D.V.Bhavanna Rao. M.Tech., F.I.E.,Chief Engineer ,

Roads & Buildings Andhra Pradesh (Retired)

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General

a) In built up areas, 6-lane divided carriagewayalong with service roads shall be provided as part of4-laning of the project Highway. Such stretcheswhere the requirement of 6-laning is dispensed withand only 4-laning with or without service road andfootpath is to be provided as indicated in schedulefootpath is to be provided as indicated in scheduleB.

b) Where there is a constraint of ROW width,the authority may specify construction of a bypass.The alignment of bypasses shall be as specified inSchedule B and in conformity with the siteearmarked in Schedule A of ConcessionAgreement.

Nature of terrain

Cross slope of the

ground

Design speed (km/hour)

Ruling Minimum

Plain and Rolling

Up to 25% 100 80

Design Speed in Km/hour

Rolling

Mountainous and Steep

More than 25%

60 40

Short stretches (say less than 1 km) of varying terrain met with on the road stretch shall not be taken into

consideration while deciding the terrain classification for a given section of a Project Highway.

Type of section

Minimum width of median (m)

Plain and rolling terrain

Mountainous and steep terrain

RaisedDepressed

MedianRaised

Open country with isolated 4.5m 7.0m 2.0m

Minimum width of median

with isolated built up area

4.5m 7.0m 2.0m

Built up Area 2.0m Not applicable 2.0m

Approach to grade separated

structures4.5m Not applicable 2.0m

Type and widths of median at various stretches shall be as indicated in Schedule B.

Type of SectionWidth of shoulder (m)

Paved Earthen Total

Open country with isolated built up

area1.5m 2.0m 3.5m

Width of shoulders in Plain and Rolling Terrain

area

Built up area 2.0m - 2.0m

Approaches to grade separated

structures2.0m - 2.0m

Approaches to bridges

1.5m 2.0m 3.5m

Width of Shoulders in mountainous and steep terrain (Hilly Area)

Type of SectionWidth of shoulder including drain and

crash barrier as applicable

Open country with isolated built up area

1.5m (on hill side)2.0m (on valley side)

Earthen shoulder

Raised footpath along with

Built up area and approaches to grade

separated structures/bridges

1.5m (on hill side)2.0m (on valley side)

along with provision of

adequate drainage along

and across footpath

In mountainous and steep terrain, the scope of work defined by the authority may be two lane carriageways on different alignments (contours). In that case IRC: SP:73-2007 shall appl y to two lane

carriageways on different alignments.

Extra width of pavement and roadwayIn each carriageway

Radius of curve extra width

75 - 100m 0.9m

101 - 300m 0.6m

The cross fall on straight portions of roadcarriageway, paved shoulders and paved portion ofmedian shall be 2.5% for bituminous surface and 2.0%for CC surface.

Super elevation shall be limited to 7%, if radiusof curve is less than desirable minimum radius. Itshall be limited to 5%,If radius of curve is more thandesirable minimum.

Minimum radii of horizontal curves

Nature of terrainDesirable minimum

Absolute minimum

Plain and rolling 400m 250m

Mountainous and steep 150m 75m

The radius of horizontal curves for variousterrain conditions shall not be less than the desirableminimum given above except for sections as indicatedin schedule B.

For such sections, the radius shall not be lessthan absolute minimum.

Safe sight Distance

Design Speed Km/hour

Safe Stopping Sight

Distance

Desirable minimum

sight distance

100 180m 360m80 130m 260m80 130m 260m60 90m 180m40 45m 90m

Vertical alignment should provide for a smoothlongitudinal profile. Grade changes shall not be toofrequent as to cause kinks and visual discontinuities inthe profile. IRC: 73 should be kept in view.

Ruling and Limited Gradients

Nature of terrain

Ruling gradient

Limiting gradient

Plain and rolling

3.3% 5.0%

Mountainous 5.0% 6.0%

Steep 6.0% 7.0%

Long sweeping vertical curves shall beprovided at all grade changes. These shall bedesigned as square parabolas.

Design of vertical curves and itscoordination with horizontal curves, shall be inaccordance with IRC:SP: 23.

Cattle and pedestrian under/ overpass

These shall be provided as specified inSchedule B.1) An under/overpass for crossing of cattle and

pedestrians may not be necessary within 2 kmfrom vehicular underpass

2) Width of crossing shall not be less than 5m.2) Width of crossing shall not be less than 5m.3) Pedestrian crossings shall have provision for

movement of physically challenged persons.4) Underpasses shall be preferred to Overpasses5) PUP/ POP shall also be provided within a

distance of 200m from a school or hospital orfactory/ industrial area.

Lateral clearance at Underpasses

1) Full roadway width at the approaches shall becarried through the underpass. This width shallnot be less than 12m (7m Carriageway + 2 × 2.5mshoulders) or as indicated in schedule ‘B’.

2) Guardrails/Crash barriers shall be provided forprotection of vehicles from colliding with theabutments and deck of the structures.

3) The width of cattle and /or pedestrian underpassshall not be less than 5m.

Vertical clearance at Underpasses

1) For vehicular underpass: 5.5m Minimum

2) For pedestrian and cattle under pass:

3.0m (to be increased to 4.5m in casecertain categories of animals such aselephant/camel are expected to cross theproject highway frequently. This will be asspecified in Schedule ‘B’)

Lateral and Vertical clearance at Over pass

Full roadway width shall be carriedthrough the overpass structure unlessotherwise specified in Schedule B. Provisionshall also be made for future widening to 6-shall also be made for future widening to 6-lane with service roads. Crash barriers shallbe provided on abutment side and on sides ofpier to protect collision.

Vertical clearance at Overpasses: 5.5m minimum at all points of the carriageway.

Access Control

Access to the Project Highway shall beprovided at the following locations:

1) Intersection with National Highways1) Intersection with National Highways2) Intersection with State Highways3) Intersection with major District Roads4) Intersection with Village roads/Other roads

subject to a minimum distance of 3 kmfrom the nearest intersection.

Service Roads1) Width of service shall be 7m. Their length and

location shall be included in schedule B.2) For stretches where bridge length is less than

60m and service road is required on both sidesof stream, service road shall continue across thestream by providing 2-lane bridges.

3) For bridges length of 60m or more, separate3) For bridges length of 60m or more, separatebridge structures may not be necessary. Serviceroad shall be merged with Project Highway at50m before the bridge structure unless otherwisespecified in Schedule B.

4) Service road crust shall be designed for 5 MSA ofdesign traffic in 4-laning and for 10 MSA in caseof 6-laning with design CBR at project site.

Grade Separated StructuresAll the details shall be specified in

Schedule B. The approach gradient to thegrade separated structure shall not besteeper than 2.5% (1 in 40).

Geometric design standards for variouselements of grade separators shall be as perelements of grade separators shall be as perIRC:92

Vehicular under/overpass shall beprovided at the intersection of projecthighway with NH and SH. Such under/overpass shall be provided on other roadscarrying Average Daily Traffic of more than5000 PCUs on the date of inviting bids .

Median Openings� Median openings shall not be spaced closer than 2

km. Additional controlled openings shall also beprovided for inspection and diversion of trafficduring repair and rehabilitation.

� Median opening shall not be provided in front of theservice road entry. Location of opening shall be sodecided to minimize intraflow. This distance shall notbe less than 150m.be less than 150m.

� All median openings shall be provided withadditional 3.5 m shelter lane by the side of median inboth directions for waiting vehicles to take U turn.

� Length of median opening shall not be less than 20m.

� Fencing shall be provided to separate service roadsand Project highway.

Design Service Volume for 4-lane highways in PCUs p er day

TerrainDesign Service Volume in PCUs per day

Level of Service ‘B’ Level of Service ‘C’

Plain and Rolling 40,000 60,000

Mountainous andSteep

20,000 30,000Steep

20,000 30,000

Unless or otherwise specified in the C.A.,the Project Highway shall be widened to 6-lanewhen total traffic including that in service roadsreaches the design service volumecorresponding to level of service ‘C’ mentionedabove.

Important Features to be studied and finalized in Road Embankment design

1)Design of embankment and remedial/ground improvement treatment where necessary.

2)Construction methodology for embankments with height more than 6m.with height more than 6m.

3)Design of retaining walls/ earth retaining structures.

4)Protection measures for slopes and drainage arrangement.

5)Design of pond ash embankment where use of pond is proposed as per IRC:SP:58.

Important Features to be studied and finalized in Road Cut Section design

1) Type of cutting involved and proposed cut slopes.

2) Slope Stability measures like pitching and breast walls.and breast walls.

3) Details of erosion control measures.4) Drainage arrangement to divert seepage

water in case of cut sections in hilly terrain like deep side trains. Their slope shall not be flatter than 1 in 200.

Method of Design of Pavement and designperiod

1) For flexible pavement, IRC:37 Guidelines fordesign of flexible pavement. Design period is 15design of flexible pavement. Design period is 15years or operation period whichever is more.

2) For Design of Rigid pavement, IRC:58 Guidelinesfor the design of Plain Jointed Rigid Pavements forHighways. Design period is 30 years

Flexible Pavement – Design and Strategy

1) Design of flexible pavement for design life of15 years or operation period, whichever is more.

2) Stage Construction:a) Thickness of sub- base and base layers fora) Thickness of sub- base and base layers for

full design period and initial bituminous surfacingfor a minimum design period of 10 years.

b) Pavement shall be strengthened bybituminous overlay as and when required to extendthe pavement life to full operation period.

Rigid Pavement – Design and Strategy

1) Design period: 30 years.2) Pavement Quality Concrete (PQC) shall

rest on Dry Lean Concrete (DLC) sub base of150mm thick.

3) DLC shall meet minimum cement and3) DLC shall meet minimum cement andcompressive strength requirements as specifiedinIRC:SP:49. It shall extend PQC by 0.5m on eitherside.

4) below DLC layer Granular Sub Base (GSB)layer 150 mm thick shall be provided throughoutthe road width. It shall be designed to obtain adrainage coefficient of not less than 20 m per day.

Performance Evaluation

1) Roughness of each lane for full lengthshall be measured bi-annually using approvedmethod and equipment.

2) Structural evaluation of the pavement2) Structural evaluation of the pavementshall be made by taking deflectionmeasurements every 5 years in accordancewith the procedure given in IRC:81, unlessneeded earlier for stretches exhibiting severedistress during the operation andmaintenance period.

Strengthening of existing pavements

1) Extent of distress, nature of deficiency andtreatment required shall be assessed.

2) Necessary corrective measures to be takenas per schedule K.

3) Extensively damaged stretches are to3) Extensively damaged stretches are todesigned as a new pavement.

4) Where the existing pavement built over anuntreated expansive/ black cotton soil sub gradeshall be treated separately and requirereconstruction.

5) No granular layer shall be provided over anexisting bituminous surfacing.

Design of Overlay

1) Thickness of overlay shall be assessed on BBD deflection technique as per IRC:81 and existing structural layers.

2) Design period shall be the same as specified for the new pavement.specified for the new pavement.

3) Design traffic will be estimated as per the procedure described for new pavement.

4) Thickness of bituminous overlay for pavement strengthening shall not be less than 50 mm BC.

Paved Shoulders

1) Paved Shoulders shall be provided fora width of 1.5m.

2) If the existing thickness of pavedshoulder, if any, is less than the thickness ofshoulder, if any, is less than the thickness ofexisting pavement, the paved shoulders shallbe reconstructed to the pavement thicknessin the adjoining carriageway.

Construction, Workmanship and Qualityof works shall be as per section 900 ofMORTH Standard Specifications for Road andBridge works.

In case of premature distress in the formof cracking, rutting, patching, loss of camberor any other structural or functional distress,necessary remedial measures shall beundertaken for conforming to the minimumrequirements prescribed in schedule K of CA.In case of repetition of distress,reconstruction shall be resorted to afterproper investigations.

Highway Drainage

For efficient drainage system for theentire Project Highway including structuresand facilities, directions contained in clauseand facilities, directions contained in clause309 of MORTH specifications, IRC:SP:42 RoadDrainage and IRC:SP:50 Urban Drainage asrelevant shall be followed.

Surface DrainageSurface Drainage: The water from

road and adjacent areas shall be intercepted and carried through roadside drains to natural outfalls.

As far as possible, longitudinal slope As far as possible, longitudinal slope shall not be less than 0.5% for lined drains and 1.0% for unlined drains.

the side slopes of unlined drains shall be as flat as possible and shall not be steeper than 2H:1V.

Sub-Surface Drains shall be provideda) for lowering the water table for

drainage of sub- grade.b) for drainage of pervious sub-base in

situations where it may not be practicable toextend the sub-base across the shoulder.

c) for control of seepage flowc) for control of seepage flowd) for control of capillary riseSub surface drains outside the road

pavement shall be sealed at the top to avoidpercolation of surface water into thesedrains.

Aggregate Drains

a) The trench for aggregate drain shall be of minimum 300mm width and cut to a depth to expose the granular pavement courses to be drained.

b) Aggregate grading shall be as per table 8 of IRC SP: 42.

c) the aggregate drain shall be provided with a geo-textile wrap to act as filtration and separation layer.

Drainage of Embankment with height above 3 m

In high embankments and approaches tobridges, special arrangement for protection of slopesshall provided as per clause 7 of IRC: 42, in order toensure that embankment slopes maintain their shapeduring the monsoon season.

Drainage arrangement shall include provision ofDrainage arrangement shall include provision ofkerb channel at the edges of roadway to channelizethe water, and CC lined chutes along the slopes atdesired intervals to discharge water into sidechannels.

The chute drains and drains at toe of theembankment shall be of Plain Concrete (M15 grade) ,over proper bedding.

Median Drainage

The median should have adequate longitudinalslope to the nearest culvert to drain off transversely.

In case the carriageway is sloping towards unkerbed median (wider than 5 m), provision of a centralswale shall be made for the drainage of median. Theswale shall slope longitudinally for drainage, waterintercepted by inlets at intervals and dischargedintercepted by inlets at intervals and dischargedthrough transverse drains into outlet channel.

Median width 7 m or less shall be turfed or pavedand could be crowned for drainage across thepavement.

In super elevated sections, proper arrangementshall be made without allowing water drain on theother carriageway.

General Requirements for Structures

1) All bridges shall have independentsuperstructure for each direction of travel unlessotherwise specified in Schedule B. culverts may havesingle or independent superstructure.

2) Viaduct spans shall be provided if the heightof solid embankment in built -up sections is more thanof solid embankment in built -up sections is more than5m.

3) Width of median in the culvert and bridgeportion shall, as far as possible, be kept same as thatin approaches. In case median width is different fromthat of approach section due to site constraints,suitable transition shall be provided near approachesfor guiding vehicular traffic.

General Requirements for Structures -continued

4) For median in structures portion, a suitablydesigned catch pit shall be provided to collect andcarry discharge from median drain. For bridges, wherethe median is more than 1.2 m wide, it shall be open tosky. Safety barrier on the median side shall besky. Safety barrier on the median side shall beprovided at a clear distance of 0.5 m from carriagewayedge.

5) Suitable provision shall be made for retainingearth in median portion either by extending abutmentwall or constructing a new retaining wall.

6) Any utility service to be carried by thestructures shall be specified in Schedule B of C.A.

Width of Structures to be provided

New Culverts : Overall width of all culverts shall beequal to roadway width of the approaches. Outermostface of railing /parapet shall be in line with the outermost edge of shoulder.

New Bridges: 1) Overall width of new bridge shallbe same as the roadway width of approaches. All newbridges shall have a footpath on left side of the traffic .bridges shall have a footpath on left side of the traffic .

2) Where the daily traffic exceeds 30,000 at thetime of feasibility study/bidding, width of new bridge thewidth of new bridge shall be as per six-lane standards.

3) Where the length of bridge structure includinggrade separated structure exceeds 1 km, provision shallbe made for passing place at the rate one passing placefor every one km. No such requirement of passing placefor 6-lane structure

Width of Structures – Existing Culverts

All culverts which are structurally distressed ornot having sufficient vent/size shall bereconstructed as new structures of standard width.

All existing culverts which are not to bereconstructed shall be widened equal to roadwaywidth of the approaches .width of the approaches .

Culverts and Hume pipe structures shall bewidened to make the standard deck width mentionedearlier. If additional widening width required is lessthan 0.5 m, widening may be dispensed with andtraffic shall be guided with the help of crash barriersin a transition of 1 in 20 on either side ofapproaches.

Width of Structures – Existing BridgesAll bridges which are structurally distressed

shall be reconstructed as new bridges.Bearings, expansion joints, railings, crash

barriers, wearing surface etc., which are not insound condition, shall be replaced.

If the width of additional widening is less than1.0 m (0.5 m on each side) or less widening may be1.0 m (0.5 m on each side) or less widening may bedispensed with and necessary traffic guidancemeasures taken.

Bridges having 2-lane carriagway particularlythose with T-beam/ box type superstructure withwell/ pile foundations, which are in sound condition,may be retained. Width of new structure constructedon other side shal be as specified earlier.

Culverts and Bridges using pipes

NP4 RCC pipes conforming to IS: 458 shall be used. Minimum diameter of pipes for new culverts sh all be 1200 mm.

Existing culverts of 900 mm diameter and above, which are in sound condition and functioning satisfactorily, may be extended using the same diam eter pipes. pipes.

All culverts with pipe diameter less than 900 mm shall be replaced with minimum 1200 mm diameter.

Minimum depth of earth cushion over pipe including road crust shall not be less than 1000 mm for new culverts. In case of existing sound and safe cu lverts a minimum cushion of 600 mm may be OK.

In case of insufficient cushion, encasing of pipe i n concrete shall be ensured.

Safety Barriers

(i) For bridges without foot paths, concretecrash barriers shall be provided at theedge of the carriageway on all newbridges.

(ii) The type design for the crash barriers may(ii) The type design for the crash barriers maybe adopted as per IRC:5. The designloading for the crash barriers shall be asper Clause 209.7 of IRC:6.

(iii) For bridges with foot paths, pedestrianrailing shall be provided on the outer side offootpath.

Road Over Bridge (Road over Rail)

(i)In case a 2-lane bridge exists over the railway tracks,another two-lane bridge shall be constructed for one side traffic.

(ii)In case the bridge is to be provided over an existing levelcrossing, twin 2-lane bridges shall be constructed with overallwidth as given in Sub-Para 7.3 (ii) of this Section. If the alignmentof road at the existing railway crossing has skew angle more than45 degrees, the alignment of road or of pier/abutment shall be45 degrees, the alignment of road or of pier/abutment shall besuitably designed to reduce skew angle up to 45 degrees.

(iii)The horizontal and vertical clearances to be providedshall be as per requirement of the Railway authorities.

(iv)The Concessionaire shall be required to obtainapprovals of all designs and drawings from the concerned Railwayauthorities.

(v)The construction of ROB within the railway boundaryshall be under the supervision of Railway authorities.

(vi)The approach gradient shall not be steeper than 1 in 40.

Road under Bridges (Road under Railway line)(i) Full roadway width as in the approaches shall passbelow the bridge structure allowing for widening ofProject Highway to 6-lane at a later date. The serviceroads where provided shall be continued in the bridgeportion also.(ii)The vertical and lateral clearances shall be as per

guidelines given in Section 2 of this Manual.(iii) These structures shall be designed to carry railwayloads. The Concessionaire shall be required to obtainapprovals of all designs and drawings from theconcerned Railway authorities. The design of structureshall be in accordance with relevant Railway codes.(iv) The construction of RUB and its approaches shall becarried out in conformity with the terms specified in theapproval granted by the Railway authorities.

Materials

i) All materials to be used in works shall be in conformitywith the requirements laid down for relevant item in IRC/MORTHSpecifications unless otherwise specified in this Section. If theConcessionaire proposes to use any material, which is notcovered in IRC/MORTH Specifications, it shall conform to relevantIndian Standards, if there are any, or to the InternationalStandards. Proprietary products proposed to be used shall beStandards. Proprietary products proposed to be used shall beproven by use in comparable international road and bridgeprojects, and shall be supported with authenticated licensingarrangement with the manufacturer.

(ii)The Concessionaire shall identify the proposed sourcesof materials and submit the proposal prior to delivery. If it is foundthat proposed sources of supply do not produce uniform andsatisfactory products at any time during execution, theConcessionaire shall procure acceptable materials conforming tothe specifications from other sources.

For manufactured items, Concessionaire shall submit the following details

a) Name of manufacturer and name of product/process/system

b) General features of the product/process/system along with specifications and standards adopted for the product /process /system

c) Authenticated copies of license/agreementd) Details of projects where the product/process/system has been successfully usede) Limitations, if anyf) Acceptance tests and criteriag) Installation and maintenance procedure and

scheduleh) Performance warranty.

Structural Concrete

The Concrete for use in structures shallconform to the provisions in Clauses 302.6 to 302.9of IRC:21 and Section 1700 of MORTHSpecifications. Wherever High PerformanceConcrete (HPC) is proposed to be used, the sameshall conform to the provisions of IRC:SP:70.shall conform to the provisions of IRC:SP:70.Sampling and testing of concrete shall be as perClause 302.10 of IRC:21. Acceptance criteria forconcrete shall conform to Clause 302.11 of IRC:21.

CementAny type of cement specified in IRC:21 may be

used for the works subject to limitations, if any,specified therein .

Coarse Aggregates

Before commencement of the works, atleast three samples, in accordance with theprocedure laid down in IS:2430, shall be takenfor each quarry source to ascertain thequality, suitability and fitness of the availablematerial for use in the works. Fresh tests shallbe conducted in case there is any change inthe source or the type of rock being quarried.The proposal, along with a copy of testreports, shall be submitted.

Sand/Fine Aggregates

(i) All fine aggregates shall conform to IS:383 and tests for conformity shall be carried out as pe r IS:2386 (Part I to VIII). The fineness modulus of f ine aggregates shall be between 2.0 and 3.5.

(ii) Before the commencement of the works, at least three samples as per IS:2430 shall be taken f or least three samples as per IS:2430 shall be taken f or each quarry source to ascertain the quality, suitability and fitness of the available material f or use in the works and the proposal along with a copy of test reports shall be submitted to the IE for review and comments, if any.

(iii) Fine aggregates having positive alkali-silica reaction shall not be used.

Water

(i) Water for use in the works for mixing andcuring of concrete shall be in conformity withClause 302.4 of IRC:21.

(ii)Water from each source shall be tested(ii)Water from each source shall be testedbefore the start of works and thereafter everythree months and after each monsoon till thecompletion of the works and the proposalalong with a copy of test reports submitted tothe Independent Engineer for review andcomments, if any.

Chemical Admixtures(i) Shall comply with IS:9103 and meet the requirementsstipulated in clause 5.5 of IS:456.(ii) Admixtures generating hydrogen or nitrogen or containingnitrates, sulphides, sulphates, or any other material liable to affectthe reinforcement/ embedment or concrete shall not be used.(iii) Compatibility of admixture with the cement being used shall betested before actual use in the works.(iv) Admixtures shall not impair the durability of concrete. They(iv) Admixtures shall not impair the durability of concrete. Theyshall not combine with the ingredients to form harmful compoundsor endanger the protection of reinforcement against corrosion.(v)The packaging of admixtures shall clearly indicate the name ofthe manufacturer/ supplier, brand name (name of the product),date of production and expiry, batch/ identification number.vi) pH value and colour.(vii) Latest date of test and name of the laboratory.(viii) Shelf life, maximum and minimum temperature for storage,precautions to be taken while mixing etc., in use.

Steel for Prestressing

In addition to the requirement mentioned inClause 1009.2 of MORTH Specifications, the steel forprestressing shall satisfy following conditions:(i) Uncoated stress relieved low relaxation steelconforming to IS:14268.(ii) Prestressing steel shall be subjected to(ii) Prestressing steel shall be subjected toacceptance tests in respect of modulus of elasticity,relaxation loss at 1000 hrs, minimum ultimate tensilestrength, stress- strain curve etc. prior to actual useon works as per guidelines contained in BS:4447.The modulus of elasticity value, as per acceptancetests, shall conform to the design value, which shallbe within a range not more than 5 per cent betweenthe maximum and the minimum .

Reinforcement/ Un-tensioned Steel(i) Only Fe 500 grade of steel shall be used on works and all reinforcingsteel for use in works shall be procured from main/ major producers. Fe415 grade of steel can also be used where permissible as per IRCCodes and Guidelines.(ii) Only fresh steel shall be brought to the site. Every bar shall beinspected before assembling on the work; and defective, brittle or burntbars shall be discarded. Cracked ends of bars shall be cut before use.(iii) Only Thermo Mechanically Treated (TMT) bars conforming toIS:1786 shall be used as reinforcing steel.IS:1786 shall be used as reinforcing steel.(iv) All reinforcement shall be free from loose rust and coats of paints,oil, mud or any other substance, which may destroy or reduce bond.The reinforcement bars bent and fixed in position shall be free fromloose rust or scales, coats of paints, oil, mud or chloride contaminationand other corrosion products. Where cleaning of corroded portions isrequired, proposal for effective method of cleaning such as sandblasting shall be submitted to the IE for prior review and comments.(v) Proprietary steel products will be permissible provided they conformto the minimum requirements.

Steel for Bearings

Mild steel, high tensile steel, cast steel,steel forgings, and stainless steel shallconform to the provisions contained in clause925.1 of IRC:83 (Part III).

Structural Steel

All structural steel, castings andforgings, fasteners (bolts, nuts, washers andrivets), welding consumables and wire ropesand cables shall conform to the provisions ofclause 505.1.2, 505.2, 505.3, 505.4 and 505.6respectively of IRC:24.

BitumenBitumen shall be paving bitumen of

viscosity grade complying with Indian StandardSpecifications for “Paving bitumen” IS:73:2006of grade appropriate for the traffic and climaticconditions of the Project Highway. The heavilytrafficked roads in hot areas may find hardergrade bitumen more appropriate whilegrade bitumen more appropriate whilepavements in mountainous regions subject tosub-zero temperatures during winter monthscarrying relatively lower traffic loads and subjectto the phenomenon of “Frost Heave” may findless viscous bitumen resistant to fatigue andcold cracking more appropriate.

Storage of Materials

All materials shall be stored at properplaces so as to prevent their deterioration orintrusion of foreign matter and to ensure thepreservation of their quality and fitness forthe work . Any material, which has deterioratedthe work . Any material, which has deterioratedor has been damaged or is otherwiseconsidered defective after review by theIndependent Engineer shall not be used in theworks and shall be removed from site by theConcessionaire at his cost. Such materialsshall not be made acceptable by anymodifications .