Structural Steelwork Work Specification-EN-Rev02

SUBSECTION 22000 STRUCTURAL WORK

DIVISION 22070 – STRUCTURAL STEELWORK SPECIFICATION

PART 1. GENERAL

1.1 Description of the Structural Works: Contractor shall submit documents to Construction Manager and Construction Manager shall submit to Project Manager as procedures. The Contract Drawings show the layout, principal dimensions and arrangement of the structure, the requirements of which are described in the following paragraphs.

Project Information: In addition to the requirements stipulated in this Specification, the Structural Steelwork (Works) shall be carried out in accordance with the requirements stipulated in all other Contract documents and Drawings which contain general information about the project.
Drawings: Tender Drawings, as listed in Bills of Quantities, show the layout, principal dimensions and arrangement of the steelwork. Unless noted otherwise on the Drawings, the Works are designed for the permanent condition only. The Contractor should assess the effects of his/her construction sequence on the design of the structure prior to commencement of the Works.
Below requirements shall apply to the whole of the structure (refer to EC0, Appendix B and BS EN 1090):
1. Consequences Class 3 (CC3)
2. Reliability Class 2 (RC2)
3. Design Supervision Level 3 (DSL3)
4. Inspection Level 3 (IL3)
5. Execution Class 3 (EXC3)

1.2 Design: The Works shown on the Drawings and described in this Specification has been designed to BS EN 1993-1-1:2005.

Applicable Specifications and Codes

Unless stated otherwise, all undated references to Building Regulations and various standards cited in this Specification refer to the editions (including any amendments) current at the time of Tender. For dated references, only the edition cited applies. Reference to a Code or Standard shall be deemed to include all other Codes and Standards referred to in the specified Code or Standard.
All materials and workmanship shall be in accordance with the appropriate British European or other relevant Vietnamese standards. Where the requirements of these Standards are in conflict with this Specification in which case the requirements of this Specification shall take precedence.
When applying standards for minutes of acceptance, the Contractor must ensure the consistency and identity. The Contractor should not combine Eurocodes and and Vietnam standards in which these both standards have same application range but they are different from the approach and requirements. If Contractor has selected Vietnam standards for acceptance criteria whilst the items to be accepted have not been stated or partially stated in Vietnam standards, the Contractor may adopt Eurocodes for acceptance with the agreement and approval of Construction Manager prior to commencement of the acceptance works.
In addition, and in conjunction with the Standards, where applicable consideration of the UK

National Structural Steelwork Specification (NSSS) 7^th Edition has been consulted.

Applicable codes:
Eurocode:
- BS EN 1993-1-1:2005 Design of steel structures – General rules and rules for buildings
- BS EN 1011-2 :2001 Welding – Recommendations for welding of metallic materials. Arc welding of ferritic steels (AMD 14926)
- BS EN ISO 15614-1:2017 Specification and qualification of welding procedures for metallic materials – welding procedure test. Arc and gas welding of steels and arc welding of nickel and nickel alloys
- BS EN ISO 9001:2015 Quality management systems – requirements
- BS EN ISO 3834-2:2021 Quality requirements for fusion welding of metallic materials. Comprehensive quality requirements
- BS EN 10025-1:2004 Hot rolled products of structural steels. General technical delivery conditions
- BS EN 10210-1:2006 Hot finished structural hollow sections of non-alloy and fine grain steels. Technical delivery conditions
- BS EN 10365:2017 Hot rolled steel channels, I and H sections – dimensions and masses
- BS EN 1993-1-3:2006 Design of steel structures. General rules – Supplementary rules for cold-formed members and sheeting
- BS EN 10219-1:2006 Cold formed welded structural hollow sections of non-alloy and fine grain steels. Technical delivery conditions
- BS EN 10219-2:2019 Cold formed welded steel structural hollow sections. Tolerances, dimensions and sectional properties
- BS EN 10143:2006 Continuously hot-dip coated steel sheet and strip. Tolerances on dimensions and shape
- BS EN 10346:2015 Continuously hot-dip coated steel flat products for cold forming. Technical delivery conditions
- BS EN 10111:2008 Continuously hot rolled low carbon steel sheet and strip for cold forming. Technical delivery conditions
- BS EN 10209:2013 Cold rolled low carbon steel flat products for vitreous enameling. Technical delivery conditions
- BS EN 10029:2010 Hot-rolled steel plates 3 mm thick or above. Tolerances on dimensions and shape
- BS EN 10051:2010 Continuously hot-rolled strip and plate/sheet cut from wide strip of non-alloy and alloy steels. Tolerances on dimensions and shape
- BS EN 10034:1993 Structural steel I and H sections. Tolerances on shape and dimensions
- BS EN 10056-1:2017 Structural steel equal and unequal leg angles – Dimensions
- BS EN 10056-2:1993 Specification for structural steel equal and unequal angles – Tolerances on shape and dimensions
- BS EN 10210-2:2019 Hot finished steel structural hollow sections – Tolerances, dimensions and sectional properties
- BS EN 10162:2003 Cold rolled steel sections. Technical delivery conditions. Dimensional and cross-sectional tolerances
- BS EN ISO 8501-1:2007 Preparation of steel substrates before application of paints and related products. Visual assessment of surface cleanliness – Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings
- BS EN 10163-1:2004 Delivery requirements for surface condition of hot-rolled steel plates, wide flats and sections – General requirements
- BS EN 10163-2:2004 Delivery requirements for surface condition of hot-rolled steel plates, wide flats and sections – Plate and wide flats
- BS EN 10163-3:2004 Delivery requirements for surface condition of hot-rolled steel plates, wide flats and sections – Sections
- BS EN 1090-1:2018 Execution of steel structures and aluminium structures – Requirements for conformity assessment of structural components
- BS EN 1090-2:2018 Execution of steel structures and aluminium structures – Technical requirements for steel structures
- BS EN 4190:2014 ISO metric black hexagon bolts, screws and nuts. Specification
- BS EN ISO 4017:2014 Fasteners. Hexagon head screws. Product grades A and B
- BS EN ISO 4014:2011 Hexagon head bolts. Product grades A and B
- BS EN 4933:2010 Specification for ISO metric black cup and countersunk head bolts and screws with hexagon nuts
- BS EN 14399-1:2015 High-strength structural bolting assemblies for preloading – General requirements
- BS 7419:2012 Specification for holding down bolts
- BS EN ISO 7091:2000 Plain washers. Normal series. Product grade C
- BS EN ISO 10684:2004 Fasteners. Hot dip galvanized coatings
- BS EN ISO 17668:2016 Zinc diffusion coatings on ferrous products. Sherardizing. Specification
- BS EN ISO 13918:1998 Welding. Studs and ceramic ferrules for arc stud welding
- BS EN ISO 3506:2009 Mechanical properties of corrosion-resistant stainless steel fasteners – Tapping screws
- BS EN ISO 7089:2000 Plain washers. Normal series. Product grade A
- BS EN ISO 7090:2000 Plain washers, chamfered. Normal series. Product grade A
- BS EN ISO 14171:2016 Welding consumables. Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels. Classification
- BS EN ISO 14174:2019 Welding consumables. Fluxes for submerged arc welding and electroslag welding. Classification
- BS EN ISO 14341:2020 Welding consumables. Wire electrodes and weld deposits for gas shielded metal arc welding of non alloy and fine grain steels. Classification
- BS EN ISO 17632:2015 Welding consumables. Tubular cored electrodes for gas shielded and non-gas shielded metal arc welding of non-alloy and fine grain steels. Classification
- BS EN 1011-1:2009 Welding. Recommendations for welding of metallic materials – General guidance for arc welding
- BS EN ISO 6507-1:2018 Metallic materials. Vickers hardness test – Test method
- BS EN ISO 9018:2015 Destructive tests on welds in metallic materials. Tensile test on cruciform and lapped joints
- BS EN ISO 15609-1:2019 Specification and qualification of welding procedures for metallic materials. Welding procedure specification – Arc welding
- BS EN ISO 148-1:2016 Metallic materials. Charpy pendulum impact test – Test method
- BS EN ISO 9692:2013 Welding and allied processes. Types of joint preparation – Manual metal arc welding, gas-shielded metal arc welding, gas welding, TIG welding and beam welding of steels
- BS EN ISO 5817:2014 Welding. Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded). Quality levels for imperfections
- BS EN ISO 14555:2017 Welding. Arc stud welding of metallic materials
- BS EN 10160:1999 Ultrasonic testing of steel flat product of thickness equal or greater than 6 mm (reflection method)
- BS EN 10164:2018 Steel products with improved deformation properties

perpendicular to the surface of the product. Technical delivery conditions

BS EN ISO 17637:2016 Non-destructive testing of welds. Visual testing of fusionwelded joints
BS EN ISO 17638:2016 Non-destructive testing of welds. Magnetic particle testing
BS EN ISO 3452-1:2021 Non-destructive testing. Penetrant testing – General

principles

BS EN ISO 17640:2018 Non-destructive testing of welds. Ultrasonic testing. Techniques, testing levels, and assessment
BS EN ISO 3923-1:2018 Metallic powders. Determination of apparent density – Funnel method
BS EN 1993-1-8:2005 Design of steel structures – Design of joints
BS EN ISO 2063-2:2017 Thermal spraying. Zinc, aluminium and their alloys – Execution of corrosion protection systems
BS EN ISO 12944-2:2017 Paints and varnishes. Corrosion protection of steel structures by protective paint systems – Classification of environments
BS EN ISO 3233 Paints and varnishes
BS EN ISO 12944-5:2019 Paints and varnishes. Corrosion protection of steel structures by protective paint systems – Protective paint systems
BS 4652:1995 Specification for zinc-rich priming paint (organic media)
BS EN ISO 11124:2018 Preparation of steel substrates before application of paints and related products. Specifications for metallic blast-cleaning abrasives – Chilled-iron grit
BS EN ISO 8503-2:2012 Preparation of steel substrates before application of paints and related products. Surface roughness characteristics of blast-cleaned steel substrates – Method for the grading of surface profile of abrasive blast-cleaned steel. Comparator procedure
BS EN ISO 12944-4:2017 Paints and varnishes. Corrosion protection of steel structures by protective paint systems – Types of surface and surface preparation
BS EN ISO 8502-4:2017 Preparation of steel substrates before application of paints and related products. Tests for the assessment of surface cleanliness – Guidance on the estimation of the probability of condensation prior to paint application
BS EN ISO 14713-1:2017 Zinc coatings. Guidelines and recommendations for the protection against corrosion of iron and steel in structures – General principles of design and corrosion resistance
BS EN ISO 1461:2009 Hot dip galvanized coatings on fabricated iron and steel articles. Specifications and test methods
BS EN 12944-7:2017 Paints and varnishes. Corrosion protection of steel structures by protective paint systems – Execution and supervision of paint work
BS EN ISO 2808:2019 Paints and varnishes. Determination of film thickness
BS EN ISO 2409:2020 Paints and varnishes. Cross-cut test
BS EN ISO 2063-1:2019 Thermal spraying. Zinc, aluminium and their alloys – Design considerations and quality requirements for corrosion protection systems
ISO 19840:2012 Paints and varnishes. Corrosion protection of steel structures by protective paint systems. Measurement of, and acceptance criteria for, the thickness of dry films on rough surfaces
BS EN 13381-4:2013 Test methods for determining the contribution to the fire resistance of structural members – Applied passive protection products to steel members
BS EN 13381-8:2013 Test methods for determining the contribution to the fire resistance of structural members – Applied reactive protection to steel members
BS EN ISO 8504-3:2018 Preparation of steel substrates before application of paints and related products. Surface preparation methods – Hand- and power-tool cleaning
BS EN ISO 4136 Destructive tests on welds in metallic materials — Transverse tensile

test

BS EN ISO 5173 Destructive tests on welds in metallic materials. Bend tests
ISO 13920:1996 Welding — General tolerances for welded constructions — Dimensions for lengths and angles — Shape and position
ISO 9712: 2012 Non-destructive testing — Qualification and certification of NDT personnel
ISO 17025:2005 General requirements for the competence of testing and calibration laboratories
BS EN ISO 23278:2015 Non-destructive testing of welds. Magnetic particle testing.

Acceptance levels

BS EN ISO 23277:2015 Non-destructive testing of welds — Penetrant testing — Acceptance levels
BS EN ISO 11666:2018 Non-destructive testing of welds — Ultrasonic testing — Acceptance levels
EN ISO 2811-1:2011 Paints and varnishes — Determination of density — Part 1: Pyknometer method
EN ISO 17895:2005 Paints and varnishes — Determination of the volatile organic compound content of low-VOC emulsion paints (in-can VOC)
ISO 11890-1:2007 Paints and varnishes — Determination of volatile organic compound (VOC) content — Part 1: Difference method

Vietnamese codes:

TCVN 5575:2012 Steel structures – Design standard
TCVN 10351:2014 Hot-rolled steel plates – Tolerances on dimensions and shape
TCVN 10307:2014 Steel bridge structure – General Specitications for manufacturing, installing and acceptance
TCVN 10349:2014 Structural steels – Surface condition of hot-rolled sections – Delivery requirements
TCVN 11227-1:2015 Cold-formed welded structural hollow sections of non-alloy and fine grain steels – Part 1: Technical delivery conditions
TCVN 11227-2:2015 Cold-formed welded structural hollow sections of non-alloy and fine grain steels – Part 2: Dimensions and sectional properties
TCVN 11228-1:2015 Hot-finished structural hollow sections of non-alloy and fine grain steels – Part 1: Technical delivery conditions
TCVN 11228-2:2015 Hot-finished structural hollow sections of non-alloy and fine grain steels – Part 2: Dimensions and sectional properties
TCVN 11244-1:2015 Specification and qualification of welding procedures for metallic materials — Welding procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys
TCVN 12705-6:2019 Paints and varnishes – Corrosion protection of steel structures by protective paint systems – Part 6: Laboratory performance test methods
TCVN 130-77 Lock Washers
TCVN 134-77 Washers – Technical requirements
TCVN 1691:1975 Manuel are welding. Main types and constructive clements
TCVN 1876-76 Hexagon bolts (rough precision) – Dimensions
TCVN 1877-76 Hexagon reduced head bolts (rough precision) – Dimensions
TCVN 1889-76 Hexagon bolts (standard precision) – Dimensions
TCVN 1890-76 Hexagon reduced headvolts (Standard precision) – Dimensions
TCVN 1916:1995 Bolts, screws, studs and nuts – Technical requirements
TCVN 2061-77 Washers – Dimensions
TCVN 2195-77 Fastenera – Packing and marking
TCVN 312-1:2007 Metallic materials – Charpy pendulum impact test – Part 1: Test method
TCVN 3734-89 Electrodes for arc welding – Symbols
TCVN 5017-1:2010 Welding and allied processes – Vocabulary – Part 1: Metal welding processes TCVN 5026:2010 Metallic and other inorganic coatings – Electroplated coatings of zinc with supplementary treaments on iron or steel
TCVN 5026:2010 Metallic and other inorganic coatings – Electroplated coatings of zinc with supplementary treaments on iron or steel
TCVN 5408:2007 Hot dip galvanized coatings on fabricated iron and steel articlesn – Specifications and test methods
TCVN 5709:2009 Hot rolled carbon steel for building – Technical requirements
TCVN 5873:1995 Welds in steel – Reference block for the calibration of equipment for ultrasonic examination
TCVN 6522:2018 Hot-rolled steel sheet of structural quality
TCVN 6524:2018 Cold-reduced carbon steel sheet of structural quality
TCVN 6525:2018 Continuous hot-dip zinc-coated and zinc-iron alloy-coated carbon steel sheet of structural quality
TCVN 6530:1999 Refractories – Methods of test
TCVN 6735:2000 Ultrasonic examination of welds – Methods for manual examination

of fusIon welds in territic steels

TCVN 7506-2:2011 Quality requirements for fusion welding of metallic materials – Comprehensive quality requirements
TCVN 7571-1:2016 Hot – rolled steel sections- Dimensions – Tolerances – Sectional properties- Part 1: Equal- leg angles- Dimentions
TCVN 7571-1:2019 Hot-rolled steel sections – Part 1: Equal – leg angles
TCVN 7571-15:2019 Hot-rolled steel sections – Part 15: I sections
TCVN 7571-2:2019 Hot-rolled steel sections – Part 2: Unequal – leg angles
TCVN 7573:2006 Continuously hot-rolled sheet products – Dimensional and shape tolerances
TCVN 7574:2006 Continuously cold-rolled steel sheet products- Dimensional and shape tolerances
TCVN 7859:2008 Continuous hot-dip zinc-coated carbon steel sheet of commercial and drawing qualities
TCVN 8790:2011 Protective paint systems for steel and bridge structures – Procedures construction and acceptance
TCVN 9276:2012 Protective paint systems for steel structures – Standard Guide for Painting Inspectors
TCVN 9311:2012 Fire – resistance test- Elements of building construction – Part 1: General requirements
TCVN 9406:2012 Paint – Method for nondestructive determination of dry film thickness
TCVN 9986-4:2014 Structural steels – Part 4: Technical delivery conditions for highyield-strength quenched and tempered structural steel plates
TCVN 8310:2010 Destructive tests on welds in metallic materials – Transverse tensile

test

TCVN 5401: 2010 Destructive tests on welds in metallic materials – Bend tests
TCVN 170:2007 Steel structures – Fabrication, assembly, check and acceptance – Technical requirements

1.3 DEFINITIONS

Shop Drawings: Drawings showing all necessary information to fabricate the Works.
Erection Drawings: Drawings showing the dimension layout of the steel structure from which Shop Drawings are made and which correlate the piece markings with the location in the structure.
Welds: For the purpose of inspection, the weld shall be defined as the weld and the adjacent material.
Full Strength Butt Weld (FSBW): A weld that is not full penetration but is designed to develop full strength of the connecting elements and may have an un-fused land in the centre.
Full Penetration Butt Weld (FPBW): A weld that is fully fused for the full thickness of the material.
Partial Penetration Butt Weld (PPBW): A weld that is similar to a FSBW but is not designed to develop the full strength of the connection and will have an un-fused land.
Fillet Weld (FW): A weld that is normally between two plates at right angles. It can also apply to plates lapped (lap weld).
Designer and Construction Manager
1. “Designer” is the party who undertook the original structural design.
2. “Construction Manager” is the representative acting on behalf of the Owner that will supervise the Construction Works.
Corrosion Protection
1. Dry Film Thickness (DFT): Minimum dry film thickness of a paint coating. Minimum local thickness of a sprayed metal or galvanized coating. Nominal dry film thickness is as defined in ISO 12944-5:2019 and shall be measured in accordance with ISO 19840:2012 or TCVN 9406:2012.
2. Hot Dip Galvanized (HDG): Galvanizing in accordance with BS EN ISO 1461:2009 or TCVN 5026:2010.
3. Flame-sprayed (FS): Flame sprayed in accordance with BS EN ISO 2063-1:2019 & 20632:2017 or TCVN 5026:2010.
Fire Protection
General Requirements
1. Unless otherwise specified on the Drawings or encased in solid structural concrete, all

steelwork shall be protected against fire by applying insulating materials to ensure that the steel section does not exceed the limiting temperature within the fire resistance period as specified by the Architect, Project Manager and/or according to the Regulations for Fire Resisting, whichever is more stringent.

When using a paint system reference to Clause 1.6.F.3 of this Specification should be made regarding the VOC emission limits that shall apply. Fire protection requirements are as stated on the Contract Drawings.
Compatibility
The Contractor shall provide evidence to demonstrate to the Project Manager that the fire protection coating to be used for the steelwork is fully compatible with (a) the material to which it is applied; (b) the decorative or protective surface finishes where required, and its fire protection performance or adhesion would not be impaired. The use of alternative primers should be in accordance with the manufacturer’s recommendations.
In all applications the properties of the surfacing finish have to accommodate any dimensional movement of the spray.
Section Factor (Hp/A)
The ‘Section Factor’ is the ratio of the surface perimeter exposed to radiation and convection, Hp, to the cross-sectional area, A, and has units of m-1.
The section factor for different types of protection methods on different shapes/forms of the structural steelwork shall be assessed by the Contractor in accordance with the manufacturer’s specifications and agreed with the Project Manager. 4 Abbreviations

A. ASTM		American Society for Testing and Materials
B. BS		British Standard
C. BS EN &/or BS EN ISO		European Standard adopted as British Standard
D. NSSS		National Structural Steelwork Specification (UK)
E. CSWIP		Certification Scheme for Welding and Inspection Personnel
F. DAC		Distance-amplitude-curve
G. ETAG		European Technical Approval Guideline
H. NDT		Non-destructive testing
I. WPAR		Welding Procedure Approval Record
J. WPQR		Welding Procedure Qualification Record
K. WPS		Welding Procedure Specification

Contractor’s Drawings and Design Calculations: The Contractor shall produce detailed shop drawings, erection drawings and relevant design calculations. The approval by the Project Manager of drawings and design calculations prepared by the Contractor does not relieve the Contractor of the responsibility for accuracy of the calculations, detail dimensions on drawings, nor for the general fit up of parts to be assembled on site. Where available and applicable the contractor should follow TCVN.
General requirements

Connection Details
1. If required by the Project Manager, the Contractor shall design and detail the connections to satisfy the loads & robustness tie forces shown on the Drawings. All details are to be substantiated by full calculations unless agreed otherwise by the Project Manager.
2. The requirements of BS EN 1011-2:2001 or TCVN 5575:2012 in avoiding lamellar tearing when designing connections is to be fully taken into consideration by the Contractor.
Temporary Works
1. Responsibility: The Principle Contractor shall be responsible for the design, fabrication, erection and removal of all temporary works. The design and details of temporary works shall be checked and endorsed by the Project Manager before fabrication and erection. Upon completion of erection and prior to operation, the temporary works shall be inspected and certified by the Project Manager that they are erected in compliance with the endorsed details.
2. Stability
  1. The Contractor shall design and provide temporary bracing or restraints to incomplete structure to suit his own sequence and method of working. Alternatively, the Contractor shall provide calculations to show that part of the erected structure at its temporary state subjected to relevant loads is still adequate. Any fixing to the permanent structure shall be agreed with the Project Manager before construction.
  2. Where temporary restraints are used during erection which do not substitute for permanent features, they may be removed after the structure has been lined, levelled and plumbed provided that sufficient steelwork and/or permanent bracing has been erected to ensure the stability of the structure under the worst expected conditions of dead, imposed and wind loading.
3. Construction Information
  1. Fabrication
    1. The Contractor shall provide the following information to the Project Manager for review, at least 5 weeks before commencing fabrication (or as otherwise stated in the Contract Documents:
      - Complete and coordinated Shop and Erection Drawings.
      - Calculations and details for connections designed by the Contractor which are required to obtain approval and consent of the Project Manager for commencement of the construction works.
      - Detailed method statements for fabrication and corrosion protection application.
      - Details of welding procedures in accordance with BS EN 1011-2:2001 or TCVN 5575:2012, TCVN 170:2007, TCVN 5017-1:2010 and approved to BS EN ISO 156141:2017 or TCVN 11244-1:2015 for all welds, including tack and sealing welds.
    2. The Contractor is entirely at his own risk to commence fabrication works before obtaining approval of the Project Manager.
  2. Erection
    1. The Contractor shall provide the following information to the Project Manager for review, at least 4 weeks before commencing erection (or as otherwise stated in the Contract Documents):

Detailed method statement for erection, taking account of all information provided by the Project Manager on design, erection and programme.
Detailed drawings and calculations for all temporary works, which are to be checked and endorsed by the Project Manager.
Details of proposed site inspection system.

Erection shall not commence until the method statement has been accepted by the Project Manager.

Holes, Chases, Inserts and Fixings:The Contractor shall obtain Project Manager’s approval for the size and position of any hole, chase, insert or fixing required, including those required by any Sub-contractor, before the related work begins. Unless otherwise specified or approved all holes and chases shall be formed and any inserts or fixings shall be built in at the time of construction. Do not cut or drill any part of the Works without the Project Manager’s written approval.
As-built Drawings: The Contractor shall provide As-built Drawings which show the works as finally fabricated and erected and shall clearly show the location, orientation and level of the erected steel within 4 weeks after completion of each level of the structural steel works or as otherwise stated in the Contract Documents.
Programme
1. Programme: The Contractor shall provide a detailed programme prior to commencement of any works to show the planned timing of the various items of work to be done, including:
  1. Preparation and submission of construction information.
  2. Sample testing, order and delivery of materials.
  4. Application of protective coatings.
  5. Transport to site.
  6. Erection of temporary works.
2. Inspection and Testing: Include in the programme the necessary time for the Project Manager’s approval and consent as required, all procedural trials, inspection and testing, and trial assemblies.
3. Progress: Arrange the programme so that actual progress can be monitored against each item.
Quality Control
1. Management
  1. The Contractor shall operate an agreed quality management system to BS EN ISO

9001:2015 and BS EN ISO 3834-2:2021, BS EN 970:1997, BS EN 1290:1998, BS EN 1714:1998 or TCVN 7506-2:2011 unless otherwise agreed with the Project Manager, which shall be accessible for audit. All documentation shall be available for inspection during the contract period.

A quality plan shall be prepared by the Contractor which includes his general standards of workmanship. A method statement shall be provided for each stage of the work. The Contractor shall show that he will be able to achieve the specified quality level at each stage and that the procedures for design, detailing, purchasing, fabrication, erection and protective treatment of steel components and structures can provide a completed steelwork that conforms to the requirements of this specification.
Unless otherwise agreed, the Contractor shall provide the Project Manager with extracts of all execution and supervision standards given in his quality manual that are relevant to the Specification.

Inspection System: The Contractor shall operate an inspection system agreed by the Project Manager to verify that all materials, workmanship and completed works comply with the specified requirements.
Tests, Procedural Trials, Trial Assemblies
1. The Contractor shall carry out or arrange to carry out all tests on operatives, procedural trials, tests on materials and workmanship and trial assemblies.
2. All tests are to be conducted by an approved Testing Firm that is assessed and certified by an accredited certification body, have ISO 17025 certificate.
Personnel: The Contractor shall ensure that all personnel performing inspections and tests have appropriate qualifications, experience or training and accreditation.
Inspection Status: The Contractor shall operate a system agreed by the Project Manager for identifying the inspection status at all stages of fabrication and erection.
Records: The Contractor shall keep records on site of all tests on operatives, procedural trials and tests on materials and workmanship. All steelwork delivered to site shall be accompanied by relevant mill certificates and delivery records which are to be cross referenced to the approved fabrication and/or erection drawings. Make records available to the Project Manager for examination.
Period of Notice: Agree a period of notice with the Project Manager for all tests and before commencing any trial assembly.

Corrosion Protection
1. Durability Exposure Conditions: Corrosive environments are classified by BS EN ISO 129442:2017, and the corrosivity of the environment must be assessed for each project before the choice of corrosion protection can be adequately made. The corrosivity risk rating is broken down into 6 categories:

Corrosivity Category and Risk	Examples of Typical Environments (1)
Corrosivity Category and Risk	Exterior	Interior
C1 – Very Low	n/a	Heated buildings with clean atmospheres; offices, schools & hotels
C2 – Low	Atmospheres with low levels of pollution. Mostly rural areas	Unheated buildings where condensation may occur; depots & sports halls
C3 – Medium	Urban & Industrial atmospheres with moderate sulphur dioxide pollution. Coastal areas with low salinity	Production rooms with high humidity & some air pollution; food processing plants, laundries, breweries or dairies
C4 – High	Industrial areas & coastal areas with moderate salinity	Chemical plants, swimming pools, coastal ship & boatyards
C5I – Very High (Industrial)	Industrial areas with high humidity & aggressive atmosphere	Buildings or areas with almost permanent condensation & high pollution
C5M – Very High (Marine)	Coastal & Offshore areas with high salinity	Buildings or areas with almost permanent condensation and high pollution

Table 1.6.F.1: Durability Exposure Conditions

Note: The above table is for a temperate climate. Hot and humid climates increase the corrosion rate, and therefore steel will require additional protection than in a temperate climate.

Protective Systems: Unless otherwise stated on the Drawings, the reference to the type of protective paint system shall have the requirements specified in Clause 3.6.D & Appendix A.
Volatile Organic Content (VOC) Limits: Contractor shall be responsible for local regulations and best practice guidance on VOC emissions from the systems used.
Location: The locations in which each of the systems is to be used are noted on the Drawings.
Unpainted Elements
The surfaces of the following elements are to be unpainted:
- In composite constructions, the surfaces of steelwork which will subsequently have concrete cast against it.
- All steel elements which will be fully encased in structural concrete.
- Other elements as specified on the Drawings.
- Inner surface hollow sections: round, square, rectangular…

Fasteners and bolt assemblies which are supplied with a protective treatment which is equivalent to the protective treatment on the steelwork need not be painted.
Compatibility: The Contractor shall provide evidence to demonstrate to the Project Manager that any further coatings to be applied to the steelwork are fully compatible with the main corrosion protective system.

PART 2. PRODUCTS

2.1 Sections, Plates and Bars

Hot Rolled Sections, Plates and Bars

Unless otherwise stated all steel material shall conform to BS EN 10025-1:2004 or BS EN 10210-1:2006 or TCVN 5709:2009 as indicated in the drawings. Quality grades as noted on the Drawings.
For dimensional tolerances follow BS EN 10029:2010, BS EN 10365:2017 or TCVN 7573:2006 and TCVN 10351:2014. B. Cold Formed Sections:
Cold Formed Sections: Steel shall conform to BS EN 1993-1-3:2006 or TCVN 7574:2006 and TCVN 6524:2018. Quality grades as noted on the Drawings.
Cold Formed Hollow Sections: Steel shall conform to BS EN 10219-1:2006 and BS EN 10219-2:2019 or TCVN 11227-1:2015 and TCVN 11227-2:2015. Quality grades as noted on the Drawings.
Pre galvanized Steel Sheet: Shall conform to BS EN 10143:2006, BS EN 10346:2015 or TCVN 7859:2008 and TCVN 6525:2018. Quality grades and coating types as noted on the Drawings.
Recycled contents and implications
To match the green credentials of the project where applicable, the material supply certificates should look to include items related to avoidance of virgin resources where possible, including but not limited to;
1. Origin of steelwork
2. Recycled content of steelwork
3. The use of recycled or repurposed steelwork should not have a detrimental effect on durability, strength or ductility and should therefore be sourced from a reputable supplier with the suitable paperwork.
Thin Materials: Steel plate, sheet and strip under 3mm thickness shall conform to BS EN 10111:2008, BS EN 10209:2013 and BS EN 1993-1-3:2006 or TCVN 6522:2018, TCVN 6524:2018. Quality grades as noted on the Drawings.
Through Thickness Properties: Specific precautions shall be taken to avoid lamellar tearing of the ‘through’ material stressed in the ‘Z’ direction for thicker tee (T), cruciform (X) and corner (L) joints. Joints between columns and base plates do not require specific precautions to be undertaken unless noted otherwise for connections under significant tension.
Dimensions and Tolerances
1. Plates: Shall conform to BS EN 10029:2010 and BS EN 10051:2010 or TCVN 10351:2014, TCVN 7573:2006 and TCVN 7574:2006.
2. Structural Steel I and H Sections: Shall conform to BS EN 10034:1993 & BS EN 10365:2017 or TCVN 7571-15:2019, TCVN 7571-1:2016.
3. Angles: Shall conform to BS EN 10056-1:2017 and BS EN 10056-2:1993 or TCVN 75711:2019, TCVN 7571-2:2019.
4. Hot Finished Hollow Sections: Shall conform to BS EN 10210-2:2019 or TCVN 11228-1:2015 and TCVN 11228-2:2015.
5. Hot Rolled Sections: All other Hot Rolled sections not referred to above shall conform to Eurocode and the UK NSSS, 7th Edition or TCVN 7573:2006.
6. Cold Rolled Sections: Shall conform to BS EN 10162:2003 or TCVN 7574:2006.
7. Cold Formed Hollow Sections: Shall conform to BS EN 10219-2:2019 or TCVN 7574:2006.
Condition of Steel
1. Steel for fabrication is not to be more heavily pitted or rusted than Grade C of BS EN ISO 8501-1:2007 or TCVN 170:2007 and TCVN 10349:2014.
2. Rectify surface defects in hot rolled sections, plates and wide flats revealed during surface preparation which are not in accordance with the requirements of BS EN 10163-1:2004 or TCVN 170:2007 and TCVN 10349:2014.
  1. Plates & flats – Class A2 of BS EN 10163-2:2004 or TCVN 9986-4:2014, and TCVN 10349:2014.
  2. Sections – Class C1 of BS EN 10163-3:2004 or TCVN 10349:2014.
  3. Rectify surface defects in cold formed hollow sections revealed during surface preparation which are not in accordance with the requirements of BS EN 10219-2:2019 or TCVN 112271:2015 and TCVN 11227-2:2015.
3. Inspection and Testing: Structural steels shall comply with the requirements of BS EN 1090-2: 2018 or TCVN 170:2007, and any additional requirements given in Contract documents and on Drawings.
4. Ordinary Bolts and Nuts
  1. Shall conform to BS EN 4190: 2014 or TCVN 1916:1995 as appropriate where preloading is not required.
  2. Also, conform to the UK NSSS 7th Edition; BS EN ISO 4017:2014 (full threaded length bolts) or BS EN ISO 4014:2011 (part threaded length bolts).
5. Countersunk Bolts: Shall conform to BS EN 4933:2010 or TCVN 1876-76, TCVN 1877-76, TCVN 1889-76, TCVN 1890-76.
6. High Strength Friction Grip (HSFG) Fasteners: Shall conform to BS EN 14399-1:2015 or TCVN 5575:2012.
7. Holding Down Bolts: Shall conform to BS 7419:2012 or TCVN 1916 – 1995.
8. Washers:
  1. Plain and tapered steel washers for use with ordinary bolts shall conform to BS EN 1090-2: 2018 and BS EN ISO 7091:2000 or TCVN 2061 – 77 and TCVN 134 – 77.
  2. High strength washers for use with HSFG bolts shall conform to BS EN 14399-1:2015 or TCVN 2195-77.
9. Spring Washers: Shall conform to BS EN 1090-2: 2018 or TCVN 130 – 77.
10. Load Indicating Devices: load indicating devices shall satisfy requirements of bolts conforming to BS EN 14399-1:2015 or equivalent subject to the Project Manager’s approval in friction grip joints.
11. Surface Finish
  1. Galvanized: Bolt assemblies are to be galvanized in accordance with BS EN 1090-2:2008& BS EN ISO 10684:2004 or TCVN 1916:1995 and TCVN 5026:2010.
  2. Sheradized: Bolt assemblies are to be sheradized in accordance with BS EN ISO 17668:2016 or TCVN 5026:2010. Coatings to be in accordance with BS 7371-8:2011 or TCVN 9276:2012.
12. Shear Studs: All shear studs to be used in the Works to be proprietary headed studs complying with BS EN ISO 13918:1998 or TCVN 1916:1995. Diameter and nominal length as noted on the Drawings.
13. Stud Welding
  1. Shear stud welding, including through-deck welding should be carried out in accordance with a WPS. If permitted by the Project Manager, the WPS may be based on previous welding experience.
  2. The primary steel element should be adequately prepared, removing any paint or surface rust to receive the shear stud weld and to prevent poor fixity of the weld.
  3. The local area around where the stud is to be welded shall be free of standing water before commencing welding.
14. Stainless Steel Bolts, Nuts and Washers
  1. Bolts and nuts shall conform to BS EN ISO 3506:2009 (Parts 1, 2 and 3) or TCVN 1916:1995. Washers should be of stainless steel and the corrosion resistance of the bolts should be equivalent to, or better than, the corrosion resistance of the material to be fastened.
  2. For fasteners with nominal diameters larger than M24 for property classes 70 and 80, the mechanical properties must be agreed by the Design Engineer and the Project Manager.
  3. High strength bolts made of stainless steel should not be used as preloaded bolts designed for a specific slip resistance, unless the Contractor can demonstrate, to the satisfaction of the Project Manager, their acceptability in a particular application from test results.
  4. Contact between dissimilar metals shall be prevented by the use of gaskets and/or washers to prevent bimetallic corrosion.
15. Drill-in Anchors
  1. Expansion or chemical anchors shall not be used except otherwise approved by the Engineer.
  2. The Contractor shall submit details of all proposed drill-in anchors to be used for the Works to the Engineer for approval prior to commencement of the works. Materials – Welding Consumable.
16. Testing
  1. All steel products for use in the Works shall have been specifically tested in accordance with the appropriate material product standards. The Steelwork for Work shall obtain the manufacturer’s test certificate and make it available to the Engineer or Inspection Authority.
  2. Any supplementary tests carried out by the supplier use shall be undertaken by a laboratory certified.
  3. Steelwork test: for each batch of steelwork with a mass of less than or equal to 50T, a group of test samples should be taken for inspection. It must include all types of steelwork in the batch, each type must take at least 3 bars from 0.5m-0.8m to determine yield strength, tensile strength and elongation.
  4. Bolt testing: The Contractor submits a specific plan (Test criteria, number of samples for testing according to current European or Vietnamese standards) of bolt testing to the Engineer/Construction Manager for approval before construction and installation.

2.2 Welding Consumables

Welding Consumables: All welding consumables used for the arc welding of metallic materials are to comply with BS EN ISO 14171:2016, BS EN ISO 14174:2019, BS EN ISO 14341:2020, BS EN ISO 2560:2009 and/or BS EN ISO 17632:2015 as appropriate or TCVN 1691:1975 and TCVN 3734-89.
Mechanical Properties: Welding consumables and procedures used in the welding of structural works are to achieve mechanical properties for the deposited weld metal not less than the minimum specified for the parent metal.

2.3 Grout

Grout: Unless otherwise stated on the Drawings, grout around foundation bolts and under column base plates is to be of non-shrink cementitious grout and have a minimum compressive strength at 28 days of 50 N/mm2 as approved by the Project Manager.
Proprietary Grouts
1. Use where specified on the Drawings. The proprietary grout shall conform to European Standards or Standards and Building Codes of Vietnam (if available, where the most onerous takes precedence). Resin based grout shall only be used where the fire resistance of material is not required.
2. Provide written confirmation that proprietary grouts used in the Works do not contain high

alumina cement.

2.4 Corrosion Protection

Proprietary Materials
1. Evidence of Compliance: Before commencement of the Works, provide evidence to demonstrate that the proposed materials comply with descriptions in Clause 1.6.F.1 and on the Drawings.
2. Complying Materials: All proprietary materials deemed to comply with coating descriptions shall be submitted to the Project Manager for approval.
Manufacturer’s Instructions
1. Obtain from the manufacturer of any proprietary product detailed instructions on the use of the product, specific to the situation found on the Contract.
2. Comply with the manufacturer’s instructions for the use of any product. If these are in conflict with the requirements of the Specification, notify the Project Manager before commencement of the Works.
Source of Paint Materials: All products in any particular paint scheme are to be obtained from a single manufacturer. In case of from different manufacturers, Contractor shall provide evidence to demonstrate to the Project Manager that all products are fully compatible.
Multiple Coats of a Product: Where two or more coats of a product are to be applied, use a different colour for alternate coats.
Organic Zinc Rich Primers: Zinc rich primers are to comply with BS 4652:1995 or TCVN 12705-6:2019.
Pigments
1. Volume: Where a paint is defined in the protective system as having a specific pigment, the total pigment is to contain at least 50% by volume of the pigment specified.
2. Primers: Primers are not to be so coloured that early signs of rust breakthrough may be masked. Red iron oxide (red oxide) is not to be used as the principal colouring agent of any primer, including optional prefabrication primers.
3. Metallic Blast Cleaning Abrasives: Abrasives used for blast cleaning shall be capable of achieving the specified level of cleanliness and surface roughness. Where metal abrasives are used, they shall comply with BS EN ISO 11124:2018 or TCVN 9276:2012.

2.5 Fire Protection: The fire protection materials and proprietary products shall comply with European Standards or ETAG 018 – Fire Protective Products and shall be approved by the Project Manager. Interior or exterior application, impact and abrasion resistance factors shall also be considered in the selection of materials. Unless otherwise noted (from Architects Specification or by the Project Manager) the minimum fire protection for all internal steelwork shall be to the following. All steel structures shall be blasted to Sa2.5 and apply minimum 50 microns epoxy primer before applying any fire protection products.

Surface Preparation:	In accordance with intumescent coating manufactures requirem ents
Coat	Material (1)	Thickness (2)	Application
Fire Protection	Intumescent Coating	According to the fire re sistance report by the specialized firefighting engineer (recruited by Client)	Shop (3)
Fire Protection	Intumescent Paint	Internal Area (4)	Class: One Component
Fire Protection	Intumescent Paint	External Area (5)	Class: Two component
Fire Protection	Cemetitious Fireproofing	Internal Area (6)	Class: concealed
Fire Protection	Cemetitious Fireproofing	Internal Area (7)	Class: Expose

Notes:

All products in any particular paint scheme are to be obtained from a single manufacturer, meet the requirements of technical instructions, have a clear origin
As required to satisfy the Architects fire protection rating
If applied in shop, care is to be taken during transportation with all connections left untreated for post erection application. A thorough inspection is to be completed by a qualified person with any making good carried out on site to achieve a suitable level of protection as per this Specification.
Intumescent Coating – One Component: test in accordance with the test procedures defined in ETAG 018 or at the request of a specialized agency in the fire protection
Intumescent Coating – Two Component: test in accordance with the test procedures defined in ETAG 018 or at the request of a specialized agency in the fire protection
Interior Concealed Cementitious SFRM: test in accordance with EN 13381 or at the request of a specialized agency in the fire protection
Interior Exposed Cementitious SFRM for smooth trowel finish: test in accordance with EN 13381 or at the request of a specialized agency in the fire protection

Fire Testing and Performance Assessment Reports

All fire protection materials should have been subjected to an appropriate fire test in accordance with European Standards or TCVN 6530:1999. The test report indicating that the construction elements and the structural members are capable of resisting the action of fire for the specified criteria shall include the information as stated in BS EN 1363-1:2012 or TCVN 9311:2012.
The performance and thicknesses of the fire protection materials should be assessed from standard fire tests at accredited laboratories. The assessment report shall include, but not limited to the following details:
Fire protection material / product / system – Brief description of generic types.
Test specimens – Number of specimens and sizes used in the analyses.
Surface preparation and primer details.
Details of method of analysis adopted.
Compliance with criteria of acceptability, details of any constraints and permitted extensions.
Predictive analyses at each critical temperature with summary of test results and summary of analysis data.
Predicted thicknesses for various Section Factors and critical temperatures – Data sheets.
Physical performance and retention of material/product/system.
Method of application (validity of assessment for the application method).
The test reports used for the assessment should be appended to the Assessment Report.
Reasons for the omission of any test data, if any.
The test and assessment reports shall be endorsed by an independent authority having the appropriate qualifications and experience in fire resisting construction. Both the reports shall be submitted to the Project Manager for record.
Mechanical Retention
For the sprayed application of coatings, mechanical retention should be provided for elements without a re-entrant profile, or when the structural members are not encapsulated unless test evidence is available to demonstrate that there is adequate bond between the spray and the substrate (including primers or other coatings); or the spray is locked into position by virtue of the shape of the element. The required test criteria include:
1. Flame retardant thickness according to approved drawings
2. Dry density according to ASTM E605
3. Adhesion strength and adhesion according to ASTM E736
Reinforcement in the form of a corrosion protected wire mesh, 25, 38 or 50mm x 0.9mm, is also required on (a) ‘I’ or ‘H’ steel sections with dimensions of web exceeding 650mm and flange exceeding 325mm; and (b) circular sections with diameter exceeding 325mm or on hollow sections with a single face exceeding 325mm except where applicable test data is available to show such reinforcement is unnecessary. The mesh should be full section and in the middle third of the thickness and be retained by welded pins and non-return washers at nominal 500mm centres.
However, if any mesh reinforcement has been used with the coating system during the fire tests, then the same system must be adopted when used in the Works.
Plastic pins, self-adhesive pins or adhesive fixed pins must not be used for mechanical retention fixings.
Where expanded steel lathing is used to form a hollow encasement, it should be spaced from any steel surface to allow penetration of the lath by the fire protection material to form a mechanical key.

PART 3. EXECUTION

3.1 Identification, Storage and Handling

Identification
1. Marking: The Contractor shall mark and document all materials, components, assemblies and sub-assemblies delivered to site, to ensure that they are used as specified, and in the locations as shown in the approved drawings.
2. Additional Paint Marking: Where appropriate, steel is to have the additional paint marking for identification of steel grade conforming to BS EN 10025-1:2004 or TCVN 5709:2009.
3. Location of Marks: Piece markings are to be in positions which are not masked by other material after erection.
4. Hardstamping: No steel is to be hard stamped. Tag mark steel which is to be blast cleaned, acid pickled, metal sprayed or galvanized.
5. End of Life Sustainable Considerations
  1. Structural steel is wholly recyclable, although it is known that there is some wastage within the industry due to several factors. However, a level of over 93% recovery during demolition is typically possible. It should be the consideration of the Designer and the Contractor to try and ensure that this percentage can be as high as possible at end of life recovery. Here are some suggestions for consideration to maximise reuse ahead to recycling of sections that can be built into the original design;
  2. Aim to use standard sections rather than built-up plate girders
  3. Use bolted connections in preference to welding where possible
  4. Use standard connection details, bolt sizes and spacing where practicable
  5. Ensure easy access to connections and reduce coverings that prevent inspection of the condition of steelwork
  6. Minimise secondary fixings that require holes or openings with a preference of clamps instead
  7. Identify section origin & properties through e-tagging, barcodes or BIM management models for ease of future inventory and identification
6. Storage
  1. Holding Areas: Lay out steelwork in separate holding areas and keep clean.
  2. Support: Steelwork is to be adequately supported clear of the ground. Individual piece markings are to be visible when members are stacked.
  3. Consumables: Consumables in the Contractor’s works and on the Site shall be stored and handled in the manner described in BS EN 1011-1:2009 or TCVN 170:2007, and in accordance with the relevant standard and the manufacturer’s instructions. Any additional drying or baking of consumables before issue shall be carried out in accordance with the manufacturer’s recommendations.
7. Handling
  1. Plan and carry out bundling, packing, handling and transport in a manner designed to prevent damage to the steelwork and any protective coating.
  2. Restore any steelwork damaged during off-loading, transportation, storage or erection to conform to the standards of manufacture as given in this specification.
  3. Refer to BS EN 1090-2:2018 for detailed recommendations on handling and storage

preventative measures.

3.2 General

Cutting
1. Process: Cut steel by an automatic or semi automatic process.
2. Hand Flame Cutting: Use only where it is impractical to use machine flame cutting and is not to be used without prior approval by the Project Manager.
Dressing
1. Dressing: Dress the edges of all plates cut by flame to remove slag, scale, irregularities and excessive hardening. The hardness value after dressing for flame cut surfaces of all grades of steel is not to exceed 350HV.
2. Grinding: Remove dross, burrs, sharp arises, ragged edges and other irregularities by grinding.
Bearing
1. Compression Joints: Joints that depend on contact bearing are to have the bearing surfaces prepared to a common plane by milling, sawing or other suitable means to the accuracy given in European Standards, UK NSSS (7th Edition) or Standards Building Codes of Vietnam (if available, where the most onerous takes precedence). The bearing surfaces are to be at right angles to the nominal axis of the member or such other angle noted on the drawings. No work need be carried out on a bearing surface which is to be grouted direct to a foundation.
2. Stiffeners: Cut and grind bearing stiffeners to ensure a tight bearing along edges in contact with web and flanges.
Curving and Straightening
1. Properties: No curving or straightening is to be carried out which may result in material properties that do not conform to the specified requirements for the as supplied material.
2. Methods: Comply with BS EN 1090-2: 2018 or TCVN 170:2007.
3. Procedures
  1. Provide curving or straightening procedures to the Project Manager for review and approval before commencement of the works.
  2. Particular restrictions include but are not limited to;
  3. Heat range for bending and curving of different steel grades should be stated. Steel up to grade S355; bending in the heat range 250⁰C to 380⁰C shall not be permitted.
  4. Hot forming is not permitted for steel.
  5. Hammering shall not be used.
  6. Following all curving and straightening works are complete, all welds within the area affected shall be visually inspected.
4. Heating
  1. Properties: No heating is to be carried out to materials that would result in changes of material properties. This applies to normalised steel, controlled rolled steel and quench and tempered steels.
  2. Procedures: Provide heating procedures to the Project Manager for review and approval

before commencement of the Works.

Temporary Attachments to facilitate Erection
1. Details of holes and fittings in components necessary for safety or to provide lifting and erection aids shall be included in the submission to the Project Manager for approval. Unless specified otherwise in the Drawings, such holes and fittings may remain on the permanent structure where approved.
2. Account shall be taken of Clause 3.3.E.5 when detailing the welding of temporary attachments.
3. When removal of attachments is necessary, they shall be flame cut or gouged at a point not closer than 3mm from the surface of the parent material. The residual material may be ground flush and the affected area visually inspected. When the base material thickness exceeds 20mm (or carbon equivalent > 0.43%) it shall also be checked by magnetic particle inspection.
4. Attachments shall not be removed by hammering.
Accuracy of Fabrication
General
1. Fabricate steelwork to an accuracy that will enable erection within the specified limits to take place without inducing excessive stresses, deflection or distortion into the structure. The accuracy of fabrication shall comply with this Specification. Unless specified otherwise permitted deviations refer to the unstressed condition.
2. Notwithstanding the permitted deviations given in the following clauses in this section, the steelwork shall be fabricated such that it can be erected within the tolerances.
Built up Members: Tolerances on built up members, including castellated beams, are to comply with BS EN 1090-2:2018 or TCVN 170:2007.
Length
1. Members with both ends prepared for contact bearing are not to deviate from the detailed length by more than 1mm.
2. Members without ends prepared for contact bearing, which are to be framed to other steel parts of the structure, are not to deviate from the detailed length by more than (L/5000+2)mm.
Straightness: The deviation of a member from a straight line drawn between adjacent points of subsequent effective lateral restraint is not to exceed the greater of 3mm or 0.1% of the distance between restraints unless noted otherwise on the Drawings.
Curve or Camber: The deviation from specified or proposed curve or camber at the mid-point in the length of a beam is not to exceed +/- L/500 or 6mm, whichever is greater.
Compression Joints: Gaps in joints that depend on contact bearing when assembled during fabrication are not to exceed 0.75mm.

Summarises the requirements for the Execution Classes 3 (EXC3)

Clause

EXC3

Specification and documentation:

– Quality documentation

– Refer to 1.6.E and 3.8

Identification, inspection documents and traceability (of constituent products):

– Inspection documents

– Traceability

– Marking

– Refer to 1.6.E and 3.8 – Refer to 1.6.E and 3.8

– Refer to 3.1

Cutting:

– Thermal Cutting

– Refer to 3.5.J

Shaping:

– Flame straightening

– Cut-outs

– Suitable procedure to be developed

– Min. radius 5 mm

Welding:

– General

– Qualification of welding procedures

– Qualification of welders and operators

– Welding coordination

– Joint preparation

– Temporary attachments

– Tack welds – Butt welds:

+ General

+ Single side welds

+ Execution of welding

– Acceptance criteria

– Refer to 3.3.A – Refer to 3.3.B

– Welders: EN 287-1 & Operators: EN 1418 or Refer to 3.3.C

– Refer to 3.3.C

– Prefabrication primers not allowed

– Use to be specified. Cutting and chipping not permitted, Refer to 3.3.E

– Refer to 3.3.E

+ Run-on/run-off pieces

+ Continuous permanent backing

+ Removal of spatter

– Refer to 3.8.D

Inspection, testing and repair after welding:

– Scope of inspection

– Correction of welds

– Refer to 3.8.E

– Qualified welding procedure

3.3 Welding A. General

Arc Welding: Arc welding of metallic material is to comply with BS EN 1011-1:2009 and BS EN 1011-2:2001 as appropriate or TCVN 5017-1: 2010, TCVN 1691-1975, TCVN 170:2007, together with clauses contained in this Section.
Welding Specialist
1. The Contractor shall appoint a person regularly employed by him and approved by the Project Manager to be the welding specialist. This person shall be responsible for maintaining established quality control standards, and for managing the welding work. He shall be especially knowledgeable and experienced in welding methods, welding metallurgy, and welded steel structures. He shall be assigned to the fabrication shop during fabrication and to the site during erection to supervise the welding work. He shall have management ability and experience and shall assure quality control by assigning the welding work to responsible, qualified and capable welders.
2. All welding documentation (welder qualification certificates, welding-procedure qualification records, welding procedure specifications and associated work instructions) shall be reviewed for applicability by the person responsible for welding coordination (welding coordinator).
3. Quality requirements: The Steelwork Contractor’s system for the management of welding shall comply with BS EN ISO 3834-2:2021, BS EN 970:1997, BS EN 1290:1998, BS EN 1714:1998 or TCVN 7506-2:2011. The manufacturer and Steelwork Contractor shall have at their disposal sufficient and competent personnel for the planning, performing and supervising of the welding production according to specified requirements.
Welding Procedures
Approval of Welding Procedures
1. Welding Procedure trials and the Qualification Records (WPQR’s) according to BS EN ISO 15614-1:2017 or TCVN 5017-1:2010, shall be witnessed and endorsed by the Project Manager.
2. Previous welding procedure approvals to BS EN ISO 15614-1:2017 or TCVN 170:2007. Where applicable the Welding Procedure Specifications (WPS’s) shall be submitted for review by the Project Manager at least 2 weeks prior to the start of production.
3. Documents required to support a WPQR(s) are as follows:
  - Welding Procedure Approval Records (WPAR’s)
  - Complete mechanical test results
  - Complete non-destructive test results
  - Original material certificates (which should have either a full chemical analysis or the carbon equivalent)
  - Consumable certificates (if available)
4. Summary documents are not acceptable.
5. Notified fillet welds, partial penetration welds, full strength butt welds and tee butt welds subject to tensile loads > 0.5 Ys, tests shall be completed by additional cruciform test performed in accordance with BS EN ISO 9018:2015 or TCVN 170:2007.
6. Preparation of Welding Procedure Specifications
7. Written welding procedure specifications (WPS’s) shall be available in accordance with BS

EN ISO 15609-1:2019 or TCVN 5017-1:2010. They shall comply with the guidance of BS EN 1011-2:2001 or TCVN 170:2007, TCVN 5575:2012 for the avoidance of hydrogen cracking. Consideration shall be made to the requirements in Annex D of BS EN 10112:2001 to ensure that there is adequate toughness in the heat affected zone (HAZ) of the weld. HAZ toughness shall be as a minimum be equivalent to the parent steel specification.

WPS shall ensure that the range of qualification is within the requirements of BS EN ISO 15614-1:2017 or TCVN 170:2007, TCVN 5017-1:2010. In addition, carbon equivalent is considered an essential variable (Note). Any change in the carbon equivalent from that given in the WPQR > + 0.01% and the production material and the procedure will require additional approval. Reduction in the recorded carbon equivalent level for production when compared to the recorded carbon equivalent in the WPQR will not require additional approval.
All WPS shall be reviewed and approved by the Project Manager before being used in production.
(Note: The suitability of WPS for the steel to be welded includes the consideration of the actual Carbon Equivalent (CE) of the steel if this differs from the CE value recorded in the

WPQR.)

Charpy V-notch Impact Test: Shall be included, either to BS EN ISO 148-1:2016 or TCVN 312-1:2007. For thicknesses less than 10mm, ASTM A370 can be applied instead.

Welder Qualification
1. All welders and welding operators shall have valid current licenses.
2. The Contractor shall provide the Project Manager with certification that all welders have passed qualification tests. If required by the Project Manager, the Contractor shall submit test pieces made by any welder whose workmanship is in question. The Contractor shall require any welder to retake the test when, in the opinion of the Project Manager, the work of the welder creates reasonable doubt as to the proficiency of the welder. Tests, when required, shall be conducted at no additional expense to the Employer. Re-certification of the welder shall be made passed the required retest. The Project Manager may require test pieces to be cut from any location in any joint for testing. Sections of welds found defective shall be chipped or cut out to base metal and properly re-welded before proceeding with the work. Should any two test pieces of any welder show strengths, under test, less than that of the base metal, it shall be considered evidence of negligence or incompetence, and the welder shall be permanently removed from the works.
3. When test pieces are removed from any part of a structure, the members cut shall be repaired, at no additional cost to the Employer, in a neat and workmanlike manner with joints of the proper type to develop the full strength of the members.
Welding Consumables: Shall be used in accordance with the manufacturer’s recommendations.
Assembly
Fit-up
1. Joints shall be prepared in accordance with BS EN ISO 9692:2013 or TCVN 170:2007, TCVN 5017-1:2010 and fitted up to the dimensional accuracy required by the WPS, depending on the process to be used, to ensure that the quality in BS EN ISO 5817:2014, level B or TCVN 170:2007 is satisfied. Precautions shall be taken to ensure cleanliness of the connection prior to welding.
2. Also refer to the UK NSSS (7th Edition).
Jigs: Fabrications assembled in jigs may be completely welded in the jig or may be removed from the jig after tack welding. It is the responsibility of the Steelwork Contractor to ensure the welds used before removal are adequate.
Tack Welding: Tack welds complying with BS EN 1011-1:2009 and BS EN 1011-2:2001 or TCVN 5017-1:2010 and TCVN 170:2007, TCVN 5575: 2012 may be used provided:
1. they are laid in an area to be welded and are thoroughly removed by grinding or gouging

such that the subsequent welding is unaffected;

they are undertaken by a welder qualified as short length normal welds of a length at least four times the thickness of the thicker part being joined, or 50mm whichever is the greater.

The welding procedure shall comply with this Specification;

they are undertaken by a welder qualified and the welding procedure complies with this Specification, and the tack is fully re-melted during subsequent welding (this will need to be substantiated by a welding procedure);
they are located away from zones where subsequent welding is to take place and in a zone where only compressive forces are present in service.

Distortion: Welding procedures and sequence of fabrication are to be such that distortion is controlled and reduced to a minimum. But in any case, distortion shall not exceed the tolerances set out in this Specification unless otherwise agreed with the Project Manager.
Temporary Attachments: Welding of temporary attachments required for fabrication or erection shall comply with BS EN 1011-1:2009 and BS EN 1011-2:2001 or TCVN 170:2007 and TCVN 5575:2012 and shall be made in accordance with the requirements for a permanent weld and inspected.
Run on and Run off Plates: Where possible, use run on and run off plates in making butt welds to ensure full throat thickness at the ends. They are to comply with the following requirements:
1. The Specification for the plates is to be identical to that for the material being welded.
2. The plates, having a sufficient length to prevent craters due to the stoppage of the weld, are to be prepared in the same profile as the parts being joined.
3. After completion of welding, the plates are to be removed by cutting. The surfaces where they were attached are to be ground smooth and inspected for cracks.
4. Production Test Plates
5. Where production test plates are specified for test purposes they shall be clamped in-line with the joint. The grade and quality of material, carbon equivalent and rolling direction shall match the parent plate but need not be cut from the same plate or cast.
6. The production test plates shall meet the requirements of BS EN ISO 15614-1:2017 or TCVN 5017-1:2010 for tensile, impacts and hardness unless otherwise agreed with the Project Manager.
Shear Stud Welding
1. Member Preparation: Where composite action is designed, the surface of the steel member onto which the shear studs are to be through deck welded is to be free of virgin steel, free of paint or other coatings to ensure a good welded bond for the shear studs. If the member arrives without this surface free of any coating, the coating is to be removed prior to the decking being placed.
2. Method (Including through deck welding)
  1. Studs shall be welded in accordance with a WPS. This may be based on previous welding experience if permitted by the Project Manager but should be in accordance with the manufacturer’s recommendations.
  2. Fix shear studs in accordance with the manufacturer’s recommendations for materials, procedures and equipment. Adequate return earth connections shall be made local to the area being stud welded. The local area around where the stud is to be welded shall be free of standing water before commencement of welding. The welding shall comply with BS EN ISO 14555:2017.
  3. If the studs are to be welded by other than drawn arc and this has not been indicated on the Drawings, the Project Manager shall be notified. Unless agreed otherwise by the Project Manager, the size of fillet weld shall be chosen such that the full tension capacity of the stud can be developed.
  4. Where the decking profile includes a central rib that does not allow the studs to be placed in the centre of the trough, unless otherwise noted, they are to be placed on the side of the rib closest to the end of the beam.
  5. Trial Welding
  6. Before commencement of the Works, carry out trial welding of studs to demonstrate the suitability of the proposed welding system and equipment. The trials shall be made using the proposed procedures and on samples of materials representative of those to be used in the work (carbon equivalent, grade and thickness). Test a minimum of ten studs in the trial.
  7. During the work, at the start of each shift, a minimum of two trial welds are to be undertaken by each welder. If either of these trial studs fails a bend test in accordance with Clause 3.8.F, then further trials shall be conducted until satisfactory performance is established.
3. Visual Inspection: Visually inspect 100% of trial welded studs. They are to exhibit full 360degree ‘flash’.
4. Bend Test: Subject 5 number trial welded studs to a 60-degree bend test according to Clause 3.8.F. Additionally, if specified by the Project Manager, a macro examination shall be undertaken on two different studs.
Removal of Slag: Remove slag by light hammering, wire brushing or other methods that do not deform the surface of the weld.

3.4 Bolting

Holes
Forming and Tolerance
1. Unless agreed otherwise by the Project Manager, the forming of holes and the tolerance of hole diameters shall conform to BS EN 1090-2:2018 or TCVN 170:2007.
2. Holes for close-tolerance bolts shall be drilled to a diameter equal to the nominal diameter of the shank subject to a tolerance of +0.15 mm and -0 mm.
3. Deviation from the intended position of an individual hole within a group of holes should be no greater than 2mm in any direction. While ovalisation of holes should be no greater than ±1mm.
4. Grade
5. Unless otherwise noted on the drawings or agreed prior to erection with the Engineer, all bolts are to be Grade 8.8.
6. Different Bolt Grades shall not be allowed in the same structure unless prior approval is granted by the Engineer.
7. Size
8. Holes for ordinary bolts are to be of diameter not more than 2mm greater than the diameter of the bolt for bolts up to 24mm diameter, and not more than 3mm greater than the diameter of the bolt for bolts over 24mm diameter, except in steel base plates and where noted on the Drawings.
9. Holding down bolt details shall include provision of loose cover plates or washers with hole diameter 3mm greater than the holding down bolts.
Length: The bolt length should be chosen so after tightening at least 2 thread plus the thread run-out will be clear between the nut and the unthreaded shank of the bolt (b), and the length of protrusion shall be at least the length of one thread pitch measured from the outer face of the nut to the end of the bolt (c).

HSFG Fasteners: Holes to comply with BS EN 1090-2:2018 or TCVN 170:2007.
Drifting: Drifting to align holes shall not enlarge the holes and must not cause damage or distortion to the final assembly.
Reaming
1. Where parts cannot be brought together by drifting without distorting the steelwork, rectification may be made by reaming, provided that the design of the connection will allow the use of larger diameter holes and bolts and is approved by the Project Manager.
2. Calculations shall be provided to the Contractor to demonstrate that the connection remains adequate for the forces in the connection if using pre-loaded bolt assemblies.
Holes in Hollow Sections: Seal bolt holes and vent holes in hollow sections to prevent the ingress of moisture. If not specified on the Drawings, the Contractor shall show the proposed method on the Shop Drawings.
Make up of Bolt Assemblies: For all bolt assemblies the strength grade combination of bolt/nuts/washers is to be as prescribed or recommended in BS EN 1090-2: 1090-2:2018 or TCVN 5575:2012.
Condition of Bolts: Bolt assemblies are to be in such condition immediately before installation that the nut turns freely on the bolt. Any bolt assemblies which seize when being tightened shall be replaced.
Galvanized Nuts
1. Nuts shall be checked after being galvanized for free running on the bolt to ensure a satisfactory tightening performance.
2. Galvanizing and re-tapping of nuts is not permitted.
Washers
Washers
1. Each bolt assembly is to contain at least one washer placed under the part being rotated, especially if the components being connected have a finished surface protective treatment which may be damaged by the nut or bolt head being rotated.
2. If full bearing capacity is required when connecting thin-gauge sections of 4mm or less to each other, washers shall be used under both the bolt head and the nut.
3. A heavy-duty or plate washer shall be used under the head and nut if bolts are used to assemble components with oversize or slotted holes.
4. Washers shall be not thinner than 4mm.
5. Taper Washers: Taper washer shall be placed under bolt head and nut bearing on surfaces sloping 2° or more from a plane at right angles to the bolt axis and be placed so as to achieve satisfactory bearing.
Installation of Spring Washers: Tighten bolt assemblies containing spring washers until the spring washer is completely flattened.
Locking of Nuts: Secure nuts shall be used in connections subject to vibration or reversal of stresses to prevent loosening. If not specified on the Drawings, the Contractor shall include the proposed method in the erection details.
Limits to Length
1. Refer to 3.4.A.4
2. For Grade 8.8 bolts, the bolt length shall be chosen such that at least one complete thread in addition to the thread run-out that shall remain clear between the nut and the unthreaded shank of the bolt after tightening (b). For higher grades, at least five clear threads shall remain (b).
3. For normal grade HSFG bolts, the bolt length shall be chosen such that at least three complete threads in addition to the thread run-out that shall remain clear between the nut and the unthreaded shank of the bolt after tightening (b). For higher grade, at least five clear threads shall remain (b).
Bolt Tightening: Bolt and nut assemblies shall be tightened to BS EN 1090-2:2018 or TCVN 170:2007.
Fitted Bolts: Precision bolts to BS EN ISO 4014 or TCVN 1916:1995 may be used as fitted bolts if holes are drilled or reamed after assembly so that the clearance in the hole is not more than 0.3mm.
Fit-up: Connected parts shall be firmly drawn together (connected parts intended to transfer force in friction shall be firmly drawn together with all bolts partially tightened). The joint shall then be examined and if there is any remaining gap which may affect the integrity of the joint, it shall be taken apart and a pack not less than 2mm thickness inserted before recommencing the tightening procedure.
Movement Connections
1. Slotted Holes: Where slotted holes are provided for movement connections, the joint is to be free to move.
2. Method: Make bolted movement connections in the following manner:
  1. The slotted hole is to be wider than the unslotted hole.
  2. A shouldered bolt is to be used, with a spring washer under the head and the shoulder bearing on the faying surface of the unslotted member.
  3. A flat washer is to be provided under the nut and the nut tightened onto the unslotted

member.

High Strength Friction Grip Fasteners
1. Using: The use of high strength friction grip bolts shall comply with BS EN 1090-2:2018 or TCVN 170:2007.
2. Tightening Method: Tightening which complies with BS EN 1090-2:2018 or TCVN 170:2007, may be by the torque-control method or load indicating device used according to the manufacturer’s recommendations.
3. Calibration of Tightening Equipment: The tightening equipment, whatever its type or pattern, shall have a calibration check at least once per shift, and shall be re-calibrated if required by the Project Manager in accordance with BS EN 1090-2:2018 or TCVN 170:2007 .
4. Discarded Bolt Assemblies: If, after complete tightening, a bolt or nut is slackened off for any reason the whole bolt assembly is to be discarded and not re used in the Works.
Faying Surfaces for HSFG Fasteners
1. Mill scale: Remove all mill scale from the faying surfaces of friction grip joints.
2. Surface Condition: The faying surfaces of friction grip joints are to be free of distortion, deformities or contaminants which may reduce the slip factor below the design value.
3. Deformed Surfaces: Machine flat. Carry out tests to BS EN 1090-2:2018 or TCVN 170:2007 to determine the slip factor after machining.

3.5 Erection

General
1. The Contractor shall check before erection of any steelwork that work abutting the steelwork to be erected has been correctly placed in position and level. Any discrepancies shall be reported immediately to the Project Manager. Checks shall be made in a timely manner which enables connections and modifications to be performed without delay to the erection.
2. The erection of structural frames shall comply with this Specification, the requirements given in BS EN 1090-2:2018 or TCVN 170:2007 . The Contractor shall ensure that appropriate safe systems of work are provided, installed and properly maintained to discharge the duties under current safety legislation.
Anchor Bolts
1. Setting in: Hold anchor bolts firmly in position during all setting in operations.
2. Damag: Protect bolts, threads and nuts against damage, corrosion and contamination at all stages of construction.
3. Pocket: Keep pockets formed around anchor bolts clean and free from all extraneous matter.
Drill-in Anchors
1. General: All drill-in anchors in the concrete structure shall be demonstrated to have sufficient strength and shall be adequately embedded in such a manner that the load is sufficiently distributed to avoid over stressing of the concrete. The location of fixings shall meet the tolerances required for installation of the fitting-out system. Anchors shall be co-ordinated such that they do not clash with any reinforcing steel bars of the concrete structure.
2. Installation: Installation of anchor bolts must strictly follow the manufacturer’s specifications. Any installation procedures or details that deviate from the manufacturer’s specifications should be appended by a written statement from the manufacturer to confirm strength of the anchors.
3. Tolerances on Placement: Any deviation from the correct position of anchor bolt should be reported, appended with justification calculation to prove the capacity of the anchor, to the Project Manager prior to the installation of the fitting-out items. Minimum edge distance and spacing of anchor bolts should strictly comply with the manufacturer’s specification.
4. Erection Stresses and Erection Loads
  1. The stress limits given in BS EN 1993-1-1:2005 or TCVN 5575:2012 during handling and erection, shall not be exceeded.
  2. The Contractor shall ensure that no part of the structure is permanently distorted by stacking of materials or temporary erection loads during the erection process.
5. Temporary Works
6. Loadings
  1. Ensure that the steelwork is adequately braced or restrained to withstand all loadings liable to be encountered during construction without inducing excessive stresses, deflection or distortion in the structure.
  2. The Contractor shall ensure that the load spread under cranes and lifting plant is commensurate with the strength of firm standing provided by the supporting structure.
7. Removal: Temporary works are to remain in position until such time as construction is sufficiently advanced to allow its safe removal.
8. Connections: Any connections for temporary works are not to weaken the permanent structure or impair serviceability.
9. Effect on Permanent Works: The Contractor is responsible for justifying the impact of any temporary works on the permanent structure.
10. Alignment: Align each part of the structure as soon as practicable after it has been erected. Do not make permanent connections between members until sufficient of the structure has been aligned, levelled, plumbed and temporarily connected to ensure that members will not be displaced during the subsequent erection or alignment of the remainder of the structure.
11. Temperature Adjustments: Take due account of the effects of temperature on the structure and measuring equipment when measurements are made for setting out and erection, and for dimensional checks carried out subsequently.
12. Packings
  1. Packs and Wedges: Plumb and level columns using steel packs and wedges of adequate strength and stiffness and these packs and wedges are not to be larger than necessary for the purpose and of adequate strength and stiffness.
  2. Position: Where packings are to be left in position and subsequently grouted, they are to be placed such that they are totally enclosed by the grout and would not prevent subsequent grouting to completely fill all spaces directly under the base plates.
13. Grouting
14. Grouting
  1. Do not carry out grouting under column base plates until a sufficient portion of the structure has been aligned, levelled, plumbed and adequately braced by other structural components which have been levelled and are securely held by their permanent connections.
  2. As directed by the Project Manager, the Contractor shall submit detailed method statements for grouting narrow gaps or gaps where the grout materials could not be placed by gravity.
15. Space Under Base Plate: Immediately before grouting, the space under column base plates is to be clean and free of all extraneous matter.
16. Proprietary Grout: Prepare, mix and place in strict accordance with the manufacturer’s instructions and recommendations.
Sliding Surfaces: Treat the sliding surfaces of uncoated expansion joints with molybdenum disulphide grease before making the connection.
Thermal Cutting: Do not use thermal cutting equipment on site unless agreed otherwise by the Project Manager for specific applications.
Site Welding
1. Where site welding is required, provide suitable staging, platforms and weather protection for welding operations. Site welding shall comply with all the requirements given in this Specification and should not damage components it passes through.
2. It should be the aim of the Designer and Contractor to avoid site welding wherever possible. However, should this be required, it should be carried out following the submission of a full method statement and by suitably trained and certified personnel.
Setting out and Tolerances
Introduction
1. All setting out of structural elements will generally be in accordance with BS EN 1090-2:2018 or TCVN 170:2007 unless noted otherwise within the project specification or drawings.
2. Except otherwise stated on the Drawings and other Contract documents, the Contractor shall erect steelwork within the limits specified in this Specification and make all necessary allowances and adjustments to achieve this accuracy, taking account of the following:
  - All measurements be taken in calm weather, and due note is to be taken of temperature effects on the structure.
  - Where deviations are shown relative to nominal centre lines of the section, the permitted deviation on cross-section and straightness may be added.
  - Notify the Project Manager of any discrepancies found.
  - Ensure that structures by others, including cast-in components and fixings, to which steelwork attaches, are constructed within the anticipated permitted deviations before commencing steelwork erection.
3. The Contractor shall carry out regular checks on the steelworks. If an accumulation of tolerances results in a position which is out of the permissible deviations as specified in this Specification or other Contract documents, whichever is more stringent, the Contractor shall propose remedial measures for agreement with the Project Manager prior to carry out any repair works.
4. The Contractor shall liaise with all Sub-Contractors and advise the Project Manager on more stringent requirements in related to the acceptable structural tolerances prior to commencement of Works.
5. When required by the Project Manager, the Contractor shall furnish all necessary instruments and labour all at his own cost for the use of the Project Manager for checking the finished steelworks.
6. Datum References
7. At commencement of the Contract, the Contractor shall agree with the Project Manager the government bench marks as datum levels and for the purpose of setting out the gridlines for the Works.
8. The Contractor shall obtain the setting out dimensions from the Architect set out the gridlines and shall be responsible for the accuracy of his work. Figured dimensions shown on the Drawings shall be taken and the Contractor shall verify all such dimensions and levels before commencement of execution of the Works. The checking of any setting-out or of any line or level by the Project Manager or his representatives shall not in any way relieve the Contractor of his responsibility for the accuracy.
9. At every structural level, the Contractor shall establish both a datum level and a horizontal reference grid which shall be related back to the approved base bench mark and base reference grid in the forms agreed by the Project Manager.
Structural Members: Unless otherwise directed structural members shall be set out from the reference grids and datum levels, and constructed such that the dimension between any two points on different constructed structural members, or between any two points on the same constructed structural member, or between any point on a constructed structural member and any reference grid or datum level, or the formed elements shall agree with the required dimension, whether shown on or calculable from the Drawings, within the degree of accuracy as stipulated in European Standards or Vietnamese Standards.
Pre-camber
1. The Contractor shall determine the exact pre-cambers required according to his proposed construction sequence and method statements for the construction of concrete floor slabs and/or glass/metal features etc., such that the specified level of the slab and/or feature is achieved within the specified tolerances. The Contractor shall allow for carrying out a trial, prior to pre-cambering of the steel, to show that the typical secondary floor beams when supported using the connection details determined by the Contractor, exhibit the predicted deflection characteristics when subjected to loads equivalent to the weight of the concrete slab or glass/metal feature.
2. The first level of each typical floor being constructed on site will be designated as trial floor to assess the construction tolerances both before and after construction of the floor slabs. The Contractor shall conduct a detailed survey of all the beams on the floor to assess their levels and deflections prior to and after construction of the floor slabs. The findings from this study will be reviewed against the predicted deflections of beams and the Contractor shall make necessary pre-camber adjustments prior to construction of the next level of floor.
3. Except otherwise agreed by the Project Manager, any concrete encasement of the columns will be carried out at the same time as the concreting of the floor slab at the level immediately above and the Contractor should not rely on the composite action of the columns when assessing the pre-camber or propping strategy of the floor beams when casting the floor slab.
4. Permitted Deviations: Refer to NSSS for guidance on the permitted deviations during erection of steelwork.

3.6 Corrosion Protection

Identification, Storage and Handling
1. Identification: All paints and other products are to be marked or labelled and stored in such a way that identification of product and batch numbers is possible at all times.
2. Transportation, Storage and Handling
3. Damage: Establish transportation, storage and handling procedures for coated steelwork to avoid contamination, damage or breakdown of the protective system.
4. Galvanized Materials: Store and transport in such a way as to avoid white rust formation.
General
1. Surface Preparation
  1. Cleanliness: Before surface preparation in accordance with the protective system requirements, clean the steel surfaces of dirt, grease and other contaminants. Surfaces cleaned by wire-brushing or flame cleaning, with loose rust removed. They shall at no stage have rusted beyond Rust Grade C of BS EN ISO 8501-1:2007 or equivalent grade from TCVN 9276:2012.
  2. Surface Roughness: After surface preparation, the surface roughness is to be compatible with the coating to be applied in accordance with BS EN ISO 8503-2:2012 or TCVN 9276:2012, but nowhere exceeding a peak to trough amplitude of 80 micrometres. c. Rectification of Defects

Rectify all defects in the substrate surface exposed during surface preparation in accordance with Clause 2.1.G.
Defects which are acceptable to BS EN 10163-1:2004, BS EN 10210-2:2019 and BS EN 10219-1:2006 or TCVN 9276:2012 and TCVN 8790:2011 as appropriate, but which nonetheless will prevent the satisfactory coating of the steelwork, are to be rectified in such a way as to allow coating to be carried out in accordance with the Specification.

Rusting: Test steelwork, which has rusted to Rust Grade B of BS EN ISO 8501-1:2007 or TCVN 9276:2012 and TCVN 8790:2011 at any stage before surface preparation, and steel which has been subject to significant contamination prior to blast cleaning, in accordance with BS EN ISO 12944-4:2017 and BS EN ISO 14713-1:2017 or TCVN 9276:2012 and TCVN 8790:2011 after surface preparation, to demonstrate that the prepared surface is substantially free of salts. Wash with high pressure water to remove any excessive salts present.

Surface Condition
1. Contaminants: Surfaces to which paint is to be applied, whether steel or previous coatings are to be clean and free of any detrimental contaminants.
2. Quality of Surface:The prepared surfaces shall be assessed with regard to visual cleanliness, surface profile and chemical cleanliness, using the methods given in BS EN ISO 12944-4:2017 or TCVN 9276:2012 . The requirements for the supervision of these aspects of the work, the frequency of assessment, and the location of the assessment work shall be agreed with the Project Manager. The quality of surface preparation specified in the protective system is required to be present at the time of painting. If the surface has degraded beyond this level, re cleaning is to be carried out.
Application Conditions: During the execution of the corrosion protection work, care shall be taken that the work is not affected by any outside influences that could lead to a reduction in the quality of the coating. In the planning stage before starting the work, the Contractor shall define the measures by which adverse effects on the environment can be avoided or reduced to a minimum.
1. Weather Conditions
  - In order to ensure the protection required from the coating, the ambient conditions on site shall be checked to ensure that they meet the requirements given in the paint manufacturer’s technical data sheet for the particular coating material. This shall also apply to drying and reaction times.
  - The lowest and highest permissible temperature of the surface to be coated and of the surrounding air plus the permissible relative humidity shall be as stated in the manufacturer’s technical data sheet. If adverse weather conditions occur during application, the work shall be stopped, and the freshly coated area protected as far as practical.
  - Coating materials shall not be applied at temperatures below 3°C above the dew point, determined in accordance with BS EN ISO 8502-4:2017 or TCVN 9276:2012. Wet surfaces shall only be painted with those coating materials which are permitted in the technical data sheet or approved by the paint manufacturer.
2. Environment Conditions: Paint work shall take place in an area separated or protected from the work of other trades (blast-cleaning, welding etc.).
Prefabrication Coatings
1. Prefabrication Coating: The Contractor may apply a prefabrication coating at his discretion.

This coating, if applied, is to be additional to the main protective system.

Evidence of Compatibility: If a prefabrication coating is applied, the Contractor shall provide evidence to the Project Manager to demonstrate that it is fully compatible with the main protective system.
Blast cleaning: If a prefabrication coating is used, all areas in which this coating is not intact after fabrication are to be locally blast cleaned to the standard required by the protective system before overcoating.

Method of Application
1. Where shop applied paint coatings are to be applied by other than airless spray, or site applied paint coatings by other than brush or airless spray, demonstrate that the method of application will result in work in accordance with the Specification.
2. When painting components are to be welded on site, such components shall be masked in all areas which will be subject to preheating and welding. In the case of multicoated systems, every coat shall be stepped back.
Stripe Coats: All steelwork that will be externally exposed in the finished works is to have an extra stripe coat of primer applied to all edges and corners, and to seal gaps between adjacent components such as bolted connections.
Hot Dip Galvanizing
1. Condition
  - Supply material to the galvanizer in a suitable condition to be acid pickled and then galvanized.
  - High strength steels (in plate, rolled section or bar) of design strength greater than 460 N/mm2 should not be galvanized in order to avoid metallurgical change or annealing. Bolts of Grade 10.9 or higher grade or equivalent should not be galvanized.
  - Hollow sections should be vented if they are to be galvanized. The Contractor shall agree with the Project Manager the position of vent and drainage holes as laid down in BS EN ISO 14713-1:2017 or TCVN 5408:2007, and any requirements for subsequent sealing.
2. Uniformity: Carry out galvanizing in such a way as to maximise the smoothness and uniformity of the deposited coating. Only use double dipping where no alternative exists. Bolts should be spun galvanized.
3. Touch up
  - In accordance with BS EN ISO 1461:2009 or TCVN 5408:2007. Preparation is to be as required by the manufacturer of the touch up product being used.
  - The maximum size of an area of touch up is to be determined by locating the point on the damaged surface which is furthest from an intact galvanized coating. If the distance from this point to the galvanizing is in excess of 10mm, then the member is to be re-galvanized or rejected.
4. Sealing of Flame sprayed Surfaces: Immediately after flame spraying, seal the surface with a suitable sealer, chosen from BS EN ISO 12944-5:2019 and BS EN ISO 14713-1:2017 and following general guidelines from BS EN ISO 2063-1:2019 or TCVN 170:2007. The chosen sealer must be compatible with any further coats to be applied.
5. Life of Shop Applied Protection
  1. Programme: The Contractor shall liaise with the paint manufacturer, to ensure that the expected life of the shop-applied protection is compatible with erection and site painting programmes.
  2. Failure: If failure of the shop-applied protection should occur, reinstate the steelwork to an equivalent condition to the unfailed protection. The scheme used is to be compatible with any further coatings.
6. Making Good
  1. Damage: The Contractor shall make good all damage, weld areas and other areas which are not coated in accordance with the Specification.
  2. Method: the Contractor shall provide details of the proposed method for making good that will result in protection in accordance with the Specification. Details are to include surface preparation of both exposed steel and other coatings, choice of materials if these differ from those originally specified, means of application and any other relevant considerations.
7. Reinstatement of Damage Protection in Existing Steel Structures: All reinstatement of damaged coatings in the existing steel structures shall be made good to the standard of the original work except otherwise specified on the Drawings.
8. Connections
9. General
  1. Equivalent Standard: Prepare and protect all connections, including fasteners, items of bracket and other small pieces fabricated separately to the main steelwork, to an equivalent standard to the adjacent steel unless noted otherwise on the Drawings.
  2. Different System: Where the Contractor proposes to use a different protective system for any part of a connection to that used for the adjacent steel, provide evidence to demonstrate its equivalence and compatibility.
10. Friction Grip Interfaces: Do not apply paint to friction grip interfaces. If necessary, the faying surfaces are to be masked to prevent rusting beyond Rust Grade C of BS EN 8501-1:2007 or TCVN 9276:2012. If galvanizing or other metal coatings have been applied, provide evidence to demonstrate that a slip factor not less than the design value will be achieved.
11. Assembly of Bolted Connections: Assemble bolted connections in externally exposed steelwork, other than friction grip connections, with a coat of primer still wet on the contact faces.
12. Coated Bolts: Prime galvanized or sheradized bolt assemblies with a compatible etch primer or treat with a mordant solution prior to overcoating.
13. Sealing of Bolted Connections: Seal all bolted joints against the ingress of water. Before site painting commences, plug gaps at joints with a compatible and suitable filler. Take care that water is not sealed within the joint.
14. Site Welds
  1. Paint: At the time of welding there is to be no paint, other than suitable prefabrication primer, within 50mm of the weld.
  2. Temporary Protection: Apply and remove before welding if this is necessary to ensure that rusting does not occur to a level beyond that allowed by the Specification.
  3. Painting of Site Weld Areas: Site weld areas which are not suitably protected shall be painted with an approved paint system to ensure similar properties, performance and compatibility with the protective treatment system being used on the surrounding surfaces.
15. Protective Paint Systems
  1. Refer to Appendix A.
  2. For areas where there is a concern over the use and possible clash of corrosion protection and compatible intumescent paint in relation to fire protection, then 1F, E2F (thin film) or EPF (epoxy) might be considered.

3.7 Fire Protection

General
1. The supplier/manufacturer’s specification for transport, storage and handling of the materials/products should be strictly followed.
2. To ensure that the adhesion of the coating system is not impaired, the application techniques of the products, including the number of coats applied as instructed by the manufacturer must be strictly followed.
3. For the surface preparation of the steel, reference should be made to the individual requirements specified by the fire protection product manufacturer.
Defects and Damage: The Contractor shall rectify all the defects and damage to the standard of this Specification.

3.8 Quality Control

Materials Test Certificates
1. Steels: Provide test certificates to demonstrate that steels used in the Works conform to the requirements of this Specification. Include at least 3 tensile tests, 1 chemical test, and 3 impact tests (depending on the requirements of the relevant material standard).
2. Bolts: Provide test certificates to demonstrate that bolts used in the Works conform to the requirements of this Specification. Include at least tensile test (quantity to be submitted by contractor to relevant standard but not less than 3 samples) and coating thickness measurement.
3. Welding Consumables: All welding consumables used in the Works need to have certificates to demonstrate that they comply with the requirements of this Specification and BS EN 10902:2018 or TCVN 170:2007. The test will be carried out by welding samples and pulling welding consumables (1 sample each).
4. Verification: All test certificates are to be verified and endorsed in accordance with the Contract.
Additional Tests on Steels
1. Additional Tests: In the areas noted on the Drawings or requested by the Project Manager, the material is to be subject to the following additional tests:
  1. Ultrasonic tests for laminations to the specified acceptance level in accordance with BS EN 10160:1999, Class S2 and E2 or TCVN 170:2007, TCVN 5873:1995, TCVN 6735:2000.
  2. Through thickness tensile tests for through thickness properties to quality class Z25 in accordance with BS EN 10164:2018 or TCVN 170:2007.
2. Test and Inspection Records: Records of all tests and inspections are to be verified and endorsed in accordance to the Contract.
Non-Destructive Testing of Welds
1. Inspection Authority: Examination of welds is to be carried out and approved by the Project Manager.
2. Information: Inspection records that fail to be identified to the project or have the correct acceptance criteria stated will be rejected and all work re-inspected. It is the fabricator’s responsibility to ensure the inspector has the information required to perform his duties.
3. Records
Keep records to demonstrate that welds have been inspected as required in this Specification and repairs completed where required.
In these records, fabrications and welds shall be clearly identified to enable traceability of any connections inspected. Identification of connections or welds should conform to the system adopted in the fabrication shop and should not be a separate system devised by the inspection company. All defects shall be recorded in a repair register along with remedial actions and final close out report to verify repair on the same sheet as acceptable work. Separate records for acceptable work and defective work are not acceptable.
The Contractor shall keep records of all weld examinations on site and shall be available for inspection when requested.
Visual Inspection: Visual examination shall be made in accordance with BS EN 17637:2016, or TCVN 170:2007 over the full length of the weld. Such inspections shall be performed before any required non-destructive inspection and results recorded.
Surface Flaw Examination
1. Magnetic Particle Inspection (MPI) shall be in accordance with Clause 3.8.E.2 conforming to the recommendations in BS EN ISO 17638:2016 or TCVN 170:2007.
2. If MPI is impractical, Dye Penetrant Inspection (DPI) may be used in accordance with the recommendation given in BS EN ISO 3452-1:2021 or TCVN 170:2007, with the permission of the Project Manager.
3. Final surface flaw detection of a welded joint shall be carried out after completion of the weld in accordance with the hold times given in Clause 3.8.C.7.
4. A suitably qualified person for surface flaw detection of welds should be a welding inspector or a welder who holds a current certificate of competence from a nationally recognised authority.
Ultrasonic Examination
1. Where ultrasonic examination is required in accordance with Clause 3.8.E.2 it shall be

made in accordance with the requirements of BS EN 17640:2018 or TCVN 6735:2000 using reference level to Method 1, evaluation reference -14dB (20% DAC) and examination Level B unless otherwise agreed by the Project Manager and recorded on the inspection report. Evaluation reference -10dB (33% DAC), as stated in BS EN 17640:2018 or TCVN 6735:2000 will not be accepted.

Guidance for the required scans should be taken from BS EN ISO 3923-1:2018, or alternatively BS EN ISO 3923-1:2018, Level 2B or TCVN 6735:2000 shall be used.
Ultrasonic inspection to AWS D1.1 is not acceptable to the specification.
Ultrasonic examination of the welded joint shall be carried out after completion of the weld in accordance with the hold times given in Clause 3.8.C.7.
Inspectors carrying out ultrasonic examination shall hold a current certificate of competence from a nationally recognised authority following ISO 9712, certificates of course completion are not accepted, only level 2 and level 3 technicians can participate in inspection and testing for the project.
Note: In addition to weld examination through thickness, ultrasonic examination of the parent material may also be necessary as directed by the Project Manager for weld geometries susceptible to lamellar tearing.

Hold Times before final NDT
1. If there is a risk of delayed cracking, a period may be needed before the final inspection is made of as-welded fabrications. Recommended minimum hold times are given in Table 3.8.C.7.
2. Whatever hold time period is used shall be stated in the inspection records.
3. If it can be demonstrated by the Steelwork Contractor through records that delayed hydrogen cracking is not a risk, hold times may be reduced or waived at the discretion of the Project Manager.
4. Notwithstanding the use of waivers or hold times, whether in accordance with Table 3.8.C.7 or otherwise, all identified cracks shall be repaired.

Material Grade	Weld Size (mm) (i), (ii)	Heat Input (kJ/mm) (iii)	Hold Time (hours) (iv)
All grades covered by the Specification unless notified otherwise by the Project Manager (S275, S355, S420, S460)	a or s ≤ 6	All	Cooling period only
	6 < a or s ≤ 12	≤ 3	8
	6 < a or s ≤ 12	> 3	16
	a or s > 12	≤ 3	16
	a or s > 12	> 3	40
Size applies to the nominal throat thickness (a) of a fillet weld, the nominal depth (s) of a partial penetration butt weld or the nominal material thickness (s) of a full penetration butt weld. For individual partial penetration butt welds, the governing criterion is the nominal weld depth (s), but for pairs of partial penetration butt welds welded simultaneously it is the sum of the weld depths (s). If two fillet welds are separated an un-fused root face of less than 10mm then the governing weld size (a) shall be taken as the sum of their individual weld sizes. Heat input to be calculated in accordance with BS EN 1011-1:2009 or TCVN 1691:1975. The time between weld completion and commencement of NDT shall be stated in the NDT report. In the case of “cooling period only”, this will last until the weld is cool enough for NDT to commence (ambient temperature). Note: In certain situations, hold times MAY need to be greater than shown. This is particularly important when considering weld metal hydrogen cracking of higher strength steels and cases where borderline conditions exist. This remains the responsibility of the Steelwork Contractor to determine.

Table 3.8.C.7: Recommenced Minimum Hold Times

Acceptance Criteria for Welds and Corrective Action
The acceptance criteria for welds shall comply with Quality Level B specified in Clause 5 of BS EN ISO 5817:2014 or TCVN 170:2007, except that the scope of weld examination shall comply with Clause 3.8.E of this Specification.
If cracking or lamellar tearing is located, inspection should increase to 100% for the weld type using the same WPS. For less serious defects in a joint, examine two additional joints in the group represented by the joint. If the results on these two additional joints are acceptable then the original weld may be repaired and re examined by similar means.
If the non destructive examination of the two additional joints reveals unacceptable defects,

increase inspection to 100% of weld type using the same WPS.

The Contractor shall inform the Project Manager and keep record of serious defects (cracks, lamellar tears, incorrect weld type). Consideration should be made as to whether the defect is a procedural problem or welder induced. All defective welds shall be repaired and retested to meet the minimum requirements at the Contractor’s own cost. The Contractor shall propose remedial measures with a specific repair and re-test procedure for the nonconforming welds for agreement with the Project Manager prior to carrying out any repair works.

Scope of Weld Examination
1. Visual Inspection: Visually inspect all welds.
2. Non destructive Examination: Frequency of non destructive examination is to be as follows:

Weld Type	Inspection Type & Frequency
Full Penetration Butt Welds (FPBW) & FullStrength Butt Welds (FSBW)	Visual = 100%, MPi = 100% of the first 5 welds of type, then 50% thereafter, Ultrasonic = material thickness ≥ 8mm, 100% first 5 welds then 50% thereafter
Partial Penetration Butt Weld (PPBW)	Visual = 100%, MPi = 100% of the first 5 welds of type, then 20% thereafter, Ultrasonic = material thickness ≥ 8mm, 100% first 5 welds then 50% thereafter
Fillet Welds (FW)	Visual = 100%, MPi = 100% of the first 5 welds of type, then 20% thereafter, reducing to 10% of weld length to include start/stop zones, Ultrasonic = 100% first 5 of weld type, then material thickness ≥ 20mm or leg length ≥ 12mm: 10% of weld length; other 5% of weld length

Table 3.8.E.2: NDT Examination Frequency

Destructive Examination is specified according to BS EN ISO 4136 and BS EN ISO 5173 or TCVN 8310:2010 and TCVN 5401:2010. This test shall be carried out at the factory upon request of the Project Manager.
Selection of Welds to be Examined: Where there is a requirement for less than 100% examination the method of selection of welds to be examined is to be agreed with the Project Manager before commencement of the Works.

Shear Stud Welding
1. Visual Inspection
  1. Prior to commencing stud work, a test piece consisting of at least 10 shear studs shall be carried out. This test piece shall be inspected for acceptability using 100% visual inspection and bending of 5 studs through 60-degrees.
  2. All studs are to be visually inspect and ring tested. Subject any stud weld that does not exhibit full 360-degree collar or ‘flash,’ to a 15-degree bend test (see below) such that the area of ‘no flash’ is put in tension. Under this test, the weld is to show no visible signs of cracking. In addition, studs should be replaced if they do not give a clear ring when struck by a metal club hammer.
2. Bend Test
  1. Subject a minimum of 5%, but not less than 2 number per beam, of the studs that have satisfied the visual inspection to a bend test at locations to be agreed with the Project Manager. Under this test, the weld is to show no visible signs of cracking or lack of fusion when bent laterally to a distance one quarter of the height (approximately 15-degrees) using a hollow steel tube placed over the stud.
  2. Where bend testing reveals an unsatisfactory stud weld, test an additional stud on each side of the defective stud. Should either of the two additionally tested studs fail, then all studs shall be considered to be at risk until further testing deems them to be acceptable by the Project Manager.
  3. Studs subjected to the bend test shall not be straightened.
3. Defective Studs
  1. Studs with defective welding or that have failed the bend test shall be replaced with a new stud in an adjacent location. The replacement stud shall be inspected according to Clauses 3.3.F.1 and tested as in Clauses 3.3.F.2 by bending it towards the defective stud. Inspection shall increase to 5 adjacent studs, if further failures are found the cause shall be determined before resuming welding.
  2. If it is necessary to remove the defective stud, it shall be detached, and the surface checked, complying with this Specification.
  3. All the costs shall be borne by the Contractor.
4. Bolted Connections: Following complete assembly of all bolted connections, check the fit and tightness of the bolts at locations to be agreed with the Project Manager.
  1. HSFG Bolted Connections:
    1. Prior to site painting, check to ascertain that the minimum shank tension has been obtained and that appropriate hardened washers have been fitted in accordance with the requirements of BS EN 1993-1-8:2005 or TCVN 170:2007.
    2. Records will be required to demonstrate that all HSFG bolts are correctly installed and tensioned.
  2. Non-HSFG Bolted Connections: Place bolts in holes without force, and then tighten to draw connected parts firmly together.
  3. Drill-in Anchors: The Contractor shall carry out loading test of the structural drill-in anchors as required by the Project Manager at his own cost and time. If the loading test fails, the failure mode shall be recorded, and the cause shall be determined and reported to the Project Manager. The Contractor shall propose remedial measures, including justification calculations for any alternate design and method statement, for agreement with the Project Manager prior to carrying out any repair works.
5. Fabrication and Erection Tolerances
  1. Survey Records: Records are to be kept of all the required dimensional inspections to demonstrate that the tolerances stipulated in the Specification have been met. Any deviations from the stated requirements will need a concession from the Project Manager which will need to be held with the records or steelwork may be rejected. All concessions should clearly identify the member or members affected and should be traceable to individual items.
  2. Verification: The fabrication tolerance records are to be verified as compliant with specified requirements by Code/this Specification.
  3. Trial Assembly: Assemble the portions of the steelwork as described on the Drawings.
6. Load Testing: When it is required and directed by the Project Manager to establish the capacity of an existing structure or component or to verify design or construction that is not entirely in accordance with the design requirements, the Contractor shall carry out the loading tests for such structure or component.
7. Corrosion Protection
  1. General
    1. Inspections and Tests
      - Before commencement of the Works, the Contractor shall provide details of the scope and frequency of all inspections and tests to be carried out to assure compliance with the Specification. As a minimum, include all relevant inspections and tests in European Standards and follow general guidelines in BS EN ISO 12944-7:2017 or TCVN 170:2007.
      - The frequency of inspection and testing is to be sufficient to detect any non-conformances.
    2. Notice: The Contractor shall agree with the Project Manager a period of notice for all tests.
  2. Method Statement
    1. The Contractor shall submit a detailed method statement for the application or reapplication of protective coating(s) explaining how it is intended to carry out the works in accordance with the Specification to the Project Manager for approval prior to the commencement of works.
    2. At locations where there are significant residual stresses inherent in the steel during fabrication (cold working) and welding, the Contractor shall provide effective measures to improve the corrosion resistance of the material.
    3. The Contractor shall carry out all works in accordance with the method statement.
  3. Test Pieces
    1. Sample Size: Prepare two sets of test pieces representative in all relevant respects of the Works to be carried out.
    2. Coating: Coat test pieces in accordance with the method statement.
    3. Test: Confirm, by means of tests on one set of test pieces, that the proposed method will result in work which complies with the Specification.
    4. Retention of Test Pieces: Protect and retain the second set of test pieces for the duration of the Contract.
    5. Results of Tests: No work is to be carried out until the Contractor has confirmed in writing that the results of the tests comply with the Specification. Provide the Project Manager with a copy of the test results.
    6. Quality Standards:The quality standards established by the test pieces are to become the minimum standard for the Works.
  4. Modification to Method Statement
    1. Test Pieces: If it is proposed to modify the method statement, produce two sets of test pieces, identical with the initial test pieces, using the proposed modified method.
    2. Tests: Confirm, by means of tests on one set of test pieces, that the proposed modification will not result in a reduction in the quality of work produced below that being produced by the current method.
    3. Retention of Test Pieces: Protect and retain the second set of test pieces for the duration of the Contract.
    4. Results of Tests: No work is to be carried out using the modified method until the Contractor has confirmed in writing that the results of the tests comply with the Specification. Provide the Project Manager with a copy of the test results.
    5. Quality Standards: The quality standards established by the test results are to become the minimum standard for the Works.
  5. Testing
    1. Coating Thickness: After the application of each coat of paint, and before the application of following coats, ensure that the coat has been applied to the required dry film thickness by the use of any of the methods in European Standards and BS EN ISO 2808:2019 or TCVN 9406:2012 for measuring dry film thickness. Wet film thickness measurements are not to be used for this purpose.
    2. Adhesion: Ensure, by means of adhesion tests to European Standards and BS EN ISO 2409:2020 or TCVN 8790:2011, carried out on representative areas chosen to be non obtrusive in the final condition, that the adhesion of any completed paint scheme is not worse than classification 2 of that standard. The test area is to be touched up in accordance with this Specification.
    3. Thermal / Flame sprayed Zinc: Test in accordance with BS EN ISO 2063-1:2019 or Standards or Building Codes of Vietnam (if available, where the most onerous takes precedence).
    4. Hot Dip Galvanized Steel Elements
      - Test in accordance with BS EN ISO 1461:2009 or TCVN 5026:2010 for coating thickness, using coupons of the same material as the element, and galvanized with the element.
      - All galvanized components shall be subjected to post-galvanizing inspection for Liquid Metal Assisted Cracking (LMAC). Unless otherwise specified this should be in accordance with procedure PGI-1 from Table 3.8.10.5 below and/or as specified on the Drawings. Any linear or crack-like indications shall be recorded and reported to the Project Manager as soon as possible.
      - Additional NDT by MPI is required when there is evidence of a susceptibility to cracking. The operator shall be trained to recognise the diffused indicators due to the presence of the coating.

Reference	Visual Inspection	Magnetic Particle Testing
PGI-0	Not required	Not required
PGI-1	100% of all surfaces with special attention to areas around copes, welded connections and joints	Not required
PGI-2A	Already required by PGI-1	On 10% of welded connections or node points of welded joints
PGI-2B	Already required by PGI-1	On specified areas
PGI-3	Already undertaken	Sufficient to establish the scope and origin of the problem (1)
Personnel	Inspection to be undertaken by a suitably experienced person	NDT to be undertaken by a person suitably qualified on the technique to be used
(1) Eddy current and alternating current field measurement tests may be used to assist diagnosis.

Table 3.8.J.5: Post-Galvanizing Inspection Procedures

If evidence of cracking is identified, then the component and all similarly shaped components fabricated with similar materials and weld details shall be identified and quarantined as non-conforming products. A photographic record of the cracking shall be made and procedure PGI-3 shall then be used to establish the scope and origin of the problem.
Quarantined components may only be repaired for use in the Works with the agreement of the Project Manager and the components shall be repaired using an appropriate welding repair procedure in compliance with the guidance on the BCSA and GA Publication No. 40/05 – Galvanizing Structural Steelwork – An Approach to the Management of Liquid Metal Assisted Cracking. The Steelwork Contractor shall prepare the welding procedure and submit to the Project Manager for approval prior to carrying out the repair works.
The results of post-galvanising inspection and any repair works shall be recorded. These records shall be made available to the Project Manager on request.

Inspection of Site Applied Coatings
1. If coatings are required, other than those covered by Clause 3.6.C.6, to be applied on site, then an inspection plan for the site application work shall be included in the project quality plan.
2. The inspection plan shall include steps to monitor the quality of the materials being used, the thickness of the applied coatings, and that the process of application is in accordance with the product manufacturer’s recommendations.
3. Fire Protection
Method Statement
1. The Contractor shall prepare and submit the method statement including spacing of fixings for the mechanical retention to the Project Manager for approval prior to the commencement of works.
2. For materials undergo dimensional changes after application, the Contractor should take special care to recognize this factor for site control purposes.
Passive Fire Protection System: Shall comply with BS EN 13381-4:2013 or TCVN 170:2007.
Reactive Fire Protection System
1. Shall comply with BS EN 13381-8:2013 or TCVN 170:2007.
2. The dry film thickness shall be measured using an instrument employing either the electromagnetic induction or eddy current principle, with a probe contact diameter of minimally 2.5mm according to BS EN ISO 2808:2019 or TCVN 9406:2012. The instrument shall satisfy the following criteria:
  - Possess a total range greater than the highest thickness to be measured.
  - Provide a digital display of coating thicknesses and be capable of storing measured

values.

Capability to calculate statistical parameters – max/min values, mean and standard deviation.
Capability to provide hard copy print out of data.

The instrument shall be operated in accordance with the manufacturer’s instruction for use. Calibration shall be carried out immediately prior to any series of measurements being taken.
In the case of a primer being employed, primer thickness shall be determined prior to application of the intumescent coating and subsequently subtracted from the measured total thickness of primer and intumescent coating.
Deviations: In respect of fire resistance, section factor (Hp/A) and thickness, together with protection details, no deviation can be made except for specific situations where some variation may be necessary. Such variations must be validated by an independent authority, or an appropriate testing laboratory and subject to the approval by the Project Manager. APPENDIX A – PAINT SYSTEM

Externally exposed steelwork:

Type E-1 (Where maintenance is unusually difficult or high corrosion risk exists)

Surface Preparation:	Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾or TCVN 8790:2011
Coat	Material ⁽³⁾	Thickness ⁽⁴⁾	Application
Primer	Zinc Rich Epoxy ⁽⁵⁾	75	Shop
Barrier	Epoxy MIO ⁽⁶⁾	125	Shop
Finish	Polyurethane	75	Shop

Type E-2 (Urban, rural & industrial locations except coastal / hard to maintain)

Surface Preparation:	Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾ or TCVN 8790:2011
Coat	Material ⁽³⁾	Thickness ⁽⁴⁾	Application
Primer	Epoxy Zinc Phosphate	75	Shop
Barrier	Epoxy MIO ⁽⁶⁾	125	Shop
Finish	Polyurethane	75	Shop

Internal steelwork:

Type I-1 (Controlled Environment with heating or air conditioning)

Surface Preparation:	None Required
Coat	Material	Thickness	Application
Primer	No corrosion protective paint required (depending on the construction sequence). If decorative finish required, then use Specification I-2.
Finish

Type I-2 (Controlled Environment as per I-1 where decorative finish is required)

Surface Preparation:	Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾ or TCVN 8790:2011
Coat	Material ⁽³⁾	Thickness ⁽⁴⁾	Application
Primer	Epoxy Zinc Phosphate	75	Shop
Finish	As specified by the Project Manager		Shop

Type I-3 (For steel that is hidden and may be exposed to condensation) ⁽⁷⁾

Surface Preparation:	Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾ or TCVN 8790:2011
Coat	Material ⁽³⁾	Thickness ⁽⁴⁾	Application
Primer	Zinc Rich Epoxy ⁽⁵⁾	75	Shop
Finish	Not required / As specified by the Project Manager

Type I-4 (Within semi-controlled environments)

Surface Preparation:

Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾ or TCVN 8790:2011

Coat

Material ⁽³⁾

Thickness ⁽⁴⁾

Application

Primer

Epoxy or Polyaspartic

primer / finish

150

Shop

Type I-5 (Frequently damp or wet internal environments)

Surface Preparation:	Blast clean to Sa2½ of BS EN ISO 8501-1:2007 ⁽¹⁾⁽²⁾ or TCVN 8790:2011
Coat	Material ⁽³⁾	Thickness ⁽⁴⁾	Application
Primer	Epoxy Zinc Phosphate	75	Shop
Barrier	Epoxy MIO ⁽⁶⁾	125	Shop
Finish	Polyurethane	75	Shop

Notes: (1) Or similar level as per TCVN 8790:2011

Or hand/power-tool clean to BS EN ISO 8504-3:2018
All products in any particular paint scheme are to be obtained from a single manufacturer.
The thickness as quoted is Minimum DFT in microns. Nominal dry film thickness is as defined in ISO 12944-5:2019 and shall be measured in accordance with ISO 19840:2012.
Zinc rich primers are to comply with BS 4652:1995 or TCVN 12705-6:2019.
MIO: Micaceous iron oxide. Note: Zinc Phosphate and MIO shall not be combined in a single coat.
Hot Dip Galvanizing to BS EN ISO 1461:2009 is an acceptable alternative to this specification

END OF DIVISION 22070

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Structural Steelwork Work Specification-EN-Rev02

PART 1. GENERAL

PART 2. PRODUCTS

PART 3. EXECUTION

Type E-1 (Where maintenance is unusually difficult or high corrosion risk exists)

Type E-2 (Urban, rural & industrial locations except coastal / hard to maintain)

Type I-1 (Controlled Environment with heating or air conditioning)

Type I-2 (Controlled Environment as per I-1 where decorative finish is required)

Type I-3 (For steel that is hidden and may be exposed to condensation) ⁽⁷⁾

Type I-4 (Within semi-controlled environments)

Type I-5 (Frequently damp or wet internal environments)

END OF DIVISION 22070

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© 2024 sonviet.vn/Designed by hoangweb

Structural Steelwork Work Specification-EN-Rev02

PART 1. GENERAL

PART 2. PRODUCTS

PART 3. EXECUTION

Type E-1 (Where maintenance is unusually difficult or high corrosion risk exists)

Type E-2 (Urban, rural & industrial locations except coastal / hard to maintain)

Type I-1 (Controlled Environment with heating or air conditioning)

Type I-2 (Controlled Environment as per I-1 where decorative finish is required)

Type I-3 (For steel that is hidden and may be exposed to condensation) (7)

Type I-4 (Within semi-controlled environments)

Type I-5 (Frequently damp or wet internal environments)

END OF DIVISION 22070

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MAP

© 2024 sonviet.vn/Designed by hoangweb

Type I-3 (For steel that is hidden and may be exposed to condensation) ⁽⁷⁾