GTC/644E/2014
EXTENSION OF DISTRIBUTION NETWORK
METHOD STATEMENT FOR ASPHALT
Revision History
GTC644E-COMPANY-C-MST-16-003
1 16/03/2016 SHYJU RAMEEZ RASIAH
GTC644E-COMPANY-C-MST-16-003
0 17/02/2016 SHYJU SAIFUDDIN RASIAH
Doc. no. Rev
. no.
Date Purpose of resubmission Prep. By (contractor) Rev. by (contractor) Appr. By (contractor)
INDEX SHEET
1. Purpose
2. Scope of works
3. References
4. Definitions and Abbreviations
5. Resources
6. Responsible Personnel
7. Permits and Licenses
8. Sequence of Activities
9. Quality Assurance/Quality Control
10. HSE issues, Risk assessment and Hazard analysis
11. Attachments
1. PURPOSE
The purpose of this method statement is to describe the sequences and methodology for construction of Reinstatement /road works with the strict compliance of the Contract Documents, Project Specific Specification i.e. sections 06 Road works and the Section 6.
2. SCOPE OF WORKS
The work consists of preparation of roads and Pipe line trenches-sub grade, formation and spreading and compaction of sub-base in preparation to lay asphalt base course and asphalt wearing course in accordance with the Specifications. Also consists of preparation of the final layer at plots area in strict adherence and compliance to Project Specific Specifications, CS 2014 and contractual scope of the work.
3. REFERENCES
1. AFC Drawings 2. Work Traffic Manual
3. Road opening in the Highway
4. DEFINITIONS & ABBREVIATIONS
4.1 DEFINITIONS
4.1.1 Sub grade- the compacted existing ground or selected fill up to 500mm beneath formation. 4.1.2 Maximum dry density- dry density of soil obtained using a specific degree of compaction
at the optimum moisture content.
4.1.3 Optimum moisture content- moisture content of soil which a specific degree of compaction will produce the maximum dry density).
4.1.4 Formation- the completed earthworks level shaped in accordance with the drawings in readiness to receive sub-base.
4.1.5 Sub-base- the compacted fill material forming the layer between the formation and the road base
4.2 ABBREVIATIONS
4.2.1 FDT- Field Density Test
4.2.2 OMC - Optimum Moisture Content 4.2.3 MDD - Maximum Dry Density 4.2.4 PM - Project Manager
4.2.5 QCM- Quality Control Manager 4.2.6 QCI- Quality Control Inspector
4.2.7 PE- Project Engineer 4.2.8 SE- Site Engineer
4.2.9 ICL- Inspection checklist
4.2.10 QA/QC – Quality Assurance Quality Control 4.2.11 MEP- Mechanical Electrical Piping
4.2.12 MSDS- Material Safety Data Sheet 4.2.13 ITP- Inspection and Test Plan 4.2.14 PTW- Permit to Work
4.2.15 AFC – Approved for Construction 4.2.16 CS – ME Construction Specifications 4.2.17 QTY – Quantity 4.2.18 IR – Inspection Request
5 RESOURCES
5.1 MATERIALSIte
m
Description
Test
Remarks
1 Fill Material Gradation MDD Chemical Atteberg FDT
As required/ instructed by the Engineer. As required/ instructed by the Engineer. As required/ instructed by the Engineer. As required/ instructed by the Engineer. 1 test per 500m2 compacted (95%).
2 Selected Fill Gradation MDD Chemical Atteberg FDT
As required/ instructed by the Engineer. As required/ instructed by the Engineer. As required/ instructed by the Engineer. As required/ instructed by the Engineer. 1 test per 500m2 compacted (95%).
3 Sub-base Gradation
MDD FDT
1 test per 1000m3 laid.
As required/ instructed by the Engineer. 5.1.1.1 test per 500m2 compacted (100%).
5.2 MACHINERY
Item Description Qty. Remarks
1 Heavy Machineries
Power crusher and screens. Excavator Bulldozer Shovel Dump trucks Grader Rollers Paver 1 1 1 1 1 1 1 1 1
Water trucks Backhoe 1 1 2 Light Machineries 1 ton roller Tamper/plate compactors 1
1 Or as and when required.
5.3 MANPOWER
Ite
m
Description
Qty.
Remarks
1 Project Engineer QA/QC Inspector Surveyor Foreman Operators Skilled workers Labours Or as required
6.0RESPONSIBLE PERSONNEL
6.1 Project manager shall have overall responsibility for implementation of this method statement while execution, described here under and inspection, testing, handing over in complete.
6.2 QA/QC is responsible to ensure the construction activities are performed as per the procedures, method statements and ITP’s.
6.3 QA/QC is responsible to inspect the installations and to ensure full compliance of ITP, Checklists, project specifications and required standards.
6.4 PE/SE to ensure that installations performed as per approved methods statements, IFC drawings/shop drawings, material submittals and to initiate, supervise and monitor the inspections and Inspections requests (IR). Related ICL and ITP’s will be implemented.
7.0PERMITS AND LICENSES
Permits & Licenses shall be renewed and valid through all over the project duration from the concerned authorities including, but not limited to, the Ministry of Environment, Traffic Management, Ministry of Municipality, Urban Planning & PWA Road Section (Before, During & After Reinstatement )
8.0SEQUENCE OF ACTIVITIES
Prior to commence road works ensure that all the required utility permits, approvals, clearances from local approving authorities are approved. Ensure that the Temporary traffic management plan is approved.
SUB-GRADE PREPARATION: Ref: CS 2014, Section6, Part3, and Clause 3.5.2
8.1 Sub-Grade Preparation in Cutting Areas
8.1.1 Excavation on high level areas in all materials including rock for the full width of the road construction down to the top of the required sub-grade.
8.1.2 For areas with suitable materials, the top of required sub grade will be
scarified further to a layer not less than 150mm deep except that this requirement shall not apply where rock is present. Surveyor to mark the setting out for sub grade and initiate the inspection request to check the
setting out for the sub grade. Upon approval proceed for the excavation.
8.1.3 Inspection request (IR) “Check Excavation (alignment & levels) prior to
Sub grade/ Preparation” shall be submitted prior to proceeding to the next
activity.
8.1.4 Upon receipt approval from the Engineer work to proceed for the next step.
8.1.5 Selected fill material will then be spread; water as required, mixed, shaped
and compacted to 95% maximum dry density. Moisture content shall be within + 2% of the Optimum moisture content.
8.2 Sub-Grade Preparation in Filling Areas
8.2.1 Filling low-level areas shall be to the level of sub-grade as designated.
8.2.2 Top soil shall be excavated up to 300mm or as directed by the Engineer. Unsuitable materials if encountered shall be excavated and replace with approved fill material. 8.2.3 A request (IR) “Check Actual Ground (alignment & levels) prior to Filling
Works” shall be submitted prior to proceed next activity.
8.2.4 During the above checking the actual site ground level will then be recorded and from this record to derived filling layers below Sub-grade.
8.2.5 Filling below sub-grade level.
o Fill material to be use shall be as per CS 2014, section 6 part 3 Earthworks clause
o Filling shall be in layers not to exceed 150 mm compacted thicknesses.
o Where existing embankment is being widened, the existing embankment slope shall be trimmed and compacted into benches of minimum width 1m and depth 500mm before placing and compacted each layer of new embankment material.
o Fill material will then be spread and compacted to 95% maximum dry density. Moisture content shall be within + 2% of the optimum moisture content.
o A request (IR) “Check Levels and FDT test (_______ layer) prior to next layer
filling Works” shall be submitted prior to go before next activity.
o Not to proceed with filling and compacting any subsequent layer unless the previous layer had been tested and pass the requirement.
8.3 Sub-Grade Preparation.
Filling works below sub-grade level must be completed and tested.
8.3.1 The layer beneath sub-base is the sub-grade for which only selected fill material will be used. For NRV area the thickness of sub grade is 300mm and for WWF area the thickness of sub grade is 500mm.
8.3.2 Selected material to be use as per CS2010 section 6 part 3 Earthworks clause 3.3.5 or as per approval of the Engineer.
8.3.3 Selected fill material will then be spread in 150mm thick; water as required, mixed, shaped and compacted to 95% maximum dry density. Moisture content shall be within + 3% of the optimum moisture content.
8.3.4 In every layer a request (IN) “Check Levels and FDT test (_______ layer) prior
to next layer filling Works” shall be submitted prior to proceed next activity. 8.3.5 Note for the Utilities and Ducts Crossing the Road- prior to preparation of
Formation all necessary utilities and ducts crossing the road must be completely installed and accepted.
8.4 PREPARATION FOR FORMATION
8.4.1 All sub-grade preparation is completed as per requirements.
8.4.2 Preparation and surface treatment of the formation has been carried out after all ducts and pipes installation crossing the road has been completed.
8.4.3 Any non-compliant sub-grade material shall be excavated, replaced and compacted to required density.
8.4.4 A request (IR) “Utility clearances (underground utilities and ducts crossing) and
Check Formation (alignment and levels) prior to Sub-Base Works” shall be
submitted prior to proceed next activity.
8.4.5 Once prepared, the formation shall be protected and maintained in the finished condition until the first succeeding course of sub-base has been placed.
8.4.6 Test Levels and Evenness of the Formation. The sub-grade shall be prepared to the levels shown in the approved drawings to a tolerance of between +15mm and -20mm when checked by level instrument
8.5 SUB-BASE
8.5.1 Source of materials: Contractor to notify the Engineer for the proposed sources of materials.
8.5.2 Storage and Handling of materials: Materials shall be so stored and handled as to assure the preservation of their quality and fitness for use in the works
8.5.3 Inspection, Testing and Control: The Contractor shall arrange to carryout necessary testing and quality control requirements. The Engineer shall at all times be provided access to check and perform his duty
8.5.4 Materials: (fine aggregates, coarse aggregates, water) to comply with the specification requirements
8.5.5 Main Equipment: The Contractor to provide the list of equipment to be utilize in this work as per specification or subject to the approval of the Engineer.
8.5.6 Mix Design: the contractor to submit the proposed design mix as per specification or subject to the approval of the Engineer.
8.5.7 Screening and mixing: To comply with CS Section 6 Part 4 Section 4.5. A Central mixing plant shall be used for the mixing of materials, in case the material stipulated in the mix design is delivered in fractions. In all other cases screens shall be utilized to
Ensure the gradation. Mixing of separate materials on the roadway by motor grader will not be permitted.
8.5.8 Spreading, Compaction and Test
o Sub-base material during spreading shall have moisture content within + 2% of the
optimum moisture content.
o Since the required thickness of sub-base is only 200mm, material shall be spread in one layer.
o Sub-base maybe laid by either a paving machine with a spreader box or end tipped from trucks and spread by grader.
o Compaction shall start immediately after the material has been laid and as per approved rolling pattern.
o Along places inaccessible to rollers, the sub-base material shall be tamped thorough with suitable mechanical tampers to achieve the required density and finish.
o A request (IR) “Sub-Base FDT Test prior to Surface Checking Works” shall be submitted prior to go before next activity.
o Completed Sub-base shall be tested for acceptance to attain a minimum density of 100% of the maximum dry density of the material. 2 tests every 500 m2 area shall be carried out unless otherwise directed by the Engineer.
o Gradation of the placed material shall be checked by taking samples from an area 0.50m x 0.50m from the full depth of the layer for every 1000 m3 laid material. Or the Engineer may also instruct that the gradation of material shall be checked by taking samples from the mixing plant.
o Once passed the required FDT a request (IR) “Check Sub-Base (alignment and
levels) prior to Prime Coat” shall be submitted prior to proceed next activity.
o The finished surface shall be checked by dips or spot levels and shall be constructed to the designated grade levels to within + 10 mm.
o All precautionary effort shall be taken to ensure the completed and approved layers are not damaged before the next layer will be laid.
8.5.9 Final layer at Plots Area: This layer is the last layer at plots area which only selected fill material will be used and it will be varied from 80mm to 300mm thickness.
9.0 QUALITY ASSURANCE/QUALITY CONTROL
All inspection and testing will be done in full compliance with the Project Specific Specifications and CS-2014, Section 6, Part 4,
10.0 HSE
ISSUES, RISK ASSESSMENT AND HAZARD ANALYSIS.10.1.To ensure all workers are briefed and follow safety procedures and with appropriate safety/ protective equipment.
10.2 HSE to ensure the approval of all the related clearances, permits, permissions from the relevant approving authorities.
10.3 HSE to confirm the implementation of the Temporary traffic management plan and Construction Environmental Plan.
10.4 To provide and erect approved safety barriers warning signs, as and wherever applicable.
10.5 Provide advance warning notice road signs will be erected on areas where works is in progress.
10.6 To carryout regular housekeeping to maintain work place tidy.
