Procedure-Part-A_Structural Works_.pdf

8/13/2019 Procedure-Part-A_Structural Works_.pdf

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HINDUSTAN PETROLEUM CORPORATION

LIMITED

ENNORE TERMINAL PROJECT

Tenderers Signature with seal:Date:

SECTION 9 (PART A) 1

Page 1 of 582010 MECON LIMITED. All rights reserved

MEC/23KM/T-25/10000012

SECTION - 9

PART - A

TECHNICAL SPECIFICATION

FOR

STRUCTURAL WORKS


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CONTENTS

CHAPTER NO. DESCRIPTION

SECTION - 1 GENERAL & FABRICATION OF STEEL STRUCTURES

SECTION - 2 ERECTION OF STEEL STRUCTURES

SECTION - 3 ROOF, SIDE CLADDING AND GRATINGS

SECTION - 4 SALIENT POINTS

SECTION - 5 PAINTING OF STEEL STRUCTURES

LIST OF ANNEXURES

ANNEXURE - APermissible Deviation In Pitch And Gauge Of Holes For Bolts Of Normal

Accuracy

ANNEXURE B Tolerance Of Assembled Components Of Steel Structures

ANNEXURE C Permissible Deviation In Assembly Of Welded Joints

ANNEXURE D Tolerance In Erected Steel Structures

ANNEXURE E Painting System

ANNEXURE F Specification For Surface Preparation With Blast Cleaning / Shot Blasting

ANNEXURE G Material Of Construction

ANNEXURE H List of Recommended makes / manufacturers


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n) Rectification of damaged structures including fixing, aligning, leveling, bolting andwelding etc.

o) Preparation of "As-built" drawings.


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3.0 PREPARATION OF FABRICATION AND ERECTION DRAWINGS

3.1 Fabrication drawings shall be prepared based on design drawings of steel structures.

3.2 Drawing shall be prepared in metric system as per IS: 813-1986. The fabrication drawingsshall specify the following details: -

(a) Type, size and length of welds in case of welded connections,(specifying clearly

shop or site weld). Length of weld specified shall be effective length (excluding endcrates).

(b) In case of bolted joints, arrangement of bolts and specification of bolts, nuts etc.(specifying clearly shop and site bolts).

(c) Specification of electrode/wire flux.

(d) If required special provision to be mentioned in the drawings for handling ofstructures during and after fabrication.

(e) Specification of paint and corresponding surface preparation for painting.

(f) General arrangement/marking plan.

(g) Reference to design drawings.

(h) Material list indicating mark number-wise material requirement giving size, weight,material specification, identification number of each items, number of piecesrequired etc.

(i) Layout with all connecting members with blown up joint details wherever required, in

order to specify clearly various fabrication and erection requirements as per designdrawings.

(j) Specification of preparation of mating surfaces in case of connection by HSFG bolts.

(k) Appropriate edge preparation in case of butt/groove welds in accordance with IS:9595-1996, for all plates and sections having thickness greater than 8 mm.


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(l) Erection clearances in order to facilitate smooth erection at site (ref clauseno.11.2.2.of IS: 800- 2007).

(m) Each erection piece shall be clearly identified by an erection mark in these drawings.All loose members shall be given part mark, which shall be 'wired on' the mainerection piece for despatch.

3.3 Fabrication drawings shall be prepared in such a manner that structures can bedespatched from fabrication shop to erection site with maximum economictransportable size, so as to reduce work involved at site to a minimum.

3.4 Bracings shall be connected for 50% of the capacity of the member or the forcespecified in the design drawing, whichever is more.(for single angle bracing member,consider full area as effective for this purpose).

3.5 Standard simple beam connections, unless otherwise stated in the drawings, shall bedesigned and detailed for 60% beam shear / moment carrying capacity.

3.6 Wherever there is risk of nuts becoming loose due to vibration, lock nuts shall beprovided, or nuts shall be welded after alignment and tightening.

3.7 For all connections by permanent bolts, two nos. of washers shall be used. One

washer bearing against the head and the other bearing against the nut.

3.8 Detailing of structural steel members subject to dynamic loading shall be such as toensure smooth transition of load, as well as best behaviour under stress due tofatigue.

3.9 For detailing connection, the allowable stress for materials, welds, bolts etc, shall beas per IS:800- 2007 and IS:816-1969, or as specified in the drawing.

3.10 The contractor shall be responsible for design and detailing all connections. Thedesign of connection shall provide adequate strength for transfer of force in the

structural elements, as indicated on design drawings. Detailing shall be such thaterection shall be convenient and free from all interfaces, drilling and cutting at site.


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4.0 MATERIALS

4.1 Structural Steel

Structural steel and other related materials for construction shall conform toANNEXURE-G.

4.1.2 Due to non-availability of specified materials, suitable substitutions may be providedwith the consent of the purchaser. Such substitution shall be incorporated in the"As-built" drawings.

4.1.3 All the items are to be cut as per requirements of the drawing. If joints are to beprovided in any item, in order to meet requirements of size and shape, cutting planshowing locations of joints shall be prepared for consideration of purchaser. Jointsprovided shall be incorporated in "As-built" drawings.

4.1.4 Rolling and cutting tolerances shall be as per IS: 1852:1985.

4.1.5 Only tested materials shall be used unless use of untested materials for certainsecondary structural members is permitted by purchaser. If test certificate for thematerial is not available from the main producer, the following tests shall be carried

out at the discretion of the purchaser.

(a) Chemical Composition

(b) Mechanical Properties

(c) Weldability test

4.1.6 Where steel castings are to be used the same shall conform to IS: 1030:1998.

4.2 Bolts and Nuts

4.2.1 Black hexagonal bolts, nuts and lock-nuts shall conform to IS: 1363:2002.

4.2.2 Precision and semi-precision hexagonal bolts, screws, nuts and lock-nuts shallconform to IS: 1364:2002.


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4.2.3 High tensile friction grip bolts shall conform to IS: 3757:1985 and high strengthstructural nuts shall conform to IS: 6623:2004, and hardened steel washers to IS:6649:1985.

4.3 Electrodes

4.3.1 Mild steel electrodes and high tensile steel electrodes shall conform to IS: 814:2004.Electrode to be used for submerged arc welding shall conform to specification IS:7280:1974.

5.0 STORING OF MATERIALS

5.1 Materials shall be stored and stacked properly ensuring that place is properly drainedand is free from dirt. It shall be ensured that no damage is caused due to improperstacking.

6.0 MATERIAL PREPARATION

6.1 Cut edges shall be finished smooth by grinding or machining wherever necessary.Sufficient allowance (3 mm to 5 mm) should be kept in the items incase machining isnecessary.

6.2 Cutting may be effected by gas cutting, shearing, cropping or sawing. In gas cutting ofhigh tensile steel, special care is to be taken to leave sufficient metal to be removedby machining so that all metal that has been hardened by flame is removed.

6.3 Sufficient shrinkage allowance (@ 1mm/M) shall be kept wherever heavy welding isinvolved.

6.4 Straightening and bending shall be done in cold condition as far as practicable.

6.5 If required, straightening and bending may be done by application of heat between

900C and 1100C. Cooling down of the heated item shall be done slowly.

7.0 DRILLING AND PUNCHING OF HOLES

7.1 Drilling and punching of holes for bolts shall be done as per clause no.11.2.4 of IS:800:2007, unless otherwise specified by the purchaser.


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8.0 ASSEMBLY FOR FABRICATION

8.1 Fabrication of all structural steelwork shall be in accordance with IS: 800-2007 and inconformity with various clauses of this specification, unless otherwise specified in thedrawings.

8.2 Fabrication of structures shall preferably be taken up as per the sequence of erection.

8.3 All erection units shall bear erection mark no. and reference drg no. at a prominentlocation on the structures for easy identification at site.

8.4 Fabricated structures shall conform to tolerance as specified in this standard and in IS:7215-1974. In case of contradiction, tolerances specified in this standard shall prevail.

8.5 All the components of structures shall be free from twist, bend, damage etc,

8.6 Assembly of structures shall be carried out by using suitable jigs and fixtures in orderto obviate distortion during welding.

8.7 Cutting of items specially for truss, bracing, portal etc, shall be done only afterchecking of sizes as per Layout.

8.8 Surface, wherever machining is specified, shall be either planed or milled or ground toensure maximum contact.

8.9 If end-milling or machining is planned after the assembly is over, sufficient allowance(5 mm to 15 mm) shall be kept in the items where milling/machining is to be done.

8.10 If pre-bending of the plate is required to avoid welding distortion, it shall be done incold condition.

8.11 If extra joints are required to be provided in column etc, approval should be obtainedfrom the purchaser. However, as general guidance following is suggested. Splice

joints of column shall of full strength butt weld and wherever possible shall be locatedat zones of minimum or substantially lesser stress.

8.12 Splice joints of flange and web should preferably be staggered.

8.13 Sufficient trial assembly of fabricated components (despatch elements) shall becarried out in the fabrication works to control the accuracy of workmanship.


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8.14 Where necessary, washers shall be tapered or otherwise suitably shaped to give theheads of nuts and bolts satisfactory bearing.

8.15 The threaded portion of each bolt shall project through the nut at least by one thread.

8.16 Tolerance of assembled components of structures are given inANNEXURE-B.

8.17 Permissible deviations from designed (true) geometrical form of the despatchelements shall be in accordance with IS: 7215-1974.


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9.0 WELDING

9.1 The Contractor shall work out welding procedure for Purchaser's approval,considering the following factors: -

(i) Specification and thickness of steel.

(ii) Specification of electrode or/and base wire.

(iii) Welding process (manual arc welding, submerged arc welding).

(iv) Type of structures to be welded (thickness of components meeting at a joint).

(v) Pre and post heating requirement.

(vi) Preparation of fusion faces.

(vii) Sequence of welding.

(viii) Weather condition.

(ix) Use of jigs and fixtures etc.

(x) Type of non-destructive testing to be carried out.

(xi) Inspection procedure to be followed

(xii) Design requirements of the joints.

9.2 Welding of any load bearing structure shall be carried out only by the person who haspassed welder's qualification as per IS: 7318 (Part-I) -1974.

9.3 All metal arc welding shall be carried out as per IS: 9595-1996.

9.4 Submerged arc welding of mild steel and low alloy steel shall be as per IS: 4353-1995

9.5 Electrode shall conform to clause no.4.3 of this standard.

9.6 Electrodes shall be stored in a dry place. Electrodes whose coatings are damageddue to absorption of moisture or due any other reason shall not be used.


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9.7 Low Hydrogen electrodes and flux for submerged welding shall be dried at 250-300C for one hour in drying even before use.

9.8 For suitability of wire flux combination, procedure test shall be carried out as per IS:3613-1974 if so required.

9.9 Welding shall be done by electric arc process. Generally submerged arc, automatic &Semi-automatic welding shall be employed. Only where it is not practicable, manualarc welding may be resorted to. In case of manual arc welding, recommendations ofelectrode manufacturer is to be strictly followed.

9.10 Welding surface shall be smooth, uniform, free from fins, tears notches or any otherdefect which may adversely affect welding.

9.11 For multi-run weld deposit, the next run should be done only after thorough removal ofslag and proper cleaning of surface.

9.12 Fillet weld shall have the correct profile with smooth transition into parent metal.Dressing of welds, if specified, shall be done by such method which does not causegrooving and other surface defects on the weld or on the parent metal.

9.13 All butt welds shall start and end with run-on and run- off plates. All such plates shallbe carefully trimmed off by gas cutting after welding is over.

9.14 Fillet welds shall not be stopped at corners but shall be returned round them.

9.15 If butt weld is to be ground flush with the surface of the member as per drawing.adequate reinforcement shall be built up and then the same shall be chipped off andground flush. The grinding is to done in the direction of stress flow till the transversemarks are eliminated.

9.16 Welding shall not be done under such weather conditions which might adversely affect

the efficiency of the welding.

9.17 Manipulators shall be used wherever necessary and shall be designed to facilitatewelding and ensure that all welds are easily accessible to the operators.


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9.18 Stress relieving after welding shall be done if especially called for in the drawing orspecification. Ends of structural members and portions of gussets receiving welding atsite, shall be left unpainted.

9.19 Permissible deviation in assembly of weld joints shall be in accordance withANNEXURE - C.


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10.0 INSPECTION & TESTING

10.1 The purchaser/Inspector shall have free access at all times to those parts ofContractor's or his Sub- Contractor's works which are concerned with the fabricationof steel works and shall be afforded all reasonable facilities at all stages ofpreparation, fabrication and trial assemblies for satisfying himself that the fabrication isbeing undertaken in accordance with the provisions of relevant specification.

10.2 All gauges and templates, tools, apparatus, labour and assistance for checking shallbe supplied by the contractor free of charge. The purchaser /Inspector may at hisdiscretion, check the test results obtained at the Contractor's works, by independent

test at the Government Test House or elsewhere, and should the material so testedbe found to be unsatisfactory, the cost of such such test shall be borne by theContractor.

10.3 Contractor shall make all necessary arrangements for stage inspection bypurchaser/Inspector during the fabrication at shop and incorporate all on-the-spotinstructions / changes conveyed in writing to the Contractor.

10.4 Material improperly detailed or wrongly fabricated shall be reported to thePurchaser/Inspector and shall be made good as directed. Minor misfits which can beremedied by moderate use of drift pins, and moderate amount of reaming and slight

chipping may be corrected in that manner, if in the opinion of the Purchaser/Inspectorthe strength or appearance of the structure will not be adversely affected. In the eventthe Purchaser/Inspector directs otherwise, the items will be rejected and a completelynew piece shall be fabricated. The cost of correcting errors shall be to the account ofthe Contractor.

10.5 i) The Purchaser/Engineer shall have the power:

a) To certify, before any structure is submitted for inspection, that the same isnot in accordance with the contract, owing to the adoption of any

unsatisfactory method of fabrication.

b) To reject any structure as not being in accordance with specifications &drawings.

c) To insist that no structure or parts of the structure once rejected isresubmitted for inspection/test, except in cases where the Purchaser /Inspector authorised representative considers the defects as rectifiable.


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ii) If, on rejection of structure by the Purchaser/Inspector the Contractor fails tomake satisfactory progress within the stipulated period, thePurchaser/Inspector shall be at liberty to cancel the contract and fabricate orauthorise the fabrication of the structures at any other place he chooses, atthe risk and cost of the Contractor, without prejudice to any action beingtaken in addition to terms of General Conditions of Contract.

iii) The Purchaser / Inspector's decision regarding rejection shall be final andbinding on the Contractor.

iv) The specifications prescribe various tests at specified intervals forascertaining the quality of the work done. If the tests prove unsatisfactory,Purchaser/Inspector shall have liberty to order the Contractor to re-do thework, done in that period and/ or to order such alterations and strengtheningthat may be necessary at the cost of the Contractor and the contractor shallbe bound to carryout such orders failing which the rectification/redoing will bedone by the Purchaser through other agencies and the cost recovered fromthe Contractor.

v) Notwithstanding any inspection at the workshop the Purchaser/Inspector shallhave the liberty to reject, without being liable for compensation any fabricated

members or materials brought to site that do not conform to specifications /drawings.

vi) All rejected materials shall be removed from the site of fabrication by theContractor at his own cost and within the time stipulated by thePurchaser/Inspector.


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11.0 CONTROLS IN WELDING

11.1 The extent of quality control in respect of welds for structural elements for bothstatically and dynamically loaded structures shall be as follows and shall beconducted by the contractor at his own cost:-

a) Visual Examination - All welds shall be 100% visually inspected to check thefollowing:

i) Presence of undercuts

ii) Visually identifiable surface cracks in both welds and base metals.

iii) Unfilled craters

iv) Improper weld profile and size

v) Excessive reinforcement in weld

vi) Surface porosity

Before inspection, the surface of weld metal shall be cleaned of all slag, spattermatter, scales etc. by using wire brush or chisel.

b) Dye Penetration Test (DPT)

This shall be carried out for all important fillet welds and groove welds for bothstatically and dynamically loaded structures to check the following:

i) Surface cracks

ii) Surface porosities

Dye Penetration Test shall be carried out in accordance with American NationalStandard ASTM E165.


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c) Ultrasonic testing

Ultrasonic test shall be conducted for all groove welds and heat affected zone indynamically loaded structures and for other important load bearing butt welds instatically loaded structures as desired by purchaser, to detect the following:

i) Cracks

ii) Lack of fusion

iii) Slag inclusions

iv) Gas porosity

Ultrasonic testing shall be carried out in accordance with American NationalStandard ANSI/AWS D1.1-96 Chapter -6: Part F.

Before ultrasonic test is carried out, any surface irregularity like undercuts, sharpridges etc. shall be rectified. Material surface to be used for scanning by probesmust allow free movement of probes. For this purpose, surface shall be preparedto make it suitable for carrying out ultrasonic examination.

d) Radiographic Testing

(X-ray and Gamma-Ray Examination) :- This test shall be limited to 2% of length ofwelds for welds made by manual or semi- automatic welding and 1 % of length ofweld if made by automatic welding machines . The location and extent of weld tobe tested by this method shall be decided by purchaser to detect the followingdefects: -

i) Gas porosity

ii) Slag inclusions

iii) Lack of penetration

iv) Lack of fusion

v) Cracks


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Radiographic testing shall be conducted in accordance with American NationalStandard ANSI/AWS D1.1-96 Part E.

Any surface irregularity like undercuts, craters, pits etc. shall be removed beforeconducting radiographic test. The length of weld to be tested shall not be morethan 0.75 x focal distance. The width of the radiographic film shall be width of thewelded joint plus 20 mm on either side of the weld.


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12.0 ACCEPTABLE LIMITS OF DEFECTS IN WELD

12.1 Limits of Acceptability of welding defects shall be as follows: -

a) Visual inspection & Dye Penetration Test - The limits of acceptability of defectsdetected during visual inspection and Dye Penetration Test shall be inaccordance with clauses 6.9 & clause 6.10 of American National Standard

ANSI/AWS D1.1-96 for statically as well as dynamically loaded structuresrespectively.

b) Ultrasonic Testing - The limits of acceptability of defects detected duringultrasonic testing shall be in accordance with clause 6.13.1 & clause 6.13.2 of

American National Standard ANSI/AWS D1.1-96 Chapter 6: Part C for staticallyand dynamically loaded structures respectively.

c) Radiographic testing - The limits of acceptability of defects detected duringRadiographic testing shall be in accordance with clauses 6.12.1 & 6.12.2 of

American National Standard ANSI/AWS D1.1-96 Chapter 6: Part C for staticallyand dynamically loaded structures respectively.


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13.0 RECTIFICATION OF DEFECTS IN WELDS

13.1 In case of detection of defects in welds, the rectification of the same shall be done asfollows:

i) All craters in the weld and breaks in the weld run shall be thoroughly filled withweld.

ii) Undercuts, beyond acceptable limits, shall be repaired with dressing so as toprovide smooth transition of weld to parent metal.

iii) Welds with cracks and also welds with incomplete penetration, porosity, slaginclusion etc. exceeding permissible limits shall be rectified by removing thelength of weld at the location of such defects plus 10 mm from both ends ofdefective weld, and shall be re-welded. Defective weld shall be removed bychipping hammer, gouging torch or grinding wheel. Care shall be taken not todamage the adjacent material.

14.0 ACCEPTANCE CRITERIA OF MACHINING SURFACE

14.1 Standard of acceptance for machined surfaces, wherever specified by designer, (eg.

in column cap plates, base plates and column shafts etc.)shall be as given as perclause 14.2 & 14.3.

14.2 Maximum surface unevenness on bearing surface of cap/ base plate shall not exceed0.5 mm.

14.3 When assembled, there must be physical contact for at least 75% of the contactsurface.(The checking shall be carried out with 0.2mm guage. Care should be takenthat these connecting members are fixed with such accuracy that they are not reducedin thickness during machining by more than 1.0 mm.

15.0 DESPATCH INSTRUCTIONS

Each despatchable structure shall bear mark no. along with reference drawing numberat two prominent locations (e.g. on flange and bottom of base plate of a column).

15.1 "As built" drawing shall be prepared after fabrication is completed to indicate additions/ alterations made during the process of fabrication. (Refer clause 4.1.2 & 4.1.3.)


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15.2 Control assembly of important structures shall be done in the shop floor beforedespatch to avoid mismatching. For all such important structures, match marking shallbe given at the control assembly stage in the shop floor and such match markingsshall be made clearly visible while assembling the structures at site.

15.3 Centre lines of column flanges and both sides of web shall be punched, preferably attop and bottom to facilitate alignment after erection.

16.0 COMPLETION DOCUMENTS

16.1 On completion of work, the Contractor shall submit to the Purchaser the followingdocuments: -

a) The technical documents according to which the work was carried out.

b) Copies of the As built" drawings showing thereon all additions and alterationsmade during the fabrication.

c) Manufacturers test certificates

d) Certificates/documents on control checking

e) Test of welds

f) Inspection Certificates issued by Purchaser/Consultant for the material/structures.

17.0 In addition to provision of erection and transport equipments, the scope of workincludes supply of tools and tackles, consumables, materials, labour and supervisionand shall cover the following:

a) Storing and stacking of all fabricated structural components/units/assemblies atsite storage yards till the time of erection.

b) Transportation of structures from storage yard to site of erection, including multiplehandling, if required.


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c) All minor rectification / modifications such as: -

i) Removal of bends, kinks, twists etc. for parts damaged duringtransportation and handling.

ii) Reaming of holes which do not register or which are damaged, for use of nexthigher size bolt.

iii) Plug-welding and re-drilling of holes which do not register and which cannotbe reamed for use of next higher size bolt.

iv) Drilling of holes which are either not drilled at all or are drilled in incorrectposition during fabrication.

d) Fabrication of minor missing items as directed by the purchaser.

e) Verification of the position of embedded anchor bolts and inserts w.r.t. line findlevels, installed by others based on Geodetic Scheme / Bench mark / Referenceco -ordinates to be furnished by the Purchaser.

f) Assembly at site of steel Structural components wherever required, includingtemporary supports and staging.

g) Marking arrangements for providing all facilities for

i) Conducting ultrasonic x-ray or gamma ray tests by reputed testinglaboratories

ii) Making available test films / graphs, with reports / interpretation.

h) Site Rectification of damaged portions of shop primer by cleaning and applicationtouch-up paint.

i) Erection of structures including making connections by bolts / High strengthFriction Grip bolts/welding as per drawing.

j) Alignment of all structures true to line, level plumb and dimensions within specifiedlimits of tolerance.

k) Application at site after erection, required number of coats of primer and finishingpaint as per specification and drawing.


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l) Rectification of structures as per Preliminary acceptance report and Finalacceptance report.

18.0 STORING AND HANDLING

18.1 Storage of structures shall be preferably be done in such a manner that erectionsequence is not affected.

18.2 While storing, care shall be taken so that structures do not come in direct contact withthe earth surface and accumulated water. Girders, beams, columns. shall be placed

and stored in such a manner that during rain, no accumulation of water on thestructures takes place.

18.3 Stacking of the structures shall be done in such a way that, erection marks are visibleeasily and handling does not become difficult. Wherever required, wooden sleepers /grilles may be used.

18.4 Handling and storage of materials shall be as per IS: 7969-1975, to ensure safety.


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SECTION 2 ERECTION OF STEEL STRUCTURE

19.0 ERECTION

19.1 General

19.1.1 Erection shall be carried out in accordance with IS: 800:2007 and other relevantstandards referred to therein.

19.1.2 For safe and accurate erection of structural steelwork, staging, temporary support,false-work etc. shall be erected as required.

19.1.3 The fabricated materials received at erection site shall be verified with respect ofmarking on the key plan/marking plan or shipping list.

19.1.4 Any material found damaged or defective shall be stacked separately and thedamaged or defective portions shall be painted in distinct colour for identification andthe same shall be brought to the notice of the Purchaser.

19.2 Erection Drawings

19.2.1 The approved erection drawings and any approved arrangement drg, specification orinstruction accompanying them shall be followed in erecting structures.

19.3 Erection of Structures

19.3.1 Erection work shall be taken up after receipt of clearance from the purchaser.

19.3.2 For safety requirements during erection, provisions in IS: 7205:1974, IS: 7969:1975and other relevant Indian standards shall be followed.

19.3.3 Erection shall be carried out with the help of maximum mechanization possible.

19.3.4 Prior to commencement of erection, all the erection equipment, tools, tackles, ropesetc. shall be tested for their load carrying capacity. Such tests may be repeated atintermediate stages also if considered necessary and frequent visual inspection shallbe done of all vulnerable areas and components to detect damages or distress in theerection equipment, if any.


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19.3.5 Following shall be taken care of during erection, whenever necessary:-

19.3.5.1 Temporary bracing, whenever required, shall be provided to sustain forces due toerection loads and equipment etc. Erected parts of the structures shall remain stableduring all stages of erection when subjected to the action of wind, dead weight anderection forces etc. Specified sequence of erection of vertical and horizontal structuralmembers shall be followed.

19.3.5.2 Erected members shall be held securely in place by bolts to take care of dead load,wind load and erection load.

19.3.5.3 All connections shall achieve free expansion and contraction of structures whereverprovided.

19.3.5.4 No final bolting or welding of joints shall be done until the structure has been properlyaligned.

19.3.5.5 For positioning beams, columns and other steel members, the use of steel sledges isnot permitted.

19.3.5.6 Instrumental checking of correctness of initial setting out of structures and adjustment

of alignment shall be carried out in sequence and at different stages as required. Thefinal leveling and alignment shall be carried out immediately after completion of eachsection of a building.

19.3.5.7 All structural members shall be erected with erection marks in the same relativeposition as shown in the appropriate erection and shop drawings.

The contractor shall design, manufacture, erect and provide false-work, stagingtemporary support etc. required for safe and accurate erection of structural steelworkand shall be fully responsible for the adequacy of the same.

19.3.5.9 The Contractor shall also provide facilities such as adequate temporary accessladders, gangways, tools & tackles, instruments etc.to purchaser for his inspection atany stage during erection.


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19.4 Field Connections

19.4.1 Assembly by permanent bolts.

19.4.1.1 The numbers of washers on permanent bolts shall not be more than two (and not lessthan one) for the nuts and one for the bolt head.

19.4.1.2 Wooden rams or mallet shall be used in forcing members into position in order toprotect the metal from injury or shock.

19.4.1.3 Where bolting is specified on the drawing, the bolts shall be tightened to the maximum

limit. The threaded portion of the each bolt shall be project through the nut by at-leastone thread. Tapered washers shall be provided for all heads and nuts to achieveuniform bearing on sloping surface.

19.4.1.4 To prevent loosening of nuts, spring washers or lock- nuts shall be provided asspecified in the design/shop drawings.

19.4.1.5 All machine-fitted bolts shall be perfectly tight and the ends shall be checked toprevent nuts from becoming loose. No unfilled holes shall be left in any part of thestructures.

19.4.2 Assembly by welding

19.4.2.1 All field assembly by welding shall be executed in accordance with the requirementsfor shop fabrication. Where the steel has been delivered painted, the paint shall beremoved before field welding for a distance of at least 50 mm on either side of the

joints to be welded.

19.4.2.2 All other requirements in welding shall be in accordance with clauses specified underSection-1 of this specification

19.4.3 Assembly by High Strength Friction Grip Bolts (HSFG)

19.4.3.1 Assembly of structures with HSFG bolts shall conform to IS: 4000-1992.

19.4.3.2 The mating surfaces shall be prepared in accordance with the requirements of designin order to achieve required properties to develop adequate friction between thesurfaces.

19.4.3.3 The mating surfaces shall be absolutely free from grease, lubricant, dust, rust etc. andshall be thoroughly cleaned before assembly.


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19.4.3.4 The nuts shall be tightened up-to the specified torque with the help of torque -wrenchor by half- turn method with the help of pneumatic wrench lever.

19.4.3.5 The direction of tightening of the nuts shall be from the middle toward the periphery ofassembly.

19.4.3.6 After desired tightening the bolt heads, nuts and edges of the mating surfaces shall besealed with a coat of paint to obviate entry of moisture.

20.0 ACCEPTANCE STANDARD OF WELDING

20.1 Acceptance standard of welding shall be as specified in SECTION-I of thisspecification.

21.0 BEDDING AND GROUTING

21.1 Base plates shall be set to elevations shown on the drawings, supported aligned andleveled using steel wedges and shims or by other approved methods. Plates shall beleveled properly, positioned and the anchor bolts tightened.

21.2 Bedding/grouting shall be carried out until sufficient number of columns have beenproperly aligned, leveled and plumbed and sufficient number of girders, beams,trusses and bracings have been put in position to the satisfaction of purchaser.

22.0 PAINTING OF STEEL STRUCTURES

Refer to SECTION-5.

23.0 ERECTION TOLERANCES

Maximum permissible tolerances in erected steel structures shall be as given inANNEXURE-D.


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24.0 ACCEPTANCE OF WORK

24.1 Acceptance of erected steel structures shall be either after completion of erection ofthe whole building or in blocks.

24.2 Preliminary acceptance certificates will be given in the following cases:-

i) Any steelwork or part thereof embedded in concrete.

ii) Steel structures, which are to be covered in the process of carrying out furtherwork.

25.0 DOCUMENTATION

25.1 The following documents shall be prepared at the time of acceptance of erectedstructures.

i) Documents showing actual deviations made during execution of erection workand approval of competent authority.

ii) Documents showing acceptance of embedded structures.iii) Certificate/documents on control checking and test of materials (if any) and weld.

iv) Data and result of geodetic measurements obtained while checking the erectionof the structures.

25.2 Copies of "As-Built" drawing showing thereon all additions and alternations which tookplace between approval of drawing and erection of structures.


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SECTION-3 ROOF AND SIDE CLADDING WITH COLOUR COATEDTROUGHED GALVANISED STEEL SHEETS (GCS)

26.0 Roof sheeting shall be of Hi-Rib profiled colour coated Galvalume / Zincalume BHPULTRA Steel sheet made of cold rolled steel of 550 MPA minimum yield strengthconforming to ASTM A 366 or AS 1595 with hot dip metallic coating of minimum 200gm/sq.m zinc-aluminium alloy coating mass (55% Aluminium, 43% zinc and 1.5%silicon), total of both sides as per ASTM A 792 or AS 1397. Base metal thicknessshall be 0.6 mm. Total thickness of colour coated profiled sheet shall be 0.68 mm.The colour shall have a total coating thickness of 40 microns of paint system as per

AS/NZS-2728:1997 of approved colour comprising of 20 microns exterior coat on topsurface and 10 microns reverse coat on back surface over 5 microns primer coat onboth surfaces (color bond ultra steel quality paint coat or equivalent). Sheeting shallbe fixed to the purlins for the full thickness of purlin top flange with extra projection of5 to 10 mm below flange with wafer head self drilling zinc coated (40 microns hotdipped) fasteners of approved make. All screws shall pass through the crown of theHi-Rib of the roof sheeting. The side laps shall also be fixed withself drilling zinccoated fasteners of approved make. Flashing, Cappings, Ridge etc., shall be of 0.68mm plain colour coated Galvalume / Zincalume BHP steel sheet with necessaryfasteners.

Translucent sheets (FRP) of thickness 2 mm at specified locations to match with thecorrugations of Hi-Rib profiled colour coated galvalume / zincalume BHP steel roofsheets, shall conform to IS:12866-1989(FRP)

WALL CLADDING:

Wall cladding shall be of Hi-Rib profiled colour coated Galvalume / Zincalume BHPULTRA steel sheet made of cold rolled steel of 550 MPA minimum yield strengthconforming to ASTM A 366 or AS 1595 with hot dip metallic coating of minimum 200gm/sq.m zinc-aluminium alloy coating mass (55% Aluminium, 43% zinc and 1.5%silicon), total of both sides as per ASTM A 792 or AS 1397. Base metal thickness

shall be of 0.6 mm. Total thickness of colour coated profiled sheet shall be of 0.68mm. The colour shall have a total coating thickness of 40 microns of paint system asper AS/NZS-2728:1997 of approved colour comprising of 20 microns exterior coaton top surface and 10 microns reverse coat on back surface over 5 microns primercoat on both surfaces (colorbond ultra steel quality paint coat or equivalent).Cladding sheets shall be of valley fixed to wall runner with hot dip galvanised selfdrilling fasteners with integral EPDM/neoprene washers of approved make. Also


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fasteners to be provided on side laps. Minimum sheet overlap at end laps shall be of150 mm. Flashing, Cappings,etc., shall be of 0.68 plain colour coated Galvalume /Zincalume BHP steel sheet with necessary fasteners.

Translucent sheets (FRP) of thickness 2 mm at specified locations to match with thecorrugations of Hi-Rib profiled colour coated galvalume / zincalume BHP steelsheets, shall conform to IS:12866-1989(FRP)

27.0 ROOF AND SIDE CLADDING WITH COLOUR COATED TROUGHED STEELSHEETS / POLY CARBONATED SHEETS

27.1 The scope of work shall cover:

a) Preparation of drawings showing layout and size of sheets used, details ofconnections and flashings, bill materials.

b) Procurement and supply of sheets of all gauges and sizes, flashings and fittingslike corner pieces, apron pieces, ridges, cutting and bending of sheets whereverrequired; drilling of holes all as per specification, drawings and fixing with thepurlins as per manufacturer recommendations to make full water proof & towithstand against wind load.

c) Procurement and supply of Galvanised Hex self drilling tapping screws andEPDM/neoprene washers.

d) Loading, transportation, unloading and delivery of sheeting material from place ofprocurement to erection site.

e) Provision of all tools, tackles, equipment. labour supervision and servicesrequired for the satisfactory completion of the work specified herein and on thedrawings.

f) Erection in position sheets for roofing, walling, louvres; erection of all flashings,

fittings like ridges, valleys, gutters, corners, apron etc. at all locations all work asper drawings and specifications.

27.2. All necessary galvanised flashings, ridging, capping, gable and corner trimming shallbe made from same material and in line with the gauge of roof/side covering where itis used. Where connection between two different gauge sheetings is involvedthickness corresponding to lower gauge may be used.


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Steelwork coming in direct contact with sheets shall be treated with two coats of zincbased primer and one coat of finish paint as topping coat.

27.3 Fixing of sheets

27.3.1 All fixing of the roof and side sheeting to purlins/walling shall be by means of selfdrilling tapping screws.

27.3.2 All screws/bolts shall pass through the crown of the corrugations for roof sheetsand through trough corrugations for side sheets. Colour Coated sheets are to beprovided with NPDM/neoprene washers. Fixing of the sheets with the purlins shall be

as per the specification of the respective suppliers.

27.3.3 Laps

27.3.4. All normal roofing shall be provided not less than 150 mm for end & side laps for roof

slopes between 15 to 18 . For roof slopes below 15end laps shall be increased by

at least 50mm for every 2 decrease in slope from 15 .

27.3.5 All side/gable end sheets shall be provided not less than 150mm side lap and 100 mmend lap.

27.3.6 Overhang of sheets on the roof and side cladding shall not exceed 300 mm.

27.4 Erection

27.4.1 Erection is to be carried out with the lay of the side laps such that under theprevailing wind, rain is not driven into the lap. The sheets shall be laid so that side lapsin any two consecutive rows are staggered.

27.4.2 Broken or otherwise damaged sheeting shall not be erected.

27.4.3 Cutting, framing and trimming of all openings required shall be carried out at site.

27.5. Grated Walkways/Grilled Floor ing:

27.5.1 Unless otherwise stated all grill flooring shall be designed for in addition to its selfweight, for a superimposed load of 500 kg/m2 or the alternative minimum loadspecified in IS: 875 or the incidental load, due to erection, operation or maintenance


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or as specified in the drawing whichever is more critical. The maximum deflectiondue to dead load and live load should not be more than 1/200 span.

27.5.2 Material used for fabrication shall conform to IS: 2062-2006.

27.5.3. Grill flooring shall be fabricated from flats of size 25x6 for main bars & 25x3 forsecondary bent rib plates. Located of main bars at a spacing of not more than 40mm and shall be provided with suitable transverse bent rib members to providerigidity. Fabrication shall make provision to connect the flooring panels by bolts or bybolts and clips or welding to supporting members as per drawings. Provision shallalso be made to interconnect the adjacent panels by bolts or by bolts and clips to

prevent movement of floor panels. Top surface of all bars/members shall be flushgiving a neat appearance. Welding of different members shall be by electroforge,electric resistance or similar type of welding so that there are no crude weld depositsor lumps.

27.5.4 If permitted, grated walkways may be fabricated by manual arc welding. However,the welding shall be finished smoothly by proper grinding/filing.

27.5.5 The fabricated floor panels shall be cleaned of all rust, dust, grease, oil, mill scale,weld flux etc., by blast cleaning to Swedish standard Sa 2 and made ready forpainting. Painting shall be by cold dip process. First dip shall be in anti-saline

metallic primer. After the primer paint has completely dried, the grill flooring shall bedipped for the second time in heavy duty anti-corrosive and wear resistantbituminous black paint. Minimum DFT of antisaline primer shall be 25 microns andminimum DFT of finishing paint shall be 75 microns. Sa 2

27.5.6 For cold dip painting a thinner recommended by the manufacturer in suitablequantities shall be added. During cold dip painting care shall be taken to guardagainst sagging or flow-down of paint.

27.5.7 The gratings when erected around openings, shall have circular bands.

27.5.8 Sample grating shall be got approved before taking up full scale manufacture.


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SECTION - 4 SALIENT POINTS

28.0 QUOTATION

28.1 The bidder should ascertain himself, by a visit to the site if necessary, the actual siteconditions, local factors etc. The contractor shall bear full responsibility for deductionsand conclusions as to the nature and conditions under which the work is to beexecuted, including effect of climate, rainfall etc. Failure to do so will not absolve thecontractor of his responsibilities about the proper execution of the job. No claims forextra payments due to any special site conditions and ignorance of site conditions will

be considered after acceptance of his quotation.

28.2 The contractor shall indicate his price as per Schedule of Quantities,

28.3 The cost of bolts (permanent and erection), washers, electrodes, putty, gases, cost ofstraightening the raw materials (hot bending not permitted), cutting of flats from platesand providing splices, paints, tool, plants, etc. as required for the work shall bedeemed to be included in the quoted price.

28.4 All handling and transport charges of raw materials and fabricated structures,including double handling if required, for completion of the work in accordance with

time schedule are deemed to be included in the quoted price.

28.5 Cost of NDT of welds as per specification shall be borne by the Contractor. For thewelds found defective, the cost of retest shall be borne by the contractor in addition tothe cost of rectification or replacement of the defective part.

29.0 PROGRAMME

29.1 A monthly time bar chart for various activities like procurement of steel, preparationand approval of fabrication drawings, fabrication, dispatch to site, erection andalignment, sheeting an painting etc. giving starting and completion dates of all

activities, shall be submitted alongwith the bid without which the bid may not beconsidered for evaluation.

29.2 The contractor shall also furnish his overall mobilization plan of constructionequipment, their capacity etc. for prior approval of purchaser.


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31.3 The Owner may plan to procure and supply from the producers/stockyards majoritems of structural steel such as RS Joists, channels, angles, plates, chequeredplates, tubes, Grating etc., required for the work. In that case these will be supplied tothe Contractor in the indented lengths or standard lengths available, as received fromthe suppliers.

32.0 CONTRACTOR'S RESPONSIBILITY

32.1 The Contractor shall at his own cost properly store all materials brought by him to thework site/ Fabrication shop to prevent damage due to rain, wind, direct exposure to

sun etc. and also from theft pilferage etc.

33.0 EQUIPMENT

33.1 All construction and equipment once brought by the Contractor within the ProjectArea, are not to be removed from there without the written authority from thepurchaser.

34.0 DESPATCH OF FABRICATED MATERIALS

34.1 The Contractor is solely responsible for any loss or damage during transit to any of the

fabricated members, and as such proper precautions shall be taken by him to guardagainst such mishaps.

35.0 SETTING OUT

35.1 The Contractor shall be responsible for checking the alignment and levels offoundations, correctness of foundation, centres of anchor bolts etc. well in advance ofstarting erection work and shall be responsible for any consequence fornon-compliance thereof. Discrepancies, if any, shall immediately be brought to thenotice of the Purchaser / Consultant. Any mistake subsequently found in alignmentand levels of the structural steelwork due to non-verification of foundation before

erection shall be corrected by the Contractor at his own expense.

35.2 One set of reference axes and one bench mark level will be furnished to theContractor. These shall be used for setting out of structures. Maintenance of suchbenchmark level shall be the responsibility of the Contractor.

35.3 The Contractor at his own expenses shall provide measuring instruments for settingout, leveling and aligning steelwork.


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36.0 STAGING

36.1 Any staging necessary for the pre-assembly work of structures shall be provided bythe Contractor at his own expense.

37.0 RULES & REGULATIONS OF SAFETY, ELECTRICITY BOARDS, FACTORY ETC.

37.1 The Contractor shall at all times comply with all relevant factory acts, electricity rules,safety regulations etc. as per statutory regulations of Central / State Government.

38.0 DEVIATIONS

38.1 Should the Contractor wish to deviate from any specification or details shown on thepurchaser's approved drawings and / or Technical Specifications, he shall obtain thepurchaser's written authority before proceeding with the deviations.

39.0 BASIS OF PAYMENT

39.1 The tenderer shall give the break-up prices as required in the Schedule of Items. Asthe quantities mentioned are estimated quantities, payment will be made on theactuals as per the agreed rates.

40.0 MEASUREMENTS

40.1 Structural Steel

Structural steelwork will be measured by the metric tonne and as per IS: 1200 (part-8)- 1993 and IS: 1200-(part-9)-1973 subject to provisions outlined below: -

a) The calculation of quantities shall be based on unit on weights for structuralsections as given in IS: 808-1989. In the case of mild steel/SAIL-MA Steel plates,the calculated weights shall be based on 78.5 kg per square metre per

centimetre thick plate. The payments will be made on the basis of weights ofmembers given in the approved fabrication drawings. However, any changes onthe above weights during fabrication erection, payment shall be based onsketches Approved by the purchaser.

b) In the event the I.S. does not specify any mode of measurement for a particularitem of work, the same shall be measured as per any other relevant internationalstandard or as directed by the Purchaser.


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c) The weight of all plates and sections shall be calculated from the approveddrawing using the minimum overall square or rectangular dimensions andtheoretical weight, no deduction being made for skew cuts, holes etc. In the caseof plates, other than gussets, the actual dimensions shown on approveddrawings will apply unless approved otherwise by the purchaser based on cuttingdiagram of mother plates.

d) The weight of all welding runs, bolt, stanchion base packing, cuttings to wasteand rolling margins, and coatings of paint, will be excluded from the measuredweight and shall be deemed to have been allowed for in the rates for structuralsteelworks quoted by the Contractor.

e) Temporary works and all other materials not included in the permanent worksshall be excluded from any measurement for payment.

40.2 Colour Coated Sheets

40.2.1 Colour coated sheets for roofing, louvres of big size and side cladding shall bemeasured by the square metre of net laid area, as specified and shown on thedrawings.

40.2.2 No allowance shall be made for wastage, cut-outs, over laps etc. in the measurement.

40.2.3 The unit rate in 40.3.1 shall include all fasteners, flashings and fitting such as ridges,corners, aprons and other accessories.

40.2.4. No deduction will be made for openings for area less than a single sheet. Also noextra payment will be made for making openings.

40.3 PRELIMINARY ACCEPTANCE

40.3.1 After completing the erection of a unit or portion thereof, the Contractor shall give anotice in writing stating that the job is complete in all respects and ready for

preliminary acceptance .The job shall be jointly inspected visually by representativesof Contractor and Purchaser. All observed defects and omissions as per drawing andspecification shall be noted down. If the defects are not major in the opinion of thepurchaser/Purchaser's representative, the Contractor will be issued a preliminaryacceptance certificate mentioning the defects, deficiencies and omissions which shallbe made good by the Contractor within a period of 2 weeks or at the earliest.


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40.4 FINAL ACCEPTANCE

40.4.1 Before commencement of inspection for final acceptance of the building or unit, theContractor shall make available six complete sets of all drawings, representing "ASBUILT" drawing, (i.e. all additions and alterations done during fabrication and erectionshall be incorporated in the drgs, Refer clause 30.4 & 30.6

40.4.2 The Contractor shall make good all defects deficiencies and omissions noted downduring preliminary acceptance (Refer clause 40.3.1) and shall inform in advance thePurchaser/ his representative for conducting inspection for final acceptance. Finalacceptance certificate will be issued by the Purchaser / his representative only after all

defects / deficiencies / omissions noted under Preliminary Acceptance have beenrectified.


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SECTION- 5 PAINTING OF STEEL STRUCTURES

41.0 SURFACE PREPARATION FOR PAINTING

41.1 General

The steel surface which is to be prepared shall be cleaned of dirt and grease and theheavier layers of rust shall be removed by grinding prior to Actual surface preparationto a specified grade.

Surface preparation to be followed prior to painting shall be based on the requirementof a particular painting system as per clause 43.0. Some of the specifications forsurface preparation is given below for reference but the particular specification forsurface preparation shall be followed as per schedule of works given to the contractorfor price bid.

41.2 Mechanical Cleaning

41.2.1 Manual/power tool cleaning.

Manual/power tool cleaning shall be done as per grade St-2 or St-3,of Swedish

Standard Institution SIS 055900.

i) Grade St-2: Thorough scraping and wire brushing, machine brushing, grindingetc. This grade of preparation shall remove loose mill scale, rust and foreignmatter. Finally the surface is to be cleaned with a vacuum cleaner or with cleancompressed air or with clean brush. After preparation, the surface should havea faint metallic sheen. The appearance shall correspond to the printsdesignated St-2.

ii) Grade St-3: very thorough scraping and wire brushing, machine brushing,grinding etc. The surface preparation is same as for grade St-2 but to be done

much more thoroughly. After preparing the surface, it should have apronounced metallic sheen and correspond to the prints designated St-3.

41.2.2 Blast Cleaning

41.2.2.1 Blast cleaning shall be done by shot blasting as per following grades according toSwedish Standard SIS 055900.


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(i) Grade Sa-2.This involves light blast cleaning. Almost all mill scale, rust andforeign matter shall be removed. Finally the surface is cleaned with a vacuumcleaner, clean dry compressed air or a clean brush. The surface shall lookgreyish in colour and correspond in appearance to the prints designated asSa-2.

(ii) Grade Sa 2 :This involves very thorough blast cleaning. Mill scale, rust andforeign matter shall be removed to the extent that the only traces remain in theform of slight stains. Finally the surface is cleaned with a vacuum cleaner,clean dry compressed air or a clean brush. It shall then correspond in

appearance to the prints designated as Sa 2.

(iii) Grade Sa-3: This involves blast cleaning to pure metal surface. Mill scale, rustand foreign matter shall be removed completely. Finally the surface is cleanedwith a vacuum cleaner, clean dry compressed air or a clean brush. Then thesurface shall have a uniform metallic colour and correspond in appearance tothe print designated as Sa-3

41.2.2.2 For details of blast cleaning and shot blasting, referANNEXURE-F.

41.2.3 Flame cleaning

Flame cleaning shall also be carried out with the help of a special oxy-acetylene torchand the loosened mill scale shall be removed with a wire brush. This process is notrecommended for cleaning steel sheet or plates less than 6 mm in thickness as it maylead to buckling .The number of flame passes on such surface shall be limited tothree. The primer coat of paint shall be applied when the surface is still warm, afterremoving the scales with brushing and wiping.

41.3 Surface preparation shall be done as shown in the schedule of works given to thecontractor for price bid.

42.0 PAINTS AND PAINTING

42.1 For use of specific painting system, the paint manufacturer's specification shall prevail.

42.2 General compatibility between primer and finishing paints shall be established throughthe paint manufacturer supplying the paints.


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42.3 Before buying the paint in bulk, it is recommended to obtain sample of paint andestablish "Control Area of Painting". On control area surface preparation and paintingshall be carried out in the presence of manufacturer of paint.

42.4 In order to ensure that the supplied paint meets the stipulation in design drawing/specification, if required, samples of paint shall be tested in laboratories to establishquality of paint with respect to (i) Viscosity (ii) adhesion/ bond of paint in steel surfaces(iii) adhesion/simulated salt spray test (iv) chemical analysis (percentage of solids byweight) (v) normal wear resistance as encountered during handling & erection(vi) resistance against exposure to acid fumes etc.

42.5 Whole quantity of paint for a particular system of paint shall be obtained from thesame manufacturer.

42.6 Thinners, wherever used, shall be as per recommendation of the paint manufacturer.

42.7 Areas which become inaccessible after assembly of structures shall be painted beforeassembly, after cleaning the surfaces as specified.

42.8 Wherever shop primer painting is scratched, abraded or damaged, the surfaces shallbe thoroughly cleaned using emery paper and power driven wire brush whereverwarranted, and touched up with corresponding primer. Touching up paint shall be

matched and blended to eliminate conspicuous marks.

42.9 If more than 50% of the painted surface of an item requires repair, the entire item shallbe mechanically cleaned and new primer coats shall be applied followed by finishingcoats as per painting specification.

All field welded areas on shop painted item shall be mechanically cleaned (includingthe weld area proper, adjacent areas contaminated by weld spatter or fumes andareas where existing primer. intermediate / finishing paint is burnt). Subsequently, newprimer and finishing coats of paint shall be applied as per painting specification.

42.10 Application of paint shall be by spraying or brushing as per IS:487-1997 and inuniform layers of 50% overlapping strokes. Painting shall not be done when the

temperature is less than 5C or relative humidity more than 85%, unlessmanufacturer's recommendations permit. Also painting shall not be done in frosty orfoggy weather. During application, paint agitation must be provided wherever suchagitation is recommended by the manufacturer.


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42.11 Paint shall be applied at manufacturer's recommended rates. The number of coatsshall be such that the minimum dry film thickness (DFT) specified is achieved. The dryfilm thickness of painted surfaces shall be checked with ELCOMETER or measuringgauges to ensure application of specified DFT.

42.12 All structures shall receive appropriate number of primer and finishing coats in order toachieve overall DFT as per design drawings/ specifications. First coat of primer paintshall be applied not later than 2-3 hours after preparation of surface, unless specifiedotherwise.

42.13 The finishing paint as specified shall be of approved colour and quality. The under

coat shall have different tint to distinguish the same from the finishing coat.

42.14 Edges, corners, crevices, depressions, joints and welds shall receive special attentionto ensure that they receive painting coats of the required thickness.

42.15 Machine-finished surface shall be coated with white lead and tallow before shipmentor before being put into the open air.

42.16 Parts of surfaces embedded in concrete shall be thoroughly cleaned of grease, rust,mill scale etc. and shall be given a protective coat of portland cement slurryimmediately after fabrication. No paint shall be applied on this part.

42.17 Zinc-rich primer paints, which have been exposed several months before finishingcoat is applied, shall be washed down thoroughly to remove soluble zinc salt deposits.In similar circumstances, the surfaces of paint based on epoxy resin should beabraded or lightly blast cleaned to ensure adhesion of next coat.

42.18 Surfaces which cannot be painted but require protection shall be given a coat of rustinhibitive grease according to IS: 958-2000 or equivalent international standard.

43.0 PAINTING SYSTEM

The recommended painting system for general service requirement of steel structurescovering surface preparation, application of primer coats, intermediate coats and finalcoats to develop the required minimum dry film thickness on steel surface is indicatedinANNEXURE-E.


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ANNEXURE-A

Permissible deviations in pitch and gauge of holes for bolts of normal accuracy (highstrength bolts included)

DescriptionHole

diameter(mm)

PermissibleDeviations inSpacing (mm)

Permissible deviations in eachgroup of holes

1 2 3

Carbon Steel

4

LowAlloyed Steel

5

a) Deviationin the holediameter

Upto 17.0Above 17.0

+1+1.5

No limits

b) Ovality(differencebetween thebiggest and thesmallestdiameter)

Upto 17.0;Above 17.0;

+1+1.5

No limits

c) Curves,

exceeding 1mmand cracks onthe hole edges

_ _ NotPermissible

d)

(i) Non-coincidenceof holes inseparate detailsof theassembled unit,upto 1mm

_ _ Upto 50% Upto 50%

(ii) Above 1 mmupto 1.5 mm

_ _ Upto 10%Upto 10%

e) Slope of axis _Upto 30% of thethickness of unit

No limits No limits


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ANNEXURE B

TOLERANCE OF ASSEMBLED COMPONENTS OF STRUCTURES

Description of Deviation () in mm for the Elements of Structures Components of Length inMetres

StructuresUpto1

1to5

5to10

10to15

15to20

20to25

Over25

1 2 3 4 5 6 7 8I.

i) Deviations from the dimensionsassembled. Length & width of theDetails Cut :

a) Manual gas Cutting asper marking

3 3.5 4 4.5 5 - -

b) With shears or with a saw as permarking

2 2.5 3 3.5 4 - -

c) With shears or with a saw with astop 1.5 2 2.5 3 3.5 - -

d) Machine Gas Cutting 2 2.5 3 3.5 4 - -

ii) Length and width of planed endsprocessed on Edge Planing Machine

1 1.5 2 2.5 3 - -

IIi) Distance between the Centres of the

End holes.

a) Drilled according to marking 2 2.5 3 3.5 4 - -

b) Drilled according to a gauge with

bushing1 1.5 2 2.5 3 - -

ii)Distance between the centres ofadjacent holes

a) Drilled according to marking or toa gauge

1.5 - - - - - -

b) Drilled according to a gauge withbushings

0.5 - - - - - -


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III. Deviation in the dimensions ofdespatch elements after completionof fabrication, Assembled inpositioners or in other Devices withclamps in fixed positioners and also

a) According to guide blocks withpins.

2 3 5 7 8 9 10

b) Assembled with bolts 3 5 8 11 12 14 15

c) Size (length & width) betweenMilled surface (for all cases of

assembly)

1 1.5 2 2.5 3 3.5 4

d) The same made in separatedetails during machining & fixedduring the assembling work withclamps

2 3 5 7 8 9 10

e) The same drilled according topositioners in finished structures

1 1.5 2 2.5 3 3.5 4


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ANNEXURE D

TOLERANCES IN ERECTED STEEL STRUCTURES

SlNo.

DescriptionTolerance (mm)

A. COLUMNS

1.Deviation of column axes at foundationtop level with respect to true axes.

i) In Longitudinal direction

5ii) In Lateral direction 5

2.Deviation in the level of bearing surfaceof columns at foundation top with respectto true level

5

3.Out of plumbness (vert.) of column axisfrom true vertical axis and measured atcolumn top :

a) For columns without any specialrequirements :

i) Upto and including 30m H/1000 or 25mm height whichever is lessii) Over 30 m height H/1200 or 35mm maximum

b) For column with special requirementslike cranes or such similarrequirements :

i) Upto and including 30m H/1000 or 20mm height whichever is less

ii) Over 30 m height H/1500 or 25mm maximum

4.Deviation in straightness in longitudinal& transverse planes of columns, at anypoint along the height

H/1000 or 10mmwhichever is less

5.

Difference in the erected position of

adjacent pairs of columns along lengthor across width of building, prior toconnecting trusses / beams, withrespect to true distance.

5

6.Deviation in any bearing or seating levelwith respect to true level.

5


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7.

Difference in bearing levels of a memberon adjacent pair of columns both acrossand along the building, from the truedifference.

5

NOTE: i) Tolerance specified under 3(a) and 3(b) should be read in conjunction with 4 and 5.

ii) "H" above is the column height in mm.

B. TRUSSES

1.

Shift, at the centre of top chord memberof truss with respect to the centre ofspan or vertical plane passing throughthe centre of bottom chord.

1/250 of height span in mm or 15 mm whichever is less

2.

Lateral shift of top chord at the centreof truss span from the verticalplane passing through the centre ofsupports of the truss.

1/1500 of span of truss in mm or 10 mmwhichever is less

3.Lateral shift in location of truss from itstrue vertical position. 10

4.Lateral shift in location of purlins fromtrue position.

5

5.Deviation in difference of bearing levelsof trusses or beam from the true(L =span) difference.

L/1200 or 20 mm whichever is less

NOTES:-

1. The tolerances specified do not apply to steel structures where deviations from truepositions are intimately linked with or directly influence the technological process. In such

cases, the tolerances on erected steel structures shall be as per recommendations ofprocess technologists / equipment suppliers.

2. The observed or calculated values of deviations of steel structures from their true positionsshall be rounded off in accordance with IS:2-1960 for comparison with permissible tolerancesspecified in this table. The number of significant places retained in the rounded-off valueshould be same as that specified in this table.


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ANNEXURE - E

PAINTING SYSTEM

Surface preparation: Sa 2 according to Swedish Standard SIS 055900

1 First Coat (Primer) : Epoxy Zinc phosphate 50 microns DFT

2 Second Coat (Intermediate) :Epoxy polymide micaceous iron oxide 75 microns

DFT

3 Third Coat (Finishing) :High Build Epoxy polymer90 microns DFT

4 Fourth Coat (Finishing) :Epoxy polyurethene35 microns DFT

Total Thickness : 250 Microns

Painting system conforming to IS: 2932-2003


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ANNEXURE-F

SPECIFICATION FOR SURFACE PREPARATION WITH BLAST CLEANING/SHOTBLASTING

1.0 General

1.1 As adhesion of the paint to surface depends on the degree of cleanliness of the metalsurface, surface preparation shall be done by Air blast cleaning to achieve maximumdurability.

1.2 Mill scale, rust, rust scale and foreign matter shall be removed fully to ensure that aclean and dry surface is obtained. The minimum acceptable standard of preparedsurface shall be SSPC SP-10 or Sa 2 as per Swedish Standard SIS-055900-1967.

Remove all other contaminants, oil, grease etc. by use of an aromatic solvent prior tosurface cleaning.

1.3 Blast cleaning shall not be performed where dust can contaminate surfaces undergoingsuch cleaning or during humid weather conditions having humidity exceeding 85%.

1.4 With in 4 hours of surface preparation, the first coat of primer must be applied on dry

surface. However, at times of unfavorable weather conditions, the Engineer-in-Chargeshall have the liberty to control the time period, at his sole discretion and/or to insist onre-cleaning, as may be required, before primer application is taken up. In general,during unfavorable weather conditions, blasting and painting shall be avoided as far aspracticable.

2.0 Procedure of Surface Preparation

2.1 Ai r Blast Cleaning

2.1.1 The blast cleaning of the surfaces shall be done using abrasive media like Al203

particles, copper slag, or other standard media at a pressure of 7 kg/cm2 at appropriatedistance and angle depending on nozzle size maintaining constant velocity andpressure.

2.1.2 Compressed air shall be free from moisture and oil. The blasting nozzles should beventuri style with tungsten carbide or boron carbide as the materials for liners. Nozzlesorifice may vary from 3/16" to ".


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2.1.3 On completion of blasting operation, the blasted surface shall be clean and free fromany scale or rust and must show a gray white metallic lusture. Primer shall be appliedwithin 4 hours of surface preparation.

2.1.4 Blast cleaning shall not be done outdoors in bad weather without adequate protection orwhen there is dew on the metal which is to be cleaned. Surface profile shall be uniformto provide good key to the paint adhesion (i.e. 35 to 50 micron). If possible vacuumcollector, shall be installed for collecting the abrasives and recycling.


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ANNEXURE - G

MATERIAL OF CONSTRUCTION (AS APPLICABLE)

1. Unless otherwise specified in the drawing:

a) All rolled sections and plates shall conform to Grade-A as per IS: 2062-2006.

b) Plated structures subjected to dynamic loading shall conform to Grade-B as per IS:2062-2006.

c) High strength micro-alloyed steel shall conform to SAIL-MA 350 HYA/HYB (SAILproduct).

2. Steel sheets shall conform to IS: 1079-1994.

3. Steel tubes for structural purposes shall conform to IS: 1161-1998 (Grade YST-240).

4. a) Colour Coated Sheets (Refer Section-3)

b) Translucent Sheets (FRP) of thickness 2mm at specific locations to match with thecolour coated troughed sheet and shall conform to IS:12866-1989(FRP)

5. Gutters and down comers shall be of copper bearing steel conforming to IS: 2062-2006.

6. Crane rails shall conform to IS: 3443-1980.

7. Glazing shall be 6 mm thick rough cast wired glass as per IS: 3548-1988.

8. All black hexagonal bolts, nuts and locknuts shall conform to IS: 1363-2002 and IS:1364-2002 (for precision and semi- precision hexagonal bolts). Washers shall conform toIS: 2016-1967.

9. All HSFG bolts shall conform to IS: 3757-1985.

10 Covered electrodes for arc welding shall conform to IS: 814- 2004. Coding of electrodesshall be as follows: -

a) ER 421 'C' x for mild steel of Grade A and Grade-B as per IS: 2062-2006.


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b) EB 542 'C' x H3X for

i) Mild Steel of Grade B as per IS: 2062-2006 for dynamically loaded structures (arisingout of crane, vibratory screen, equipment etc.)

ii) For SAIL-MA micro alloyed steel 350 HYA/HYB.

iii) When combined thickness (CT) for steel conforming to IS: 2062-2006 exceeds40mm as per Fig.1

"C"is the value of current as recommended by the electrode manufacturer.


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ANNEXURE-H

LIST OF RECOMMENDED MAKES/MANUFACTURERS

General: The makes and manufactures shall be preferably from the following list. In case someof the items not available in the market or some of the particular products are not producing bythe following manufacturer or incase of change in trade name etc. equivalent makes orredesignated product shall be used conforming to the specific IS codes with the prior approvalof purchaser/consultant.

In case of some items not covered in this list like fasteners, fixtures etc. may be procured form

the market conforming to IS codes with test certificates and prior approval from thepurchaser/consultant.

Sl.No. Item Manufacturer

1 Structural Steel SAIL,RINL,TISCO,JINDAL,ESSAR

2 Electrodes ADOR (Advani orlikon), D & H, ESAB

3 PaintBERGER, SHALIMAR, AKZO-NOBEL, SIGMA Coating,

ASIAN.

4 Colour coated sheet

Japan metal building system,Interarch building products,Tata Blue scope,Lloyd Insulation (I) Ltd.Colour Roof India,CRIL colour roof India,G.K.Roofing India (P) Ltd.

5 FRP GratingERCON CompositesSANGIR Plastics

Associated Engineering Corporation

6 CGI Sheet SAIL, JINDAL

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