INCLUDING CORRIGENDUM 1 (January 2023) and CORRIGENDUM 2 (April 2023)
Temporary condition of reinforcement cages prior to concreting
Part 2 (technical guidance)
Prior to being encased in concrete a reinforcement cage should be considered as an item of temporary works. This guide (‘Part 2’) has been produced to supplement ‘Part 1’ (Ref. TWf2020: 03) by providing further detailed engineering explanation of the issues involved. It also provides design guidance for cages assembled in their final position on site and those pre-fabricated and requiring lifting, transporting and positioning in their final position.
Until a cage is encased in concrete it is a temporary structure made from vertical, longitudinal, diagonal and transverse bars which are generally connected with tying wire, though sometimes welded connections may be used. Tying wire does not contribute to the final strength of the reinforced concrete structure but plays an important part in cage stability prior to concreting. Cages can be pre-fabricated in workshops off-site (especially if welded intersections are preferred), pre-fabricated on-site and lifted into place or assembled in-situ. All these options are susceptible to inaccuracies and variations in workmanship to some extent.
NOTE:In due course, supplementary information will be made available here, LINK
David ThomasTWf Director and Company Secretary11.11.22
NOTE:
Corrigendum 1Corrects some values in Appendix A. (The changes made are indicated on Page 76 - and the front cover annotated.)
Corrigendum 2Amends some of the advice on 'wind loading' on Pages 12 to 14. (The worked examples are, accordingly, marked as "Under Review").#rebar#guide#Part2#technical#guidance