BRE SD3 PDF

After a few well-publicised building collapses in the early 1970s, reference to high alumina cement concrete (HACC) was deleted from the code of practice for the structural use of concrete but much remains in service. This Digest explains current guidance for the assessment of HAC concrete construction, taking account of developments since 1975. It focuses principally on buildings containing the more common pre-cast, pre-stressed 'I' or 'X' beams, and not on cast in-situ HACC, which is typically of much lower quality. Recent information comes mostly from site investigations of structures; the findings have a bearing on how HAC construction should be appraised. This Digest also describes testing regimes to identify HACC and check for cases of chemical attack. It assesses the current level of protection afforded to the reinforcement and gives advice on durability management, maintenance and refurbishment. Digest 392 is now withdrawn.