BS 7973-2:2001

This standard BS 7973-2:2001 Spacers and chairs for steel reinforcement and their specification is classified in these ICS categories:

• 77.140.99 Other iron and steel products

This part of this British Standard specifies fixing and application requirements for spacers and chairs sufficient to achieve and maintain cover to reinforcement in in situ reinforced concrete members subject to normal construction loads. Application requirements include tying and spacing.

This British Standard applies to all types of reinforcement conforming to BS 4449 and BS 4482 and some types of welded fabric conforming to BS 4483, supplied to the preferred shapes and tolerances given in BS 8666.

Other important aspects such as clear and unambiguous detailing, the need to consider buildability, formwork tolerances and reinforcement are not specified. Standards of workmanship and supervision are also outside the scope of this British Standard as is a means of resisting wind loads or enabling the lifting of prefabricated reinforcement cages.

NOTE 1 Where appropriate, the basic principles can be applied to precast concrete or proprietary systems.

NOTE 2 Straight reinforcement for curvilinear members to be formed to a radius exceeding the maximum radius of bending given in BS 8666 may require extra tying and support to resist additional loads caused by the springing effect of the bars.