BS 8548:2017 pdf free download.Guidance for arc welding of reinforcing steel.
BS 8548 has been prepared with the aim of clarifying the requirements and providing suitable guidance for the arc welding of carbon steel reinforcing bars produced in accordance with 85 4449 and 85 4482. BS 8548 has been developed to reflect current best welding practice, standards and specifications.
BS 8548 also gives recommendations and guidance on friction welding in Annex A.
BS 8548 gives general guidance for the satisfactory production and control of the welding of steel reinforcement in accordance with the requirements of 85 EN 101 1-2, BS EN ISO 17660-1 and BS EN ISO 17660-2. In order to aid the specifier and manufacturer using these standards, additional informative guidance has been added, especially regarding the steps to be taken to avoid hydrogen cracking.
The procedures and test requirements contained in BS 8548 apply to the assessment of the weld and its potential effect on the welded reinforcement but do not take into account design criteria, e.g. fatigue, that are the responsibility of the relevant application standard.
The preferred method of control of welding is under factory conditions. Construction site welding, if conducted, should be carried out under similar controlled conditions.
These and other products give the designer a broad range of options for specifying pre-assembled welded fabrications.
Reinforcing steel bars manufactured in accordance with the requirements of BS 4449 and 85 4482 are produced by a number of differing process routes, typically quenched and self tempered, cold reduced and to a lesser extent micro-alloyed steel. In addition to this the profile of the reinforcement bar is ribbed and as such the welding of steel reinforcement requires a specific level of skill and job knowledge, both for the welder and the organization exercising control over the whole process, from purchasing of the steel to the eventual supply of the prefabricated item to the customer.
Whilst the specific requirements for the welding of steel reinforcement are set out in BS EN ISO 17660-1 and 85 EN ISO 17660-2, BS 8548 gives general guidance for the satisfactory production and control of welding and details some of the possible detrimental phenomena which might occur, with advice on the methods by which they can be avoided.
The recommendations in this standard are relevant to the metal arc welding processes, which are commonly used for the welding of reinforcing steels, although other welding processes may be used by agreement between the contracting parties.
1 Scope
BS 8548 gives guidance for the metal arc welding of reinforcing steel bars produced in accordance with 85 4449 and BS 4482 and welded in accordance with the requirements of 85 EN ISO 17660-1 and BS EN ISO 17660-2.
The welding of stainless reinforcing steels is not covered by this standard.
BS 8548 can be used by clients, specifiers, construction companies and fabricators of welded steel reinforcement as a means of agreeing the technical requirements of welded steel reinforcement.
BS 8548 applies to the welding of load bearing joints (structural and semi-structural) and non-load bearing joints, including prefabricated assemblies, produced either in a factory, workshop or in a site environment. It also applies to the welding of reinforcing steels to other steel components such as connection devices, inserts, and anchors.
BS 8548 gives recommendations on the information to be included in the Project Specification and also covers the materials of construction, methods for the approval of welding procedures and welding, workmanship, inspection, testing and acceptance requirements for the welded joints. It can be used for all types of reinforced concrete structures designed for static loading conditions.
The recommendations in BS 8548 can be introduced into a construction contract by a Project Specification.
V does not apply to factory production of welding fabric and lattice girders using multiple spot welding machines. Annex A addresses the requirements for the friction welding of steel products to reinforcement.
BS 8548 gives general guidance on joints between reinforcing steels and other steel components. It only includes more detailed information on the most commonly used joints.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
BS 4449:2005+A3:2016, Steel for the reinforcement of concrete — Weldable reinforcing steel — Bar, coil and decoiled product — Specification BS 4482, Steel wire for the reinforcement of concrete products — Specification BS EN 1011-2:2001, Welding — Recommendations for welding of metallic materials — Part 2: Arc welding of ferritic steels
BS EN 10020:2000, Definition and classification of grades of steel
BS EN ISO 2553, Welding and allied processes — Symbolic representation of drawings — Welded joints
BS EN ISO 3834-2, Quality requirements for fusion welding of metallic materials
— Comprehensive quality requirements
BS EN ISO 4063:2010, Welding and allied processes — Nomenclature of processes and reference numbers
BS EN ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) — Quality levels for imperfections BS EN ISO 9015-1, Destructive tests on welds in metallic materials — Hardness testing — Part 1: Hardness test on arc welded joints
BS EN ISO 9606-1:2013, Qualification testing of welders — Fusion Welding — Part 1: Steels
BS EN ISO 13916, Welding — Guidance on the measurement of preheating tempera ture, interpass temperature and preheat maintenance temperature
BS EN ISO 14731:2006, Welding coordination — Tasks and responsibilities
BS EN ISO 15613:2004, Specification and qualification of welding procedures for metallic materials — Qualification based on pre-production welding test
BS EN ISO 15614-1, 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
85 EN ISO 15620, Welding — Friction welding of metallic materials
85 EN ISO 15630-1, Steel for the reinforcement and prestressing of concrete — Test methods — Part 1: Reinforcing bars, wire rod and wire
BS EN ISO 15630-2, Steel for the reinforcement and prestressing of concrete — Test methods — Part 2: Welded fabric
85 EN ISO 17639, Destructive tests on welds in metallic materials — Macroscopic and microscopic examination of welds
85 EN ISO 17660-1, Welding — Welding of reinforcing steel — Part 1: Load-bearing welded joints
85 EN ISO 17660-2, Welding — Welding of reinforcing steel — Part 2: Non load-bearing welded joints
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of BS 8548, the following terms and definitions apply.
3.1.1 company welding coordinator
person or persons responsible for ensuring that welding is performed in accordance with the defined welding conditions, procedures and practices
3.1.2 customer
Individual, or company, placing the contract with the manufacturer
3.1.3 factory
suitably enclosed rigid structure, consisting of a solid floor, walls and ceilings and constructed from recognized construction materials, providing a weatherproof envelope for the assembled products being welded so as to protect them from deleterious environmental factors such as wind, rain and snow
3.1.4 load bearing welded joint
welded joint for the transmission of specified loads between reinforcing steel bars, or between a reinforcing steel bar and other steel products
NOTE There are two types of load bearing welded joints in pre-assembled welded fabrications: semi-structural joints and structural joints.
31.5 manufacturer
enterprise carrying out the welding works within workshops or on site
5 Materials — Parent materials
5.1 Reinforcing steels
Reinforcing steels should conform to the requirements of BS 4449 or BS 4482.
5.2 Other steel components
Other steel components should have carbon equivalent, sulphur and phosphorus levels not greater than those specified in 7.1 of BS 4449:2005+A3 and in BS 4482 for the reinforcing steel being welded. Other steel components may include hot rolled products of structural steels in accordance with BS EN 10025.
5.3 Material test certificates
All the steels being welded should have a material test certificate available which should include the carbon equivalent value (ç) and the manufacturing process route.
5.4 Welding consumables
5.4.1 General
Welding consumables should be designated in accordance with the relevant product standard. Consumables should be selected with regard to the particular application, e.g. joint design, welding position and the properties required to meet the service conditions. Any special recommendations given by the manufacturer/supplier should be observed.
Many welding consumables are now required to be CE marked and relevant documentation should be verified before use of materials.
5.4.2 Supply, storage and handling
All consumables should be stored and handled with care and in accordance with the relevant standards and/or the manufacturer’s/supplier’s recommendations. All covered electrodes, wire electrodes, rods and fluxes, etc. as well as their packaging, which show signs of damage or deterioration should not be used. NOTE Examples of damage or deterioration are cracked or flaked coatings on covered electrodes, rusty or dirty wire electrodes and wire with flaked or damaged protective coatings.
Consumables returned to the stores should be treated in accordance with the manufacturer’s/supplier’s recommendations before re-issue.
6 Workmanship — Welding processes and joints
6.1 Welding processes
The welding processes covered by this standard are listed in Table 2. Other welding processes may be used by agreement between the contracting parties.
Table 2 List of most common welding processes
Welding process — Ref Term
No. from BS EN ISO 4063
111 metal-arc welding with covered electrode (MMA)
131 metal-arc inert gas welding (MIG welding)
135 metal-arc active gas welding (MAG welding)
8.2 Validity of welder qualification test
A welder qualified in accordance with Clause 8 should remain qualified within the range of the original qualification for three years, provided the welder is confirmed as having worked in the range of qualification every six months. After this time, the welder should undertake the revalidation tests or the qualification may be prolonged in accordance with BS EN ISO 9606-1. For prolongation of the welder qualification for load bearing joints, records of at least eight production weld tests, welded in the most difficult position, should have been documented in the preceding 24 months. For prolongation of the welder qualification for semi-structural joints, records of at least four production weld tests, welded in the most difficult position, should have been documented in the preceding 24 months. For prolongation of the welder qualification for locational welded joints, records of at least four production weld tests should have been documented in the preceding 24 months. Prolongation of the plate fillet weld joint is not required.
8.3 Production weld test
A production weld test should be carried out to verify that the same quality of weld is produced under local fabrication conditions as for the weld procedure qualification. The number of test pieces required for each welder and WPS are set out in Table 9.
The production weld tests should be prepared in the most difficult welding position used during production.
In the case of routine work under factory conditions, weld tests should be undertaken at least every three months (structural joints) or six months (semi-structural joints). For welding under site conditions, tests should be taken at the start of the contract and every month thereafter.