Asphalt Work Method Statement

Scope of Work

The asphalt work method statement defines the responsibilities, execution procedure, quality aspect, safety factors, and mandatory documents for the activity.

This asphalt paving describes the sequences and methodology for the construction of a 60 mm Polymer Modified Bitumen (PMB) asphalt wearing course.

This asphalt paving method statement is specifically constructed over concrete road slab as compared to pavement construction over sub base course. However, for asphaltic paving works over sub base course, check down here.

Method Statement for Asphalt Paving works | Asphaltic Concrete | Asphalt Pavement Construction | Asphaltic Road Construction | Highway Pavement

Definitions

SC-Supervising Consultant

SE-Site Engineer

QA/QC-Quality Assurance/Quality Control

SF-Site Foreman

PM-Project Manager

SA-Site Agent representative from the third-party testing lab

ITP-Inspection and Test Plan

HSE-Health, Safety & Environmental

CEMP-Construction Environmental Management Plan

HSE Plan-Health, Safety, and Environment Plan

NCR-Non Conformance Report

PMB-Polymer Modified Bitumen

– Asphalt Concrete Works

References for Asphaltic Paving Method Statement

Project Specifications
HSE Plan
CEMP
Asphalt Paving Wearing Course
Tack Coat

Highway Asphalt Pavement

Responsibilities

Project Manager

• Responsible for accomplishing the stated project objectives which include creating clear and attainable project objectives, building the project requirements, and managing the constraints of the project management triangle, which are cost, time, scope, and quality.
• The Project Manager shall be responsible for ensuring that the Project Quality Plan and the Inspection and Testing Procedures, Asphaltic Concrete Method Statement, HSE safety and all contractual documentations are maintained up to date and accessible to all parties.

Construction Manager

• Responsible for overall construction activities ensuring that all quality and safety procedures are implemented and required approved permits are obtained.

Site Engineer

• Performs their duties on the different branches of construction activity pavement works, and all types of activities related to the site works.
• Performs their duties in the manner in which they have been correctly trained and instructed.
• Comply at all times with approved qc procedures.
• Monitors production services and materials and report to the Project Manager any non-complying activities.
• Responsible for the quality of materials supplied and used for the construction activities.
• Supervise the execution of works in the Site to ensure that the work phase required and assigned by the Project Manager is accomplished within the approved time, plan, specification and standards.
• Supervise and ensure all the works are carried out as per the safest manner complying with the approved Project HS&E plan requirements.

Site Foreman

• To liaise with the Site Engineer and Supervisor for the works execution.

Site Supervisor

• Supervise closely, the activities designated to them and ensure that all instructions and safety procedure are followed and strictly adhered to.
• Supervise the works to ensure that technical, quality, safety and purchase order requirements are met.
• Attend daily site meeting and communicate his daily report with the Project/Site Engineer; Participate in training and development of his subordinates.
• Organize with the Project/Site Engineer to ensure the availability of plant, equipment and labor to his designated work activities.
• Closely monitor the usage of consumable and materials by his crew in order to minimize wastage.
• Assess craftsmanship of subordinates under his control.

QA/QC Engineer

• Ensure that the Inspection and Test Plans has been carried out as per method statement for asphalt.
• Ensure that the repair shall be in accordance with approved procedure and specification.
• Verify the damage or defects.
• Ensure the quality of repair.
• Ensure the approval of materials, if required.
• Follow site HSE rules and shall ensure the works are carried out as per approved asphalt method statement & risk assessment.

HSE Manager

• Health, safety and environmental (HSE) managers generally plan, coordinate and implement issues and directives within the organization. They ensure safe environmental working conditions for all employees.

HSE Engineer

• Ensure enforcement of safety procedures shall be in accordance with the approved HSE Plan. Will be closely monitoring the strict implementation of the asphaltic paving method statement for asphalt and risk assessment, the use of proper tools and equipment to maintain safety, certifications of equipment and their adherence to safety regulations, reporting of any unsafe works or stopping works that do not comply with HSE procedures.
• Advises for health & safety requirements and monitor the hazard controls implemented on site as per the method statement for asphalt & risk assessment.

Chief Surveyor

• Carry out pre-construction survey to fix the locations and corresponding elevations as per the approved shop drawings.
• Ensure the quality and compliance during phases of surveying works and the regular checking of the surveying equipment or periodic calibration from third party.
• Ensure validity and serial number of calibration certificates is available and posted in the survey equipment.
• Ensure proper safety guarding of surveying equipment.
• To maintain the records of all surveying equipment handled.

Survey Aide

• Maintain and use surveying equipment. Assist surveyors in taking measurements, record measurements manually or electronically, and peg out boundaries.

Equipment Operator

• The only authorized person to operate any equipment to be used in the project.

Asphalt Road Construction

Resources for Asphaltic Road Construction

Tools

Shovel
Spreader
Wheelbarrow
Air compressor/electric air blower
Drilling machine
Measuring tapes
Markers
Warning tape
Traffic Cones
Safety Barriers
Grading Stakes
Temporary Signages

Equipment

Paving Machine-Vogele
Pneumatic Tyre Roller-14 tons
Steel Roller
Plate Compactors
Skid Steer Loader/Bobcat
Road Brush Mounted Skid Loader
Pick-up Truck
Tipper/Trailer
Surveying Equipment (Levelling Machine and Total Station)
3 Meter-Aluminum Straight Edge
Core Cutting Machine

Asphalt Pavement Construction

Workforce

Project Manager
HSE Manager
QA/QC Manager
QA/QC Engineer
Pavement Engineer
HSE Supervisor Officer
Foremen
Land Surveyor
Equipment Operators
Helpers
First Aider

Aspahaltic Concrete

Materials

Aggregates: Coarse and fine gabbro aggregates will be from approved sources.

The bitumen binder shall be PMB PG 76-10 as mentioned in project details. All tests shall be carried out
as per the approved Inspection and Test Plan (ITP). The bitumen shall meet the requirements of AASHTO MP 19
and equivalent ASTM, EN, and BS International Standards and test methods. The PMB shall comply with
the contract specification.

In addition to an asphalt mix design submission, the laboratories and standardization affairs (lsa) shall require a copy of a valid calibration certificate for the batching plant as well as the appropriate laboratory equipment such as balances, proving rings, and load devices.

Asphalt Road Pavement

Hot mix asphalt (hma) should meet all requirements for levelness, thickness, and homogeneity.

To select and proportion aggregate and asphalt materials for pavement construction, the marshall method of mix design is used in construction materials laboratories.

Site Planning

Preparation of Asphaltic Concrete

Permits from the concerned authorities shall be obtained prior to starting work at the site.

The contractor shall ensure that all gate passes, necessary work permits, tools, materials for safety precautions, manpower, and equipment are available before commencement of work.

Prior to mobilizing on-site, all major equipment must be checked and approved by a third party.

The site team shall make sure that access roads are always clear from any obstruction and the site is always
accessible.

Provision of access and egress such as ladders, steps, ramps, or other safe means of egress and be with
reasonable distance.

Site Clearance

Before commencing the work, the area shall be cleared of all debris, materials, or other obstructions.

Traffic Management

The site team with the assistance of the safety officers shall coordinate logistics and materials
movement through the site following the direction and road signs displayed on site. The required diversion
routes shall be marked on drawings including the required traffic signs.

The work permits and operator certificates shall be compiled for the reference of authorized personnel.

Highway Pavement

Methodology

Production of Wearing Course Mix

Wearing course mix will be batched as per the approved job mix from the asphalt plant. The capacity of asphalt plants is 240 tons/hour for varied types of asphalt mixes.

The production, laying and compaction of the mixed wearing course shall be monitored by taking samples in accordance with the frequency given in the approved inspection test plan. If for any reason the material does not comply with the approved job mix limits, the method of sampling, testing and the workings of the plant shall be investigated.

For control purposes, the samples will be taken from the plant as well as from behind the pavers during laying.

Transportation of Wearing Course 76-10 Mix

Tippers and trucks will be provided to convey the wearing course mix, from the mixing plant to the site. These tippers will be lightly sprayed with a very thin layer of lubricant material to prevent the mixture from sticking to the tipper body.

The number of trucks utilized will depend on the haulage distance and the quantity of material required, a sufficient number of trucks/trailers will be used at the commencement of production. Asphalt material shall be as much as possible supplied continuously to the pavers and shall be laid as soon as possible after delivery.

All precautions shall be taken to protect the mix from the weather during transit and while waiting to discharge.

Preparation of the Surface

Prior to application of tack coat, the concrete structural slabs surface shall be swept clean of loose material using the road brush-mounted skid loader and air compressor and manual cleaning to the satisfaction of the inspector.

Tack coat shall be applied on concrete structural slabs surface.

The tack coat shall be applied when the weather is not foggy, rainy, windy; and stormy. The ambient temperature shall not be below 13°C.

The tack coat shall be applied uniformly by using a Liquid Bitumen Distributor. The application rate shall be between 0.150 to 0.380 liter/sq. m. Application temperature shall be between 10°C-60°C and as per the consultant’s instruction.

The surface of any nearby structures, kerb stones, and other fixed objects adjacent to areas being treated shall be protected in such a manner as to prevent they’re being spattered or marred.

During application, it shall be observed that no ponds in hollows will take place and in the event, it does occur, the excess material shall be removed immediately. Sufficient time shall be allowed after application to ensure that the emulsion breaks completely and it is in a proper condition of tackiness to receive asphalt wearing course. During this period the area coated shall be closed to traffic.

Before the start of asphalt laying, the tack coat applied area shall be protected from traffic movements.

Paving Plan for Asphalt Wearing Course

The paving operations will be performed by two (2) Nos. VOGELE asphalt paving machine equipped with multiplex ski beams on each side.

Paving Screeds Detail

AB 600-2 TV Screeds, width ranging from 3.0 m to 6.0 m.

Larger widths by addition of bolt-on extensions up to a maximum of 9m.

Screed Width Selection

The paver’s screed width will be selected according to the width of the road to be paved in such a way to ensure that the hot to hot joints created in the echelon paving will have at least 1.5 meters offset with the ones in the upper layer, or as directed by the consultant/inspector.

Below is the typical paving example for laying of wearing course by paving machine in echelon movement.

The width shall be adjusted as per variance of road width.

Paver Setting in Echelon Paving

The below settings will be adjusted to meet the site requirements:

Paving Speed

Angle of Attack

Tampers and Vibration Setting

Head of Material

Spreading and Finishing

The paver is to be equipped with multiplex averaging beams on each side. The mixture at delivery shall be not more than 165 °C and the laid material shall be compacted as soon as rolling can be effected without causing undue displacement and while the temperature does not fall below 150 °C.

The Multiplex Ski Beam is based on the well-proven technology of the VOGELE sonic grade sensor.

Compared to a single sonic sensor, the Multiplex Ski translates the advantages onto a greater length. By arranging 3 sonic grade sensors in a row, it is possible to tap the physical reference at several points lying far apart from each other. Based on the values picked up by the sensors, the grade and slope control, calculates a virtual reference.

The 3 sonic sensors fitted to the Multiplex Ski cover a distance of up to 9 meters. The advantage is that irregularities extending over a long distance are recognized and leveled out. This system offers higher accuracy than a single sonic grade sensor.

The paving operation will start at the lower side of the road.

The operational speed of the pavers shall be adjustable from 2 to 6 m/min in accordance with the instructions of the consultant/inspector.

While paving is in progress, all asphalt mix required for making the PMB wearing course shall be at the site to avoid delay due to an insufficient amount of mixture.

An accurately calibrated thermometer suitable for measuring the inner and surface temperature of the material shall be used at the site. The material temperature shall be checked immediately before rolling and at least every 30 minutes thereafter while the work is in progress.

The grade checking team will constantly monitor the level as work continues under the supervision of a full-time surveyor.

The asphalt course shall be constructed to proposed levels and shall be homogeneous, providing after compaction an even surface free from undulations, rises, or depressions and within the tolerances stipulated.

In applying PMB PG 76-10 special attention must be paid to the temperature in all stages.

Hand raking should not be done unless absolutely necessary. The most uniform surface texture can be obtained by keeping the handwork behind the screed to a minimum.

Similarly, workers must not walk on the newly laid mat before compaction. Workers’ boots will pick up asphalt from the mat and also leave indents which will show even after compaction. The running plate on the back of the screed should be used to cross the mat if necessary and side working where necessary should be restricted to off mat areas.

All asphalt trucks shall be reversed with the aid of a banksman through the site.

Asphalt Road Construction

Compaction

One rolling pass is defined as being the movement of a roller from the start-point, to the asphalt-paver and back to the start-point, noting that rollers must keep a five-meter safety distance’ from any plant in the direction of travel.
Below is an example of a rolling pattern however, the final rolling pattern will be established based on the approved site mock-up incorporating all tests reports to be submitted for final approval of the consultant.

In no case shall the mix temperature be allowed to drop below 150°C before the breakdown rolling.

Breakdown rolling will follow immediately behind the paving machine, with a steel wheel vibratory roller will follow closely behind the paver, moving in an orderly manner, starting from the edge and progressing towards the center, maintaining an overlap as the rolling continues. The rolling shall start from the low side and to be progressing toward the higher side in the longitudinal direction of the road.

The first pass for the breakdown rolling with steel wheel roller will be a static-without vibration. Thereafter, there will be a maximum number of 3 further passes with vibration.

The vibratory roller speed shall not exceed 4-5 km/h.

To prevent adhesion of the mix to steel-wheeled rollers, the wheels shall be kept properly moistened but excess water shall not be permitted.

Immediately after completion of the rolling by the steel-wheeled roller, a 14 tons pneumatic smooth tire roller will be deployed to continue the rolling in a similar way by making 12 passes.

Fresh asphalt sticks to PTR (Pneumatic Tire Roller) cold tires. Sticking may be a problem the first few minutes until the tires heat up therefore it is recommended that the PTR runs up and down on adjacent hard paved surfaces until the tyres are warmed. The application of vegetable oil (light application) shall be allowed to avoid sticking the fresh asphalt to tyres. When applying vegetable oil to tyres, a long lance is ideally used so that the application operator is kept well away from the running path of the PTR.

The spray man must apply the spray with the roller direction of travel moving away from – never with the roller moving towards him.

The final finish will be accomplished when the compacted surface has stabilized and does not show signs of displacement or cracking, by deploying a steel-wheeled roller without vibration for a further two (2) passes.

A team of 2 persons including Surveyor shall continuously monitor surface regularity of wearing course by 3m aluminum straight edge, if any hump/depression is found out of tolerance, it will be rectified prior to completion of the rolling for the PMB wearing course.

Sections of the newly finished work shall be protected from passage of any kind until the mix has been properly compacted and cooled.

Construction Joint-Asphalt Paving Work

Construction joints shall be prepared by cutting the layer vertically down with an asphalt saw cutting machine or a jackhammer.

Fueling of Paving Equipment

The layer of the wearing course shall be protected from oil/fuel spills by the contractor.

Fueling of equipment is strictly prohibited on the paving surface and it shall be done outside the paving area.

In case any oil/fuel spills are found on the pavement surface, they shall be rectified to the satisfaction of the inspector before continuing with paving.

Laying and Rolling Procedure during Echelon Paving

50mm to 100mm of the edge which the second paver is following shall be left unrolled when applying in the echelon. The edges between the first and the second paving machine shall not be exposed for more than 15 minutes nor 50 m by distance without being rolled. Particular attention shall be given to the construction of transverse and longitudinal joints in all courses.

Then rolling pattern shall be applied as described below:
• The first pass for the breakdown rolling with steel wheel rollers will be static (without vibration), thereafter, there will be the maximum number of three (3) passes with vibration. Immediately after completion of the rolling of the steel heeled roller, a (PTR) Pneumatic, Smooth Tire Roller will be deployed to continue the rolling in a similar way by making twelve (12) passes.
• The final finished rolling will be accomplished when the completed surface is stabilized and does not show signs of displacement or cracking by deploying a steel-wheeled roller without vibration for a further two (2) passes.

Protection of Laid Courses

Sections of the newly finished work shall be protected from passage of any kind until the mix has been properly compacted and cooled. In no case shall traffic be permitted less than 24 hours after completion of the asphalt course unless a shorter period is authorized by the inspector.

After completion each asphalt laid area shall be protected by hard barricading and safety signboards shall be placed to restrict the traffic movement on the newly laid area.

The safety team will monitor for the closure and opening of the particular stretch.

Asphalt Pavement Construction

Risk Assessment

Refer to the attached document in Appendix A.

Permit and Licensing Requirements

Refer to Appendix C for Permit to Work.

Drawings, Diagrams, Maps and Survey Data

Refer to approved Shop Drawings

Pre-Start Safety Briefing Arrangements

Refer to Risk Assessment on Appendix A.

Protective and Safety Equipment

All workers Involved shall be equipped with adequate PPE as stated below:
a. Safety Helmet with Company Logo
b. Safety Boots
c. High Visibility Vest
d. Safety Goggles
e. Hand Gloves
f. Coveralls

Information to Personnel

a. Safety Induction
b. Job Training
c. Superintendents Notices/Memos
d. Toolbox talks
e. STARRT Card

Safety Requirements

a. All necessary personal/protective equipment (PPE), as well as harness, be provided.

b. Banksman, wearing distinctive vests, shall be assigned to help operators maneuver their equipment.

c. The equipment operators shall possess the required licenses and certificates.

d. Generated dust shall be controlled by periodic water spraying.

e. The project safety officer is responsible along with the project zone site engineer for ensuring that all
operations are carried out with due regard to the safety of all project personnel & property.

f. All working activity shall comply with the client’s safe work method statement.

g. First aid material.

h. General management of protection/operation hazards are to be observed.

i. In case of working at night, please refer to Method Statement for Night Works.

Supervision

This asphalt concrete work method statement involves all key personnel who are experienced in asphalt pavement construction.

Construction Manager

He is in charge of all construction activities. Schedule the project in logical steps and budget time required to meet deadlines. Inspect and review projects to monitor compliance with building and safety codes and other regulations.

Site Engineer

The Site Engineer shall evaluate the number of materials consumed by each trade to be compared against the planned quantity.

Site Foreman

A site foreman is responsible for supervising the workers and also doing actual construction work.
The foreman monitors employees to ensure that the work is done efficiently and within project standards.

Chief Surveyor

A Chief Surveyor shall ensure that surveying data are collected and recorded accurately and that all company procedures are followed by crew members.

QA/QC Engineer

The QA/QC Engineer shall monitor whether the installation works are conforming to the required quality otherwise he shall notify the Site Engineer should he find non-conformance to the ongoing activities. The Site Engineer shall immediately rectify the work to avoid receipt of NCR from the qa qc engineer.

HSE Engineer

The Safety Engineer shall be full-time at the site and shall frequently visit all the ongoing works at the site. All safety violations and on-conformance of the HSE Plan shall be registered and immediate action shall be done in coordination with the Site Engineer.

Environment and Quality Issues

Precautionary Measure

All precautionary measures shall be briefed to all workers prior to commencing the activity.

Disposal Requirements

All waste shall be disposed of as per the Construction and Environmental Management Plan, and as per government-approved disposal areas.

Inspection, Test and Sampling

Request for Inspection and Testing will be submitted prior to and after execution of works.

Bituminous materials will undergo QC sampling and testing at the mixing plant for specification compliance regarding aggregate gradation binder content and marshall design properties.

Asphalt core cutting test to be carried out to confirm the quality of the works like the density of the asphalt, the thickness of the layer, air permeability, asphalt compression strength, asphalt mix test, etc.

Testing shall be conducted by approved third-party laboratory.

Quality Assurance Requirements

Ensure that work is executed as per approved shop drawing, method statement for asphalt, and records are generated referring to approved ITP.

Best management practices shall also be considered which may be stated by product manufacturer or suppliers.

Authority requirements will take precedence over all requirements in case authority approval is to be secured.

For non-authority approval activities, the approved latest project specification will take precedence.

It is to ensure that regular toolbox training related to work quality is conducted and records are maintained.

Wearing Course Laying Checklist

Erect barricades to prevent traffic until the mix has been properly compacted and cooled.

Check evenness and road surface.

The road shall be allowed to dry for a minimum period of 24 hours or as authorized by the inspector.

All Inspection/ sampling and tests as per requirement are conducted and results are ok.

Survey reports generated.

Confirm no defects (undulation, settlement, cracks, holes, etc.)

Confirm if core samples are collected.

Check weather conditions are ok for asphalt paving work (production and spreading shall not be permitted if ambient temp. is less than 8°C nor during rain, fog, dust-storms or other unsuitable weather)

Check if the tack coat applied has been completed and is not damaged.

Pre-heating of the paver is done (to prevent the mix from sticking to sensitive parts of the machine.)

Check if the concrete base has been approved by the consultant and no pending issue or NCR is open.

Confirm mix design is known to supervisor in charge of mixing and a copy of mix design at the site and delivery to compare against it.

Confirm course aggregate has been tested and is of acceptable quality and adequate quantity.

Confirm fine aggregate is of correct gradation and adequate quantity.

Confirm equipment and plant necessary are available and in working order.

Checks that the paving machine is adjusted to give the specified minimum thickness and camber & width.

Check the delivered mix temperature value

Ensure that delivered mixture temperature is in range (within 14°C of JMF and 135°C above absolute min.)

Check the reference guide string line for controlling the levels of the laid mix is available at no more than Sm interval.

Ensure the laid uncompacted asphalt temperature is above 120°C.

Observe the spreading and compacting operations. Ensure the material is being spread without significant segregation.

Confirm that the gradation of spread materials is as per the job mix of wearing course by taking samples from the spread materials and conducting gradation tests.

Confirm the thickness of laid asphalt (check the approved erected reference guide string line if the required thickness is achieved).

Check if the compaction achieved is as required. Observe the compacting operation to confirm that the material forms a firm, stable base throughout the spread width.

Ensure all the test and their minimum frequencies as specified ITP is conducted.

Confirm all tolerance are within the limits as specified in the ITP.

Appendices-Asphalt Paving Work Method Statement

Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Risk Assessment
Inspection and Test Plan (ITP)
Permit to Work
Mix Design & Conformity Certificate

II-Method Statement-Asphalt Roadworks

Scope of Work

This asphalt method statement outlines how to apply and lay asphalt pavement for road construction. It includes sub base of aggregate, road base of crusher run, asphaltic concrete binder, and asphaltic concrete wearing courses.

References

Project Specifications
Inspection Checklist for Roadwork
Approved Drawings & Specifications

Asphaltic Concrete

Machinery and Equipment

Paving Machines
Bitumen spray tankers
Diamond Cutter
Backhoe
Back pusher
Tipper Trucks
Total Station
Vibratory roller
Leveling Instrument

Material

• Crusher run
• Sand
• Bituminous Prime Coat
• Bituminous Tack Coat
• Asphaltic Concrete Binder Course ACBC 28
• Asphaltic Concrete Wearing Course ACBC 20

Asphalt Concrete

Construction

General

Before pavement construction can begin the horizontal and vertical alignments must be jointly inspected and confirmed by the consultant.

A surveyor shall use a proper instrument total station and dumping level to mark on-site in a visible and protected location during construction.

Construction of the pavement shall not begin until the subgrade layer has been approved and accepted.
Contractors must check alignment, all dipping pegs, and confirm with the consultant before permanent work begins.

Sequence of Work

Laying of the following construction materials:
100mm granular material sub base
200mm crusher run road base
60mm Asphaltic Concrete Binder Course
40mm Asphaltic Concrete Wearing Course

Asphalt Road Construction

Formation Preparation for Road Pavement

Unless otherwise agreed by the Consultant, the preparation of the formation shall precede laying of the sub base only after completion of either piped or box culverts, existing services, utilities, and ducts (if applicable), or any other drainage work that might affect the works.

To ensure compliance with technical specifications, all materials for sub base, road base, ACBC, and ACWC shall be sent to an approved laboratory to conduct necessary testing.

Throughout its entire width, the formation surface must be substantially uniform in density and conform to the density requirements for compaction. Utility lines crossing the road, such as water mains and cables, should be protected before the road base works begin. For example, using lids for u-drains and GI conduit for cables.

Trim it according to the lines, camber, grades, and typical cross-sections are shown on the drawings or as directed by the Consultant.

Level pegging should be done at a suitable distance for inspection.

Soil Formation

Soft spots and unsuitable materials should be removed, backfilled with approved material, and compacted according to the rolling pattern.

Highway Pavement Sub Base

Material for the sub base shall be hard, durable, and clean. There shall be no organic matter, clay balls, or other contaminating substances in these granular materials.

Delivery of materials will be made by tipper lorries and they will be spread and leveled by means of a back pusher across the entire sidewalk width.

As specified in the drawing, the material shall be filled and compacted to the required thickness.

Vibrating rollers shall be used for compaction of the sub base layer to achieve the specified relative dry density.

Vibrating rollers shall be used for compaction of the sub base layer to achieve the specified relative dry density.

The surface will be aligned, leveled, and checked for regularity and shall be in accordance with the technical specification.

It is necessary to regulate and trim the surface of the granular sub base layer by the back pusher to the required level and cross fall within the specified vertical tolerances.

Compaction work will be carried out using roller compactors.

According to the specifications, a Field Density Test (FDT) or CBR Test shall be conducted on the subgrade.

Placing the road base material

On top of the sub base, the crusher run road base shall consist of crushed aggregate laid in layers of not more than 200mm each, to give the specified total compacted thickness and width, with the proper line and level as shown in the drawings.

Materials shall consist of crushed rock of hard durable particles or fragments of rock that are well graded, crushed to the appropriate size, and fit within the following grading limits.

In order to prevent material segregation into coarse and fine fractions, it must be kept evenly mixed.

Spreading of sub base material should begin after receiving the results of the compaction test for sub grade. Sub base material loads should be spread outside the area on which they are spread to avoid segregation and should be spread evenly using a grader to maintain layers’ levels and thickness.

The average MDD for each layer must be 100%, with no single value below 98%. There shall be one field density test for every 300 square meters of granular sub base laid. As per the project specifications, there shall be one sample for every 1000 cubic meters of material, and tests shall be performed as follows: grading, plasticity index, sand equivalent, MDD, and CBR, loss by abrasion.

Asphalt Pavement Construction

Bituminous Prime Coat and Tack Coat

Prior to laying the asphaltic concrete binder course, an approved bituminous prime coat submitted through material submission shall be applied to the top of the completed crusher run base course.

It is imperative that the surface is thoroughly cleaned prior to priming.

Bituminous should be applied by a distributor at suitable rates but not less than 0.435 liters per square meter. A primer coat shall be applied with SS1K, while a tack coat is applied with RS1K.

Clean the surface of the dense asphaltic concrete binder course immediately before applying an approved tack coat.

The bituminous shall be applied by a distributor at appropriate rates, but not less than 0.35 liters per square meter.

Prime coats should be sprayed well in advance and left to cure for 24 hours. The overspread area must be cured for at least 24 hours or until all of the excess prime coat has evaporated.

Asphalt Concrete Surfacing

General

Asphaltic concrete binder and asphaltic concrete wearing course shall be used for the surfacing, and these shall be laid according to BS 1621.

The two courses shall be built to the width and thickness shown in the drawing after compaction.

Material

1) Coarse Aggregate
Coarse aggregate shall be hard, un-weathered, clean, durable, angular, free from dust, and tested which shall be in accordance with B.S. 812.

2) Fine aggregate
A fine aggregate shall be approved to clean natural banks, rivers, dunes, pits, or quarry sand produced by a secondary plant. It shall be composed of hard, non-absorbent sharp grains and shall be free of clay, loam, loosely bound aggregations, and other foreign matter.

3) Filler
Filler must be Portland cement compliant with B.S. 12 or limestone, having a bulk density in Toluene.

ACBC 28 -Asphaltic Concrete Binder Course

The ACBC 28 mix shall follow the approved mix design and trial mix.

Surface-dry aggregates must be mixed at an appropriate temperature.

The mixed material delivered to the laying site shall be between 140 degrees Celsius and 160 degrees Celsius.

Laying Procedure

Work on-site will begin once the road base has been approved and accepted.

Sweeping shall be conducted to ensure that the surface to receive the asphaltic concrete binder course is free of all damage, loose materials, and standing water.

Prior to laying the asphaltic binder course to the prepared surface, a primer coat of approved bitumen emulsion shall be placed as per specifications.

Plant-mixed asphaltic concrete binder with approved bitumen content is required.

Tipper trucks will supply the approved asphaltic concrete binder course to the job site. The mixture should be covered with tarpaulin to avoid heat loss.

A paver should apply for the asphaltic concrete binder course in a single layer.

Compaction must be done with compactors of the specified nearly equivalent types.

Rolling must always begin on the lower side of the carriageway and work its way up.

The rolling temperature must be at a minimum of 80 degrees Celsius.

The asphaltic concrete binder course’s surface must be finished to the line and grade specified in the drawings.

Asphalt Roadworks

ACWC 20 – Asphaltic Concrete Wearing Course

ACWC 20 mix shall follow the approved design mix and trial mix.

The aggregates must be surface-dry and mixed at an appropriate temperature. When delivered to the laying site, the mixed material should have a temperature between 140 and 160 degrees Celsius.

Laying Procedure

As soon as the asphaltic concrete binder course is approved and accepted, work will commence on site.

Sweeping is required to ensure that the surface to be covered with the asphaltic concrete wearing course is free of any damage, loose materials, and standing water.

After the asphaltic wearing course is laid, a tack coat of approved bitumen emulsion should be applied according to specifications to the prepared surface.

Wearing asphaltic concrete shall be plant mixed with bitumen content.

Tipper trucks will deliver the approved asphaltic wearing course to the site. The mixture shall be covered by tarpaulin or canvass to prevent heat loss.

Pavers must lay the asphaltic concrete wearing course in a single layer. Utilize the specified equivalent type of compactors for compaction. In all cases, rolling shall begin from the lower to the higher side of the carriageway.

A minimum rolling temperature of 125 degrees Celsius is required.

The asphaltic concrete surface of the wearing course shall be finished to the line and grade shown in the drawings.

Once the laying and compaction are complete, a joint survey should be conducted to check for compliance with the specifications.

When all of the above work has been completed, the supervisor is responsible for tidying up the site and disposing of excess materials.

Transport/Delivery

Transport of bituminous materials should be made in clean vehicles, and the material must be covered while in transit or awaiting tipping.

In order to prevent contamination with foreign matter, every precaution must be taken to avoid the segregation of mixed materials.

To keep materials at a satisfactory temperature during transit and to prevent undue heat loss, adequate precautions must be taken to ensure the materials are properly protected.

Asphalt Paving Works

Laying

Immediately after arriving at the laying site, the mixed materials must be continuously fed to the paver and laid without delay.

Pavement materials with bitumen as the binder shall, whenever possible, be spread, leveled, and tamped by self-propelled pavers capable of laying to the required width, profile, camber, or cross fall.

Immediately after any course is placed and before the rolling begins, the surface should be checked and any defects or irregularities in alignment, grade, or texture should be corrected by adding or removing the mixture.

Compaction

Ideally, the material should be compacted as soon as possible so that rolling can be achieved without displacing the mixture.

Bituminous base course and wearing course shall have a compacted thickness of 60mm & 50mm, respectively, (as per the contract.)

The bituminous material will be compacted using steel wheel tandem vibratory rollers and pneumatic tire rollers.

The rollers should be equipped with beepers.

Roll the materials longitudinally from the sides to the center of the carriageway. Rolling needs to produce equal amounts of air voids longitudinally and transversally.

Two times, rolls pass through a vibrating compactor before passing through a non-vibrating compactor twice. At least 12 tonnes must be the weight of the roller.

The tire roller should be used for compaction eight times during the roll pass process.

Non-vibratory compactors should be used for the last compaction.

Asphalt Pavement Construction

Key Takeaways

It is believed that the terms asphalt (or asphaltic) concrete bituminous asphalt concrete and bituminous mix are generally employed in construction and civil engineering documents. These documents defines concrete as any material made up of mineral aggregates that are bonded to binder. Abbreviations, AC, is frequently used to describe asphalt concrete but it could also mean the content of asphalt and asphalt cement in reference to the portion of asphalt that is liquid in the composite material.

Asphalt concrete pavements consist of layers, including an asphalt concrete surface constructed over a granular or asphalt concrete base and a subbase.

Asphalt binder is a by-product of the petroleum refining process that produces gasoline, diesel fuel, lubricating oil, and other petroleum products.

Asphalt binder is made from the thick, heavy residue left over after petroleum has been distilled to remove fuels and lubricants.

The asphalt binder component of an asphalt pavement typically constitutes about 5 to 6 percent of the total asphalt mixture and binds the aggregates together.

A prime coat consists of a sprayed application of a cutback asphalt or asphalt emulsion (ae) applied on the surface of an untreated subgrade or base layer.

Hot mix asphalt (hma) is a mixture of fine and coarse aggregate with an asphalt cement binder mixed, placed, and compacted in a heated condition.

Cold mix asphalt is made with emulsified asphalt and aggregate, and it is produced, placed, and compacted at ambient air temperatures. This kind of pavement usually requires an overlay of hot mix asphalt or surface treatments to resist traffic.

Base course: one or more layers of bituminous material under the wearing course and above the unbound road base layer.

Wearing course: top surface bituminous course, which resists skidding, traffic abrasion, and climate-related deterioration.

Asphalt Pavement Work

There you have it the two scenarios of asphalt road works with each method statement:

Asphaltic Road Method Statement | Asphalt Paving Works | Asphalt Concrete| Asphalt Pavement Construction | Asphaltic Road Construction | Highway Pavement

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