Method Statement For Dbst Road Maintenance

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Revised 1

Method Statement For the Overall Maintenance Works of National Road No. 3 (From PK147+100 to PK 201+400) AND PERFORMANCE/OUTPUT BASED ROUTINE MAINTENANCE

Date: 05/07/2012 (Revised 1) 1

| CAMRA TECHNICAL PAPER No. 2 – All rights Reserved 2013

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Contents 1.

General Information

2.

Quantities of Works

3.

Reference

4.

General Construction Layout

5.

Construction Method Statement 5.1 Earthwork 5.2 Sub-bases and Base Course 5.3 Bitumen Works 5.4 Drainage and Protection Works Construction Process Chart 6.1 Repairs of Cracks 6.2 Repairs of Potholes 6.3 Repairs of Patches 6.4 Repairs of Edge Breaks 6.5 Spread of Seal Coat Quality Control of Works 7.1 Quality of Works 7.2 Quality Control of Works

6.

7.

8.

Safety of Works 8.1 Establishment of Safety Organization 8.2 Safety Organization Requirements 8.3 Safety Management of Transportation, Mechanical Operation

9.

Protection of the Environment 10.1 Water Quality 10.2 Air Quality 10.3 Noise 10.4 Control of Wastes

10. Methodology of Performance/Output Based Routine Maintenance 10.1 Performance Monitoring and Procedures 10.2 Contract Staffing and Sub-Contractors

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| CAMRA TECHNICAL PAPER No. 2 – All rights Reserved 2013

Revised 1

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

1.

Revised 1

General Information

The project – the road maintenance cover part of National Road No 3 from KM0+000 (Existing PK 147+100) to KM 54+300 (Existing PK 201+400) of the length 54.3km in Kampot Province and on overall this project is scheduled to complete in 24 months. The project road has been separated into 3 sections with two different ways of maintenance works as follows: Section 1 km 0+000 – km 12+300

Section 2 km 12+300 – km 32+850

Section 3 km 32+850 – km 54+300

Maintain under terms of performance/output based routine maintenance

Pavement restoration - repair under terms of quantity/unit-priced maintenance works

Maintain under terms of performance/output based routine maintenance

However, due to the current severe-damaged conditions of the road, the repair under terms of quantity/unit-priced maintenance works will be implemented for the first 3 months on the Section 1 and 3 to restore the road to the “maintainable” condition. In the meantime the performance base routine maintenance will also be implemented on these sections where there are maintainable conditions. Nevertheless, on overall the Work components include the following:  Repair of potholes, pavement failures, edge breaks and other pavement distress areas.  Repair of damaged embankment side slopes, including reinstatement of shoulders.  DBST/AC repair/overlay of the several lengths of road.  Maintenance of the road during defect liabilities and performance base routine maintenance.

2.

Quantities of Works

2.1

Earthwork: Embankment fill is 1400 m3, and sub-grade material is 980 m3. Of which roadway excavation is 10313 m3 and channel excavation is 4000 m3 while clearing and grubbing is 60000 m2.

2.2

Sub-base and Base Course: The sub-base is 2800 m3, aggregate base course is 6930 m3 and soil aggregate shoulder is 1200 m3.

2.3

Bitumen Works: The bituminous seal coat (12 mm) is 43500 m2, while sealing aggregate (12 mm) is 43500m2, bituminous seal coat (19.0 mm) is 32510 m2, while sealing aggregate (19.0 mm) is 33251m2. Others are the repair of cracks (5500 m), repair of potholes is 2000 m2, repair of edge break is 1950m; leveling with Bitumen surface treatment 3600 m2; repair of base course failure is 4330 m2

2.4

Drainage and protection works include Grouted Riprap (Class A) of 150 m3, Block Sodding slope protection of 20000 m2, and Topsoil for embankment slopes of 20000 m2, and cleaning existing drainage systems for pipe less than 1m dia 744m and for pipe greater than 1m dia 1014m and Cleaning existing channel through bridges 1164m.

3.

Reference    

Contract Documents of Road Maintenance National Road No 3 (NR-3) of Cambodia and Clarification to Questions American Association of State Highway and Transportation Official (AASHTO) American Society for Testing and Material (ASTM) Australian Standards (AS)

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

4.

General Construction Layout

4.1

Facility Layout

Revised 1

With the approval of the Engineer/Employer, the Engineer’s Facilities (Office, Material Testing Laboratory, and Housing Accommodation) to be provided and located at khum Prek Tnot Srok Chhouk Kampot (at nearby Kdat Primary school, about PK 20). As requested by the Employer, the Contractor’s Project Management Office is alos located next to the Engineer Office. However, to be appropriate distance for road maintenance of NR3 the material stockpiling yard will be established at PK 27+000.

4.2

Water Use

The water from pond and waterfall from Bokor Mountain along National Road is used for the curing of the sub-grade, pavement, and other construction work. The water from the wells nearby is also used for the construction purpose.

4.3

Electricity Supply

Kampot electric network is connected to the Project Management Offices. In order to ensure sustainability of site construction, the generator sets have been already put in place at the Project Management Offices.

4.4

Communication

Key personnel have been provided with cell phones and internet modem to facilitate the internal and external communication.

5.

Construction Method Statement

The construction works are being carried out in compliance with the Technical Specification and Engineer’s instruction.

5.1

Earthwork

5.1.1 Description The sub-grade material is 980 m3, while the embankment fill is 1400 m3. The quantity of the roadway excavation is 10313 m3 and the channel excavation is 4000 m3, while the quantity of clearing and grubbing is 60000 m2. The earthwork is executed mechanically, which is assigned for construction team to complete.

5.1.2 Clearing and Grubbing With the direction and instruction of the Engineer, at the designated areas, the motor graders and excavators are used to clear, remove, and dispose all vegetation, silt and grubbing roots, down timber and other unacceptable materials.  

Large trees and stumps within construction area is cut down by hand and then be transported and stockpiled at designated place directed by the Engineer. Small vegetation, timber piles, roots, and silt is curved by excavators and then is transported to the spoil area directed by the Engineer.

The clearing and grubbing, unless otherwise instructed by the Engineer, include also the removal of all roots, stumps, untidy vegetation, rubbish, garbage and to the extent that these materials are not, in the opinion of the Engineer, obstruct the future maintenance. All unsuitable materials are wasted and re-spread at designated locations in a neat and orderly way as agreed by the Engineer.

5.1.3 Roadway Excavation The works shall be composed of common, unsuitable excavation, and the excavation of bituminous materials, which is accounted for 10313 m3. Roadway excavation includes the removal, hauling and proper utilization, or disposal of all excavated materials, the shaping of excavation and the preparation of exposed surfaces of excavation on the entire length of roadway. The survey team marks all excavated locations, lines, level, grades, dimensions, and cross section, which is shown on the Drawings and as directed by the Engineer. 4

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Revised 1

5.1.4 Channel Excavation The work consists of excavation for channels of 4000 m3 both inside and outside the right of way, where shown on the Drawings, or specified in the Special Provision, or directed by the Engineer. The work includes the proper utilization and hauling or disposal of all excavated materials, constructing, shaping and finishing all earthworks involved in conformity with the required alignment, levels, grades and cross sections. Based on the Drawing, the Survey Engineer set out the level line and measure the original ground elevation, then figure out the excavation depth according to the designed bottom elevation, and then mark it up with stakes. During the construction, the channel is kept drained as far as practicable and the work is constructed in a neat and workmanlike manner. The unsuitable materials are transported to the spoil area, while the materials that could be used for sub-grade filling or slope block sodding and formation of embankments are stocked together nearby. The channel sidelines are trimmed manually to ensure lines smooth and fluent.

5.1.5 Embankment This work consists of the construction of embankment by furnishing, placing, compacting and shaping suitable material of acceptable quality obtained from approved sources in according with the Specification, and to the lines, levels, grades, dimensions, and cross section shown on the Drawings and as required by the Engineer. The embankment filling materials are tested in accordance with the Specification to determine the appropriate materials prior to execution. Not until approved by the Engineer, the filling shall not be started. Natural ground situated less than 1.5 m below the design surface of the road or side slopes, after proper clearing and grubbing or scarifying of existing road surface, are compacted to a depth of 150 mm, to not less than 90 % of the maximum dry density of the material as determined by AASHTO test method T180. If unsuitable materials occur in some areas under embankment or in existing embankment, such materials are removed to levels as directed by the Engineer, the bottom of the excavation is compacted, and areas backfilled and compacted layer by layer with suitable material

5.2

Sub-base and Base Course

5.2.1

Description

The work consists of repairing sub-base and base course failure and spreading sub-base and base course in accordance with the Specification and the Drawings. 5.2.2

Sub-base

This work consists of furnishing, placing and compacting sub-base material on a prepared and accepted sub-grade to the lines, levels, grades, dimensions and cross sections shown on the Drawing and as required by the Engineer. Based on the Drawing, the Engineer sets out the horizontal position of sub-base, determine the thickness of spreading, and then mark it up with stakes. Prior to sub-base spreading, watering cart is used to wet the sub-grade to ensure the cohesiveness between them. The sub-base is shaped, compacted and completed for at least 150 m ahead of the placing of the sub-base course material and subject to the requirements of the Contract for the Engineer’s approval of the sub-grade before it is covered up. The sub-base is spread in even layers not exceeding 150 mm after compaction. Care is taken to prevent segregation, and oversized particles are hand-picked from the deposited layer prior to compaction. Immediately after each layer has been spread and shaped satisfactorily, each layer is thoroughly compacted with suitable and adequate compaction equipment. Each layer is compacted to at least 95 % of the maximum dry density, as determined by AASHTO T180. 5.2.3

Base Course

The work shall be composed of aggregate base of 6930 m3 and soil aggregate shoulders of 1200 m3. This work is determined to execute in accordance with the above method of sub-base.

5.3

Bitumen Works 5

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

5.3.1

Revised 1

Description

This work shall consist of repairing existing defective bitumen pavement, including bituminous surface treatment, longitudinal cracking, block cracking, patches, and edge breaks, which is assigned for two construction teams to complete for NR3. 5.3.2

Bituminous Prime Coat

This work consists of the preparation for and application of a bituminous prime and blotting material to a previously prepared and untreated surface. via: earth sub-grade, crushed aggregate base course, cement or lime, stabilized base course, top of roadway shoulders, concrete bridge deck, etc in accordance with the Specification and in close conformity with the lines shown in the Drawing or established by the Engineer. Slow setting cationic emulsified bitumen is chosen as the prime coat, whose quantity and quality are in conformity with the Specification. Pre-distribution is done to check the consistency of bitumen:   



The prime coat is sprayed after clearing the cutting left over of existing defective pavement. A slight application of water is made if the surface is over dry. It is determined to execute by a bitumen distributor, which is fitted with a handheld, manually operated bar fed by a flexible line for use on areas too small to be satisfactory sprayed with the main bar. Before any bitumen distributor is used on the works, the calibration of the nozzle shall be checked in a series of field tests to maintain appropriate speeds for the proper application of the bitumen. During the progress of the work, it is sprayed uniformly at one time in accordance with the designated bitumen capacity in case of bitumen's flowing to penetrate into the base course. Oil slick formed on the surface is not permitted. Once any omission occurs, remedial spraying is done manually. After the spraying, the traffic is strictly regulated in case of any vehicle or person passing through. No spraying is carried out on a wet pavement, while rain appears imminent or during high winds; the extra prime coat bitumen, which has not penetrated into base course, is cleared immediately.

5.3.3

Bituminous Seal Coat

This work shall be applied to the execution of the prime coat. Reference shall be made to 5.3.2. 5.3.4

Sealing Aggregate

Aggregate spreader is used in the execution of construction:  



The crushed stone aggregate is spread before emulsion breaking. To ensure a good cohesiveness between aggregate and bitumen, crushed stone aggregate is spread once emulsion stops flowing. The crushed stone aggregate is spread uniformly and not be overlapped, which cover the full pavement with no exposing bitumen. Manually remedial work is done when any local omission occurs. The crushed stone aggregate adheres to bitumen emulsion through rolling and integrates with it after its breaking. Where there is excess aggregate, the unsuitable is removed immediately to make the surface level uniform. Pneumatic-tired roller of 10 tons is used to compact, which is executed when the bitumen becomes fully black and emulsion has been breaking. One to two-time light rolling is done firstly and re-rolling be started after it is dry.

5.3.5

Repair of Cracks

This work applies to the repair of linear cracking, or narrow-sections of block cracking in accordance with the Specification or otherwise directed by the Engineer. The method of repair depends on the width of cracking and the area of block cracking. Larger areas of block cracking are treated as patches. The operation of preparing and filling cracks is completed in the same day to ensure open traffic on time. 

For the linear cracking less than 2 mm:  All cracks are cleaned out with compressed air (and a wire brush, if necessary), to remove all dust and loose particles.  Cracks are dried with a heat gun, or similar, if moisture is present. 6

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA



Revised 1

After cleaning and drying, cracks are to be filled with a modified bituminous material or bitumen emulsion, having a viscosity low enough to enable it to be penetrated into the crack.



For the linear cracking less than 6 mm:  All cracks are cleaned out with compressed air (and a wire brush, if necessary), to remove all dust and loose particles.  Cracks are dried with a heat gun, or similar, if moisture is present.  After cleaning and drying, cracks are to be filled with a modified bituminous material or bitumen emulsion, having a viscosity low enough to enable it to be penetrated into the crack.  A single bituminous treatment surface (SBST) sealing coat, with a width of 20 cm regarding the cracks as the central line, is spread.



For the linear cracking more than 6 mm:  Regarding the cracks as the central line, the excavation and removal of bituminous pavement within 15 cm from the line are completed. A cutting line, which has to be parallel or vertical with the central line of road pavement, is drawn by chalk in the fields intended to excavate before executing. Then, the cutting with a depth of 75 mm or otherwise directed by the Engineer is made along the drawn line in order to ensure longitudinal and leveling sides of the cutting groove straight.  The materials of base course are loosened arid re-compacted and all unsuitable materials must be removed if any.  A bitumen prime coat is spread manually.  A double bituminous treatment surface (DBST) is spread.

5.3.6

Filling Potholes and Patch Repairs:

This work includes repair of potholes, patching, and areas of block cracking in all types of bituminous pavement. It also includes the removal of all failed material, in the pavement course and, if necessary, below the pavement, until the root cause of the failure is removed. The replacement of material is as high a standard as that which was originally specified for the pavement layer; the compaction, trimming and finishing of the surface of all patches shall be able to form a smooth continuous surface, level with the surrounding road. For pothole and patch repair: 

A cutting line of a regular straight sided rectangular shape, which has to be parallel or vertical with the central line of road pavement, is drawn by chalk in the fields intended to excavate before executing. Then, the cutting with a depth of 75 mm or otherwise directed by the Engineer is made along the drawn line in order to ensure longitudinal and leveling sides of the cutting groove straight.



The repair area is thoroughly cleaned with compressed air or other method approved by the Engineer to remove all dust or loose particles. Damaged or disturbed layers below the level of the bituminous construction is excavated into the shapes of benches, each of which is with a width of 20 cm, be repaired or replaced using material of the equivalent to original ones and be compacted in accordance with the Specification. A double bituminous treatment surface (DBST) is spread. The bituminous material chosen for the repair is to be applied or laid, and compacted in accordance with the relevant clause of the Specification. While placing the final layer, the mix is spread slightly proud of the surface so that after rolling, the surface is flush with the adjoining surface. If the area is large, the spreading and leveling are done using hand shovels and wooden straight edges. During the process of compaction, the surface is checked using 3 m straight edge and required camber or cross fall is maintained.





5.3.7

Repair of Edge Break

Damaged sections of the edges of carriageways or pave shoulders are removed and renewed with fresh material, as indicated on the Contract Drawings, using materials and a methodology as for the repair if potholes etc above. The 7

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Revised 1

adjacent earth verge or soil-aggregate shoulder is subsequently brought up to the level of the bituminous pavement or shoulder in order to protect future protection of the repair. 5.3.8

For Depressions in the Pavement

This work consists of depressions of bridge abutments and service pipes, wheel ruts and shoving. As for these defective pavement, they are rectified by recourse to appropriate techniques as indicated on the Contract detailed Drawings, such as the application of a leveling course or courses, scarifying to remove excess material (subsequent to an overlay), or implementing a patch repair or full-depth reconstruction. 

For depressions less than 6 cm:  A cutting line of a regular straight-sided rectangular shape is drawn by chalk in the fields intended to excavate before executing. Then, the cutting with a depth of 25 mm is made along the drawn line. Finally, all bituminous material is carved out of sides of the cutting groove.  A bituminous tack coat is spread along the sides of the cutting groove.  The bituminous concrete then is spread and compacted.



For depressions more than 6 cm:  A cutting line of a regular straight-sided rectangular shape is drawn by chalk in the fields intended to excavate before executing. Then, the cutting is made along the drawn line.  The sub-base, base course and DBST or AC (asphalt concrete) pavement are excavated into benches with a width of 20 cm one by one. All loose material on the roadbed is also removed if any.  All materials, which is of the same as the original ones of existing layers are backfilled and compacted one by one in accordance with the Specification.



For Shoving:

Shoving is a type of small-localized failure of bituminous pavement, due to pick up of heavy vehicle on the soft bituminous surface treatment. The method to repair this type of failure is as below steps:      

  

 



Cut the defect area in square Remove the defected bituminous surface treatment and other disturb materials. Clean the cut areas by air Compressor. Apply CRS-2 as per calculation rate for first layer is 1.80 liter / sq-m. Hand spreading of chip seal aggregate 19 mm as per calculation rate. In order to press the stone on to the binder, remove the stone so that their least dimensions are vertical and to achieve mechanical interlock between the stone, rolling should continue until the aggregate has been well embedded in the binder and uniformly textured surface is obtained. Apply CRS-2 as per calculation rate for second layer is 1.1 liter/ sq-m Hand spreading of chip seal aggregate 12.5 mm as per calculation rate. In order to press the stone on to the binder, remove the stone so that their least dimension are vertical and to achieve mechanical interlock between the stone, rolling should continue until the aggregate has been well embedded in the binder and uniformly textured surface is obtained. In case, third layer is required to carry out a same procedure as per second layer. In case of repaired surface is overlaid after repair works; only the fill with DBST on the lower part is needed and cut back to design level on the rough and hump of surfaces.

For repair of base course failure

This work include repair of base course failure in all types of existing bituminous pavement. It also includes the removal of all failed material, in the pavement course and, if necessary, below the pavement, until the root cause of the failure is removed. The replacement of material is as high a standard as that which was originally specified for the pavement layer; the compaction, trimming and finishing of the surfaces of all patches are able to form a smooth continuous surface, level with the surrounding road.

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA



 





Revised 1

A cutting line of a regular straight sided rectangular shape, which has to be parallel or vertical with the central line of road pavement, is drawn by chalk in the fields intended to excavate before executing. Then, the cutting with a depth of 75 mm or otherwise directed by the Engineer is made along the drawn line in order to ensure longitudinal and leveling sides of the, cutting groove straight. The repair area is thoroughly cleaned with air compressor or other method approved by the Engineer to remove all dust or loose particles. Damaged or disturbed layers below the level of the bituminous construction are excavated into the shapes of benches, each of which is with a width of 20 cm, be backfilled using material of the equivalent to original ones with the depth of 20 cm and be compacted in accordance with the Specification. A double bituminous treatment surface (DBST) or AC is spread. The bituminous material chosen for the repair is to be applied or laid, and compacted in accordance with the relevant clause of the Specification. While placing the final layer, the mix is spread slightly proud of the surface so that after rolling, the surface is flush with the adjoining surface. If the area is large, the spreading and leveling is done using hand shovels and wooden straight edges. During the process of compaction, the surfaces level is checked using 3 m straight edge and required camber or cross fall is maintained.

For full depth reconstruction of failure:

This work is referred to the Repair of base course failure, but the depth of repairs of which the sub-base and base course. In the event that sub-grade has been already failed, this work is reconstructed together as directed by the Engineer. 5.4

Drainage and Protection Works

5.4.1

Description

This work consists of cleaning existing drainage pipes along the road and existing channels through bridges, of which drainage pipes, which is less than 1 m diameter, used for the drainage pipeline of local residents along the road, are of difficulty to dredge because of their small aperture dimension and long pipeline that is out of reach, and channels through bridges are almost free-flowing. As for protection works, it places slope protection block sodding against the road sections where the embankments are washed out seriously. 5.4.2

for drainage pipe system

The blockage of debris and silts in existing drainage system and proposed solution method are submitted to the Engineer in accordance with site condition. Not until the approval of the Engineer, the works of dredging are not executed. As for the drainage pipes, it is suggested that they be jetted with high-pressure gun; channels are cleared up by hand while water level is in depression in dry season. 5.4.3

for protection works

The washout of embankment and proposed protection method are submitted to the Engineer in accordance with site condition. Not until the approval of the Engineer, the works of protection are not executed. Where there are no suitable topsoil at the sections of washout embankment, the topsoil suitable for growing with a thickness of 10 cm is spread and compacted by hand in approval of the Engineer, 4 cm thickness of which is wetted if moisture is not enough. Sods used for planting are obtained from the nearby place the Engineer approved. The size and space between each other of sods are in accordance with the Drawing, which are watering regularly to ensure the survival ratio.

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

6. 6.1

Revised 1

Construction Process Chart Repairs of Longitudinal Cracks

Close Traffic

Measure the Width of cracks

More than 6mm

Less than 6mm

Less than 2mm

Cut and carve out of the pavement

Clean out the cracks

Clean out the cracks

Distribute the prime coat

Cast emulsified bitumen

Inject emulsified bitumen

Spread and compact DBST

Spread and compact DBST

Check up the work

Clear up the site

Open Traffic

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

6.2

Revised 1

Repairs of roughened and Loose Pavement

Close Traffic

Collect the loose material

Clean out base course Unacceptable Approved by the Engineer

Acceptable

Distribute the prime coat

Spread and compact DBST

Clear up the site

Open Traffic

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

6.3

Revised 1

Repairs of Patches Close Traffic

Determine defective surface

Cut sides Unacceptable Approved by the Engineer

Acceptable

Brush sides and distribute bitumen

Spread asphalt concrete

Compact

Clear up the site

Open Traffic

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

6.4

Revised 1

Repairs of Edge Breaks Close Traffic

Cut defective edges

Clean out loose material Unacceptabl Approved by the Engineer

Acceptable

Distribute the prime coat

Spread asphalt concrete

Compact

Clear up the site

Open Traffic

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

6.5

Revised 1

Spread of Seal Coat Close Traffic

Clean out base surface Unacceptable Approved by the Engineer

Acceptable

Distribute the prime coat

Distribute emulsified bitumen

Distribute sealing crushed stone

Compact

Clear up the site

Open Traffic

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

7.

Quality Control of Works

7.1

Quality of Works

Revised 1

The works are executed in accordance with Conditions of the Contract, the Specification, the directions of the Engineer, and various regulations of quality control management established on site to meet the requirements of the Specification.

7.2

Quality Control of Works

7.2.1

Preparation of Quality Control of Works

a. All labor and staff are trained on the quality of works to improve their sense of quality on the basis of expectations and characteristics of works. b. The relevant personnel are organized to study the Specification comprehensively and carefully to make good preparation for technical solutions. c. The detailed mobilization plan for material and equipment is prepared, which is kept in good condition. In order to ensure the accuracy of testing, special attention is paid to the purchase and identification of quality testing instruments. d. The general construction layout, including water, electricity and available acquirement method, and traffic dispersion plan and civilized construction plan are prepared. 7.2.2

Implementation of Quality Control



Testing of arrived material All procured material has to be with a certificate of QA (Quality Assurance), samples of which are tested by the lab assistant. The material is not used until re-tested as acceptable. It is labeled “unacceptable” and stored separately; or replaced with approval of the material manager as for the unacceptable material to ensure the quality of arrived material.



Future testing a. Each procedure is tested and experimented in accordance with the method of construction or the Specification of the Contract by the quality control manager, lab assistant and surveyor of Project management office, records of which are made accordingly. b. The self-test of concealed works is organized to make by the quality control manager, which is accepted prior to submitting to the Engineer or his representative for acceptance.



Monitoring of records Surveying records are made and calculated carefully and correctly, the designated surveying location be protected, and the surveying instruments be calibrated and maintained regularly.



The technical personnel are strengthened to operate in strict accordance with the methods specified in the construction method statement.



Key technique and difficult parts, especially the common faults and easy-occurred faults in the project are precautioned, which are nipped in the bud under the guidance of Chief Engineer.

8.

Safety of Works

8.1

Establishment of Safety Organization

The Security Department has to be set up under Project management office, which is in charge of daily safety specifically, the establishment of various safety regulations and rules and the implementation of each

safety measures. A full-time safety man is appointed for each construction team, who is in responsible for the safety of the project and under the guidance of the ganger of each section and project manager. Safety education and safety publicity on employees are carried out monthly as practically as possible. 15

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Method Statement for Maintenance National Road of DBST Road in CAMBODIA

8.2         

8.3

Revised 1

Safety Organization Requirements The striking warning signs are erected on site, traffic divided blocks be placed in accordance with the Specification and a full-time person be appointed to direct the traffic in case of accidents. The detailed safety consequences are warned for labors and staffs prior to commencement, in the meanwhile safety education and inspection are made to labors on site from time to time. Construction personnel on site have to wear unified uniform, chest card and safety helmet in designated color. The uniforms and the safety helmets are tied on the red reflecting membrane. The installation of all kinds of electric facilities and use of electricity on site must meet the requirements of related regulations and rules of power supply authorities. Any violation here is prohibited. The travel route of various equipment and vehicle is arranged reasonably in case of accidents. Safety check is carried out to the plant and the equipment; Driving in spite of illness is not permitted. All personnel must abide by local laws and regulations, comply with the local government regulations and obey the rules of the site to ensure the safety. All construction vehicles are strictly forbidden to turn around and retrograde randomly in urban road; if needed, a full-time safetyman is arranged to direct the traffic and safety signs are placed for exclusive use. The operation is suspended in case of heavy rain, snow, strong storm and dense fog.

Safety Management of Transportation, Mechanical Operation

A. Safety Management of Transportation The operator of all equipments and vehicles must have work license. No operation is permitted without licenses. No person except the operator is allowed to stay in the dump truck. B. Safety Management of Mechanical Operation When operating in hazardous sections (including high-voltage section), striking warning signs must be placed, as well as special person appointed to direct. C. All the machinery and equipment used in construction are painted in orange or installed with red (yellow) warning lights, and pasted with red reflective membrane. All transportation vehicles have to be in good condition and stable performance, which are maintained and repaired periodically or occasionally.

9.

Protection of the Environment

9.1

Water Quality

The Contractor has to prevent any interference with the supply to or abstraction from or the pollution of water resources (including underground percolating water) as a result of the execution of the Works. Areas where water is regularly or repetitively used for dust suppression purposes (including, without limitation, stockpiles for concrete-batching and asphalt plants) are laid to fall to specially-constructed settlement tanks to permit sedimentation of particulate matter. All water and other liquid waste products arising on the Site are collected and disposed of at a location on or off the Site and in a manner that does not cause either nuisance or pollution.

The Contractor does not discharge or deposit any matter arising from the execution of the Works into any waters except with the permission of the Engineer and the regulatory authorities concerned. The Contractor has to protect all watercourses, waterways, ditches, canals, drains, lakes and the like from pollution, silting, flooding or erosion as a result of the execution of the Works. The Contractor has to submit details of his temporary drainage work system (including all surface channels, sediment traps, washing basins and discharge pits) to the Engineer for approval prior to commencing work on its construction.

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| CAMRA TECHNICAL PAPER No. 2 – All rights Reserved 2013

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

9.2

Revised 1

Air Quality

The Contractor has to devise and implement methods of working to minimize dust, gaseous or other air-borne emissions and carry out the Works in such a manner as to minimize adverse impacts on air quality. The Contractor has to utilize effective water sprays during delivery and handing of materials when dust is likely to be created, and to dampen stored materials during dry and windy weather. Stockpiles of friable materials are covered with clean tarpaulins, with application of sprayed water during dry and windy weather. Stockpiles of material or debris are dampened prior their movement Any vehicle with an open load-carrying area used for transporting potentially dust-producing material have to have properly fitting side and tailboards. Materials having the potential to produce dust are not loaded to a level higher than the side and tail boards, and are covered with a clean tarpaulin in good condition. The tarpaulin is properly secured and extend at least 300 mm over the edges of the side and tailboards.

9.3

Noise

The Contractor has to consider noise as an environmental constraint in his planning and execution of the Works. The Contractor has to take all necessary measure that the operation of all mechanical equipment and construction processes on and off the Site does not cause any unnecessary or excessive noise, taking into account applicable environment requirements. The Contractor has to use all necessary measures and maintain all plant and silencing equipment in good condition so as to minimize the noise emission during construction works.

9.4

Control of Wastes

The Contractor has to control the disposal of all forms of waste generated by the construction operations and in all associated activities. No uncontrolled deposition or dumping is permitted. Waste to be so controlled includes, but is not limited to, sewerage, all forms of fuel and engine oils, bitumen, cement, surplus concrete, surplus aggregates, gravels etc. The Contractor has to make specifies provision for the proper disposal of these and any other waste products, conforming to local regulations and acceptable to the Engineer. In the event of any spoil or debris or silt from the Site being deposited on any adjacent land, the Contractor immediately remove all such spoil debris or silt and restore the affected area to its original state to the satisfaction of the Engineer.



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| CAMRA TECHNICAL PAPER No. 2 – All rights Reserved 2013

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Revised 1

10.

Methodology of Performance/Output Based Routine Maintenance

10.1

Performance Monitoring and Procedures

This Contract, we will responsible for managing and maintaining the following indicators:  Pavement and Road Side Assets  Vegetation & Trees  Litter within clearway (No foreign objects on the road clearway)  Drainage System  Bridges  Signs and Road safety Table of Service Level Criteria that the Contractor will responsible for:

Item

Pavement, Roadside Slopes, and Clearway Service Level Criteria Service Quality Measurement/Detection Pavement Visual inspection.

Potholes

No potholes allowed.

Patching

Patches shall be level with and be made using material similar to the surrounding pavement and shall not have unfilled cracks wider than 3 mm.

Cracks in pavement

No unfilled cracks wider than 3 mm.

Depressions and settlement

There shall be no depressions or settlement greater than 50 mm. Corrective measures shall meet the patching service quality above. The edge of pavement shall be even with or have no more than a 50 mmm drop off to the adjacent earth/gravel shoulder extension. The road surface must always be clean and free of soil, debris, trash and other objects

Evenness of edge of pavement

Cleanliness of the pavement surface and paved shoulders.

Roadside slopes (both in cut and fill areas) 18

Without deformation or erosion.

Visual inspection for check of material used and if >3 mm cracks are filled. A ruler or straightedge to check if level with surrounding pavement, and a small transparent ruler with mm gradations to check crack widths. Crack widths will be measured with a small transparent ruler with mm gradations. Visual inspection confirmed by measuring under a 3 meter straight edge with a ruler with mm gradations.

Time allowed for repairs or Tolerance permitted Potholes must be repaired within seven (7) days of detection. Non-complying patches must be corrected within seven (7) days of detection.

Cracks more than 3 mm wide must be filled within seven (7) days of detection Depressions or settlement greater than 50 mm must be repaired within seven (7) days after their detection.

Visual inspection confirmed by measuring with ruler with mm gradations under a 3 mm straight edge extended 1 meter out from the pavement.

Repairs must be completed within seven (7) days after the detection of the defect.

Visual inspection.

Dirt, debris and obstacles must be removed : -within one (1) hour if they pose a danger to traffic safety -within three (3) days if they do not pose any danger to traffic safety

Roadside Slopes Visual inspection confirmed by measurement with rulers.

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Repairs must be completed within seven (7) days after the detection of the defect.

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Tree branches within clearway

Grass/vegetation within clearway (outside pavement or shoulders)

Litter within clearway

Item Ditches

Culverts and similar

Item Bridge deck

Expansion joints

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Trees within clearway must have branches cut back to be no closer than 2 meters from the edge of shoulder and 4 meters from the pavement surface. Height of grass and vegetation (except trees) must be: -less than 20 cm to toe of slopes or outermost side of lateral ditches. -less than 2.0 m otherwise. -must not disturb drainage. The clearway outside the edge of the pavement must be clear of litter, trash, debris, etc.

Revised 1

Clearway Visual inspection. Measurement with an appropriate 4 meter pole or staff marked at 2 meters.

Tree branches exceeding the threshold clearance must be cut back within seven (7) days after detection.

Visual inspection. Measurement with a ruler or marked stick.

Vegetation exceeding the threshold height must be cut back within seven (7) days after detection.

Visual inspection.

Litter, trash, debris and other objects must be removed within seven (7) days after detection.

Drainage Systems Service Level Criteria Service quality Measurement/De tection Must be clean and without any Visual Inspection significant damage of the lining, if present. Must be clean and free of Visual Inspection. obstacles, and without structural damage. Must be firmly contained by surrounding soil or material.

Structures (Bridges) Service Level Criteria Service quality Measurement/De tection The bridge deck shall be clean Visual inspection and deck material shall be fully intact (for concrete and asphalt decking), and bolted down for metal decking. Drainage system/gullies/scuppers shall be clean and fully operational. Clean and in good condition. Visual inspection.

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Time allowed for repairs or Tolerance permitted Obstructions equivalent to greater than 10% of the design or intended cross-sectional dimensions or capacity of an item that has not been purposefully engineered into the design, must be cleared within seven (7) days of detection.

Time allowed for repairs or Tolerance permitted Any loose or missing deck materials shall be corrected within three (3) days. Decks and deck drainage systems shall be cleaned within seven (7) days determination of noncompliance. Damages and defects must be repaired within seven (7) days.

Method Statement for Maintenance National Road of DBST Road in CAMBODIA

Item Traffic signs

Pavement markings

Kilometer posts and guide posts

Guardrails

Signs and Road Safety Service Level Criteria Service quality Measureme nt/Detection Signs have to be present, Visual complete, clean, structurally inspection sound, and meet MPWT standards. Have to be present and firmly Visual attached to pavement. Glass inspection spheres/beads must be firm and visible. Have to be present, complete, Visual structurally sound and surface inspection painted as per MPWT specifications. Have to be present, clean, without Visual any significant damage or inspection corrosion.

Revised 1

Time allowed for repairs or Tolerance permitted Absent, defective, or non-standard signs must be replaced or repaired within fourteen (14) days. Absent or defective pavement markings must be replaced or repaired within fourteen (14) days. Absent or defective kilometer posts and guide posts must be replaced or repaired within fourteen (14) days. Absent, defective or damaged guardrails must be replaced or repaired within fourteen (14) days.

1 Routine Maintenance Unit will be set up by mid-July 2012 and will works for Section 1 & 3 of performance/output based routine maintenance (Section 1: KM0+000 to KM12+300, at the beginning of road section and Section 3: KM32+850 to KM 54+300). This unit will manage and control 2 pools of mobile pavement/shoulder repair. Each pool will be equipped with mobile/patrol trucks, machineries, materials and tools for potholes/patching, cutting trees and grassing, removing/collecting all foreign objects on the carried-way and shoulders. They also will regularly check drainage/culvert/bridges to remove any blocking of water way. The Routine Maintenance Unit will be responsible to maintain at all times a detailed and complete knowledge and inventory of the condition of the road sections included in the contract, and to provide to the management of all the information needed in order to efficiently manage and maintain the road sections. The Unit will be also obliged to carry out, in close collaboration with the Engineer, the formal and scheduled inspections of service quality levels which will take place regularly. The compliance (or non-compliance) report will be prepared by the Routine Maintenance Unit and will be submitted to the Engineer in the form of tables (a mandatory standard format table and report, with assistance of a Performance Base Specialist of Engineer), will be prepared and adopted within the first month of the Contract’s commencement date. One table required for each road and one table required for each 1 km test section. The tables form part of the Contractor’s monthly statement for IPC, and they may be complemented by comments for which a specific format is not required. The monitoring of the performance will be done on a daily, monthly, and annual basis.

10.2

Contract Staffing and Sub-Contractors

In-house staff will be provided only approximately 15% of Contract’ services. The remaining services will be subcontracted to the several local sub-contractors. In order to raise the quality of services of subcontractors and improve competition among them, we will engage in an extensive training program for small contractors.

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| CAMRA TECHNICAL PAPER No. 2 – All rights Reserved 2013