تويت
This road construction method statement shall apply to all roadworks. The purpose of this statement on the work method is to provide general guidance for the construction of roadwork. Description of the herein specified procedures can be adjusted in compliance with existing ground and project site requirements.
Below is a list of equipment and tools that are required for construction work:
Diamond Cutter
Backhoe
Back pusher
Thermometer
Paving Set
Tipper Lorries
Total Station
Vibratory roller
Leveling Instrument
Below is the list of materials that we need for road construction work:
Sand
Asphaltic Concrete Binder Course ACBC 28
Asphaltic Concrete Wearing Course ACBC 20
Crusher run
Bituminous Tack Coat
Bituminous Prime Coat
Road Construction Method Statement
It is necessary for both the horizontal and the vertical alignment to be joint inspection and confirmed by the Consultant before pavement construction can be allowed.
Make sure the surveyor uses the appropriate instrument total station and dumping level. Also ensure that the on-site mark is visible and properly protected during construction work.
Pavement construction works may only begin on site upon approval and acceptance of the sub-grade layer.
The Contractor shall re-check the alignment and all dip pegs and confirm with the Consultant prior to permanent work.
Sequence For Road Construction Works
Below is a typical sequence that can be followed for the construction of roads on the site:
1- Preparation & laying 100 mm granular material sub-base
2- Laying the 200 mm crusher on the road base
3- Preparation and laying of 60 mm Asphaltic Concrete Binder Course
4- The 40 mm Asphalt Concrete Wearing Course
Preparation of Formation To Receive Road Pavement
Make sure that piped or box culvert services, utilities and ducts (if any) or any other drainage work that may have an impact on the work are completed prior to the preparation of the training. If this step is not complete, the planning shall be carried out immediately before the sub-base is laid.
All materials for subbase, road base, ACBC and ACWC shall be sent to the nominated laboratory and approved to carry out the necessary tests and to comply with the technical specifications.
The surface of the formation shall be substantially uniform in density throughout its entire width and shall comply with the compaction density requirements. Trial compaction to be carried out in order to determine the degree of compaction indicated as required in the presence of a supervisory consultant for road construction activities.
Other road-crossing utilities, such as water mains and cables, shall be protected prior to the operation of the road base. For example, use a lid for u-drain and G.I. Duct for cables.
It shall be trimmed to conform to the lines, the camber, the grades and the typical cross sections shown in the drawings of the roadworks or as directed by the road construction consultant.
The soil sample to be sent to the laboratory for the MDD test for the comparison of the degrees of compaction.
To perform the test compaction required to determine the pass roller.
Level pegging to be performed at an appropriate distance for inspection.
Soil Formation: Where soft spots and unsuitable materials have been found, they shall be removed and filled back with approved suitable material and compacted in accordance with the agreed rolling pattern.
Sub-Base Procedure
The subbase material is hard, durable and clean. It is a granular material and is free of organic material, clay balls and any other deleterious substances.
The materials will be delivered to the site by tipper trucks and spread out and leveled by means of a back pusher for the full width of the pavement. The material shall be filled and compacted to the required thickness as specified in the approved road construction drawing.
The subbase layer is compacted using a vibrating roller to achieve relative dry density as per specification.
The alignment, level and surface regularity shall be checked in accordance with the technical specifications.
The final surface of the granular subbase layer shall be regulated and trimmed to the required level by the rear pusher and shall fall within the specified vertical tolerances. Compacting work will be done using a roller compactor.
Field Density Test (FDT) or CBR Subgrade Test shall be performed as specified.
Laying Base Material
The crusher road base to be placed on the top of the sub base shall consist of crushed aggregates laid in layers each of a thickness not exceeding 200 mm and shall give the specified total compacted thickness and width, the correct line and the levels shown in the road construction drawings.
The material shall be crushed by hard, durable particles or fragments of rock crushed to the correct size, well graded and within the following grading limits specified in the specification.
Care must be taken to prevent the material from segregating into large and fine fractions
.
Bituminous Prime Coat & Tack Coat
The approved bituminous prime coat, which is submitted by means of a material submission, shall be applied to the top of the finished crusher base course prior to the laying of the asphalt concrete binder course.
The surface shall be cleaned immediately before the application of the prime coat. The bitumen shall be applied by means of a distributor at an appropriate rate, but not less than 0,435 liters per square meter. SS1K is used for prime coat while RS1K is used for tack coat.
The surface of the dense asphalt-concrete binder shall be cleaned immediately prior to the application of the approved tack coat. The bitumen shall be applied by means of a distributor at an appropriate rate, but not less than 0,35 liters per square meter.
The prime coat shall be sprayed well in advance and leave for 24 hours for curing.
Asphaltic Concrete Surfacing
The surface shall be two courses and shall consist of asphalt-concrete binder and asphalt-concrete, bearing the course and laying in accordance with BS 1621. After compaction, the two courses shall be constructed to the width and thickness as shown in the drawing.
Course Aggregate: The course aggregate shall be hard unweathered, durable, clean crushed rock, angular in shape, free from dust and tested in accordance with the methods described in B.S. 812. 812.
Fine aggregate: The fine aggregate shall be approved as a clean natural bank, river, dune, pit or quarry sand produced in a secondary plant. They shall consist of hard, non-absorbent sharp grains and shall be free from clay, loam, loosely bound aggregates and other foreign matter.
Filler: Filler shall be either Portland Cement complying with B.S. 12 or limestone, having a bulk density in Toluene
Asphaltic Concrete Binder Course, ACBC 28
ACBC 28 mix will follow the approved mix design & trial mix. The aggregates shall be surface dry and must be mixed at an appropriate temperature. The mixed material as delivered to the laying site shall be between 140 degrees Celsius to 160 degrees Celsius.
Road Construction Laying Procedure
1- Work shall begin on site upon approval and acceptance of the road base.
2- The surface to be covered by the asphalt-concrete bonding process shall be free of all damage, loose materials and standing water by sweeping.
3- Prime coat of approved bitumen emulsion shall be applied as specified on the prepared surface prior to the layout of the asphalt binder course.
4- The asphaltic concrete binder shall be plant mixed with approved bitumen content.
5- The approved asphalt concrete binder track shall be delivered to the site by tipper trucks. In order to prevent heat loss, the mixture is covered by tarpaulin.
6- The asphaltic concrete binder course must be laid by a paver in single layer.
7- Compaction shall be performed by means of the specified equivalent type of compactors. Rolling shall always begin from the bottom to the top of the carriageway. The minimum rolling temperature is 80 degrees Celsius.
8- The surface of the asphalt-concrete binder shall be finished in line and grade as required by the drawings.
Asphaltic Concrete Wearing Course ACWC20
ACWC 20 mix will follow the approved design mix and test mix. The aggregates shall be dry on the surface and shall be mixed at an appropriate temperature. The mixed material delivered to the laying site shall be between 140 degrees Celsius and 160 degrees Celsius.
Work shall begin on-site upon approval and acceptance of the course of the asphalt concrete binder. The surface to be covered with asphalt concrete shall be free from all damage, loose materials and standing water by sweeping.
Tack coat of approved bitumen emulsion shall be applied as specified on the prepared surface prior to the asphalt loading. The asphalt concrete to be worn shall be mixed with bitumen content. The approved asphalt wear route shall be delivered to the site by tipper trucks. In order to prevent heat loss, the mixture is covered by tarpaulin.
The asphaltic concrete wearing course must be laid by a paver in single layer. Compaction should be carried out using the specified equivalent type of compactors. Rolling should always commence from the lower to the higher side of the carriageway. The minimum rolling temperature shall be 125 degrees Celsius. The surface of asphaltic concrete wearing course shall be finished to the line and grade as required by the Drawings.
Upon completion of the laying and compaction, a joint survey shall be carried out to verify compliance with the specified requirement. Once all of the above works have been completed, the supervisor shall ensure that the site is tidyed up and that all excess materials are disposed of away from the site.
Bituminous materials Transportation
Bituminous materials are transported in clean vehicles and covered when in transit or waiting for tipping. Every precaution must be taken to avoid the separation of mixed materials and to ensure that they are not contaminated with foreign matter. In order to maintain satisfactory temperatures of the materials in transit and to prevent undue loss of heat, appropriate precautions must be taken to ensure that the materials are properly protected.
Laying Procedure
Supply the mixed materials continuously to the pavers and lay without delay as soon as possible after arrival on the laying site.
Where practicable, road pavement materials having bitumen as a binder shall be spread, leveled and tamped by approved self-propelled pavements capable of laying to the required width, profile, camber or cross-section.
Immediately after any course has been established and before rolling is started, the surface shall be checked and any defects and irregularities in alignment, grade or texture corrected by the addition or removal of the mixture
Compaction Procedure
The laid material shall be compacted as soon as possible, as soon as possible, without causing undue displacement of the mixed material. The rollers are to be fitted with beeper.
The materials shall be rolled in longitudinal direction from the sides of the carriageway to the center of the carriageway.
For compaction, two times rolls pass by non-vibrate compactor prior to two times rolls pass by vibrate compactor. The roller shall weigh not less than 12 tonnes.
Eight times rolls pass compaction shall be carried out by Tyre roller.
The last compaction shall be done by non-vibrate compactor.
Health Safety and Environment Compliance
Safety inductions to be made to all new workers involved in this activity and safety toll box meetings shall be held every day to remind workers of safety concerns. All workers shall be provided with PPE (Personal Protective Equipment) and shall be worn on-site at all times. The Safety Manager/Security Supervisor shall ensure that all workers wear all the safety equipment provided.
All workers are advised to report any accident or injury to the supervisor. Proper and adequate provision of temporary signage and barricades for diversions and temporary road haulage as necessary (if applicable).
All workers shall educate on good environmental management practices and well disciplined to environment. The garbage bin shall be provided at the working area and Supervisor shall ensure its must be collected regularly and disposed off at the approved dumpsite. All workers shall ensure that all tools and equipment machinery are in good condition to avoid any oil leakage that could harm to environment.
