Technical Specifications of Roads_part2

8/12/2019 Technical Specifications of Roads_part2

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Rock fill may be utilized except for the top 2m ofEmbankment 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 thearrangement and payment for all borrow

material.

3.7.3 WaterWater 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 Execution3.8.1 ProtectionProtect benchmarks and other permanent structures in the Site area from damage or

displacement.

3.8.2 ClearingA. General

1. Contractor shall clear the Site area ofall 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 accessroutes to the Site and any other areas

deemed necessary by the Engineer to

facilitate the construction of theWorks.

3. When clearing vegetation, theContractor 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 allcleared vegetation, rubbish, debris

and other objectionable materials in a

controlled manner to a location

approved by the relevant authorities.

5. Contractor shall be responsible forthe 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 therelevant authorities to determine

what existing underground services

are present in the Site area.

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2. Contractor shall locate andeffectively seal off drain ends.

3. When necessary, the Contractor shalldivert 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 preparation1. 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 widthdown to the bottom of the excavation.

3. The ground surface shall be scarified and loosened to a minimumdepth of 200 mm (except where the material is classified as rock).

If unsuitable materials are encountered, they shall beexcavated to a depth as directed by the Engineer.

The scarified material shall watered as necessary toachieve uniform moisture content suitable for

compaction.

The scarified material shall then be compacted to at least95% 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 andbonded 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 foundationsor 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 originalslope shall be removed and re-compacted as the new fill

is brought up in layers.

3.8.4 Placement of fill material1. Placement of fill materials shall comply with the following

requirements:

Distribution of materials throughout each layer shall beessentially uniform.

Fill shall be free from lenses, pockets, streaks, or layers ofmaterial differing substantially in texture or gradation from the

surrounding material.

If the surface of any layer becomes too hard and/or smooth forproper 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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Top surface of each layer of fill shall be approximately levelduring 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 inloose lifts up to 250mm thick to at least than 90% MDD.

Fill material below structures and paved areas shall becompacted 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 moisturecontent to within a range of 3% of the optimum moisture

content when compacted.

Uniform moisture distribution shall be obtained by anyapproved method prior to the compaction of the layer.

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

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4 ROADS AND FOOTPATHSThis 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 DefinitionsThe following definitions shall pertain to words or phrases as utilized in this Section:

Embankment shall mean any fill placed above the existingground or cut.

Fill shall mean suitable material utilized to raise an embankmentup 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 finalcompaction.

Formation shall mean the top surface of the subgrade afterpreparation for subsequent layers of material.

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Wearing course shall mean the top layer of asphalt concretedirectly supporting the traffic.

Asphalt concrete shall mean a hot mixture of asphalt cement andwell-graded, high quality aggregate, thoroughly compacted into auniform dense mass.

Borrow material shall mean suitable fill material taken from anapproved 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 apreviously prepared bituminous course or to an existing bituminous

surface.

Foot Path shall mean a passage paved by interlocking blocks forpedestrian traffic.

Coarse aggregate shall mean that material retained on a 4.75 mmsieve.

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

4.2 General RequirementsProduct 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 unlessotherwise approved by the Engineer.

All materials for use in construction shall be obtained only fromsources approved by the Engineer.

The specific source of materials shall not be changed without priorwritten approval of the Engineer.

If the grading and quality of material delivered to the site does notconform to the grading and quality as previously inspected and

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Sufficient materials must be stored in stockpiles to allow for testingand approval of such materials prior to use in works.

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

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

4.3.2 Method StatementThe 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 baseand wet-mix.

Method of surface preparations and application of primeand tack coat.

Method of mixing, laying and compaction of bitumenmixtures.

Asphalt plant calibration.

4.3.3 Shop DrawingsThe 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-upThe 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 theEngineer.

Size: 15 - 20 m2. 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 Control1. 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 asuitably equipped site laboratory or in an

approved independent laboratory.

Routine materials testing and site testing shall always beconducted in the site laboratory, unless otherwise agreed by the

Engineer.

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All sampling shall be witnessed by the Engineer, unlessotherwise directed by the Engineer.

During the course of the work, all required tests shall be carriedout 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 outfor 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 determinedby BS 1377: Part 9 Method 2.1 or 2.2 (as appropriate).

Cone penetration test: TRL Method or BS 1377 asdirected by the Engineer.

Density tests shall be made prior to removal ofdewatering systems.

Contractor shall adjust his operations to permit time tomake 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 ofthe proceeding layer has been tested and the area

approved.

At least one field density test shall be conducted foreach layer at each structure (or every 200m2), unless

otherwise directed by the Engineer.

At least one compaction test (MDD/OMC) shall beconducted 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 oneach type of material as specified in relevant Clauses or

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

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d. Any damaged products deemed unsuitable for repair by theEngineer shall be removed from site and replaced at the

Contractors expense.

4.6 Products4.6.1 Subgrade1. 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 subgradelaid.

4.6.2 Rock fill1. 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 smallerfragments sand or gravel.

Materials should be approved by the Engineer.

4.6.3 Pre-cast Concrete Curbs1. 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 asmodified in this Section.

3. This Section covers non-mountable curbs, dropped curbs, heelcurbs, 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/m3.

Aggregatesa. 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 Weight

Passing

20.0 95 -100

14.0 80 - 100

10.0 60 - 855.0 40 - 65

2.36 22 - 42

1.18 12 - 32

0.600 7-23

0.300 4 - 15

0.150 2 - 10

0.075 0 - 2

5. Manufacturer: Elements shall be manufactured to thedesignated 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 otherdefects and shall have well defined arises.

b. If required by the Engineer 100mm diameter cores shall betaken 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 shallnot be less than 250kg/cm2.

Mean water absorption of cubes when tested inaccordance with B7263: Part 1 shall not be greaterthan 3.0%.

Cure units by either: low-pressure steam, steamvapor, 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 todevelop 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 anyone 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 curbs1. A. Cast in-situ curbs shall comply with the following except as

modified by the Engineer.

Min. compressive strength of cubes after 28 days, 250kg/cm2.

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Cement used shall conform BS4027 or ASTM C150 TypeV.

Use of additives may be allowed if approved by theEngineer.

4.6.5 Interlocking paving blocks1. Concrete Paving Blocks

Manufacturer: A company specializing in exteriorconcrete paving block manufacturing with three (3) years

experience unless otherwise agreed by the Engineer.

Installer: A company specializing in installing exteriorpavers 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, unlessotherwise shown on the Drawings or instructed by the

Engineer.

Color and pattern of the blocks shall be as noted on thedrawings 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/cm2for roads (8 cm thickness).

b. Strength 250 kg/cm2for footpath (6 cm thickness).

Water Absorptiona. 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 Chloridesa. The total sulphate content shall not be more than 4.0% by weight of the

cement 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

10 100

5.0 95 100

2.36 80 100

1.18 50 85

0.300 10 30

0.150 5 15

0.075 0 3Test Standard Limit

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

Sulphates (SO3) 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 Base1. 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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Technical Specifications of Roads_part2

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