Method Statement for Road Construction

This roadwork method statement describes work methodology for road construction covering the activities from subgrade to asphalt work.

All personnel working at site shall have full knowledge and expertise in the excavation, backfilling, compaction and road testing process.

Occupational health and safety program shall be properly communicated and implemented.

Everyone should be aware of the completion date and quality requirements in accordance to the project specifications.

Site Planning & Preparation

Prior to commencing of work a Site Supervisor will be assigned for the activity covered by this method statement.

Also provide pre-task briefing, red man/green man training.

Provide training for vehicle/ equipment breakdown procedure.

All equipment/trucks must be thoroughly inspected for any defects prior to mobilization on site.

No feet on the ground policy must be communicated to all work forces.

Risk assessment and the emergency procedures will be provide to all operatives and a briefing register will be signed.

A copy of the method statement and emergency procedures will be kept on site.

The certification of all equipment operators will be checked to ensure they have the correct training for the equipment required for the work.

Make sure that temporary bench marks have already been established in the area. Providing rebars having wood cap.

Areas will also be identified for welfare facilities, storage of other materials and access routes for vehicles and pedestrians.

Welfare facilities will be established at site which includes toilets, Heat shelter, washing facilities, drinking water, and mosque prayer area and smoking area.

Road safety signs/road diversion signs shall be installed wherever applicable for the safe movement of vehicles and equipment.

Major equipment shall be tested by third party prior to mobilization to site.

All moving vehicle/equipment shall have reverse back up alarm flashing beacon lights and totally inspected prior to mobilization on site.

Sequence of Road Construction Work

Below are the steps that are covered in this method statement.

• Survey
• Alignment
• Preparing the subgrade
• Preparing the sub base
• Preparing the base course
• Apply MC-1 (prime coat)
• Apply asphalt base course
• Apply binder course
• Put the asphalt wearing course
• Protection of Asphalt

Organization, Responsibility & supervision

PROJECT MANAGER: The Project manager is responsible for assuring that adequate tools, equipment and qualified manpower, Forman and supervisors are provided to implement the work without delays and performing the work right the first time.

CONSTRUCTION MANAGER: The construction manager shall be responsible for the overall implementation of this Method statement and shall be responsible for execution and control of

Procedures. He shall also be responsible for coordinating the Activities of the Site survey team, ensuring all setting out and inspection functions are performed accurately and reported efficiently to avoid delay on site.

QUALITY CONTROL MANAGER: The Quality Control Manager is responsible to review the method statement and overseeing all the activities are in conformance with Project Quality Plan, approved technical submittals, Project contract specifications and IFC drawings.

CIVIL SUPERINTENDENT/FIELD ENGINEER: The assigned Superintendent/Field engineer shall be responsible for specific works, to control and supervise roadwork operations and workmanships and efficient use of resources to progress work in accordance with the approved drawings specifications, material submittals and schedules to achieve the required quality. Will report directly to the construction manager on all matters concerning the work and liaise with the survey and quality control department to ensure that the planned activities are done and inspection activities are done as detailed in the quality control documents.

QUALITY CONTROL ENGINEER: The QC Engineer is responsible for compliance from an applicable Specifications, conducting surveillance and inspection duties at various stages of road works as detailed in the QC program and efficient recording and reporting of results As required.

SURVEYOR: The survey department is responsible for the setting out the works, dimensional Control and the preparation of as-built records as required.

HSE Manager: Health and safety Manager shell be responsible for the implementation of all safety measures at site, provide risk assessments, give special attention to housekeeping and to ensure site is always in tidy and clean condition.

Foreman/ Field Supervisor: The Foreman/ Field Supervisor shall be responsible for the full time supervision of works, making sure that works are carried out in accordance to the specifications, quality procedure and approved drawings.

Health Safety and Environmental Requirements

Site safety control will be conducted in accordance with the guidelines stipulated in approved risk assessment and project HSE plan.

Standard operating procedures from contractor shall be applied for the following areas:

• Personal Protective Equipment
• Warehouse & Storeroom
• Hand Tools
• Electrical Safety
• Safety Signage & barricades

In absence of accepted standards, best accepted industry practice shall be engaged in the implementation of activities which includes the following but not limited to;

• Provision of protection to utilities
• Provision of flagman for every equipment
• Related to training to all workers
• Provision of safe access and egress to all personnel

Road construction ES&H Manual shall be followed and discussed to all workers prior to execution of work.

EMERGENCY PROCEDURES

In the event of any accident or emergency, workers should immediately inform their immediate supervisor and safety officers at site.

Work site shall be evacuated as needed and all personnel shall proceed to the nearest Assembly Point.

Should there be any patient that needs to be treated / transferred, ambulance and site nurse shall be deployed immediately to accident area.

Emergency Phone numbers shall be posted in all areas for immediate reporting any emergency situation.

Road Construction Methodology

Survey:

Establish and protect enough stations to re-establish the stations if they are disturbed during work.

Post wooden stack for line and gradient of the road.

Elaborate from survey set out to control of points and elevation from road preparation to the paver application.

Supervisors and labors must have complete PPE including HI-Visibility Vest.

Before using the survey Equipment calibrate the devices.

Sub grade:

The above title consists of the dressing, scarifying, shaping, and wetting and compacting, as per requirements of the sub grade, to the full width of the road bed, under curb and sidewalks, all requirements need to be as per project specifications and IFC Drawings.

All soft and unstable material and other portion of the sub grade which will not compact to readily serve the intended purpose will be removed.

After removing the soft material and excavation, prepare the first layer of sub grade of sand material with CBR 10% as per specifications.

If any area needs backfilling, so backfill as layer by layer with approved materials, each layer thickness must be 30 cm.

Operators, drivers and workers must wear complete PPE as applicable for the task.

Sub Base and Aggregate Base Preparation

After the sub grade has been shaped to approximate line, grade, and cross section, the entire roadbed shall be loosened by harrowing or scarifying the material brought to the proper moisture content and compaction minimum as per specifications.

Compaction test result shall be complied as per contract requirements and specifications. Compaction test shall be done by approved 3rd party.

• Sub Grade minimum compaction 95% 3 tests per 2000 m2
• Sub base minimum compaction 100% 1 test per 500 m2
• Aggregate Road Base minimum compaction 100% 1 test per 500 m2

For spreading the material use paver machine or grader.

The final appearance of the grading behind curbs or sidewalks shall present a neat and trimmed appearance, and such grading shall be included as an item incidental to the road grading operation.

After compaction and grading the base surface shape appearances shall look like a complete road.

All the lose materials and dust to be removed prior to start the asphalt paving work.

After completion of shift or work day all equipment/trucks must be parked in designated areas with safe distance from nearby equipment/truck.

Preparation of grade sensor system will be made ready for use in advance approximately 100m to 300 m in front of the asphalt pavers so that paving operation are continuous without disruption.

The general system for elevation and thickness control will be based on the design and data, actual elevation points will be taken at each pin location, prior to the placing of the asphalt material layer.

Based on actual data, the design heights will be calculated, and then transposed onto the height setting for each pin.

Detailed records of all elevation data will be kept and maintained by the Engineer and Surveyor, to be transferred on to the as built drawings.

Preparation of Grade sensor System & Setting

Lane marking with paint and chalk on the edge of pavement will be established.

The marking will also provide a holding line to assist rake men face sharp and clean.

Sensor wire (steel wire 3mm diameter) with capstan shall be pre installed initially on both side of the lane by means of steel pin firmly fixed at intervals of 10m.

Pin intervals on bend or slops changes shall be set at 5 CM.

Sensor pin levels will be checked by surveyor.

The sensor wire shall be tight.

Once the laying of one lane is complete, installation of sensor wire system for one side is adequate for adjacent lane.

The pre laid adjacent surface can be used to guide rest of the pavers.

Preparation of grade sensor system will be made ready for use in advance approximately 100m to 300 m in front of the asphalt pavers so that paving operation are continue without disruption.

The general system for elevation and thickness control will be based on the design and data, actual elevation points will be taken at each pin location, prior to the placing of the asphalt material layer.

Based on actual data, the design heights will be calculated, and then transposed onto the height setting for each pin.

Detailed records of all elevation data will be kept and maintained by the Engineer and Surveyor, which shall be transferred on to the as built drawings later.

Asphalt Paving Work:

Prime Coat:

Prime coat is a cutback bitumen spray that shall be applied to the entire crushed aggregate base course.

The proposed prime coat and bond coat materials are respectively MC-70.

Immediately prior to application of the prime coat all loose material shall be removed from the surface with mechanical sweeper and hand broom.

No prime coat shall be applied until the swept surface has been removed without objection by the engineer.

Heating and mixing of bituminous materials will be done in accordance with the relevant project road specification sections.

The bituminous material for the prime coat shall be applied by means of bitumen spray tankers, and this shall be applied in a single layer at the rate of 0.65 – 1.75 liters/ sq. m and at a temperature not exceeding 70 degree C. This surface shall be cured for 24 hours.

Over spread area shall be cured for more than 24 hours / until excess prime coat is evaporated.

Preparation of grade sensor system will be made ready for use in advance approximately 100m to 300 m in front of the asphalt pavers so that paving operation are continued without disruption.

The general system for elevation and thickness control will be based on the design and data, actual elevation points will be taken at each pin location prior to the placing of the asphalt material layer.

Based on actual data, the design heights will be calculated, and then transposed onto the height setting for each pin.

Detailed records of all elevation data will be kept and maintained by the Engineer and Surveyor and transferred on to the as built drawings.

Paving the Binder Course

Immediately before paving the binder course material, the surface of the prime coat shall be cleaned with compressed air and shall be ensured that the surface is dry.

Asphalt temperature must be on site between 135-163 °C as per the road specification clauses.

The hot asphalt mix shall be brought from the mixing plant by 6-wheel trucks or trailers.

Upon arrival at site, the asphalt mix shall be discharged into the asphalt paver.

Asphalt paver shall lay the material to the required thickness and level.

The mix shall be compacted immediately after spreading the material.

Tandem rollers shall follow the laying operation to carry out breakdown rolling up to temperature of 139- 163 °C.

Pneumatic tired rollers and tandem rollers shall follow the breakdown rolling and enough passes shall be made to achieve the required compaction.

Rolling shall start from the sides and proceed toward the center.

Each trip of the roller shall overlap the pervious trip by at least 30 cm.

Roller wheel shall be kept moistened.

The roller shall be capable of reversing without backlash and shall be free from worn parts.

Heavy rollers shall be used to complete all rolling including elimination of waves caused by the lighter rollers.

Full compaction shall be obtained before the asphalt temperature reaches 100°C.

Compaction shall be in accordance with the road work specifications and relevant standards as applicable.

The construction joints shall be prepared by cutting the layer vertically down by means of asphalt saw cutting machine or with jack hammer.

Construction joint shall be cleaned well by compressed air and tack coat material shall be applied on the vertical and horizontal surfaces for better bonding.

Extreme care shall be taken when asphalt is added at construction joints.

Tack Coat:

The material (which shall be primarily approved) shall be applied at the rate of 0.20 to

0.50 lit/ sq. m according to the specifications at the temperature not exceeding 54 °C above the binder course and at where there is a joint with existing asphalt surface.

The surface shall be cured for the period as per manufacturer’s recommendations until a tacky surface is visible.

Wearing Course:

The hot asphalt mix shall be spread over the cured surface of tack coat by automatic asphalt paver to the profile thickness of 50mm according to the specifications.

Asphalt temperature on site must be between 135-163 °C, according to the specifications.

Protection of the Works

After final rolling, the Contractor shall not permit traffic on asphalt concrete pavement until it has cooled and hardened, and in no case sooner than 24 hours unless otherwise permitted by the client/consultant.

The Contractor shall cover openings of structures in the area of paving until permanent coverings are placed.

Care shall be taken to prevent damage to the work during subsequent construction operations forming part of the road construction contract.

All means and materials required to protect the work from damage shall be provided by the road contractor as part of the contract.

Works damaged by traffic, construction operations, weather conditions or due to any other cause during the contract period, shall be repaired, or removed and replaced on contractor’s cost as directed by the client.

TOLERANCES: 

All asphalt concrete shall be laid within the grade tolerances shown in in below table as compared to the elevations shown and interpolated from the drawings for Aggregate Concrete base courses and surface course profiles.

Base Course	Surface Course
± 8 mm	± 6 mm

Surface Smoothness

Compacted surfaces will be tested with a 4 m straightedge at selected Locations.

The variation of the surface from the testing edge of the straightedge between any two contact points with the surface when placed parallel or perpendicular to the centerline of the highway shall at no point exceed the limits specified in table below:

Location	Base Course	Surface Course
Straightedge parallel to the centerline	6 mm	4 mm
Straightedge perpendicular to the centerline	6 mm	4 mm

Wearing Course with Asphalt Paver Machine

The mix shall be compacted as soon as possible after spreading the material.

Tandem roller shall follow the laying operation to carry out breakdown rolling up to a temperature of 135- 163 °C .

Self-propelled rollers and Tandem rollers shall follow the breakdown rolling and enough passes shall be made to achieve the required compaction.

Rolling shall start from the sides and proceed toward the center, each trip of the roller shall overlap the previous trip by at least 30 cm.

Roller wheels shall be kept moistened.

The roller shall be capable of reversing without backlash and shall be free from worn parts.

Heavy tandem roller shall be used to complete all rolling including elimination of waves caused by the lighter rollers.

Full compaction shall be obtained before the asphalt temperature reaches 80 °C.

Compaction shall be in accordance with specification of relevant standard.

Traffic shall not be allowed on this layer until it is properly cooled, a minimum period of 24 hours shall be considered after the completion of the rolling.

The test holes shall be filled with hot asphalt mix and compacted using Marshal Hammer.

Road Construction Joint Methodology

Mat Overlap:

A proper mat overlap is about 25mm, the hot lane should be overlapping the cold lane such that enough material is available for compression.

A lack of material or inadequate overlap will lead to high longitudinal joint air voids.

Because joint overlap is so small, it is critical that the paver be operated on as straight a path as possible for both cold and the hot lane.

The notches are at least as deep as nominal maximum aggregate size of the mix, hot lane overlaps the cold lane notch by about 12.5 t0 25mm and is bumped back to the notch to ensure enough material at the notch for adequate compaction.

Compaction:

Compaction starts from the hot side almost 150mm away from the joint.

The first roller pass occurs in the vibratory mode with the entire roller wheel on the hot lane and about 150mm from the joint.

This technique pushes the material between the roller and joint towards the joint during the initial roller pass, which crowds the mix at the joint producing a high density.

Road Repairing:

Filler

Most driveways are made with cold asphalt, which is easier to repair than hot asphalt, because no special tools are required.

Asphalt suppliers and home improvement stores frequently sell cold asphalt in bulk or by bag for minor repairs.

Apply new asphalt to a crack or hole as a filler.

Compact over it several times until the material is thoroughly compacted and smooth.

Patching Potholes

Asphalt contractors commonly patch potholes.

Depending on their severity, potholes are repaired in two basic ways.

A minor pothole, which only impacts the surface layer, involves removing debris from the hole and filling it with new hot asphalt.

Once the hole is patched, the asphalt is flattened using a hand tamper or roller.

A section of pavement must be cut to the sub-grade, or base layer, to repair a large pothole.

Once the material is removed with a jackhammer, each layer of the pavement needs to be refilled, including placing an asphalt patch on the surface.

Compact the repaired area with a hand tamper or roller until it is level.

Surface Treatment

Asphalt contractors sometimes spray old, brittle roadways with a protective coating, such as a fog seal or rejuvenator, to stop them from crumbling.

A fog seal is made of tar or diluted asphalt and is sprayed on the pavement, it fills minor cracks and gets rid of surface blemishes.

Road Marking Procedure:

Set out the center line and get approvals from consultant/client about the center line before commencement of line marking.

Road surface shall be cleaned manually using wire brush and wash the surface where necessary.

As per the approved road marking design the road marking lines & symbols will be set out by means of white chalk and approval will be taken by consulting engineer.

The thermoplastic material is heated in the range of temperature around 170 ~ 200 °C and maintained in the range during the entire laying process.

After getting the approval of the temporary marking on the asphalt surface permanent marking shall be carried out by considering required color.

The road marking machine has the facility of adding glass beads in to the paint while painting.

All roads marking shall be protected from traffic until the marked paint gets dry.

Road signs and reflectors shall be installed as per approved drawings, specifications, standards and material submittals.