technical specifications of roads

8/12/2019 Technical Specifications of Roads

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TECHNICAL SPECIFICATIONS OF ROADS

September 2010

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Table of Contents

1 ................................................................................................ 1-1SUMMARY OF WORK

2 ................................................................................ 2-1DEMOLITION AND REMOVAL2.1 ................................................................................................................... 2-1General2.2 ......................................................................................................... 2-1Requirements2.3 .............................................................................................................. 2-3Submittals2.4 ............................................................................................................... 2-4Inspection2.5 ............................................................................................................. 2-4Preparation2.6 ............................................................................................................. 2-5Demolition2.7 ......................................................................................... 2-7Disposition of materials2.8 ................................................................................................. 2-7Cleanup and repair

3 ........................................... 3-1GENERAL EARTHWORK AND SITE PREPARATION3.1 ................................................................................................................... 3-1General3.2 ......................................................................................................... 3-1Requirements3.3 .............................................................................................................. 3-3Submittals3.4 ....................................................................................................... 3-4Quality control3.5 .............................................................................. 3-6Delivery, storage and handling3.6 .................................................................................................... 3-7Site investigation3.7 ................................................................................................................. 3-9Products

3.7.1 .............................................................................................. 3-9Existing ground3.7.2 .................................................................................................... 3-9Fill material3.7.3 ............................................................................................................ 3-10Water

3.8 ............................................................................................................. 3-10Execution3.8.1 ..................................................................................................... 3-10Protection3.8.2 ........................................................................................................ 3-10Clearing3.8.3 ......................................................................... 3-12Existing ground preparation3.8.4 ............................................................................. 3-13Placement of fill material

4 ........................................................................................ 4-1ROADS AND FOOTPATHS

4.1 ............................................................................................................. 4-1Definitions4.2 ............................................................................................ 4-2General Requirements4.3 .............................................................................................................. 4-3Submittals

4.3.1 .......................................................................................................... 4-3Samples4.3.2 .......................................................................................... 4-3Method Statement4.3.3 ............................................................................................... 4-4Shop Drawings4.3.4 ......................................................................................................... 4-5Mock-up

4.4 ...................................................................................................... 4-6Quality Control4.5 ............................................................................. 4-8Delivery, Storage and Handling4.6 ................................................................................................................. 4-9Products

4.6.1 ........................................................................................................ 4-9Subgrade4.6.2 ......................................................................................................... 4-9Rock fill4.6.3 ............................................................................... 4-10Pre-cast Concrete Curbs4.6.4 ................................................................................... 4-12In-situ concrete curbs4.6.5 ........................................................................... 4-13Interlocking paving blocks

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4.6.6 ....................................................................................... 4-14Granular Sub Base4.6.7 ................................................................................... 4-16Aggregate Road Base4.6.8 .................................................................... 4-18Materials for Asphalt Concrete4.6.9 .......................................................................................... 4-21Asphalt Concrete4.6.10 ................................................................................... 4-29Prime and Tack coats

4.6.11 ............................................................................... 4-29Road marking materials4.6.12 ................................................................................................. 4-30Traffic signs

4.7 ............................................................................................................. 4-35Execution4.7.1 ........................................................................................... 4-35Placement of fill4.7.2 ................................................................................... 4-38Subgrade preparation4.7.3 .................................................................................................. 4-39Compaction4.7.4 ........................................................... 4-41Installation of precast concrete curbs4.7.5 ......................................................................... 4-43In-situ concrete curb laying4.7.6 ........................................................................................ 4-43Granular sub-base4.7.7 .................................................................................... 4-44Aggregate road-base4.7.8 ............................................................. 4-47Placement of asphalt paving course4.7.9 ........................................................ 4-67Application of road marking materials4.7.10 .......................................................................................... 4-68Erection of signs4.7.11 ...................................................................................................... 4-69Footpaths4.7.12 ......................................................... 4-69Installation of concrete paving blocks4.7.13 ................................................. 4-71Lifting and relaying concrete block paving


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1 SUMMARY OF WORKThe project includes the upgrades of existing road network as a part of the upgrading of

existing sanitary and storm sewers in a city. The contractor shall supply all supervision,

labors, materials, temporary works, plant, machinery, equipment, parts, tools, supplies,transportation, testing and handling over the infrastructure works and facilities in perfect

working condition.

The contractor should note that there might be other contractors working in the same vicinity

during the contract period. The contractor must consider this and coordinate his work to

minimize any disruptions to others working in the area. Access to the work sites shall be

maintained by the contractor at all times and he shall take all necessary steps to ensure thesafety of persons on the sites. All construction operations and site-established facilities shall

be confined to within the site boundaries as shown on the drawings, unless otherwise

approved by the engineer and the relevant authorities. Following such approvals, all such

areas shall also be designated and treated as included within the site. The contractor shall be

responsible for safeguarding all structures, plant or property near the site and shall provide all

shoring, or supports as may be necessary to preserve their stability.

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2 DEMOLITION AND REMOVAL

2.1 General

This Section specifies requirements for demolition and removal of structures and includes,

but is not limited to, the following:

1. Complete demolition of designated existing buildings and/or

structures.

2. Removal of existing underground tanks, manholes and pipes

3. Cutting into existing structures to make connections to new and

existing work.

4. Removal of existing protective coatings from concrete surfaces to

permit resurfacing, patching and recoating of surfaces.

5. Arrangement with relevant utility owners for renewal and/or

relocation of their existing services.

6. Removal or salvage of designated mechanical, electrical or other

equipment.

7. Removal from site and disposal of trash, debris, demolished

materials and salvable materials.

8. Removal and disposal of any hazardous material relating to or

associated with demolition or new work.

2.2 Requirements

1. Demolition shall include removal of all below grade structures

foundations, piles and pipes cables, etc and restoration to original

conditions unless otherwise approved by the Engineer.

2. The Contract Drawings are prepared using existing record

drawings and they may not show all items to be removed. The

Contractor shall therefore visit the site as necessary prior to

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3. Use of explosives shall not be permitted.

4.

Comply with all applicable safety precautions.5. Conform to applicable codes for demolition work, safety of

structures, dust and noise control.

6. Notify affected utility companies, pipeline owners and relevant

authorities before starting work and comply with their

requirements.

7. Obtain required permits from the governing authorities and pay for

all associated licenses, permits and inspections required by these

authorities.

8. Conform to applicable procedures when discovering hazardous or

contaminated materials.

9. Occupancy and use of facilities Client may continue to use process piping, equipment, and treatment

facilities near and adjacent to the areas designated for selective

demolition.

Conduct selective demolition work in a manner that will not interfere

with normal plant operations. This may require temporary facilities to

be constructed as necessary, at no cost to the Client, to comply with

this provision.

Provide at least 72 hours advance notice to the Engineer and Client for

those activities, which affect normal plant operations. No demolition

can be started without prior approval of Engineer and Client.

10. Conditions of facilities requiring demolition All facilities shall be handed over to the Contractor in an as is

condition.

Any preliminary work necessary to permit the main works to start shall

be at the Contractors expense. This may include, but not be limited to,

removal of tanks, pipelines or other structures containing raw or

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Conditions existing at the beginning of the project will be maintained

by the Client so far as practical; however, the Client makes noguarantee that conditions will be the same when demolition is

performed.

All facilities will continue to be used for their intended purpose until

turned over to the Contractor for rehabilitation.

2.3 Submittals

The Contractor is to prepare a method statement, which shall detail all aspects of the

proposed demolition and associated work. The method statement shall be approved by the

Engineer before any demolition work commences. The method statement shall incorporate at

least the following items:

1. Detailed description of the methods and equipment to be used for each

operation as well as proposed sequence of demolition operations.

2. Safety precautions required to ensure the safety of the workers,

members of the public, and users of adjacent facilities or properties.

3. The controlled demolition, removal and disposal of hazardous

materials.

4. The removal, protection and transportation of salvable materials.

5. Coordination of the demolition work with other work in progress, and

with any existing facility operations.

6. Shut down schedule of equipment and disconnection sequence of the

utilities involved.

7. Accurate record of disconnected services and utilities

8. Videotape of existing conditions prior to demolition.

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2.4 Inspection

The Contractor shall inspect each area prior to performing any demolition work and record

on videotape existing conditions as well as the condition of surrounding areas, clearly

marking the location, date, time taken and the items which are to be demolished. Theoriginal film and a copy of it must be submitted to the Engineer prior to starting any

demolition works. The Contractor shall ascertain that the property to be demolished lies

within the project area as shown on the drawings and is the lawful property of the Client.

2.5 Preparation

1.

Provide interior and exterior shoring, bracing and support as necessaryto prevent movement, settlement or collapse of both, facilities to be

demolished and adjacent facilities, which are designated to remain.

Stop all demolition work and notify the engineer immediately, if the

stability of the facilities, which are to remain, appears to be in danger.

If required, extra support shall be provided by the Contractor as

deemed necessary by the Engineer.

2.

Temporary barricades and other forms of protection shall be providedto safeguard personnel and the facilities, which are to remain.

3. Ensure free and safe access for Clients personnel to move to and from

occupied portions of the facility.

4. Prevent the migration of dust and dirt to occupied areas by

constructing temporary partitions.

5. Remaining facilities must be protected in the interval between

completion of demolition and the beginning of the new construction.

6. Cover and protect equipment, fixtures, surface finishes and floors

remaining in the demolition area to prevent soiling or damage.

7. Remove protective measures when work is completed

8. Maintain and protect utilities, which are to remain, against damage

during demolition.

9. Provide bypass connections where necessary to serve occupied

portions of facilities.

10. Do not shut down any utilities without prior approval of Engineer.

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11. Do not interrupt existing utilities serving occupied facilities, unless

authorized in writing by the Engineer.

2.6 Demolition

A. General

Support or reinforce existing construction that is weakened by

demolition in order not to over load structural elements.

Completely backfill voids and below grade areas resulting from

demolition work.

Dust spread must be kept to a minimum by sprinkling anyrubbish with water twice daily.

Maintain adequate fire protection, including extinguishers and

operative water-hose lines during demolition of flammable

materials.

B. Traffic Control

Demolition work and debris removal operations are to be

carried out in such a manner that shall minimize interference

with roads, streets, walks and/or other adjacent facilities.

Provide alternative routes around closed or obstructed traffic

ways as directed by the Engineer.

Do not close, block or otherwise obstruct roads or facilities

without written permission from the Client.

C. Concrete and Masonry

Demolish concrete and masonry in small sections. Saw cut concrete along straight lines to a depth of not less than

50 mm, unless otherwise indicated on the Drawings.

Make cuts in walls perpendicular to the face and aligned with

the cut in the opposite wall face, and break out the remainder of

the concrete.

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Use removal methods, which will not crack or structurally

disturb the concrete, which will remain.

Distribute demolition equipment throughout structure and

promptly remove debris to avoid overloading supporting walls,slabs, and framing.

Seal all wall and floor openings as directed by the Engineer.

D. Pipes, Utilities and Conduits

All pipelines to be connected shall be cleaned and purged as

necessary to assure a safe environment before any cutting

activities.

The appropriate locations of pipes and conduits are generally

shown on the Drawings. Where the cutting location is not

shown, the pipe or conduit shall be removed back to the first

joint or valve, or to a location approved in advance by the

Engineer. Seal all remaining pipe ends as directed by the

Engineer.

Contractor shall inform the Engineer 72 hours prior to the

cutting of any pipes or conduits leading to or from a structure

to be demolished or to be relocated. These operations shall be

coordinated with the relevant Department/Authority to assure

that no interruptions are caused.

All pipes or conduits which are encountered and which are not

shown on the Drawings shall be brought to the attention of the

Engineer.

Utility lines not specifically noted for disposition, but which

are encountered in the Work shall be capped, extended,

protected or reworked as necessary for completion of the work

as directed by the Engineer.

E. Record of all disconnected services and utilities

The Contractor shall keep on site, an accurate, up to date record

of all disconnected services and utilities. Upon completion of

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2.7 Disposition of materials

1. All materials resulting from the demolition work, except those

specifically identified to be salvaged, shall become the

contractors property.

2. Remove debris, rubbish, dust, fluids and other demolition

materials not intended for salvage from the project site bytransporting and legally disposing of the materials off site to a

dumping site, which is approved by all relevant authorities.

The Contractor is responsible to pay all costs associated with

transport and disposal.

3. If any hazardous materials are encountered during demolition

operations, the contractor must comply with all applicable

regulations, laws and ordinances concerning removal, handling

and protection against exposure or environmental pollution.

4. Burning of removed materials shall not be permitted on the

project site.

2.8 Cleanup and repair

1. Remove tools, equipment, demolished materials and protective

devices from the site upon completion of demolition work, and

leave all areas clean to the satisfaction of the Engineer.

2. Restore all remaining structures, surfaces and facilities, which

may have been damaged during demolition work to their

original condition as required by the Engineer.


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3 GENERAL EARTHWORK AND SITE PREPARATION

3.1 General

This Section specifies general requirements for earthworks and site preparation and includes, but is not limited to, the following:

General Requirements Submittals and samples Quality Control Site Investigation

Suitable fill material Clearing Preparation of existing ground Placement of fill materials

3.2 Requirements

Earthwork shall comply with the following requirements, unless otherwise approved by theEngineer.

1. No trees or shrubs shall be disturbed, unless approved by

the Engineer in writing.

2. Blasting is not permitted.

3. All excavation and backfilling shall be performed in dry

conditions.

4. Earthwork shall be constructed to the lines, grades,elevations, slopes, and cross sections indicated on the

Drawings. Allowance shall be made as required for the

thickness of any pavement, blinding concrete, lining and

riprap.

5. Levels to be recorded: Benchmarks and baselines are to be agreed with Engineer.

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Before the surface of any part of the Site is disturbed, the

Contractor shall take and record levels on 10 m grids, unless

otherwise agreed with the Engineer.

Two working days notice is to be given to the Engineer so that therecording of levels can be performed in the presence of the

Engineer.

6. Slopes shall be smooth and uniform upon completion of

the work.

7. All excavated materials shall be utilized for the

construction of embankment, shoulders and other such

places as directed by the Engineer, unless the material is

found to be unsuitable. If not immediately re-used, the

excavated material shall be stockpiled in an area

designated by the Engineer. Before excavating any

material, the Contractor shall test to existing material to

determine if it is suitable to the requirements of fill or

subgrade material as specified. Suitable and unsuitable

materials shall be stockpiled separately.

8. The Contractor shall not waste or otherwise dispose of

suitable excavated materials without written permission of

the Engineer.

9. Any excavated material not required or not suitable for use

as filling material shall become the property of the

Contractor and the Contractor shall be entirely responsible

for its removal from the Site and for its appropriate

disposal.

10. If unsuitable materials are encountered in fill areas, such

unsuitable materials shall be removed as instructed by the

Engineer. Cross-sections shall be taken before and after

cutting.

11. Contractor at his own expense shall remove from the Site

all material resulting from excess excavations below that

required for the foundation, lining or bedding and shall

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12. If the bottom of any trench or structure excavation, while

acceptable to the Engineer at the time of his inspection,may subsequently become unacceptable due to exposure to

weather conditions, equipment traffic, flooding or other

conditions encountered during the progress of the works,

the Contractor shall remove such damaged, softened or

loosened material as directed by the Engineer. The cost

of the extra excavation and of the additional foundation

materials required will be the Contractors responsibility if

necessitated by his negligence.

3.3 Submittals

1. The contractor shall submit sufficient information to the

Engineer, prior to purchase, in order to verify compliance

with the specifications. Such information shall include at

least the following: manufacturers name, suppliers name,

product description, manufacturers technical data sheet,

storage instructions, and application instructions.

2. Samples shall be supplied for at least the following

products or as requested by the Engineer.

Borrow pit material (50 kgs) Excavated material (50 kgs) Water for soil compaction (1.5 l) Geotextile (30cm x 30cm)

3. The Contractor shall provide separate method statements

for at least the following activities or as requested by the

Engineer.

General excavation, backfill and compaction.

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Dewatering activities

4. The Contractor shall submit drawings for at least cross

sections for cut and fill areas.

3.4 Quality control

1. Inspection Requests shall be submitted to the Engineer

during the on site installation work prior to proceeding

with at least the following activities. Minimum

notification time shall be 24 hours. Start of excavation Start of backfilling Sampling and testing

2. Testing of all fill materials shall be carried out by a

suitably equipped laboratory. The proposed laboratory

shall be submitted to the Engineer for his review and

approval at least 30 days before commencing earthwork.

3. During the course of the work, tests shall be carried out

under the supervision of the Engineer, to :

Identify materials, and determine suitability. Determine compaction characteristics. Determine moisture content, and field

density.

4. Test Methods Maximum dry density of all soils shall be

determined by BS 1377: Part 4: Method

3.5/3.6.

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In situ field density of compacted soils shall

be determined by BS 1377: Part 9 method

2.1 or 2.2 (Sand Replacement Method).

Other tests (C.B.R., Sieve analysis,Atterberg limits, etc.) shall be determined

by relevant BS, AASHTO & ASTM

methods as directed by the Engineer.

5. Testing Density tests shall be made prior to removal

of dewatering systems.

Contractor shall adjust his operations to

permit time to make tests and shall excavate

and fill such holes as may be required for

sampling and testing.

A subsequent layer cannot be placed until

the density of the proceeding layer has been

tested and the area is approved by the

Engineer.

The minimum number of field density tests

to be performed shall be one for every 1000

m2 per layer of compacted existing ground

or fill, unless otherwise approved by the

Engineer.

The minimum number of compaction tests to

determine the maximum dry density (MDD)

of the soil shall be at least one for every 30

consecutive field density tests conducted or

as directed by the Engineer due to changes

in the soil.

All other specified tests shall be carried out

on every 2500m3 of fill material or as

directed by the Engineer due to changes in

materials.

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The Contractor shall maintain a daily log of

all tests carried out for the Engineers

review.

6. Allowable Tolerances Finished surfaces: + 25 mm from specified

level, unless otherwise approved by the

Engineer.

3.5 Delivery, storage and handling

Delivery, stockpiling, storage and handling shall be according to the method statement or

manufacturers recommendations along with the following provisions:

Transportation, handling and storage shall at all

times be performed in a manner to avoid product

damage.

Do not store products directly on ground, unless

approved by the Engineer. Ensure adequate timber

blocking is utilized to provide sufficient support.

If stored outside, cover products as recommended

by the manufacturer.

All excavated or borrow materials shall be stock

piled at least one meter away from the edge of the

trenches.

Stockpiling of the materials shall be in such a

manner that segregation shall be kept to a minimum.

The Contractor shall visually inspect all products

upon delivery and report any damage to the

Engineer. Any products damaged during delivery,

storage or installation shall be marked by the

Contractor and set aside. Any damaged products

deemed unsuitable for repair by the Engineer shall

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3.6 Site investigation

1. A soil investigation report may be provided

by the Client or Engineer. Such reports are

for information only and without any

warranty as to the correctness of the

information contained therein. Availability

of this report to the Contractor does notrelieve him of his:

a. Obligation to thoroughly investigate for himself the nature of the Site and

the sub-soil conditions therein.

b. Obligations and responsibilities under the terms and conditions of the

Contract.

2. Contractor shall be deemed to have visited

the Site prior to submitting his Tender and

made all necessary inspections and

investigations and allowed for the following

in his Tender:

a. Means of access and working space.

b. Nature of the ground and sub-soils.

c. Presence of existing foundations or other hidden obstructions.

d. Level of the water table.

e. Extent of rock.

f. Support to neighboring properties and structures.

g. All factors affecting the Work.

3. Any information made available to the

Contractor, either in these documents or by

any other source, will not relieve the

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4. Contractor shall be deemed to have

contacted the relevant authorities to establish

the existence of any existing, live or

redundant services adjacent to or passing

through the area of work and shall be

deemed to have allowed in his Tender for

their location, diversion, demolition or

removal.

5. Boring logs and related information depict

subsurface conditions only at the specific

locations and at the particular time

designated on the logs.

a. Soil conditions at other locations may differ from conditions occurring at

the boring locations.

b. Passage of time may result in a change of the subsurface conditions or

water levels at the boring locations.

c. Client does not guarantee any statements, opinions, or conclusions

contained in the report.

d. Contractor shall assume all responsibility for:

Deductions and conclusions made by him

regarding the nature of the materials to be

excavated;

Maintaining the required excavations; Carrying out the work affected by the subsurface

conditions at the site of the works.

e. Neither the Client nor the Engineer shall be liable for any loss sustained, if

the actual conditions encountered during progress of the work differs from

the borings, samples, tests, and/or reports provided.

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3.7 Products

3.7.1

Existing groundAfter site clearing, the top compacted 200mm of the existing ground shall be comprised of

material having the minimum qualities of suitable fill and shall be compacted to 95% of the

MDD, unless otherwise directed by the Engineer.

3.7.2 Fill material

1. Suitable fill material shall consist of

excavated or borrow material free fromrubbish, vegetation, perishable matter, tree

and plant stumps and other objectionable

matter.

2. Suitable fill material shall comply with the

following requirements, unless otherwise

approved by the Engineer.

For Embankments with maximum height 2m, fill materials

should comply with "AASHTO" classifications A-1, A-2-4

or A-2-5 materials with min. C.B.R. Soaked value of 10%

at 95% of M.D.D., Materials classified as A-3 may only be

utilized in areas approved by the Engineer. Generally,

materials classified as A-5,A-6, A-7 shall never be used to

construct any Embankment height .

For Embankment higher than 2m, the top 2m shall comply

with the previous requirement. The remaining height (lower

part of Embankment) should comply with the same req.

except if A-2-6, A-2-7 or A-4 have been improved and

accepted by the Engineer to comply with the following:

Min.C.B.R. soaked value = 3% at 95% of M.D.D. Max. swelling of C.B.R. test 3%

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Rock fill may be utilized except for the top 2m of

Embankment only as directed by the Engineer and

specified later.

3.

When sufficient quantities of suitable fillmaterials cannot be obtained from site

excavations, additional material meeting the

requirements of Fill Materials shall be

obtained from approved borrow areas.

4. The Contractor shall be responsible for the

arrangement and payment for all borrow

material.

3.7.3 Water

Water used for compacting fill shall be clean and free from oil, grease, organic matter,

suspended fine sediment or deleterious materials, unless otherwise approved by the Engineer.

3.8 Execution

3.8.1 Protection

Protect benchmarks and other permanent structures in the Site area from damage or

displacement.

3.8.2 Clearing

A. General

1. Contractor shall clear the Site area of

all vegetation, rubbish, debris and

other objectionable materials. Soils

suitable for landscaping or

agricultural purposes shall be

stockpiled separately for replacement

if directed by the Engineer.

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2. Contractor shall also clear the access

routes to the Site and any other areas

deemed necessary by the Engineer to

facilitate the construction of theWorks.

3. When clearing vegetation, the

Contractor shall ensure that the roots

of the trees, bushes, shrubs, etc. are

fully removed. Holes left by stumps

or roots shall be filed with suitable

material to the satisfaction of the

Engineer.

4. Contractor shall dispose of all

cleared vegetation, rubbish, debris

and other objectionable materials in a

controlled manner to a location

approved by the relevant authorities.

5. Contractor shall be responsible for

the proper upkeep and maintenance

of the Site and the Works and shall

remove from the Site, rubbish and

other waste as it accumulates.

6. Existing roads, improvements,

facilities, adjacent property etc. shall

be protected to the satisfaction of the

Engineer.

B. Existing services

1. Contractor shall check with the

relevant authorities to determine

what existing underground services

are present in the Site area.

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2. Contractor shall locate and

effectively seal off drain ends.

3. When necessary, the Contractor shall

divert services still in use and provide all temporary works

necessary to maintain such services

in full functional order. Such

services shall be reinstated to the

approval of the relevant authorities at

the earliest opportunity when

carrying out such work. The

contractor must comply with

regulations and obtain necessary

permits and No Objection

Certificates.

3.8.3 Existing ground preparation

1. After site clearing, the existing ground surfaces shall be graded to

remove surface irregularities.

2. In cut areas, excavation shall extend for the full-designated width

down to the bottom of the excavation.

3. The ground surface shall be scarified and loosened to a minimum

depth of 200 mm (except where the material is classified as rock).

If unsuitable materials are encountered, they shall be

excavated to a depth as directed by the Engineer.

The scarified material shall watered as necessary to

achieve uniform moisture content suitable for

compaction.

The scarified material shall then be compacted to at least

95% MDD below structures, roadways or parking areas

and at least 90% below landscaped or open areas.

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4. Surface materials of the existing ground shall be compacted and

bonded with the first layer of earth fill as specified for subsequent

layers of earth fill.

5.

Rock Foundations All rock foundation and abutment surfaces shall be

cleared of all loose materials by hand or other effective

means and shall be free of standing water when fill is

placed.

Fill placed immediately adjacent to such rock foundations

or where not accessible with large compaction equipment

shall be compacted to the specified density by means of

manually directed power tampers or plate vibrators.

6. Benching Where slope of existing soils to receive fill exceeds

1H:3V, horizontal benches shall be cut to key the new fill

material to the existing soils.

At least 600 mm of existing soil normal to the original

slope shall be removed and re-compacted as the new fill

is brought up in layers.

3.8.4 Placement of fill material

1. Placement of fill materials shall comply with the following

requirements:

Distribution of materials throughout each layer shall be

essentially uniform.

Fill shall be free from lenses, pockets, streaks, or layers of

material differing substantially in texture or gradation from the

surrounding material.

If the surface of any layer becomes too hard and/or smooth for

proper bond with the succeeding layer, it shall be scarified

parallel to the axis of the fill to a depth not less than 75 mm

before the next layer is placed.

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3-14

Top surface of each layer of fill shall be approximately level

during construction. The final surface of fill shall be finished

with a 2 percent crown or cross-slope as suitable for site

drainage, unless shown otherwise on the drawings.2. Field Compaction

Fill material in landscaped or open areas shall be compacted in

loose lifts up to 250mm thick to at least than 90% MDD.

Fill material below structures and paved areas shall be

compacted to at least 95% MDD in 200mm maximum loose

lifts, unless otherwise directed by the Engineer.

All fill shall be moistened or aerated to control the moisture

content to within a range of 3% of the optimum moisture

content when compacted.

Uniform moisture distribution shall be obtained by any

approved method prior to the compaction of the layer.

If the top surface of the preceding layer of compacted fill or

foundation becomes too dry or wet to permit suitable bond, it

shall be scarified and moistened by sprinkling or aerated to

acceptable moisture content prior to the placement of the next

layer.


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4 ROADS AND FOOTPATHS

This section covers all road works and footpaths and includes, but is not limited to, the

following: Geo-textile Fabric Pre-cast Concrete Curbs Interlocking Paving Blocks Free draining materials Stabilizing rock fill Rock fill

Subgrade Granular Sub Base Granular Road Base Bituminous Paving Courses Road Markings Traffic Signs Trench Excavation and Reinstatement in Roads

4.1 Definitions

The following definitions shall pertain to words or phrases as utilized in this Section:

Embankment shall mean any fill placed above the existing

ground or cut.

Fill shall mean suitable material utilized to raise an embankment

up to the bottom of subgrade. Subgrade shall mean the compacted top surface (150 to 300mm)

of the existing ground (or in some cases fill) below the formation

level.

Formation level shall mean top of subgrade after final

compaction.

Formation shall mean the top surface of the subgrade after

preparation for subsequent layers of material.

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Wearing course shall mean the top layer of asphalt concrete

directly supporting the traffic.

Asphalt concrete shall mean a hot mixture of asphalt cement and

well-graded, high quality aggregate, thoroughly compacted into auniform dense mass.

Borrow material shall mean suitable fill material taken from an

approved source.

OMC shall mean optimum moisture content. MDD shall mean maximum dry density. CBR shall mean California bearing ratio. Prime Coat shall mean a thin film of liquid asphalt applied on a

previously prepared untreated soil.

Tack Coat shall mean a thin film of liquid asphalt applied on a

previously prepared bituminous course or to an existing bituminous

surface.

Foot Path shall mean a passage paved by interlocking blocks for

pedestrian traffic.

Coarse aggregate shall mean that material retained on a 4.75 mm

sieve.

Fine aggregate shall mean that material passing a 4.75 mm sieve.

4.2 General Requirements

Product manufacturer, testing and installation shall comply with the following requirements,

unless otherwise approved by the Engineer.

Paving shall conform to the lines and levels on the drawings unless

otherwise approved by the Engineer.

All materials for use in construction shall be obtained only from

sources approved by the Engineer.

The specific source of materials shall not be changed without prior

written approval of the Engineer.

If the grading and quality of material delivered to the site does not

conform to the grading and quality as previously inspected and

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Sufficient materials must be stored in stockpiles to allow for testing

and approval of such materials prior to use in works.

4.3 Submittals

The contractor shall submit sufficient information to the Engineer, prior to purchase, in order

to verify compliance with the specifications. Such information shall include at least thefollowing, unless otherwise required by the Engineer.

Manufacturers name. Suppliers name. Product name and description. Manufacturers technical data. Storage instructions. Relevant test results of all materials specified. Application or installation instructions. Details of asphalt plant, location and calibration results

4.3.1 Samples

Samples shall be supplied for at least the products included in Table 4-1 or as requested by

the Engineer. All sampling shall be witnessed by the Engineer, unless agreed otherwise.

4.3.2 Method Statement

The Contractor shall provide separate method statements for at least the following activities

or as requested by the Engineer.

Site clearing and earthwork. Dewatering activities (if necessary).

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Method of mixing and laying for sub-base, road base

and wet-mix.

Method of surface preparations and application of prime

and tack coat. Method of mixing, laying and compaction of bitumen

mixtures.

Asphalt plant calibration.

4.3.3 Shop Drawings

The Contractor shall submit shop drawings for at least the proposed roadway Sections.

Table 4-1. Sampling Schedule

Item Sample

Geo-textile Fabric: 20cm x 20cm sample of each proposed fabric.

Pre-cast Concrete Curbs If requested, three sample of each size.

Concrete Paving Blocks Fifteen sample of each size and color and as required for

testing.

Aggregates 100 kgs of each size and type.

Fill Material 100 kgs from each source.

Existing Material 100 kgs from each source.

Free Draining Material 50 kgs from each source.

Subgrade Material 100 kgs from each source.

Rock fill Material 500kgs from each source.

Granular sub-base Material 100kgs from each source.

Road Base Material 100kgs from each source.Bedding Sand 25kgs from each source.

Bituminous Mixes 50kgs from each source.

Prime Coat 3 liters from each source.

Tack Coat 3 liters from each source.

Bitumen 3 liters from each source.

Road Marking Materials Applied samples and or as requested by the Engineer.

Signs Prepared samples as requested by the Engineer.

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4.3.4 Mock-up

The Contractor shall prepare a mock-up for at least the following installations or as requested

by the Engineer.1. Concrete Paving Blocks

Provide mockup of paving layout where directed by the

Engineer.

Size: 15 - 20 m 2. Laying of bedding course, installation of paving blocks and

accessories to indicated pattern shall be included.

Show range of shades, color, and texture of pavers. Accepted mockup may become part of the work.

2. Rock Fill Provide mock-up of laying trial as directed by the Engineer. Length 100 m, width 4 m.

3. Sub-Base Provide mock-up of laying trial as directed by the Engineer. Length 30 m, width 4 m.

4. Road Base Provide mock-up of laying trial as directed by the Engineer. Length 30 m, width 4 m.

5. Binder Course Provide mock-up of laying trial as directed by the Engineer. Length 30 m, width 4 m.

6. Asphalt Wearing Course Provide laying trial as directed by the Engineer. Length 30 m, width 4 m.

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4.4 Quality Control

1. Prior to dispatch from the factory, the

Contractor shall notify the Engineer, insufficient time to allow the Engineer or his

representatives to inspect and test the products,

if so desired. All notifications shall be made by

written Inspection Requests. An advance

copy may be faxed to the Engineers office, but

the original must arrive before the scheduled day

of inspection.2. Inspection Requests shall be submitted to the

Engineer during the on site installation work

prior to proceeding with at least the following

activities. Minimum notification time shall be

24 hours.

Start of excavation Start of backfilling Start of free draining material Start of stabilizing material Start of rock fill Start of subgrade Start of sub-base and road base and wet mix mixing and laying. Start of prime coat and tack coat application. Start of bituminous paving mixtures. Sampling and testing.

3. Testing of all materials shall be carried out by a

suitably equipped site laboratory or in an

approved independent laboratory.

Routine materials testing and site testing shall always be

conducted in the site laboratory, unless otherwise agreed by the

Engineer.

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All sampling shall be witnessed by the Engineer, unless

otherwise directed by the Engineer.

During the course of the work, all required tests shall be carried

out under the supervision of the Engineer, to ascertain thesuitability of materials according to this speciation.

The Contractor shall maintain a daily log of all tests carried out

for the Engineers review.

4. Test Methods Compaction tests to establish maximum dry density for

all soils shall be determined by BS 1377: Part 4:

Method 3.5/3.6 as appropriate.

In situ density of compacted soils shall be determined

by BS 1377: Part 9 Method 2.1 or 2.2 (as appropriate).

Cone penetration test: TRL Method or BS 1377 as

directed by the Engineer.

Density tests shall be made prior to removal of

dewatering systems.

Contractor shall adjust his operations to permit time to

make tests and shall excavate and fill such holes as may

be required for sampling and testing.

A subsequent layer cannot be placed until the density of

the proceeding layer has been tested and the area

approved.

At least one field density test shall be conducted for

each layer at each structure (or every 200m2), unless

otherwise directed by the Engineer.

At least one compaction test (MDD/OMC) shall be

conducted for every 30 field. Density tests conducted or

as directed by the Engineer due to changes in the soil.

At least one complete soil analysis shall be carried on

each type of material as specified in relevant Clauses or

as directed by the Engineer due to changes in the soil.

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The allowable soil-bearing load shall be verified by

dynamic cone penetration test if directed by the

Engineer.

4.5 Delivery, Storage and Handling

Delivery, storage and handling shall be according to the manufacturers recommendations

along with the following provisions:

Transportation, handling and storage shall at all times be

performed in a manner to avoid product damage.

Only nylon slings shall be allowed for lifting products.Steel chains, clamps or cables shall not be allowed for

lifting purposes, unless approved by the Engineer. Steel

chains or cables may be allowed for securing products

during transport or storage provided protective padding or

timber blocking is utilized.

Do not store products directly on ground, unless approved

by the Engineer. Ensure adequate timber blocking is

utilized to provide sufficient support.

Where product manufacturer recommends storage under

controlled temperatures, the Contractor must provide an

enclosed, insulated, cool store maintained at the proper

temperature 24 hours a day.

If stored outside, cover products to prevent UV degradation

as recommended by the manufacturer.

The Contractor shall visually inspect all products upon

delivery and report any damage to the Engineer.

a. Any products damaged during delivery, storage or

installation shall be marked by the Contractor and set aside.

b. Proposals for repair of any damaged products shall be

submitted in writing to the Engineer for approval.

c. No repairs to damaged products shall be attempted without

the Engineers approval.

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d. Any damaged products deemed unsuitable for repair by the

Engineer shall be removed from site and replaced at the

Contractors expense.

4.6 Products

4.6.1 Subgrade

1. Suitable subgrade materials shall be a minim. 30

cm thick after compaction in both Embankment

and cut areas using materials of the followingrequirements:

Materials classified by "AASHTO" as A-1-a(0) , A-1-b(0) and A-

2-4(0).

Materials having a min. soaked C.B.R. of 15% at 98% of M.D.D. Materials being reasonably well graded with sufficient fines to

permit compaction and compaction testing.

Materials with max. size 75mm. Materials free from organic matter, shale and other deleterious

material

2. Minimum test frequency One sample shall be tested to confirm the above properties for

every 1500m (or part there of) placed or compacted.

Two in-situ density tests shall be made every 800m2 of subgrade

laid.

4.6.2 Rock fill

1. Rock fill used as stabilizing materials where Embankment

foundation is found unstable:

Shall be 100% hard durable crushed rock of suitable size. Free from organic matter, shale and other deleterious material.

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Shall bind readily to form a stable mass with sound, smooth, well-

knit upper surface free from loose material.

2.

Rock fill used to construct high Embankments: Materials consisting predominantly of rock fragments of such a

size that it cannot be placed in layers of the thickness allowed

without crushing , or further breaking down, may be placed in high

Embankment in layers not exceeding twice the average size of the

larger fragments. However, no layer of rock fill shall exceed 80 cm

loose thickness.

Top surface voids should be completely filled with smaller

fragments sand or gravel.

Materials should be approved by the Engineer.

4.6.3 Pre-cast Concrete Curbs

1. A company specializing in curbstone manufacturing with at

least three (3) years experience, unless otherwise agreed by the

Engineer.

2. Pre-cast curbs shall conform to BS 7263: Part 1: 1994 except as

modified in this Section.

3. This Section covers non-mountable curbs, dropped curbs, heel

curbs, quadrants, flush curbs, curb ramps, noses, channel

blocks and edgings.

4. Materials for precast curbs Cement

a. Portland cement, conforming to BS 4027 or ASTM C 150, Type V.

b. Minimum cement content shall be 300 kg/m 3.

Aggregates

a. Combined gradation shall be as follows, unless otherwise agreed by the

Engineer. Sieve analysis shall be according to BS 812: Part 103.

Table 4-2. Aggregate gradation for precast curbs

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ASTM Sieve Size(mm)

% By WeightPassing

20.0 95 -10014.0 80 - 100

10.0 60 - 855.0 40 - 652.36 22 - 421.18 12 - 32

0.600 7-230.300 4 - 150.150 2 - 100.075 0 - 2

5. Manufacturer: Elements shall be manufactured to the

designated dimensions as shown on the Contract Drawings,

unless otherwise directed by the Engineer. Precast curbs shall

be formed by elements 900 mm long where required to be laid

in straight lines, unless otherwise approved by the Engineer.

May be reduced to 200 mm long where required to be laid to

curves depending on the radii of the curves. Pre-cast

curbstones shall be hydraulically pressed precast products

manufactured in a fully automatic batching plant and

complying with the requirements of BS 7263: Part 1 except as

modified hereunder.

a. They shall be uniform in color free from cracks, flaws of other

defects and shall have well defined arises.

b. If required by the Engineer 100mm diameter cores shall be

taken from the pre-cast elements to ascertain that the concrete

strength is not less than specified value.

Cores shall be tested to BS 1881: Part 120 A sample of 3 products shall be taken from a

consignment of not more than 1000 products.

Two cores shall be cut form each of three samples. Mean compression strength of two cores shall

reported as the compressive strength of that

product.

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Average compressive strength of 3 products shall

not be less than 250kg/cm 2.

Mean water absorption of cubes when tested in

accordance with B7263: Part 1 shall not be greaterthan 3.0%.

Cure units by either: low-pressure steam, steam

vapor, or other similar process as approved by the

Engineer.

c. Finishes Ensure exposed-to-view finish surfaces of pre-cast

concrete members are fair faced, uniform in color

and appearance.

Cure members under identical conditions to

develop required quality. Minimize appearance

blemishes such as non-uniformity, staining, or

surface cracking.

Small surfaces holes, normal form joint marks,

and minor chips are acceptable, if approved by the

Engineer. Major or unsightly imperfections,

honeycombs, or structural defects are not

acceptable.

d. Tolerances: Tolerances of manufacture shall be 3 mm in any

one dimension and end faces shall be truly perpendicular to the

base.

e. Testing Frequency: As directed by the Engineer.

4.6.4 In-situ concrete curbs

1. A. Cast in-situ curbs shall comply with the following except as

modified by the Engineer.

Min. compressive strength of cubes after 28 days, 250

kg/cm2.

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Cement used shall conform BS4027 or ASTM C150 Type

V.

Use of additives may be allowed if approved by the

Engineer.

4.6.5 Interlocking paving blocks

1. Concrete Paving Blocks Manufacturer: A company specializing in exterior

concrete paving block manufacturing with three (3) years

experience unless otherwise agreed by the Engineer.

Installer: A company specializing in installing exterior

pavers with three (3) years experience, unless otherwise

agreed by the Engineer.

2. Materials and Manufacture Portland cement conforming to BS 4027 or ASTM, C150

Type V.

Thickness shall be 60mm or 80mm on footpaths, unless

otherwise shown on the Drawings or instructed by the

Engineer.

Color and pattern of the blocks shall be as noted on the

drawings or as directed by the Engineer.

Pigment (inorganic) shall comply with BS 1014.

Minimum pigment content shall be 5% by weight of

cement, unless otherwise approved by the Engineer.

Compressive Strength.

a. 350 kg/cm 2 for roads (8 cm thickness).

b. Strength 250 kg/cm 2 for footpath (6 cm thickness).

Water Absorption

a. Average of 3 specimens tested in accordance with ASTM C140 shall not

be greater than 5%.

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b. No individual result shall be greater than 7%.

Sulphate and Chlorides

a. The total sulphate content shall not be more than 4.0% by weight of thecement in the mix.

b. The total chloride content shall not be more than 0.15% weight of mix.

Bedding Sand Shall consist of non-plastic sand meeting the following

properties, unless otherwise approved by the Engineer.

Table 4-3. Properties of bedding sand

Sieve Size (mm) Percent Passing by Wet Sieving

10 1005.0 95 100

2.36 80 1001.18 50 85

0.300 10 300.150 5 15

0.075 0 3Test Standard Limit

Clay, silt and dust content BS 812: Part 103.1 3.0% Max

Sulphates (SO 3) BSI 377: Part 3 Method 5 0.3% Max

Chlorides (Cl) BSI 3777: Part 3 Method 7 0.5% Max

4.6.6 Granular Sub Base

1. Hard, durable gravel and/or crushed gravel or crushed stone

with sand and silt.

2. Free of clay balls or other deleterious substances.

3. If required approved binding material shall be added to the

coarse gravel to improve the binding property of sub-base

material but in no case, the percentage of binding material

added shall not be more than 20% of the sub-base.

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4. Grading shall be one of the following classes when tested in

accordance with BS 1377: Part 2: Method 9.2. Selected class

shall be as directed by the Engineer

Table 4-4. Gradation of Granular Sub Base

% By Weight PassingSieve Size / No.

Class A Class B Class C

3" 100 100 100

2" 90 - 100 90-100 90-100

No. 4 35 - 70 40-90 50-100

No. 200 0 - 20 0-20 0-30

5. Materials shall conform with the following requirements:

Table 4-5. Requirements of Granular Sub Base

Test Standard Limit

Liquid Limit BS 1377: Part 2 : Method 4.5 max 30%Plasticity Index BS 1377 : Part 2 : Method 5 max 8%

% water absorption after 24 hours

submerged in waterLocal codes max 10%

Clay lumps and friable particles in

aggregatesLocal codes-T 113 max 10%

Los Angeles Abrasion ASTM C131/C535 max 50%

Compaction Test (MDD) BS 1377: Part 4: Method 3.6 2.1 Mg/m Min

In-situ Density Test BS 1377: Part 9: Method 2.2 min 98%

CBR at 98% MDD (96 hour soaked) BS 1377: Part 4 Method 7 min 25%

Swelling of soaked C.B.R. moulds No swelling

6. Minimum Test Frequency

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One sample every 1000m shall be tested for

complete analysis unless otherwise approved by

the Engineer.

Three in-situ density tests shall be made every1000m of granular sub base laid, unless


One in-situ density shall be carried out for every

150 linear meter of shoulder or footpath, unless

otherwise approved the Engineer.

4.6.7 Aggregate Road Base

1. Hard, durable crushed gravel or crushed stone. The amount of

crushing shall be such that at least 80% (by weight) of the

pieces retained on 4.75mm sieve shall have at least one

mechanically fractured face. Material shall consist of uniform

mixtures of gravel and or crushed gravel with sand, silt and

clay conforming to the following gradation limits.

2. Free of organic matter or other deleterious substances.

3. Grading shall be one of the following classes when tested in

accordance with BS 1377: Part 2: Method 9.2. Selected class

shall be as directed by the Engineer

Table 4-6. Gradation of Aggregate Road Base

% by Weight PassingSieve Size

/No. Class A Class B Class C

2" 100

1.5" 70 -100 100

1" 55 - 85 70-100 100

3/4" 50 - 80 60-90 70-100

3/8" 40 - 70 45-75 50-80

No.4 30 - 60 30-60 35-65

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No.10 20 - 50 20-50 25-50

No.40 10 - 30 10-30 15-30

N0.200 5 - 15 5-15 5-15

4. Material shall conform with the following requirements:

Table 4-7. Requirements of Aggregate Road Base

Test Standard Limit

Liquid Limit BS 1377: Part 2: Method 4.5 max 30%

Plasticity Index BS 1377: Part 2: Method 5 max 8%

Linear shrinkage BS 1377: Part 2: Method 6.5 Max 7%

Organic Impurities BS 1377: Part 3: Method 3 Max 0.2%

% absorption submerged in water for 24

hours.

Local codes max 10%

Clay lumps and friable particles Local codes T-113 max 5%

Los Angeles Abrasion ASTM C131/C535 max 50%

Thin and Elongated particles Local codes Max 10%

Compaction Test (MDD) BS 1377: Part 4: Method 3.6 min 2.2

Mg/m

In-situ Density Test BS 1377: Part 9: Method 2.2 100%

CBR at 100% MDD (96 hr. soaked) BS 1377: Part 4: Method 7 min 80%

Swelling of soaked C.B.R. moulds No swelling

5. Minimum Test Frequency

One sample every 1000 m 3 shall be tested. Two in-situ density tests shall be made every 500 m 2 of

aggregate road base laid.

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4.6.8 Materials for Asphalt Concrete

1. Mineral aggregates for bituminous paving course shall consist

of coarse aggregates, fine aggregates and filler material all

complying with the following requirements.2. Prior to the production of aggregates or delivery of aggregates

the Contractor shall notify the Engineer of the source of

aggregates for inspection of the borrow or quarry area. All

sources of aggregates shall be approved by the Engineer prior

to the processing of material.

3. The properties of aggregates specified in this section shall be

for aggregates from individual sources or individual stockpiles.

4. If the grading and other specified properties of the material

delivered to the site does not conform to the same properties of

originally approved samples or does not comply with the

specification, the Engineer reserves the right to reject such

materials at the site of the work. If required by the Engineer

the Contractor shall submit to the Engineer the original

invoices for any delivery of mineral aggregates including filler.

5. Coarse Aggregates (those retained on a 4.75mm sieve) Shall consist of crushed rock or crushed gravel. Shall be clean, hard, tough, durable and sound. Shall be of uniform quality and free from decomposed

stone, shale, clay lumps and other deleterious substances.

Mineralogical tests shall be carried out on the aggregates,

if requested by the Engineer

Crushed gravel. Consists of products obtained by

crushing material that has first been screened in such a

manner that not less than 90% of the material to be

crushed is retained on an ASTM 9.5 mm sieve.

100% (by weight) of each stockpile of aggregate retained

on 2.36mm sieve shall have at least one crushed face.

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At least 85% (by weight) of each separate stockpile of

aggregate retained on 2.36m sieve shall have all faces

crushed, unless otherwise approved by the Engineer.

Coarse aggregate in each individual stock pile shall have

properties which comply with the following values:

Table 4-8. Requirements of Materials for Asphalt Concrete

Test Standard Binder Course Wearing Course

Los Angeles Abrasion ASTM C131/C535 max 40% max 40%

Thin & Elongated particles Local codes max 10% max 10%

Clay lumps and friable particlesLocal codes 0%* 0%*

% water absorption Local codes max 5% max 5%

Organic Impurities BS 1377 Max 0.05% Max 0.05%

6. Fine aggregate shall be obtained from 100% crushed gravel or

crushed rock, unless otherwise approved by the Engineer.

If approved by the Engineer, a maximum of 25%

(by weight) of fine aggregate may be uncrushed if it

is separately fed into the plant.

Use of dune sand shall not be permitted. Fine aggregates shall be Non-Plastic when tested for

Plasticity Index:

7. Filler Material When the combined grading of the coarse and fine

aggregates is deficient in material passing the

ASTM No. 200 sieve, external mineral filler shall

be added as approved by the Engineer at the

Contractors expense.

Mineral filler shall consist of finely ground non-

plastic particles of limestone or cement.

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Mineral filler shall be thoroughly dry and free from

organic substances and clay.

Test frequency is as directed by the Engineer.

8. Bitumen Binder Shall be penetration grade 40/50 or 60/70 as


Bitumen shall be prepared by refining crude

petroleum.

Shall be homogeneous and free from water. Shall not foam when heated to 175C. Shall conform to the following requirements, unless

otherwise accepted by the Engineer.

Bitumen heated 100C above the maximum

temperature obtained form viscosity temperature

relationship shall be considered over-heated and

shall be removed from site and disposed of by the

Contractor at his own expense. Bitumen shall be

heated only in approved boilers or bulk storage

containers equipped with adequate and accurate

thermometers.

When filling the bitumen from distributors boilers

or bulk containers, the bitumen shall be passed

through a filter of fine wire gauge.

The Contractor shall take every reasonable pre-

cautions to avoid fire or heath hazards.

A sample of bitumen that the Contractor propose to

use in the work together with a statement as to its

source and properties shall be submitted to and

approved by the Engineer at least 45 days before

Construction begins.

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The properties of bitumen shall be as specified by

the Local code unless otherwise approved by the

Engineer.

Only the bitumen represented by the approvedsample shall be used by the Contractor.

Blending of bitumen from different refineries will

not be permitted.

Test Frequency. One full analysis shall be carried

out on a sample from every 80ton.

4.6.9 Asphalt Concrete

1. When tested according to ASTM C117 and ASTM C136, the combined

aggregates shall conform to the following grading having a smooth curve

to the appropriate limits and shall not vary from the low limit on one sieve

to the high limit on the adjacent or vice-versa.

Table 4-9. Gradation of aggregate to used in asphalt concrete

Sieve size/No. % By Weight Passing

Binder Course Wearing Course

1" 100 100

3/4" 75-100 80-100

1/2" NA NA

3/8" 45-70 60-80

No 4 30-50 48-65

No 8 20-35 35-50

No 30 5-20 19-36

No 50 3-12 13-23

No 80 2-8 7-15

No 200 0-4 3-8

2.

Combined mineral aggregate shall be non-plastic.

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3. Coarse aggregate, shall show no detrimental amount of stripping when

tested in accordance with ASTM D 1664. The area coated shall be

evaluated not only at 25C but also after the aggregate has been soaked

in water at 40C and 60C. Minimum value of non-stripped area shall be 95%. If stripping occurs, the aggregate shall be rejected

unless:

a. An approved method of treatment shall be carried out as specified to

change the material from a hydrophilic to a hydrophobic state.

b. Only approved additives shall be used with the bituminous binder.

4. When necessary to change the hydrophilic character of aggregates to

hydrophobic, additives of approved type will be added to the

bituminous material in such percentage as required to obtain

satisfactory results from the test performed in accordance with ASTM

D1664. Approved additive will be used in accordance with Technical

Specifications issued by the manufacturer and approved by the

Engineer after appropriate testing. No extra payment will be made for

required anti-stripping additives.

5. Design Criteria: The following table summarizes the design criteria of

asphalt concrete. However, the exact percentage of bitumen to be used

shall be fixed by the Engineer based on the laboratory mix and full-

scale plant trial mix results.

Table 4-10. Design Criteria of Asphalt Concrete

PropertiesBinder

course

Wearing

course

Bitumen Content (% of total mix) Marshall Specimens: 3 - 6 4 - 7.5

Number of Compaction blow at each end of specimen. 75 75

Air voids in total mix (VIM %) 3 - 8 3 - 5

Voids in mineral aggregate (VMA %) Min. 14 Min. 15

Stability (kg) Min. 700 Min. 900

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Flow (mm) 2 - 4 2 - 4

6.

Job mix for Bituminous Paving Courses: field trials with the followingrecommendations shall be taken into account.

Combined aggregate gradation should be

adjusted within the allowable limits to achieve

maximum stability whilst not going below the

minimum requirement for void content.

Minimum bitumen binder content should be

used according to the results of the Marshall

Method of Mix Design, if it will still satisfy all

the specified requirements.

Final job mix must display all characteristics as

specified for Asphalt Concrete mixes.

After receiving approval of the aggregates and

bitumen from the Engineer, the Contractor shall

make a written request for the approval of the

job-mix formula from the Engineer at least

thirty, (30) days prior to the date he intends to

begin production of plant-mix Bituminous

Paving Course Mixes. Formula will be

prepared by the Contractor under the

supervision of the Engineer in the Laboratory.

The laboratory job mix formula shall define:

a. Percentage of aggregate passing each required sieve size.

b. Percentage of bitumen binder to be added to the aggregate.

c. Temperature at which the mix is to be emptied from the mixer.

d. Temperature at which the mix is to be delivered to the works site.

Before the start of the permanent work, mock-

ups or trial areas having lengths of at least 30

m shall be laid to the specified layer thickness

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a. Materials used in the trials shall be those

approved for use in the bituminous paving courses.

b. Equipment used shall be that according

to the Contractors approved method

statement and the program of work.

c. The object of these trials is to determine

adequacy of the Contractors equipment,

loose depth measurements necessary to

result in the specified compacted layer

depths, and relationship between the

number of compaction passes and the

resulting density of the material.

d. Additionally at least two samples of non-

compacted material and two cores of

specified diameter shall be taken from

the trial area in accordance with

AASHTO T-168 and analyzed in the

presence of the Engineer to determine

aggregate grading, binder content,

stability, flow, bulk density, and voids.

Results shall be submitted to the

Engineer for approval before further

mixing and laying are carried out.

If the laboratory job mix formula fails to

produce a satisfactory trial, the mix proportions

may be modified by agreement with the

Engineer, within the applicable specification

requirements to produce a mix of satisfactory

workability and acceptable surface finish.

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All mixes produced shall conform to the

properties of Job Standard Mix approved by the

Engineer, within the ranges of tolerance

specified in Table 22. Should a change in a material be encountered or

should a change in a source of material be made,

a new Job-Standard Mix shall be submitted by

the Contractor and approved by the Engineer

before the mix containing the new materials is

delivered. Job materials will be rejected if they

do not possess the same characteristics of the

approved Job Standard Mix.

Table 4-11. Job Mix Tolerance

Aggregate retained on 4.75 mm sieve or larger + 5%

Aggregate passing 4.75 mm sieve and retained on 0.075mm sieve

+ 4%

Aggregate passing 0.075 mm sieve + 2%Bitumen Binder + 0.25%

Temperature for mixing and placing 10C

7. Samples of Bituminous paving course mixes shall be taken from the

mixing plant and/or behind the paver prior to compaction, as decided

by the Engineer, to check compliance with the approved job mix

requirements. Density of the compacted mixes shall be related to the

job standard density or the daily Marshall Density at the option of the

Engineer, which shall be determined by making four Standard

Marshall specimens from samples of the mix taken from the mixing

plant or paver.

Density of each sample shall be determined and

compared with the mean value.

Any individual result, which varies from the

mean by more than 0.015 g/cc, shall be rejected.

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Marshall tests shall be repeated on a daily basis

to establish the daily Marshal Density for that

particular days production.

Daily Marshall Density shall not vary from theJob Mix Design Density by more than + 1%.

8. Assistance of the Engineer in the preparation of the job standard mix

shall in no way relieve the Contractor of his responsibility for

producing a bituminous mix meeting the requirements of the

Specifications.

9. Preparation of Bitumen Binder Temperature of the bitumen binder for mixing

and compacting shall be in accordance with

ASTM D1559. The Contractor shall submit a

temperature / viscosity chart for each grade of

bitumen to be used.

10. Preparation of Mineral Aggregate for Bituminous Mix Coarse and fine aggregate shall be stored at the

asphalt plant in such a manner that separate

stockpiles will not become intermixed.

a. Stockpiles shall be of sufficient size to provide a minimum quantity of one

weeks continuous production of asphalt mix.

b. Aggregates brought to the asphalt plant to supplement stocks should be

tested and approved prior to placing in the existing approved stockpiles.

Cold bins shall be calibrated with the materials

to be used and the settings shall be such as to

produce a combined gradation in accordance

with the job mix formula.

a. Proportioning shall be such that surpluses and shortages

in the hot bins will not occur.

b. Neither the dryer nor the screens shall be overloaded.

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c. All the above shall be as approved by the Engineer.

Materials shall be thoroughly dried and heated

so that their temperature is within 8C of the

temperature needed to satisfy the viscosityrequirements of the asphalt cement.

a. Moisture content of the heated and dried materials shall not exceed 0.5%.

b. Quantity of materials fed through the drier shall in all cases be held to an

amount, which can be thoroughly dried and heated within the limits

specified.

Immediately after heating, the aggregates shall

be screened into at least five sizes and conveyed

into separate bins ready for batching and mixing

with bituminous materials. When the aggregates

supplied are of such size and grading that

separating into five bins is impractical, the

number of required separations may be reduced

to four or to three with the approval of the

Engineer.

Efficiency of the screening operations shall be

sufficient to produce (at plant operating

capacity) gradations (in all sizes of heated and

dried aggregates) which are reasonably uniform

and result in the production of a mix complying

with the limits specified for the aggregate

gradation.

11. Preparation of Bituminous Mix Asphalt concrete shall be prepared in a central

mixing plant conforming to the requirements of

ASTM D995.

a. The plant shall be equipped with an efficient mechanical dust extraction

system and storage silos.

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b. Its design shall be provided for the controlled return of some of the filler to

the mix, when necessary, by means of filler weighing bin discharging in to

the pugmil.

c. The dust collection system shall be powerful enough to keep the mineralfiller contents the in hot sand bin below 2%.

d. The plant settings once established shall not be changed without the

approval of the Engineer.

e. The minimum mixing time shall not be less than that recommended by the

manufacturer. The mixing time may be increased by the Engineer if

additional time is necessary to obtain a homogeneous mix and satisfactory

coating.

f. Bitumen binder shall be introduced into the mix in the proportion specified

by the job-mix formula.

Initial mixing time will be designated by the

Engineer. Mixing time may be increased by the

Engineer if additional time is necessary to obtain

a homogeneous mix and satisfactory coating.

Timing at the batch plant for mixing shall begin

at the start of the introduction of the bitumen

into the pugmill.

Temperature of the aggregate immediately prior

to mixing shall be within + 8 C of the

temperature of the bitumen binder.

a. Temperature of the aggregate and asphalt prior to mixing shall be

approximately that of the completed mix as defined in the job mix formula

approved by the Engineer.

b. Mix temperature shall be within the limits set out in the job mix formula

when emptied from the mixer.

12. Minimum test requirements for bituminous courses Bitumen material: One sample shall be tested for

penetration and Ring ball test for every 80 tons

or part thereof, unless otherwise agreed by the

Engineer.

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Aggregate: One sample for each stockpile or

every 1,000 m. Perform all the required tests.

Bituminous mix: one sample of mix shall be

obtained from at least every 200 tons. Performall the required tests.

4.6.10 Prime and Tack coats

1. Prime coat shall be a medium curing cut back

asphalt (MC-70) .

Sampling shall be in accordance with ASTM D140. Frequency of the testing shall be as directed by the

Engineer.

2. Tack Coat shall be Rapid Curing cut back asphalt (

RC-250 ).

Sampling shall be in accordance with ASTM D140. Frequency of the testing shall be as required by the

Engineer.

3. Depending on the possibilities of obtaining

Bituminous materials, the Engineer may modify the

type and gradation of the materials for the prime

coat and tack coat.

4.6.11 Road marking materials

1. Thermoplastic Materials shall comply with

BS3262 hot-applied thermoplastic road

marking materials and shall be suitable for

road surface temperature of up to 80C,

unless otherwise approved by the

Engineer. Proportions, testing

requirements and type of materials used

shall be as mentioned in the Contractors

approved method statement.

2. Road marking paint shall be either

chlorinated rubber, one pack epoxy or

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4.6.12 Traffic signs

1. Permanent traffic signs shall be

reflector and shall comply with the

following requirements except as

modified here under or as directed by

the Engineer.

2. Sign plates shall be manufactured

from sheet aluminum with a

minimum thickness of 3mm, unless


3. Information on signs shall be

constructed in extruded aluminum

plank sections, which will either be

self-locking or rear fixing, and the

aluminum shall be BS EN 485, or BS

1490 or other approved equivalent

International Standard.

4. All sign plates shall have clean,

smooth edges cut to the required

shape of the sign and shall be etched

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5.

Sign shall be covered with HighIntensity reflective sheeting.

Sheeting must have

the manufacturers

guarantee for a period

of not less than 5

years for Engineering

Grade and 7 years for

High Intensity.

Rear faces shall be

non-reflective grey

and should give a

similar life span to the

sign face.

Reflective sheeting

shall be fixed to the

sign plate either with

a heat activated

adhesive using

vacuum applicator or

with a pressure

sensitive adhesive

using a pressure roller

in accordance with the

sheeting

manufacturers

instructions.

Sign faces shall be

formed from a single

piece of reflective

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Sheeting, after

application to the sign

base, will not come

off at the edges nor

shall it peel off or

warp. Surface shall

be smooth, flat and

free from any bubbles,

pimples, edge

chipping or edge

shattering. Surface

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Corners of all

direction signs shall be rounded to a radius

of 75 mm.

6. Stiffening and Framing All stiffening and

framing shall be of hot

dipped galvanized

steel.

Signs constructed of

aluminum sheet shall,

when recommended

by the Traffic Sign

Manual, be framed on

all edges using hot

dipped galvanized

steel angle.

Stiffening to signs

constructed of

aluminum sheet,

having an area

exceeding 0.10 sq.m.

shall be confined to

horizontal lengths at

the top and bottom

edges of the sign

plate.

7. All rivets or other devices fixing sign

plates to their framework shall be of

non-staining steel or other materials

approved by the Engineer and shall

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All rivet and boltholes

shall be edge-sealed

with clear lacquer

after the application of

the plastics sheeting.

Rivets shall be spaced

at not more than 150

mm apart, around the

outside edge of the

sign plate and on

cross braces the

spacing shall be not

more than 300 mm.

Any rivet brought

through the sign face

shall be colored to

match the sign face.

Any rivet or other

device fixing sign

plates to their

framework shall have

protective washer of

nylon or other

approved insulating

material inserted

where they would be

in contact.

8. All materials shall be supplied in

new and unused condition except in

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4.7

ExecutionAll operations shall be performed in accordance with the specification, and in conformity

with the lines, grades, thickness and typical cross Section shown on the plans or established

by the Engineer. Only approved material shall be used in the construction. The embankment

and sub grade in fill shall be constructed utilizing only suitable material obtained from

roadway excavation or imported fill material from sources previously approved by the

competent authority.

4.7.1 Placement of fill

1. Prior to the placement of any fill

materials, the Contractor shall

conduct trial compaction tests as


Fill material used in the trials shall be with the proposed borrow or

excav

technical specifications of roads

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