federal electricity & water authority water directorate

WAM

Client: FEDERAL ELECTRICITY AND WATER AUTHORITY (FEWA) Project: STANDARD SPECIFICATIONS FOR WATER WORKS

Engineer WATER DIRECTORATE - ASSET MANAGEMENT DEPARTMENT

Title: Technical Terms / Chapter-4 / Engineering Specifications / Civil Engineering Works Specification

CS09-STRUCTURAL STEEL/CLADDING WORKS

Office:

DUBAI Order:

Document: MWA_PRO_07/WAM-04-CS09 Rev: OCT/2014 sheet: 1 of: 33

Federal Electricity & Water Authority

Water Directorate

Asset Management Department

STANDARD SPECIFICATIONS

FOR WATER WORKS

TECHNICAL TERMS

Chapter – 4

Engineering Specifications

[C-Civil Engineering Works Specifications]

CS09-Structural Steel/Cladding Works

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Office: DUBAI Order: Document: MWA_PRO_07/WAM-04-CS09 Rev: OCT/2014 sheet: 2 of: 33


TABLE OF CONTENT

1. GENERAL

2. STANDARDS AND CODES 3. MATERIALS

3.1 Plates and Sections 3.2 Bolts, Nuts and Washers 4. DESIGN 5. SUBSTITUTION 6. ANCILLARY STEELWORK 7. Expansion Joints 8. Electrodes 8.1 Mild Steel and Medium Tensile Steel Electrodes 9. TESTS

9.1 Tests of Material 9.2 Tests and Controls During Fabrication 9.3 Tests and Controls After Erection 9.4 Quality Assurance

10. WORKMANSHIP 11. SHOP FABRICATION

11.1 Fabrication Tolerances 12. DELIVERY AND HANDLING 13. CONSTRUCTION

13.1 Marking 13.2 Cutting 13.3 Fitted Stiffeners 13.4 Smithing and Bending 13.5 Assembly of Trusses and Girders 13.6 End Clearance of Beams 13.7 Nuts, Bolts and Washers 13.8 High Strength Friction Grip Bolts 13.9 Holes for Bolts 13.10 Welding 13.10.1 General Welding 13.10.2 Welds 13.10.3 Quality of Welds 13.10.4 Quality of Welders 13.10.5 Site Welding 13.10.6 Welding Filler Materials 13.10.7 Weld Joint Preparation 13.10.8 Joint Back-Up Requirement 13.10.9 Pre-Heat Requirements 13.10.10 Weld Contour and Finish 13.10.11 Post Weld Heat Treatment 13.10.12 General Welding Inspection 13.10.13 Non-Destructive Testing (N.D.T.) Requirements 13.10.14 Charpy Impact Testing

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13.10.15 Welding Repairs

14. ERECTION 14.1 General Procedure 14.2 Connections 14.3 Base Plates 14.4 Platforms, Gallaries and Stairways

15. SUBMISSION OF SAMPLES AND TEST CERTIFICATE 16. PROTECTIVE COATING 16.1 General 16.2 Coating Materials 16.3 Application of Paint 16.4 Paints to be used 16.4.1 Surface Preparation for Ordinary Steel 16.4.2 Structural Steel

16.4.3 Galvanized Steel 16.4.4 Steel to be Embedded in Concrete 16.4.5 Steel to Receive Intumescent Paint 16.4.6 Galvanizing

17. QUALITY 17.1 Protection of the joints

18. PREFORMED ROOF PANELS AND WALL CLADDING PANELS SYSTEM 18.1 Description of Work

18.2 Quality Assurance 18.3 Panel Performance Testing 18.4 Warranties 18.5 Wall Cladding and Roof Decking Panel Design 18.6 Material and Finishes 18.7 Fabrication 18.8 Inspection 18.9 Installation

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1. GENERAL This specification covers the supply, fabrication, delivery, erection and preparation for painting of structural steel work. The Contractor shall adhere to sound design and construction practices with regard to codes and material specifications in order to warrant operational safety and ease of maintenance of plants as well as simplicity of control and stability in operation. The Contractor shall design and furnish all labour, services, tools equipment, materials necessary for and incidental to carry out all the works required for the supply and construction of the steel structure system in accordance with Drawings and Specification detailed hereinafter.

The structural steel works are to be carried out by an experienced and specialized Sub-Contractor

approved by FEWA/Engineer. The system of the structural steel shall satisfy all the structural and architectural requirements of the

project.

2. STANDARDS AND CODES

BS 4-1 Structural steel sections. Specification for hot-rolled sections BS EN 10034 Structural steel I and H sections. Tolerances on shape and

dimensions BS EN 10250-2 Open steel die forgings for general engineering purposes.

Non-alloy quality and special steels BS 449 The use of structural steel in buildings BS EN 1993-1-3-8 Design of steel structures. General rules. Supplementary rules

for cold-formed members and sheeting . Design of joints. BS 499 Welding and cutting of metals BS EN ISO 9018 Destructive tests on welds in metallic materials. Tensile test

on cruciform and lapped joints BS EN ISO 1461 Hot dip galvanized coatings on fabricated iron and steel

articles. Specifications and test methods BS PD 970 Wrought steels for mechanical and allied engineering

purposes. Requirements for carbon, carbon manganese and alloy hot worked or cold finished steels

BS 1449 1-1 Steel plate, sheet and strip BS EN 1435 Non-destructive examination of welds. Radiographic

examination of welded joints BS 2853 Design and testing of steel overhead runway beams BS EN 10143 Continuously hot-dip coated steel sheet and strip. Tolerances

on dimensions and shape BS EN 10162 Cold rolled steel sections. Technical delivery conditions.

Dimensional and cross-sectional tolerances BS EN 10293 Steel castings for general engineering uses BS 3692 ISO metric precision hexagon bolts, screws and nuts BS 3923 Methods of ultrasonic examination of welds

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BS 4190 ISO metric black hexagon bolts, screws and nuts BS EN ISO 8503-3 Preparation of steel substrates before application of paints BS 4320 Metal washers for general engineering purposes BS 7668 Weldable structural steels. BS EN 14399 High-strength structural bolting assemblies for preloading.

System HV. Hexagon fit bolt and nut assemblies BS 4592 Industrial open type metal flooring and stair treads BS EN ISO 15614-1 Specification and qualification of welding procedures for

metallic materials. Welding procedure test. BS EN 287-1 Qualification test of welders. Fusion welding. Steels BS 4921 Standardized coatings on iron and steel articles BS EN 1011-2 Welding. Recommendations for welding of metallic materials.

Arc welding of ferritic steels BS 5493 Protective coating of iron and steel structures BS EN 10296-1 Welded circular steel tubes for mechanical and general

engineering purposes. Technical delivery conditions. Non-alloy and alloy steel tubes.

BS EN 571-1 Non-destructive testing. Penetrant testing. General principles BS EN 1991-1-4 Actions on structures. General actions. Wind actions BS EN 1991-1-1 Actions on structures. General actions. Densities, self-weight,

imposed loads for buildings BS 7079 Preparation of Steel Substrates before application of paints

and related products. BS EN 287-1 Approval testing of welders for fusion welding - Steels. BS EN ISO 15614-1 Specification & qualification of welding procedures for metallic

materials. Welding procedure test. Arc and gas welding of steels

BS EN ISO 2560 Welding consumables. Covered electrodes for manual metal arc welding of non-alloy and fine grain steels.

BS EN ISO 17637 Non-destructive testing of welds. Visual testing of fusion-welded joints

BS EN 571-1 Non-destructive Testing BS EN 10025 Hot rolled products of non alloy structural steels. BS EN 10095 Specification for Stainless and Heat Resisting Steel Plate,

Sheet and Strip (Supersedes BS 1449 Part 2). BS EN 10164 Steel products with improved deformation properties

perpendicular to the surface of the product. BS EN ISO 12944 Code of Practice for Protection of Iron and Steel Structures

from Corrosion. BS EN 22553 Welded, brazed and soldered joints. Symbolic representation

on drawings. BS 4620 Specification for rivets for general engineering purposes BS 2SP 151-153 Specification for Unified alloy steel washers BS 4872-1 Specification for approval testing of welders when welding

procedure approval is not required. Fusion welding of steel BS EN ISO 9934-1 Non-destructive testing. Magnetic particle testing. General

Principles The standards shall include all latest amendments and revisions.

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3. MATERIALS

The Contractor shall supply FEWA/Engineer with the relevant manufacturer’s certificate for every load or batch of structural steel sections delivered to the Site. The certificate shall state the process of manufacture and a test sheet giving mechanical test results on the steel and chemical composition of the steel. As per Mill Test Certificates, the heat numbers of the structural members shall be traceable. Each certificate shall be signed by the manufacturer. The Contractor shall also submit to FEWA/Engineer for testing, whenever required and at the Contractor’s expense, samples of all structural steel sections and materials for use in connection therewith. The quality of the samples so provided shall be representative of the sections of materials being used and shall be chosen at random by FEWA/Engineer. All materials shall be free of seams, cracks, flaws, laminations, injuries and other defects of any kind. FEWA reserves the right to inspect any or all stages of manufacturer and subsequent fabrication of all structural steel, of structural steel sections or frame works destined for incorporation in the works and may reject any steel or sections or frameworks, that do not conform to the stated standards, at any time, and any material proving defective shall be rejected irrespective of any previous certification or acceptance. The Contractor shall notify FEWA/Engineer at least four weeks in advance of the manufacture of any structural steel for use in the works. 3.1 Plates and Sections Plates and Sections - the dimensions of rolled steel sections shall comply with BS 4, Part 1. The dimensional tolerances for plate shall be as referenced in clause 2.2 of BS EN 10025. Plates with a thickness greater than 25 mm shall be through thickness tested to BS EN 10164. Impact tests are required and shall be in accordance with clause 7.4.2 of BS EN 10025. The maximum test temperature shall be 20 degrees Centigrade. These requirements shall be specified in the material order.

Structural steel plates, sections and bars shall comply with the requirements of BS BS 7668, mild

steel grade 43A and high yield grade 50A, with regards to manufacture, chemical composition, quality, rolling margins, weight, test requirements and marking.

The structural steel plates, sections and bars shall be steel grade complying with BS EN 10162.

High yield stress steel in welded steel work shall comply with BS 7668. Floor plates shall be non-skid mild steel plates with raised pattern (not diamond), shall be minimum

of 10 mm thick and shall be adequately supported. Open steel flooring and stair treads shall comply with BS 4592 and shall be of the square grid type. Dimensions and properties of cold formed steel sections, shall comply with the requirements of BS

EN10162 and all steel used for cold formed sections shall comply with BS 1449 and shall have a yield stress of not less than 500 N/mm2 unless otherwise specified.

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3.2 Bolts, Nuts and Washers All bolts, nuts and washers shall be galvanised in accordance with BS EN ISO 1461.

- All bolts shall comply with the requirements of BS 4190 & 3692, normal series. - Metal washers for bolts shall be in accordance with BS 4320. High strength friction grip bolts shall comply with the requirements of BS EN 14399. Mild steel rivets shall comply with the requirements of BS 4620. The number of spare site bolts, nuts and washers to be supplied by the Contractor shall be: Net number of Nuts, Bolts and Washers Percentage of Spares to be Provided of each specified size required.

1 - 10 25 11 - 50 10 51 - 80 8 81 - 100 6 101 - 200 5 201 – 500 4 501 - 750 3 ½ 751 and over 3

In the case of high strength friction grip bolts, a sufficient number of additional spares over and above the percentage quoted above shall be provided to enable calibration tests to be carried out. 4. DESIGN

The design of all steel structures shall be carried out in accordance with BS 449 or BS BS EN 1993

and shall be submitted for approval prior to works commencement. Steel overhead runway beams shall be designed and tested in accordance with BS 2853. The design calculations should show but not limited to, constant loads, dead loads, superimposed loads, erection loads, thermal loads, wind loads, seismic loads, etc. When computer calculated results are presented, full details of the source programme shall be provided. 5. SUBSTITUTION

If it is found necessary to substitute alternative sections for any of the steel sections specified a written approval of FEWA/Engineer for the substitution with a detailed drawing showing the substitution shall be obtained before fabrication is put in hand.For all substitution cases, the Contractor shall prepare and submit supporting design calculation, test reports and all necessary documents for approval. 6. ANCILLARY STEELWORK

Gratings, Handrails, Sag Roads, etc. Gratings for flooring, stair tread and platforms shall be galvanised and painted as specified.Handrails shall consist of 1½ inch sch. 40 pipe and shall be supplied with all jointing materials, fixing bolts, nuts, washers, clips etc. Handrails standards and components other than bolts, nuts and washers shall be galvanised and painted as specified in Specifiaction for Painting. Bolts, nuts and washers shall be given protective

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coatings and painted as specified in Specification for Painting. Sag rods shall be made from steel to BS EN 10025 Grade S 275 JR or equivalent. The diameter shall be as specified on the drawings and the rods shall be threaded both ends for a length of 4 diameters and be supplied with two nuts and washers at each end.

Holdings down bolts shall be made from grade 4.6 steel to BS 4190 and shall be securely anchored in the foundations by washer plates or other methods specified on the drawings. Holdings down bolts and assemblies shall be dispatched to the site in advance of the main structural steelwork in order that they may be cast into the foundation. Steel forgings shall comply with the requirements of BS EN 10250-2. Steel castings shall comply with the requirements of BS EN 10293. Stainless steel shall comply with the requirements of BS PD 970 Part 1 or BS 1449 and the quality shall be either 302 S25 or 321 S20. 7. EXPANSION JOINTS

All sliding surfaces in steelwork expansion joints, where specified on the drawings, shall be separated by 1 mm thick Poly Tetra Fluoro Ethylene (P.T.F.E.) pads. These pads shall be fitted to reduce friction between contact surfaces and mechanical damage to the steelwork finishes at sliding joints.

8. ELECTRODES

8.1 Mild Steel and Medium Tensile Steel Electrodes Electrodes for use in the metal arc welding of mild steel and medium tensile steel shall be covered rods in accordance with BS EN ISO 2560 and be suitable for the work on which they are to be used. The types of electrodes to be used shall be selected by the Contractor in accordance with the requirements of BS EN ISO 2560 to suit the particular grade of steel to be welded and the required properties of the joint to be formed. The types of electrodes proposed shall be submitted to FEWA/Engineer for approval specifying the locations where each type of electrode is to be used. All electrodes shall be stored in accordance with the manufacturer's instructions and particular care shall be taken to ensure that such instructions are strictly adhered to when dealing with Hydrogen controlled electrodes, which shall be stored in special ovens, supplied by the Contractor.

9. TESTS

All galvanized structures shall be offered for inspection by FEWA/Engineer, before despatch for

erection. Post galvanisation testing and measurement of zinc deposit shall be as per BS. Nuts and bolts and small components are to be tested in accordance with BS EN ISO 1461 or equivalent.

FEWA/Engineer may select for test as many components to be weighted after pickling before and

after galvanizing as he may think necessary.

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9.1 Tests of Material

Structural steel shall be delivered with mill certificate. FEWA/Engineer may order tests to be carried out according to relevant standards.

9.2 Tests and Controls During Fabrication

Further to the tests and controls inserted in the here above mentioned B.S., but not limited to these, the following checking will be performed during execution by the Contractor:

- Conformity with the drawings - Dimensions of the junctions - Connections with HT - bolts - Aspect of the welded joints. The connections must be regular without bulges. The tolerances of

the convexity and concavity of the welds must be respected. The joints must be free from clefts, cracks, grooves or other irregularities. The joints will be checked by means of a liquid penetrant method, or by an electromagnetic procedure, or by an ultrasonic method or by RX to be imposed by FEWA/Engineer.

9.3 Tests and Controls After Erection

The tests and controls after erection will be made before application of the protective coatings. The tests are relative but not limited to :

- Control of the general dimensions of the structure (distance between columns, levels, ....) - Control of the plumbing, alignment and adjustment - Checking of the connections.

The Contractor shall be responsible for the accuracy of all setting out and construction

tolerances. These shall not be greater than the following:

Setting out 1 in 3000

Structural steel work

Position of first erected column 10mm

Linear Dimensions

Up to 8m 10mm

From 8 to 15 m 15mm

From 15 to 25 m 20mm

Over 25 m 25mm

Plumb of columns in 30m height 15mm

Level of base of first erected columns 5mm

Level of beam at junction with column

measured from transferred bench mark 15mm

Level of beam at junction with column measured from transferred bench mark

of story in which beam is located 10mm

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Levels of upper or lower surfaces of two

or more beams meeting at a column 6mm

Difference in level of ends of a beam

Up to 8 m long 5mm

From 8 to 15 m 10mm

9.4 Quality Assurance

Before the start of fabrication, supply FEWA/Engineer with mill test reports properly correlated to the materials and certified by the inspection agency. The onus for proving the properties of the material supplied rests with the Contractor.

10. WORKMANSHIP

The Contractor will be responsible for the design of all connections, the preparation of fabrication drawings for approval by FEWA/Engineer and the submission of as-built drawings as per specifications/terms of contract. The Contractor shall arrange for corresponding parts of each unit manufactured from the same drawing to be interchangeable as far as economic manufacturing conditions permit and shall advise FEWA/Engineer of the precise arrangements made in this respect. Two copies of all detailed working drawings, fabrication drawings and calculations prepared by or on behalf of the Contractor shall be submitted to FEWA/Engineer approval. The drawings shall include full details of and dimensions of all the various joints, connections and welds required to complete the work. Joints extra to those shown will not be allowed without permission. The shop drawings are to indicate clearly the types, dimensions, lengths and welding procedure of all welds. All joints shall be designed to resist the moments and forces specified on the contract drawings and where insufficient information is provided reference shall be made to FEWA/Engineer for clarification. The arrangement of the fixings at joints shall be designed to take into account the distribution of stress and any eccentricities arising from the disposition of welds or bolt groups relative to the axis of the member. The erection drawings, which shall be submitted for approval by the FEWA/Engineer shall indicate the identification marks to be painted on the steelwork and shall include a complete list of bolts showing the sizes, types and locations where they are to be used. The containers in which the bolts are delivered to site shall be marked to correspond with the bolt lists. FEWA/Engineer shall have access at all reasonable times to all places where the work is being carried out and shall be provided, by the Contractor, with all the necessary facilities for inspection during construction.

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11. SHOP FABRICATION

The fabrication and erection of the works shall generally be in accordance with BS EN 1993-1. The Contractor shall submit to FEWA/Engineer details of the workshops where he intends to have

the structural steel framework fabricated. FEWA/Engineer will not permit shop assembly or fabrication at workshops with insufficient or unsatisfactory facilities, nor will fabrication by unqualified or incompetent workmen or welders be permitted.

FEWA/Engineer reserves the right to be present during any or all fabrication of steel work destined

for incorporation in the works. Clearances, cutting, holding, assembly, bolting, welding, matching, marking and painting shall also

be carried out in accordance with the requirements of BS 449, Part (5) or equivalent standard.

Any fabricated units may be rejected on arrival at the Site should they not comply with the approved drawing or should they not be in accordance with the above mentioned standard in any respect. All connections shall have a minimum of 2 bolts per connections. The minimum thickness of gusset plates shall be 10 mm. Any other steel member shall have a minimum thickness of 6mm.

Surfaces which will be in contact after assembly shall be thoroughly cleaned and protected by approved paint before assembly. After assembly the steel shall be thoroughly descaled and painted with one priming coat of approved paint. The contact surfaces of friction bolt connections shall be left unpainted. Fabrication and assembly shall be done in the shop to the greatest extent possible. Structural steelwork surfaces to be site-welded shall be prepared in the shop and contact surfaces of friction-type high-strength bolted connections shall be surface treated e.g. by grit blasting or paint burning. All materials shall be clean and straight. Shearing, flame cutting and chipping shall be done carefully and accurately. Finished members shall be free from undue twists, bends warping distortion and other irregularities. Holes shall not be made nor enlarged by burning. Material shall be properly marked and match-marked where site assembly requires. Column and beam stiffeners shall be cut and fit to give full bearing over the cross section, connections shall be located as shown on the drawing. Care shall be taken to ensure that the specified clearances are adhered to. The erection clearance for cleated ends of members shall not be greater than 2 mm at each end. The erection clearance at the ends of beams without web cleats shall not be more than 3 mm at each end, but where for practical reasons this clearance has to be increased, the seating shall be suitably designed. Where black bolts are used the holes may be made not more than 2 mm greater than the diameter of the bolts up to 24 mm diameter, and not more than 3 mm greater than the diameter of the bolts over 24 mm diameter.

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Structural sections cut to "exact" lengths are to be accurately cold sawn or machined. Hot sawing or machine gas cutting will be permitted for the ends of beams and other parts not bearing compression. Hand cutting in lieu of machine gas cutting, where the latter is impracticable, may be used for the wall ends of beams, but is not to be otherwise employed without the FEWA/Engineer's approval. The cutting of slabs, notches in joints and perforations in plates etc., by gas cutting machines, will be permitted provided the edges are ground smooth, burrs removed and radii smoothly formed. Where the Contractor requires to make close butted joints they shall be indicated on the drawings and the abutting end of the parts shall be machined to ensure close contact when the joint is made. Close contact shall be deemed to have been achieved when 90 percent of the area is in close contact and the remaining 10 percent has clearance not exceeding 0.2 mm. Light structural sections, such as angles etc., may be cut by cropping provided the ends are dressed to a smooth finish, true to shape and free from burrs and jags.Where plates or flats are used as part of a build-up section with their edges exposed, such edges shall be true or planed true. Drilling of bolt holes shall be in accordance with BS EN 1993 Part I. Generally all the allowable tolerances shall be as per the relevant codes and standards. The Contractor shall make provision for the drilling of holes for bolting onto existing steel work on site. The size of holes will be as given on the drawings and will be formed by portable power tools which shall comply to the specified safety requirement. Due to the nature of the work the position of anchor bolts will vary according to the actual position of existing steel columns onto which permanent support brackets will be bolted. Therefore the Contractor must check the as-built position of anchor bolts before drilling anchor bolt holes in base plates. Holes through more than one thickness of material in built-up sections shall, where possible, be drilled after the members are assembled and tightly clamped or bolted together. Punching may be permitted before assembly, providing the holes are punched 2 mm less than the required diameter and reamed after assembly to the full diameter. The thickness of materials to be punched shall not exceed 15 mm. Holes in members built up by welding shall be drilled after welding has been completed.Holes which are drilled through two or more separable parts shall have all burrs removed after separating the parts. No holes shall be punched full size without FEWA/Engineer's approval. Matching holes for rivets and black bolts shall register with each other so that a gauge 2mm less in diameter than the hole will pass freely through the assembled members at right angles to such members.

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Holes for close tolerance and barrel bolts shall be drilled to a diameter equal to the nominal diameter of the shank or barrel subject to a tolerance of + 0.15 mm and - 0 mm. Parts to be connected with close tolerance or barrel bolts shall be firmly held together by tacking bolts or clamps and the holes drilled through all the thicknesses in one operation and subsequently reamed to size. All holes not drilled though all the thicknesses in one operation shall be drilled to a smaller size and reamed out after assembly. Where this is not practicable the parts shall be drilled and reamed separately through hard bushed steel jigs. Holes for countersunk bolts shall conform to the precise requirements of the countersunk bolt heads and the countersink shall be concentric with the shank hole. Holes in supporting steelwork for floor plates shall be drilled 3 mm over size. Bolt heads shall be dressed flush where necessary. Holes for rivets and bolts shall not be formed by gas cutting. Stanchion splices and butt joints of compression members dependent on contact for the transmission of compressive stresses, shall be accurately prepared to butt, by machining, so that the permitted stress in bearing is not exceeded nor eccentricity of loading created which would induce secondary bending in the members. Slab bases and slab caps, except where cut from material with true surfaces, shall be accurately machined over the bearing surface and shall be in effective contact with the end of the stanchion. A bearing face which is to be grouted direct to a foundation need not be machined if such face is true and parallel to the upper face. To facilitate grouting, check holes shall be provided where necessary in stanchion bases for the escape of air. Component parts shall be assembled in such a manner that they are neither twisted nor otherwise damaged, and shall be prepared so that the specified cambers, if any, are provided. Where camber to trusses is not indicated due allowance for a suitable camber should be made in setting out. All tubular members shall be sealed to prevent the ingress of moisture to the inside of the members. All bolts shall be provided with washers under the nuts and heads of bolts and washers shall be tapered or otherwise suitably shaped to give nuts and heads of bolts a satisfactory bearing. The threaded portion of each bolt shall project not less than 2 full threads through the nut after tightening. After erection the ends of the bolts shall be burred to prevent removal of the nuts. In all cases where the full bearing area of the bolt is to be developed, the bolt shall be provided with a washer of sufficient thickness under the nut to avoid any threaded portion of the bolt being within the thickness of the parts bolted together. Where a tubular member is drilled to take bolts or studs, provision shall be made to prevent the access of moisture to the interior of the tube. For example, a transverse sleeve has to be inserted where a bolt passes through a tube, or grommets have to be used under heads and nuts.

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Stiffening angles, or plates to brackets, flanges of joists etc. are to be accurately ground to fit the profile of the member stiffened. Small radius bends and forged parts are to be formed by methods which will not injure the metal, and are to be true to form and finished in a workmanlike manner. Burning-in welding, filling or plugging-up of defective work will not be permitted without the sanction of the FEWA/Engineer in writing. Each piece of steelwork shall be distinctly marked before delivery, in accordance with a marking diagram and shall bear such other marks as will facilitate erection. All markings shall be a minimum of 50 mm high in a contrasting colour.

11.1 Fabrication Tolerances

All steelwork shall be fabricated to the tolerances below.

- On length 3 mm

Twist and deviation from the required profile shall not exceed 1 in 1000. 12. DELIVERY AND HANDLING

The Contractor’s arrangements for packing, handling, transporting, storage and assembly of steel

work shall be subject to all times to the approval of FEWA/Engineer.

All loading, transporting, unloading, and erection work shall be carried out carefully and in such a way as to avoid damage to the steelwork.

Loose items shall be securely packed or bundled so as to prevent separation or damage in transit and bolts, nuts and washers shall be crated. Where possible cleats, fittings, internal braces and other similar items, which are contained within the outline of prefabricated units shall be assembled at the workshop before despatch. All large units shall have their reference marks clearly painted on both sides with stencilled figures and numbers not less than 75 mm high. 13. CONSTRUCTION

All work on Site in connection with the erection of steel work including storage, handling, setting

out, security during erection, painting after erection, bedding of bases and encasing and bearing of beams and girders shall comply with the requirements of BS 449 : Part 5 or other equivalent standard.

The Contractor shall provide on Site experienced steel erection supervisors, at all times when

erection of structural steel work is in progress. The Contractor shall furthermore employ only such steel erectors as are fully qualified and experienced for erection bolting up work.

All bolted Site connections shall be made with bolts as specified elsewhere in this Section. Any

bolt which in the opinion of FEWA/Engineer is sub-standard or has in any way become damaged or weakened, before during or after tightening shall be replaced with a new bolt nut and washers at the Contractor’s expense.

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Where holes are required in steel work for new connections, such holes shall be formed by drilling and in no case will burning of holes be permitted. Where a connection has to be made by high strength friction bolts, mating surfaces shall have the paint carefully removed by flame cleaning.

After the erection of the steel work has been completed and approved by FEWA/Engineer, the

steelwork shall be thoroughly cleaned and all shop primed surfaces damaged during transport or erection shall be made good with approved primer to the satisfaction of FEWA/Engineer. The steelwork shall then be painted as specified. No Site drilling of steelwork shall be permitted without the approval of FEWA/Engineer.

13.1 Marking Each loose part of the steelwork shall be marked to facilitate the erection at the Site, and the

material for each section of the building (roof trusses, roof girders, stanchions, etc.) shall bear a distinguishing prefix in order that all materials for each part can be readily identified. All erection marks shall be clearly painted on the steelwork in a contrasting colour.

13.2 Cutting Structural sections cut to exact lengths shall be accurately cold sawn or machined. The radius of re-entrant gas cuts shall be as large as possible and no over-cutting will be permitted.

Burrs left by the cold or hot saw shall be removed and gas cuts shall be dressed free from oxidized metal to a neat and workmanlike finish.

Light structural sections, such as angles, etc. may be cut by cropping, provided the ends are dressed to a workmanlike finish and true to shape.

13.3 Fitted Stiffeners Stiffening angles or plates to brackets, flanges of joints, etc. shall be accurately ground to fit the

profile of the member stiffened.

13.4 Smithing and Bending Small radius bends and forged parts shall be formed by methods, which will not injure the metal

and shall be true to form and finished in a workmanlike manner.

13.5 Assembly of Trusses and Girders The members shall be assembled as shown on the approved drawings and shall be adequately

secured by service bolts prior to bolting or welding.

13.6 End Clearance of Beams Except in special approved cases, beams without end cleats shall not have more than 1.5 mm

clearance at each end, but where end cleats occur, 1.5 mm end clearance will be permitted beyond the beam.

13.7 Nuts, Bolts and Washers Unless permitted otherwise, bolts shall have well formed heads, to be formed from the solid, and

nuts shall be dipped in boiled oil immediately after they are made. Nuts shall closely fit the bolts so that they can only just be turned by hand. Bolts shall show two clear threads through the nuts and shall have a minimum diameter of 10 mm. Bolts shall be sherardised to BS 4921 or galvanized to BS EN ISO 1461. Sheradised bolts shall be passivated and lanolin dipped for protection during shipment and until incorporated in the works.

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Where bolt heads bear upon bevelled surfaces, they shall be provided with square taper washers of 5mm thickness to afford a seating square with the axis of the bolt. Holding down or anchor bolts shall be provided where indicated on the drawings.

Special quality high strength friction grip bolts, nuts and washers shall comply generally with the

requirements of BS EN 14399. Plain and tapered washers, other than for high strength friction grip bolts, shall comply with the

requirements of BS 2SP 151-153 and BS 4320.

13.8 High Strength Friction Grip Bolts High strength friction grip bolts shall be used where required and shall comply with and be used in

accordance with the requirements of BS EN 14399. The bolts shall be of the load indicating washer type to the approval of FEWA/Engineer.

A high pressure liquid lubricant shall be used on the threads of the HSFG bolts to facilitate

tightening. The lubricant used shall be approved by FEWA/Engineer and this lubricant shall be compatible with the type of paint applied to the steelwork.

13.9 Holes for Bolts Holes shall be drilled accurately to template and burrs shall be removed from the edges of the

holes before assembly. The diameter of the holes for black bolts shall not exceed the size of the black bolt under the head by more than 1.5mm unless otherwise directed. Holes in purlins, side rails and gutter supports shall be punched full size. No other holes shall be punched.

The use of drift pins will only be allowed for bringing together the several parts of the structure and shall not be used in such a way as to distort the structure or enlarge the bolts holes.

13.10 Welding 13.10.1 General Welding

Structural welds are defined as welds that are necessary for the development of strength between adjoining pieces of structural steel work.

Unless otherwise approved, metal arc welding shall comply with BS EN 1011-2. Site welding will only be allowed in exceptional circumstances with the express permission of FEWA/Engineer. The general arrangement drawing of each item shall show weld locations and reference identification of the procedures to be employed.

All welding shall be carried out under cover in the fabricator’s shop and the layout and sequence of the operations shall be arranged to eliminate distortion and accidental stresses.

The welding procedures shall be submitted for approval to FEWA/Engineer before the start of

works. Welding tests will be performed by the welders, after approval of the welding procedures.

For structural welds, longitudinal weld seams shall be parallel to the longitudinal axis and shall be complete (100%) penetration butt welds. Longitudinal seams of adjoining rolled plates or pipes shall not be in line, but shall be offset from other longitudinal seams by at least five times the wall thickness of the plate of pipe. All structural fillet welds shall have a minimum leg length of 6 mm.

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All welds shall be continuous and full profile. Intermittent welding is not allowed.

Electrodes and fluxes shall be used in accordance with the manufacturer’s instructions. Unless otherwise described in the contract, all buttwelds shall be complete penetration welds made

between prepared fusion faces.

Back-up rings or strips, temporary and permanent types, when used, shall be made from material of the same chemical analysis as the base material.

In the fabrication of the built-up assemblies, all buttwelds in each component part shall be

completed, whenever possible, before final assembly. Where butt welds are to be ground flush, there shall be no loss of parent metal. The final grinding

shall be in the direction approved. Stud shear connections shall be welded in accordance with FEWA’s instructions or approved

drawings. In butt joints, the root edges or root faces shall not be cut off alignment by more than one eighth of

the thickness of the thinner material for materials up to 12 mm thick or by more than 1.5 mm for thicker materials.

All welded joint types shall require a written welding procedure specification (W.P.S) according to the requirements of the current edition of BS EN ISO 15614-1.

All ferritic welding quality procedures shall include hardness surveys. Downhand flat position welding is preferred. Vertical and overhead welding at site shall be avoided where possible. the Contractor shall show the applicable welding procedures and non-destructive testing on his shop drawings. The N.D.T.

13.10.2 Welds The size and length of every weld shall be as specified and as approved by FEWA/Engineer. The

arrangement of the runs in multi-run welds shall be such as to avoid formation of slag traps and to ensure adequate root penetration and correct shape of weld. If not otherwise specified, the sizes of electrodes and number of runs necessary to make a welded joint shall comply with the recommendations of the electrode manufacturer. The current setting used in making a weld shall be within the range recommended by the electrode manufacturer.

13.10.3 Quality of Welds

The deposited weld metal shall be free from cracks, imperfect fusion, lack of penetration, undercutting and be substantially free from porosity, slag inclusions and blow holes of such nature as would adversely affect the strength and ductibility of the welds.

13.10.4 Quality of Welders

The welders in charge of the structural welding must pass the quality welding tests performed on the same materials and under the same working procedures.

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Performance qualification shall be verified by the FEWA/Engineer for the type of material and processes to be used, prior to the start of fabrication. FEWA/Engineer reserves the right to require the testing or re-testing of any welder for qualification in accordance with BS EN 287-1. All costs and material required for qualification of welders shall be at the Contractor's expense.

The preparation, the thickness, etc. of the materials will be the same as for the work they have to

perform. FEWA/Engineer may accept a welder qualification if this has been obtained previously and

delivered by an official accepted organization. The delivery date of this document may not exceed a period longer than 6 months before start of

the works. All tests, agreements, deliveries, etc. will be at Contractor’s cost. The agreement complies with the requirements of the applicable standard e.g. BS 4872 or

approved equivalent.

13.10.5 Site Welding Welding on Site will not be permitted except in exceptional circumstances, when the extent of Site

welding shall only be as described in the approved drawings, considering the following:

a) All Site welding shall be carried out in the dry. When the weather is inclement, protective covers shall be put up to keep the work dry and the wind off the arc.

b) The source of the welding current shall be DC. c) Immediately prior to the commencement of Site welding the surfaces of the prepared

weld joint shall be free from all paint, grease and deleterious matter. d) The working platform, scaffold or cradle shall comply with all safety requirements at

all times. e) An efficient clamp shall be provided to the earth return. This shall be firmly affixed

to the steelwork. f) The electrode holder shall be provided with a cut-out switch or alternatively the lead

shall be fitted with plug and socket near the holder with the socket fitted the electrode holder cable. The plug must be suitably sheathed with insulating material to prevent accidental short circuiting. The plug socket and welding equipment shall comply with BS EN ISO 2560 and be weatherproof. The welding leads shall always be made dead when not in use.

g) A device for automatically ensuring low voltage on open circuit shall also be incorporated in the equipment.

h) All joints to be welded shall be truly aligned and levelled and be firmly held in position by temporary clamps or bolts.

13.10.6 Welding Filler Materials

All filler material shall be selected to match the mechanical and chemical requirements of the base materials to be joined, unless otherwise specified or agreed by FEWA/Engineer in writing. Filler metals for welding materials of differing strengths and toughness together, shall be required to develop only the same strength and toughness as the lower quality member.

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Tack welds shall be made with the same welding process and consumables that are used for root pass welding. Electrodes, filler wires, fluxes etc., must be readily identifiable and each type kept separate from all other types of different consumables. All consumables must be kept clean, dry and properly stored according to the manufacturer's recommendations. Consumables which may have become contaminated, or cannot be positively identified shall not be used. For submerged arc welding on ferritic materials a neutral (non-active) flux which does not increase the alloying content shall be used. For submerged arc welding, the filler wire shall not exceed 5.0 mm dia. and the heat input shall be restricted so as not to exceed 39,000 joules per centimeter (100,000 joules per inch).

13.10.7 Weld Joint Preparation Weld bevels may be made by machining, grinding, or flame-cutting and grinding. The joint surface shall be reasonably smooth and true. Materials that require pre-heat for welding shall be pre-heated in the same manner for flame-cutting, arc gouging and tack welding. Parts to be joined by fillet welds shall be brought together as closely as possible. The gap between facing surfaces of lap joints should not exceed 2 mm. If the separation is greater than 2 mm after straightening and assembly the leg of the fillet weld shall be increased by the amount of the separation but the increase shall not exceed 5 mm. The use of filler or packing pieces for excessive gaps is not permitted. Joint misalignment or excess root openings for single side welds, shall be corrected by applying weld build-up to the bevel face, as permitted and qualified by welding procedure. On oblique intersection tubular joints the build-up shall be applied to the minor member. The corrected root opening shall be capable of closure by a single pass of the approved electrode. Weaving techniques shall not be employed for closure of excessively wide root gaps. Arc gouging to widen tight grooves will be permitted only when followed by grinding to bright metal. All surfaces to be welded shall be free of paint, oil, dirt, scale, oxides, and all other foreign matter that may be detrimental to weld quality. Fit up lugs, strongbacks, cleats and other temporary welded attachment shall be removed by oxy-fuel gas cutting. The attachment shall cut above the surface of attached parts and the remaining weld and metal ground flush to the parent plate. All arc strikes, burrs, gouges, and other superficial surface damage shall be dressed smooth, flush or rounded 1 to 2 mm by grinding as instructed by FEWA/Engineer.

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13.10.8 Joint Back-Up Requirement

Permanent back-up rings or back-ups bars are permitted on all structural joints. When temporary back-up rings or back-ups bars are removed, the weld area shall be dressed and examined for cracks etc., using magnetic particle or dye penetrant examination. Cracks and other linear discontinuities shall be removed and the surface repaired.

13.10.9 Pre-Heat Requirements Pre-heat is not required unless recommended by BS EN 1011-2 .

13.10.10 Weld Contour and Finish Weld beads shall be properly contoured to permit complete fusion at the sides of the bevel, and to prevent slag entrapment.

Weld reinforcement shall be as required by the applicable code but in no case shall height exceed 3 mm. Welds which are to be examined by non-destructive testing techniques, shall be surface finished as required by the applicable codes and the examination technique concerned. Fillet weld size shall be maintained to the sizes specified on the shop drawings. Over welding of fillets must be avoided.

13.10.11 Post Weld Heat Treatment

Post weld heat treatment is not required for structural carbon steel joints in sections up to 38 mm in thickness. For structural carbon steel joints in sections greater than 38 mm in thickness the requirements of the applicable welding and structural codes shall apply (BS EN 1993/BS EN-10025). Where the design has 'Special' requirements for post weld heat treatment, these will be specified on the relevant drawings and in the Contract.

13.10.12 General Welding Inspection All completed welds shall be inspected and found acceptable by the Contractor according to BS EN ISO 17637. Linear discontinuities, surface porosity, undercutting, excessive weld reinforcement and other defects shall be removed to sound metal and repaired. Welds which are deposited using procedures differing from those properly qualified and approved shall be rejected and completely removed from the Works and replaced at the Contractor's expense. Cleanliness shall be maintained after completion of welding. All stub ends, rods, flux, slag and other foreign material shall be removed from the Works. The following non destructive testing shall be carried out unless instructed otherwise by FEWA/Engineer and written procedure shall be submitted for review and approval.

a) Ultra sonic testing on 100% of full butt welds in accordance with BS 3923. b) Dye penetration testing or magnetic particle testing on 20% of fillet welds, BS EN

571-1, BS EN ISO 9934-1.

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Unless permanent records are required, at the option of FEWA/Engineer any weld designated for radiographic examination may be examined ultrasonically instead and similarly evaluated. The Contractor shall submit for FEWA/Engineer 's review, an outline of the quality control procedures that will be enforced by the Contractor to ensure that only the approved welding procedures are used for all structural welding. The Contractor shall provide continuous inspection of the total fabrication, particularly of the welding.

13.10.13 Non-Destructive Testing (N.D.T.) Requirements

The Contractor shall submit for review the N.D.T. procedure, extent and acceptance criteria intended to be applied in establishing weldment integrity. FEWA/Engineer reserves the right to request additional N.D.T. at the Contractor's expense. Any weld which does not conform to this Specification, shall be replaced at the Contractor's expense.

13.10.14 Charpy Impact Testing

When required by the applicable material specification, Charpy V-Notch impact tests of the weld and heat-affected zone shall meet the minimum requirements specified for the base metal. When impact tested materials are used, then for both manual and automatic welding processes, impact test results shall be included in the welding procedure qualification.

13.10.15 Welding Repairs

Repair of general welding defects: Defects, except cracks, in weld deposits may be repaired without prior authorisation from the FEWA/Engineer. Removal of the defect may be by any method which produces a clean surface for installation of the repair weld deposit, except oxy-acetylene flame gouging. If arc-air gouging is employed, the resultant cavity shall be power disc ground or grit blasted to remove all traces of residual carbon and oxidation. Repair of cracked welds: The removal and repair of cracks in weld deposits or base metal shall be witnessed and approved by FEWA/Engineer. The crack shall be removed by grinding or arc-air gouging to sound metal (plus 50 mm of sound metal on each end of the crack) as determined by magnetic particle examination. If arc-air gouging is employed, the resultant cavity shall be power disc ground or grit blasted to remove all traces of residual carbon and oxidation. The entire weld joint shall be removed if, in the opinion FEWA/Engineer, the members cannot be properly inspected and repaired. Responsibility: Repair of all weld defects and faulty workmanship shall be in accordance with the approved procedures and at the Contractor's sole expense. The Contractor shall submit for FEWA/Engineer approval, a plan for corrective action to be taken for each specific instance of rejection of a major component.

14. ERECTION 14.1 General Procedure

Erection of structural steelwork shall be in accordance with the requirements of BS EN 1993. Erection shall be to the satisfaction of the FEWA/Engineer and to the requirements of the manufacturers.

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Steelwork which is to be stored prior to erection shall be stacked clear of the ground with packing between parts. The stacks shall be arranged so as to avoid the accumulation of dirt and water on the surfaces and if cover is provided it shall be ventilated to the satisfaction of FEWA/Engineer. All bolts, nuts and washers for any component shall be delivered to in a suitable container which shall be clearly marked on the outside with details of its contents and the location in the works in which the contents are to be used. Erection work shall be permitted only after foundation or other structure over which steel work is to be erected is accepted and is ready for erection. The Contractor shall satisfy himself about the level, alignment, etc. for the foundation well in advance, before starting the erection. Minor chipping etc. shall be done at no extra cost. All fabricated steel shall be true and in its designed location with members plumb and level. Steel base plates shall be welded, shimmed or supported at the required elevations, set level and true, provided during erection of steel as required for proper alignment and stability of the framing assembly. The bracing members shall be designed and placed to carry all superimposed loads that the structure may be subjected to while construction operations are underway. Any faulty erection carried out by the Contractor shall be made good at his own cost. Approval FEWA/Engineer at any stage of the work does not relieve the Contractor of any of his required guarantees of the Contract. During erection the works shall be securely bolted or otherwise fastened and, if necessary, temporarily braced so as to make adequate provision for all erection stresses and conditions including those due to erection equipment and its operation. Neither permanent bolting nor welding shall be done until proper alignment has been obtained. All stanchions are to be adequately braced until connections have been finally bolted up.

14.2 Connections In general all shop connections shall be welded unless otherwise instructed by FEWA/Engineer. Attention is drawn to the need with welded shop connections to consider the effect of the rigidity provided by welding on the stresses at the connection. In cleated end connection the cleats shall project 2 mm (nominal) beyond the end of the section unless full bearing is required when the end shall be machined. Load carrying connections shall be designed for a minimum load of 50 kN if welded, or if riveted or bolted shall have not less than two rivets or two bolts. All site connections shall be bolted, unless otherwise instructed by FEWA/Engineer. High strength friction grip or high tensile bolts in accordance with BS EN 14399, shall be used for all main site connections except that load indicating devices may be used instead of part turn or torque method.

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Main connections shall include main beam to beam, main beam to column, column splices, main bracing, crane brackets and all beams carrying equipment loads, except as noted on the drawings.

No paints or contaminants shall be allowed on the contact surfaces of High strength Friction Grip bolted joints. Only after the full permanent connections have been made and inspected shall the joint be protected in accordance with the specification. In general galvanised bolts shall be used for site connections of secondary beams, purlins, light bracing, ladders, stair stringers, handrailing and removable members except as noted on the drawings. Field connections employing high strength bolts shall be checked for ample clearance for operating an impact wrench. As a minimum all structural bolts shall be high-strength bolts, grade 8.8 to BS 3692. The computed length of all bolted bracings shall be reduced by 1/1000 to provide for draw. The minimum size of permanent connection bolts shall be 20 mm diameter, unless limited by the size of the connected parts or where changing out original bolts of smaller diameter on existing structures. Other exceptions are bolting of stair treads, ladder hoops, etc., when 12 mm diameter bolts are acceptable. Washers to BS 4320 parallel or tapered shall be provided under each nut. Drilling of holes on site will be necessary in certain circumstances where attachment have to be made to existing steel work. In these circumstances the portable drilling equipment used will require to be safety checked in accordance with the relevant clauses of the documents. The minimum size for anchor bolts shall be 20mm. Anchor bolts shall be galvanised in accordance with BS EN ISO 1461.

14.3 Base Plates

- All baseplates with lesser dimensions greater than 600 mm to be provided with grout check holes not less than 25 mm diameter at maximum 300mm centres.

- Grouting of pockets and under base plates shall be done only after the steel work has been levelled and plumbed.

- The top of foundations shall be cleaned free of dirt, loose particles, oil or grease, and shall be wetted thoroughly just prior to grouting. Grout contact surfaces shall be free from standing water and care shall be taken not to flood anchor bolt sleeves when wetting.

- The bearing surfaces of the baseplate shall be thoroughly cleaned. A strong well braced form shall be held tightly around the foundation and all joints shall be tight to prevent leakage. The form should be sufficiently high to create a fluid head which will help to force the grout completely under the base plate, in accordance with manufacturers technical data sheets. Top of grout shall be set at underside of baseplate elevation.

- Pre-packed bags of non-shrink grout material as specified on the drawings or the main specification shall be used.

- Approved mechanical mixer shall be used for mixing the grout. - Compressive Strength shall be 65 N/mm² at 28 days unless otherwise specified on the

drawings or in the main specification. - Concrete Adhesion (tensile strength of bond) for concrete 6 N/mm² at 28 days.

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Grout shall be placed by an applicable method (pouring, dry packing etc.). Trapped air shall be eliminated from anchor bolt wells and all other grout spaces.Forms shall not be removed until the grout has gained the appropriate set.

14.4 Platforms, Gallaries and Stairways

All platforms, galleries and stairways shall be provided with standards and double handrails on each side. Handrail heights, measured vertically between the top of handrails and the floor level or, in the case of a stairway, the pitch line, shall not be less than:

Top Rai Lower Rail Platforms & Stairways 1100 mm 550 mm

The base of standards shall be the flat or side palm type for use on platforms and the flat base type for steel stairways. Tubular or solid forged standards shall not be spaced at pitches greater than 2 metres. Standards shall not be fixed to toe plates. Handrails at the bottom of stairways where not fixed to a wall or standard shall be extended to form a loop between the top and bottom rails. There shall be no joints in these loops. Connections between the ends of handrails and walls or steel columns shall comprise flanged connections each having an internal dowel for fitting inside the handrail tube. The handrail end flange connection shall be drilled for two fixings when fittings to concrete or blockwork or where drilling of steelwork is permitted. Otherwise connection to steelwork shall be welded.

The handrail may be fitted to the spigot by any of the following methods :

(a) Welding. (b) Indentation. (c) Works plug welding and site riveted or countersunk socket screws. (d) Countersunk socket screws. (e) Joints may also comprise a screwed plug or nipple, fitted between internal threads in

the adjoining section or rail, or an internal dowel split to permit expansion by means of an externally operated adjusting screw.

All joints shall be designed to ensure that they do not fail before failure of the members they connect. Joints shall be filed or ground smooth unless a finishing treatment has been applied after manufacture. Where rails are fitted with ball type standards in straight runs, rails shall be secured to the standards by countersunk screws to prevent movement. No packing, shimming or welding will be permitted to correct imperfect work. Use of fittings up bolts and drift pin to bring improperly fabricated members and parts into place so as to cause a strain on bolts in finished work shall not be allowed. Drift pins shall not be driven with such force as to deform adjacent metal. All shop errors shall be reported and the proposed method of correction shall be submitted for approval.

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15. SUBMISSION OF SAMPLES AND TEST CERTIFICATE

As soon as possible after the contract has been awarded, the Contractor shall submit to FEWA a list of the suppliers from whom he proposes to purchase the materials necessary for the execution of the works. The Contractor shall deliver samples of materials for approval. Samples shall be taken in accordance with the relevant British Standards where applicable. Materials subsequently supplied shall conform with any specified tolerances for the quality of samples which have been approved.

The information regarding the names of the suppliers may be submitted at different times, as may

be convenient, but no sources of supply shall be changed without the prior approval of FEWA/Engineer. The Contractor shall submit to FEWA/Engineer test certificates furnished by the supplier or manufacturer of the material or article indicating compliance with the relevant codes and standards.

16. PROTECTIVE COATING

16.1 General The materials to be used in connection with the works shall be applied and used in strict

accordance with the Specifications or with printed directions of the manufacturer and those Specifications or printed directions shall be strictly adhered to. The manufacturer’s guarantee specifying the minimum life of the adopted paint system shall be supplied.

The painting shall be carried out by qualified painters. Properly qualified supervisors are to be

constantly on the job whilst the work is proceeding. All paints, enamels, water paints, distempers and varnishes shall be of first quality, without any

dilution, ready made in shades to be chosen by FEWA/Engineer and supplied directly from the maker’s workshop in their original containers.

Thinning may possibly be done immediately prior to application and only according to manufacturer’s instructions written on the containers and with the approval of FEWA/Engineer.

Throughout these Specifications the paint thickness is defined as the dry film thickness. Dry film thickness gauges must be calibrated on a surface representative of the surface profile to

be painted and not on smooth steel.

The surfaces of steelwork to be painted shall be prepared in the following manner:

Cleaning: steelwork shall be blast cleaned to remove all millscale and other contamination to BS 7079. The surface shall be cleaned to second quality standard.

Abrasive and Roughness: the abrasive used during blast cleaning shall be steel, malleable iron or chilled iron shot of a grading suitable to give a maximum surface amplitude of 100 microns.

Surface Defects: all surface defects likely to be detrimental to the protective system such as cracks, surface laminations and deep pitting, shall be removed in accordance with BS 7668.Fabrication surface defects such as fins at saw cuts and burrs shall be similarly removed.

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Surface Contamination: all dirt and debris shall be removed from surfaces after blasting, by vacuum cleaner, airline or brush. If residues are trapped in the paint the affected area shall be reblasted and recoated. Shop Connections: all shop weld areas and shop bolted or riveted connections shall be blast cleaned to the same standard as adjacent steel. All weld slag and spatter shall be removed. Maximum Interval Before Coating: blast cleaned surfaces shall be over coated within four hours of the start of cleaning, and the steel shall not be exposed out of doors during this period.

16.2 Coating Materials The colour codification will be according to the RAL Colour register 840 HR.The Contractor shall

submit to the approval of FEWA/Engineer, the name of the manufacturers of the paint and the paint system he proposes to use in the work.

Full data sheets will be supplied for all material, detailing at least the following information : brand

name, colour, recommended surface preparation, practical spreading rate, dry film thickness, wet film thickness, surface drying time, hard drying time, in function of temperature and humidity, recoatable time, minimum and maximum, recommended methods of application, recommended thinners and pot life.

Unless otherwise approved by FEWA, all the different paint, forming part of the system applied to a

particular surface, will be supplied by the same manufacturer. The Contractors shall not change the source of supply of any paint, or the formulation, without first

obtaining the approval of FEWA. Where appropriate, the Contractor shall certify that materials supplied are compatible with any fire

proofing treatment detailed in the Specifications.

16.3 Application of Paint The paint protective system to be adopted shall be as specified on the structural drawings.

Paint shall be applied :

- on thoroughly dry surfaces. Moisture content indicator based on resistivity shall be supplied by the Contractor.

- immediately after surface cleaning (at the latest 1 and half hours after cleaning for any outdoor work or indoor work after sand blasting and within 4 hours for other indoor works).

Paint shall not be applied : - during wet or foggy weather and sandstorms

- when condensation is likely to occur (steel surface temperature lower than 8C or when the

steel temperature is lower than 1C above dew point of ambiance); - until work likely to cause dust and dirt has been completed.

The Contractor shall supply the necessary instruments for measuring the temperature of the steel surface, the dry and wet bulb temperature.

All field finish coats shall be applied after erection except for surfaces inaccessible after erection.

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These shall be prime and finish coated before erection, cleaned and touched-up immediately after erection to insure a continuous film.

All painting shall be done in a neat, thorough and workmanlike manner. All coats shall be applied

so as to produce coating of uniform thickness, without wrinkling or lifting previous coats. Paint thickness specified in this document shall be taken as a minimum and shall fully comply with the manufacturer’s recommendations.

Paint shall be evenly spread and free from runs, visible laps and brush marks. All adjoining surfaces and material shall be protected and any paint spots removed without damage to other work.

Primer Painting : Contact surfaces of connections to be assembled with black bolts shall each receive immediately before being assembled one coat of inorganic zinc rich primer. Secondary Painting Preparation: Any contamination of the treated steelwork surface shall be removed before further protective coatings are applied. While spirit or naptha may be used to clean the steelwork followed by scrubbing with a 2% solution of Teepol and a thorough rinsing with clean water. Where the contamination (e.g. oil and grease) cannot be removed completely by white spirit or naptha a suitable solvent shall be obtained from the paint manufacturer and used, followed by scrubbing and washing as above. Where the surface has become dirty (as opposed to contaminated) or has been exposed in the open air for more than two days, it shall be scrubbed down with a 2% solution of Teepol and hosed with clean water. Inaccessible Areas: Areas of steel inaccessible after erection shall be treated during fabrication, so that they receive the full treatment specified. Drying and Overcoating Period: the maximum and minimum over coating period and drying periods before exposure to weather or to being transported shall be those stated by the paint Manufacturer/Supplier. Outside Storage Limit: Steelwork only protected by pre-fabrication primer shall not be stored outside for more than 21 days. Making Good: Any damaged areas of paint shall be cleaned and made good within 14 days to a standard equivalent to that of the adjacent paint work. If damage has exposed parent metal local re blasting may be required to prepare the steel for remedial painting. The maximum time lag between cleaning steel and applying primer shall not be more than two hours. Site connections shall be treated in the following manner : Standard of Protection: joints shall be painted with the specified materials to give the standard of protection achieved on adjacent steel. Strip coats shall be used, particularly to seal all edges of steel and gaps between adjacent steel surfaces.

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High Strength Friction Grip Bolted Connections: No paint or contaminants shall be allowed on the contact surfaces of high strength friction grip bolted joints. Only after the full permanent connections have been made and inspected shall the joint be protected in accordance with the specification. Site Welds: Site welds and adjacent areas shall be cleaned to remove all welding slag, spatter and flux residues by chipping, blast cleaning and washing, before painting commences. Cleaning of Jointing Bolts: Bolted joints shall be thoroughly cleaned to remove all oil and grease, before painting. Plated bolts and nuts shall be primed with an etch primer suitable for use on the particular type of surface.

Each paint coat must differ slightly from the preceding one in colour.

a) Primer coat shall be applied only by brushes. Spraying of primer may nevertheless be permitted if some parts cannot be reached

with brushes. b) To secure uniformity of each paint film coat, the surface shall be either cross

brushed or sprayed in two directions at right angles. c) Care shall be exercised during spraying to avoid excessive evaporation of the

volatile constituents, loss of material into the air, and bridging over the crevices and corners.

d) An extra primer coat shall be applied before general priming on all steel rivets, bolt heads, nuts, edges and corners, ridges, welds and the like.

e) Each finish coat shall be a complete coat. f) Miscellaneous and structural steel which have been painted shall not be handled,

worked on, or otherwise disturbed until the paint coat is completely set. Sufficient time but not longer than 5 days shall elapse between coats to permit them

to dry hard. All coats of painted surfaces shall be unscarred and completely integral at the time of application of all succeeding coats.

g) At time of application of any coat, all undercoats shall be freed of dust, grease or any foreign matter, which might affect inter-coat adhesion.

16.4 Paints to be used 16.4.1Surface Preparation for Ordinary Steel

- Grinding of surface irregularities such as scale, burrs, welding drops, etc. - Rust, loose paint and other impurities to be scraped to the bright metal. - Dust to be removed with soft brush. - Washing, when necessary, with white spirit followed by drying with cloth. - In general, the surface preparation shall correspond to grade SA2 1/2 (SIS) or second

quality to BS EN ISO 8503-3.

The procedure of surface cleaning and preparation and the and to obtain proper bond between water stops and concrete equipment will be proposed by the Contractor to FEWA. The Contractor is obliged to propose another acceptable procedure if the first does not comply with the requirements of these Specifications and this without price adjustment.

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16.4.2 Structural Steel The Contractor shall paint all structural steel surfaces.

- one coat of inorganic zinc silicate primer DFT 65 microns to be applied in fabrication shop; - one coat polyamid epoxy high build with micaceous iron oxide (M.I.O.) DFT 120 mircrons; - one coat polyurethane top coat DFT 60 microns.

16.4.3 Galvanized Steel The Contractor shall paint all galvanized steel surfaces.

- etch primer or touch-up of damaged part with anti-corrosive primer based on epoxy resins. - first coat of two components polyamide cured epoxy primer, DFT 50 microns. - second coat of two component high build polyamide cured recoatable epoxy paint, DFT

100 microns. - two coats of two component isocyamate cured acrylic finish, DFT 40 microns each coat.

16.4.4 Steel to be Embedded in Concrete - Hot dipped galvanized The minimum thickness to be applied shall be 85 microns.

16.4.5 Steel to Receive Intumescent Paint - first coat of two component zinc rich polyamide cured epoxy primer D.F.T. 50 microns

- epoxy based intumescent paint to manufacturer’s recommendations - top coat of two component polyamide cured epoxy, pigmented with micaceous iron ore

to manufacturer’s recommendations - The intumescent paint shall provide a 2H fire resistance to the structure. The product

shall be approved by FEWA. Surface preparation by blast cleaning is the minimum acceptable standard for all

paintworks unless other methods, such as flame cleaning, mechanical cleaning or acid pickling, are specifically proposed and accepted. The products resulting from blast cleaning or the abrasive shall not contaminate wet paint films or equipment in adjacent locations.

16.4.6 Galvanizing Attention shall be paid to the detail design of members in accordance with BS EN 1993 or BS EN ISO 1461.

Galvanizing shall be applied by the hot dip process and shall consist of a smooth clean zinc

coating, free from defects and of uniform thickness and shall present a bright clean surface with crystalline structure.

Adequate provision for filling, venting and draining shall be made for assemblies fabricated from hollow sections. Vent holes shall be suitably plugged after galvanising.

All materials to be galvanized are to be of the full dimensions shown or specified and all drilling,

punching, cutting, bending and welding of parts shall be completed and all burrs removed before galvanizing is applied.

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The preparation for galvanizing and galvanizing itself shall be done according to BS BS EN ISO

1461, BS EN 10143 and BS 5493 and shall not affect the mechanical properties of the coated material. The minimum thickness to be applied shall be 85 microns.

The minimum average coating weight shall be as specified in Table 1 of BS EN ISO 1461. Structural steel items shall be initially grit blasted to BS 7079, second quality (SA 2.5) and the minimum average coating weight on steel sections 5 mm thick and over shall be 915 g/m2.

Areas or structures in contact with oil shall not be galvanized.

- Zinc Quality Used zinc shall have 98.5% purity. It shall conform to :

type prime western (ASTM 56)

type Zn 98.5 (ISO/TC 18) Nuts and bolts and small components are to be tested in accordance with BS 792 or equivalent. FEWA may select for test as many components to be weighted after pickling before and after galvanizing as he may think necessary. On removal from the galvanising bath the resultant coating shall be smooth, continuous, free from gross surface imperfections such as barespots, lumps blisters and inclusions of flux, ash or dross. Bolts, nuts and washers shall be hot dip galvanised and subsequently centrifuged (according to BS EN ISO 1461). Nuts shall be tapped up to 0.4 mm oversize after galvanising and the threads oiled to permit the nuts to be finger turned on the bolt for the full depth of the nut. During off-loading and erection the use of nylon slings shall be employed. Galvanised workwhich is to stored in works or on site shall be stacked so as to provide adequate ventilation to all surfaces to avoid wet storage staining (white rust). Any areas of the galvanised coating damaged in any way shall be repaired by:

(1) Cleaning the area of any weld slag and thoroughly wire brushing to give a clean

surface. (2) The application of two coats of zinc-rich paint, or the application of a low melting point

zinc alloy repair rod or powder to the damaged area, which shall be heated to 300°C. After fixing, bolt heads and nuts shall receive two coats of zinc-rich paint. Connections between galvanised surfaces and copper, copper alloy or aluminium surfaces shall be protected by suitable tape wrappings to FEWA/Engineers's approval.

17. QUALITY 17.1 Protection of the joints

a) Non Friction - Grip Bolted Joints For all components coated to any extent during fabrication the contact surfaces shall be coated to

the same standard.

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Joint surfaces erected uncoated shall be hand or power tool brushed and coated with one coat of the appropriate primer. Just prior to making the joint, a further coat of primer shall be applied so that the joint surfaces are brought together while the paint is wet.

b) Welded Joints Primer spray shall be kept at least 15 mm clear of areas to be welded and these areas will be

masked off during spraying. Where paints other than blast primers are to be applied to the parent surfaces before the making

of a joint they shall be stepped back at 30 mm intervals commencing at 80 mm from welded joints. Before painting, all welds shall be cleaned to the same standard as originally specified and

dressed to a smooth contour. Weld scale and spatter will be removed by grinding or chipping. If the welding process leaves alkaline deposits these shall be washed from the weld area with

clean water. Unless otherwise specified, welds and surfaces, which have been affected by welding, shall

receive the protective system, which is applied to the parent surfaces.

18. PREFORMED ROOF PANELS AND WALL CLADDING PANELS SYSTEM 18.1 Description of Work

Steel faced ,pre-finished, factory injected with CFC-free polyisocyanurate fire retardant foam insulation composite roof panels with over lapping and integral vapour seals Metal trim, accessories, fasteners, and sealants and related to the roof panel system

18.2 Quality Assurance Products will establish the minimum level of quality and performance required

Manufacturer shall demonstrate a minimum of five years of experience in the specified products and application. No substitution will be considered unless otherwise approved by Authority in return. However such substitution shall match with the original in all respect including performance, colour, dimension etc.

18.3 Panel Performance Testing

The insulation foam of the panels Shall have the following properties when tested in accordance with the relevant standard:

1. Density-ISO 845 42 KG/M3 2 Compression strength-ISO844 c10=1.2kg/cm2 3. Modulus of compressibility-ISO844 37KG/CM2 4. Tensile strength-ISO 1926 2.8kg/cm2 5. Thermal conductivity-ISO 2581 0.019W/m2 Deg C 6. Flame resistance-ISO 3582 foam only-B2 rated 7. Water vapour transmission-ISO 1663 72G/M2(AT 38deg C,90%R.H)

The supplier shall demonstrate all properties when requested by the Authority. the panel external coating system shall have the following performance when tested in accordance with the relevant standard.

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1. Total coating thickness-ASTM D 4138-94 100 microns 2. Flexibility-ASTM D 968-93 1T No cracking 3. Abrasion-ASTM D 968-93 950 Ltrs minimum 4. Humidity-ASTM D 4585-97 No change at 1500 hours 5. Kesternich(SO2 test)- ASTM G 87-97 No change at 30 cycles 5. Salt fog-ASTM B117-97 Upto 0.4 mm creep from scribe at

at 1000 hrs The supplier shall demonstrate all properties when requested by the Authority. the panel external coating system shall have the following performance when tested in accordance with the relevant standard.

All performance testing shall be conducted in the presence of Authority through a third party.

18.4 Warranties

Supplier shall warrant for a period of ten year for the external coating system shall not suffer undue chalk and fade, shall not crack or delaminate and shall not allow corrosion of substrate forming the panel external skin

18.5 Wall Cladding and Roof Decking Panel Design

Wall cladding and roof decking panel units shall consist of factory manufactured units, produced on a continuous online injection facility with the bonding foam completely filling the space between panel skins. temperature control of the metal substrades, of the chemical dispensing area and of the online conveyor shall be mandatory to ensure uniformity of foam density and of foam to substrate adhesion.

Panels shall provide an effective cover width of 100mm and shall be manufactured in exact lengths to suit the structures and to minimize end jointing. panels shall have encapsulated side tapes to ensure maximum side-lap joint uniformity

Panels unit shall be minimum 50 mm thick or equal and approved. panels shall have interlocking joints with rubber seals to insure an air permeability less than 10 cu.m per hour/m2 at an applied pressure of 50 pa. 3D perspective fascia colour drawing from all 4 sides shall be submitted to Authority for approval

18.6 Material and Finishes

Panel exterior skin shall be ASTM A 653,Grade37/ aluminium, non-directionaly embossed in 1 mm thickness for roof decking and0.7 mm thickness for wall cladding.

Panel interior skin perforated shall be ASTM A 653,Grade37/ aluminium of at least 0.7 m thickness for roof decking and 0.5mm thickness for wall cladding generally flat perforated with shallow 3 mm plank profile.

Panel exterior finish to both sides of external skin shall be of the following in manufacturer's standard color for that finish.

Multi layer coating system consisting of:-

Prime coat: epoxy primer of nominal thickness 8 micron

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Base coat: two components polyamide cured and flexibilised epoxy of nominal thickness 70 microns or equal approved coating system which meets the performance criteria

External weather coat: polyurethane pigmented colour coat of nominal thickness 50 microns.)RAL 1001 shade for roof decking and projection of roof, RAL 1015 shade for wall cladding works or any approved shade approved by Authority

Panel interior finish shall be in a polyester coating in an off white colour

Rigid closed cell fire retardant CFC-free polysocyanurate foam core shall be poured in place to fill voids in the panel

18.7 Fabrication

Flashing and trims shall be the same material, finish and thickness as the exterior and/or interior of panels.

Panels and trim bundles shall be protected with water resistant paper and provided with wood collars to permit handling and stacking in the field

18.8 Inspection

Building tolerances on the panel support steel shall not exceed those defined by the panel manufacturer.

1. 9mm in any 6.00 metre length. 2. 18mm over any single roof plane

Alignment of the panel support system should be checked and defects corrected prior to

installing panels.

18.9 Installation Panel erector shall demonstrate at least five years of experience installing similar products and similar application. Panels, trim, accessories, and sealants shall be installed in accordance with approved shop drawing to ensure a functional and weather tight installation

Dry wipe –down of the exterior surface should be done as the panels are installed.

Almost care should be taken while designing the wall cladding and roof decking panels as to avoid accumulation of sand/dust and nuisance of birds sitting nearby the window seal, door top portions.

federal electricity & water authority water directorate

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