for placing panels. Generally this pad is 150mm thick and 300mm wide. Facing Panel Joint Materials Rubber Bearing Blocks are placed in the horizontal joints throughout the structure to prevent concrete to contact. Rubber shims are used as needed to adjust for minor variations in panel height.
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Filter cloth is applied with adhesive to the backfill side of the panels to cover all the horizontal and vertical panel joints. Reinforcing Strips ?Ribbed strips are supplied in a 50-mm width and varying lengths as required by the design of the structure. ?High Adherence (HA) ladder strips are supplied in 100-mm width and varying length as required by the design of the structure. Both types of reinforcing strips are either galvanized for permanent applications or black steel for temporary applications Fasteners During construction, reinforcing strips are fastened to tie strip connections embedded in the back of each facing panel using 12mm diameter bolts, washers and nuts made of structural steel that has been galvanized. Select Granular Backfill Backfill conforming to Contract Specifications must be used within the reinforced volume.

3. Equipment, Materials, Tools and Work Supplied by Contractor. Materials and Equipment supplied by the Contractor will include; Panel lifting A hydraulic crane, boom truck or similar equipment is required for lifting the concrete
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panels. (A standard 137.5mm thick facing panel weighs 770 kg; a 180mm thick panel weighs 950 kg; the heaviest panel weighs 1360 kg.) Backfilling Dump trucks, scrapers, dozers, graders, front-end loaders, water trucks, etc, are used for hauling dumping and spreading backfill. (Specific equipment selection will depend on backfill, lift thickness, compaction specifications, etc). Compaction Large smooth-drum vibratory rollers are used for mass compaction of most backfills. Fine uniform sands are compacted using a smooth-drum static roller. Summary of Work Performed by Contractor Site preparation including excavation and installation of drainage systems as required. ? Forming and pouring concrete leveling pad(s). ? ?Mark wall layout line on leveling pad(s). ? ?Construction of the Reinforced Earth structure consisting of the erection and positioning of facing panels, installation of joint materials, connection of reinforcing strips, placement and compaction of Select Granular Backfill. ? ?Placement of any concrete coping, traffic barrier, etc.

II. Handling Reinforced Earth Materials
1. Concrete Facing Panels Panel delivery Prior to the start of construction, the Contractor shall establish a panel delivery schedule that will allow production of The Reinforced Earth to match the panel production and delivery to the construction schedule. Panels are usually delivered on flatbed trailers in stacks of four or five panels high. The delivery point is made as close to the retaining walls as a truck can be driven under its own power. Unloading of panels Under normal conditions, a two hour unloading period is allowed per delivery to unload panels. In this time, panels may be placed directly into the structure being constructed or temporarily stacked following either of these methods: 1) by using lifting devices to lift and handle individual panels, or 2) by using nylon slings to lift and handle individual panels or stacks of panels Care must be taken to protect facing panels from damage during handling and storage.
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Panels can be stored at the job site by re-stacking. Select a location with firm, level ground for both stability and to protect panels from staining. Carefully lift and place each panel face down on the nylon pads of the dunnage. Stacks should be no more than five panels high with dunnage used between each panel. 2. Reinforcing strips, fasteners, and joint materials Reinforcing strips Strips may be up to 10.8m long and are delivered to the site in bundles of 25 each. Each bundle weighs approximately 45kg/m. Storage in the open is acceptable but bundles should not be placed directly on the ground. Bearing Blocks Rubber Bearing Blocks are packed in cartons each weighing 22.5 to 35 kg Fasteners Sets of 500 bolts, washers and nuts are packed in containers, each weighing 57 kg. Filter cloth Filter cloth is supplied in 450mm. wide rolls. Adhesive for filter cloth is supplied in appropriate containers. Foam strips (if required) are supplied in plastic bags, each containing up to 100 of the 50mm square, 2.15 to 2.75m strips. In addition to normal security, foam must be stored in a sheltered location, protected from sunlight.

III. Construction Procedures
The basic erection sequence for a Reinforced Earth wall structure can be summarized in these steps: ? Prepare the site including excavation and installation of drainage systems if required. ? Form and pour leveling pad ? Set and brace the initial course of facing panels, which consists of alternating half- and full-height panels. ? Use wood wedges and clamps to hold panels in position. ? Attach filter cloth with adhesive. ? Spread and compact backfill in lifts up to 25 or 50mm above the lowest level of panel tie strips ? Connect reinforcing strips to panel tie strips. ? Spread and compact backfill in lifts to within 75 or 125 mm of the top of the half panels. ? Place Bearing blocks and set the second course of full panels ? Repeat cycle of backfilling and compacting in lifts, connecting strips, placing
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? ? ? ?

filter cloth and Bearing Blocks and setting panels until design height is reached. As each course is completed, remove the wooden wedges from the panels in the course three levels below. Set top panels; connect strips, complete backfilling and compaction. Remove all wedges and clamps. Install concrete coping, traffic barriers, etc as required.

The following panel position and alignment procedures should be reviewed prior to the start of construction. Lifting, placing and spacing of panel Panels can be lifted from the horizontal or stacked position, directly to a vertical position by attaching a lifting device to each of the two cast-in-place lifting inserts at the top edge of the panel. Use dunnage as blocking to prevent damage as each panel rotates from horizontal to vertical position. As each panel is lowered into its place in the structure, use the 20mm wooden spacers to achieve approximately a 20mm joint. Check alignment Visually check the alignment of each panel in relation to either the control line on the leveling pad for the initial course of panels or to the panel below in subsequent courses. Check horizontal level The horizontal level of each panel should be checked and adjusted in order to assure a uniform appearance and even joints throughout the structure. Small rubber shims are provided to aid in leveling the panels. Set batter Panels must be given a slight batter, or tilt, toward the backfill in order to compensate for a subsequent outward movement, which occurs during backfill placement and compaction. This movement will tend to push the panel to a true vertical position. Measure the batter using a 1.2m level. Set the batter by pulling back on the top of the panel from the fill side. To maintain the batter, drive one wooden wedge from the face of the structure into each of the short horizontal panel joints at the shoulder of the panel and clamp the panel to the adjacent panels. Note that wooden wedges should remain in place during the erection of three subsequent courses but then must be promptly removed, if wedges are left in place for more than three courses, removal will be difficult and spalling may occur. The amount of batter varies and depends on the type and moisture content of the backfill, required compaction, type of compaction equipment, and length of the reinforcing strips. A batter of 1 in 100 is generally used as a starting point. Coarse backfill, such as crushed
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stone, may require less batter, while fine backfill, such as sand, may require more. Monitor the actual movement of panels during the placement and compaction of each lift of backfill; adjust the amount of batter according to field conditions. Vertical Alignment Check During construction, check the overall verticality of the structure using a plumb bob. This should be done on panels completely backfilled. Make any changes in batter necessary to ensure that final verticality is within tolerances, in subsequent lifts of panels. Erection Tolerances ? The overall vertical alignment tolerance, or plumbness, from top to bottom of the structure, shall not exceed 20mm, per 3m of height. ? Vertical and horizontal alignment tolerance, and plumbness, shall not exceed 20mm when measured with a 3m straight edge on a selected wall section. Vertical and horizontal alignment should be checked at every course throughout the erection process ? The maximum allowable offset between any too panels shall not exceed 25mm. ? Horizontal and vertical joints should be uniform in appearance. 1. Foundation Preparation Step A-1, Excavation Excavate the site to the depth and width specified on the Plans for the length of the section to be built. Remove all unsuitable material and replace it, as necessary, with compacted fill as directed by the Engineer. If required by the Specifications and as directed by the Engineer, proof-roll the foundation to a density suitable for the bearing pressure shown on the Plans. In the event of an over-excavation of the sub-grade, the Engineer must approve the gradation, placement, and compaction of replacement material. Evaluation and approval of foundation suitability is the responsibility of the Engineer. Any foundation soils found to be unsuitable shall be removed and replaced with material approved by the Engineer. The material shall then be compacted, as directed by the Engineer, to a density suitable for the bearing pressure as shown on the Plans, Specifications, and Contract Documents. Foundation evaluation and control are critical; the behavior and performance of a Reinforced Earth structure is largely dependent upon the foundation on which the reinforced volume is placed. Step A-2, Drainage System(s) Install any drainage systems as required by the Plans and Specifications or as directed by the Engineer. Step A-3, Leveling Pad An un-reinforced smooth finish concrete leveling pad is formed and cast at each foundation elevation. Leveling pads have nominal dimensions of 150mm thick by
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300mm wide and are cast using a minimum 2,000-psi, 28-day compressive strength concrete. Leveling pads should cure for a minimum of 12 hours before the setting of panels. Leveling pads must be cast to the design elevations as shown on the Plans. The allowable elevation tolerances are +3mm and –6mm at design elevation. An improperly placed leveling pad can result in subsequent panel misalignment and decreased wall construction productivity. If the Plans call for the structure to have a step-up in elevation, pour the higher leveling pad so that its surface is 375 or 750mm above those of the lower pad depending on the Plans Leave a 300mm gap between the higher pad and the start of the lower pad at the step-up location. Step A-4, Wall Line On the leveling pad, establish a layout line for the face of the structure. This may be different than the wall’s level given in the contract documents. 2. Erecting the Initial Panel Course Step B-1, Panel Placement Panel layout usually begins at the lowest leveling pad and from left to right when facing the front of the structure Place the first Base (half) panel 1 on the leveling pad. Check the horizontal level and shim as needed. Align the face of the panel along the layout line; and using wooden wedges at the base of the panel, set the batter for the panel. Throughout construction it is of utmost importance that the panel type and number of tie strips of each panel match the requirements as shown on the approved Plans. Bearing Blocks are not used under the first course of panels between the leveling pads, unless specifically shown on the Plans. If needed, only rubber shims may be used to shim between the leveling pad and first course of panels. Wood shims are not permitted at any point in the structure. Panels should be free of any surface defects that may occur in transportation, unloading, or storage at the construction site, including: ? Chipped or broken front corners. ? Permanent stains on exposed face. ? A crack in panel’s exposed face. These panels may be repaired before they are used in the structure. Any repairs to panels must be completed to the satisfaction of the Engineer. Step B-2 Place the second panel 2 on the leveling pad and place a 20mm spacer between it and panel 1 these spacers should remain in place until the wall is backfilled to the height of the half size panels. Spacers must be used during panel erection. Spacers are supplied by the Contractor and may be fabricated from any available 20mm material. Panels must be
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braced as shown in Figures 17 and 18 prior to releasing the crane from the panel. Step B-3 Set the panel’s batter as before. Wooden wedges are used temporarily at the panel shoulders to set batter in the panels. These wedges must be removed once the wall is three panels high. Tighten clamps sufficiently to hold the panel in position without movement. Brace the initial course of panels by securely attaching an adequate lumber brace to a bracing clamp attached to the top of each full panel and to any panel in excess of 900mm in height. Bracing is not required on subsequent courses. Bracing must remain in place until the braced panel has all the reinforcing strips attached and the backfill has been placed and compacted up to the top of the braced panel. Step B-4 Place a third panel 3, aligning the panel with the control line and use a 20mm spacer to ensure spacing. Check the horizontal level of the panel and shim as necessary. Set the panel’s batter. Step B-5 Continue setting the panels in this manner and site back along the tops of the full height panels to assure that each new panel is at the elevation of the others in that course . After ten panels have been set, recheck the wall’s alignment by sighting along the wall face. Adjust panels if needed to obtain a true line. 3. Joint Materials Step C-1 Joint materials are installed only from the backfill side of the structure only. Filter cloth prevents the loss of fine backfill particles while allowing the structure to be free draining. Bearing Blocks prevent concrete-to-concrete contact between facing elements vertically. ? Filter Cloth is affixed to the backfill side of both the vertical and the horizontal panel joints using several dabs of a contact adhesive. ? Bearing Blocks are placed in grooves on top of each panel. Thickness and/or quantity at various levels within the structure may differ and must be in strict accordance with the Plans. 4. Backfilling The constructability and performance of a Reinforced Earth structure directly relates to the quality of the Select Granular Backfill and to the manner in which it is installed. Prior to placing the Select Granular Backfill, the Contractor shall certify to the Engineer that the material conforms to the requirements stated in the Plans, Specifications, and Contract Documents for Reinforced Earth structures.
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Select Granular Backfill material to be used in the reinforced volume must be tested and shown to strictly conform to the Specifications. Material, which does not conform, cannot be used as Select Granular Backfill. Step D-1 Place and compact initial lifts of Select Granular Backfill up to bottom row of panel tie strips. Note that the uniform loose thickness placement of each lift of backfill material must not exceed 300mm. The level of the compacted backfill should be 50mm above the tie strips. In order to avoid pushing the braced panels out of alignment, initial lifts of backfill are neither placed nor compacted against the back of the panels. Only after the first layer of reinforcing strips has been connected to the panel tie strips as detailed in section E-and a lift of backfill placed and compacted over the strips can backfill then be placed and compacted against the back of the panels. Compact each backfill lift using a large smooth-drum vibratory roller except within a 900mm zone directly behind the panels where a small hand-operated vibratory compactor must be used to avoid undue panel movement. After compaction has taken place, check wall alignment visually and with a level adjust panels as necessary. The gradation of the Select Granular Backfill should be tested periodically during construction to assure compliance with the Specifications. This gradation testing should be performed for every 1550m3 of material placed and/or whenever the appearance or behavior of the material noticeably changes. Immediate gradation and moisture testing is required if either excessive panel movement or backfill pumping occurs during construction. Step D-2, Compaction Large smooth-drum vibratory rollers are used to accomplish mass compaction of Select Granular Backfill materials, except for fine uniform sands. Sheep foot Rollers are never to be used for compaction of Select Granular Backfill. Fine uniform sands, which contain more than 60 percent passing a No. 40 sieve used for Select Granular Backfill, must be compacted using a smooth drum static roller. Vibratory compaction equipment should not be used to compact fine uniform sands. Compaction within 900mm of the back face of the panels shall be achieved by at least three passes using a lightweight mechanical tamper, roller or vibratory compactor. Compaction testing should not be performed in this 900mm zone. At a minimum, Selected Granular Backfill material must be compacted to 95% of maximum density, per AASHTO T-99, methods C or D If 30% of the Select granular Backfill material is greater than 20mm in size, AASHTO T-99 is not applicable. For such material, the acceptance criterion for compacting is either a minimum of 70% of the Relative Density of the material as determined by ASTM D-4253 and D-4254, or a Method Specification based on a test compaction section which defines the type of equipment, lift thickness, number of passes of the specified equipment and placement moisture content. Moisture content of Select Granular Backfill material during placement should be
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approximately 1% to 2% less than its optimum moisture content. The minimum frequency of compaction testing shall be one test per lift of Select Granular Backfill material placed. Test locations are determined by the Engineer. Step D-3, Grading At the end of each day’s work, backfill must be graded to slope away from the back of the panels in order to divert water runoff from the structure area. Failure to properly grade the backfill can result in excessive water in the Select Granular Backfill and cause subsequent movement of the panels beyond alignment tolerances. 5. Reinforcing Strips Step E-1 Place reinforcing strips on the compacted backfill. Position strips perpendicular to the facing panels, unless otherwise shown on the Plans. Reinforcing strips are supplied in lengths as shown on plans, with a tolerance in length from 0 to + 200mm. Connect each reinforcing strip to the embedded panel tie strip by inserting the end of the reinforcing strip into the gap between the two exposed ends of the tie strip. Match the three holes and push a bolt through the holes from below, placing a washer on top, threading on a nut, and tightening. Bolts must fit up through both tie strip flanges, perpendicular to the steel surfaces, and have full bearing of the bolt head and washer/nut against the tie strip flanges. Use a crescent or socket-head ratchet to securely hand tighten the nut. In specific, limited situations it may be necessary to skew a reinforcing strip from its design location (perpendicular to the facing panel) in either the horizontal or vertical plane. Design of the Reinforced Earth structure is based on the perpendicular placement and connection of reinforcing strips, unless otherwise detailed on the Plans, and on installation of the correct density and length of strips to each panel. The placement of any reinforcing strip in a skewed manner, unless shown on the Plans, Specifications, and Contract Documents, must be authorized in writing by The Reinforced Earth Company prior to placement in the field. Step E-2 Dump backfill onto the reinforcing strips so that the toe of the backfill pile is 900 to 1200mm from the panels. Spread the backfill by pushing the pile parallel to the panels and wind rowing it toward the panels and toward the free end strips. If strips are long, a second load may be required to backfill to the ends of the strips. If so, dump and spread this load only after spreading the first. Continue to backfill to the full height of the half panels. Metal tracks of earthmoving equipment must never come in contact with the reinforcing strips. Rubber-tired vehicles, however, can operate directly on the exposed strips if backfill conditions permit and care is exercised.

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Step E-3, Step-up If required to make a step-up in elevation of the wall, use the following procedure. Mark a wall layout line on the upper level pad to establish a wall-face control line. Place the next required panel along the control line, space 20mm set its batter and brace if necessary. Then continue construction of the upper course using the procedure used on the lower level. 6. Completion of Wall StepF-1 In placing top course panels, the construction sequence continues as previously outlined. However, top course panels have either a flat or a sloping edge and may be supplied in varying heights to meet finished-elevation requirements. Refer to the Plans for the location of specific top panels. Step F-2 After backfilling is complete, remove all clamps and wooden wedges from the structure. Step F-3 Install top wall treatment. If required. Several types are commonly used: ? Cast-in-Place. If required, rebar for connection will protrude from top panels. All necessary attachment details for a barrier, coping, parapet, or paved ditch will be shown in the plans. ? Pre-cast Coping. If approved, pre-cast coping will be supplied. Attachment details will be shown in the Plans. ? Plain. The top of panels will remain exposed with no further treatment necessary. Sometimes called stepped top.

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