ABSTRACT
The developing awareness and acceptance of alkali-silica reaction (ASR) in the UK is traced from the late 1940s to the present day. Seemingly extensive studies at the Building Research Establishment during the 1950s were optimistically interpreted by the construction industry as reassurance, and this led to more than a decade of near-complacency when ASR was widely regarded as ‘a foreign problem’. In the early 1970s, however, major structures in Jersey and on the UK mainland, particularly in the south-west and Midlands of England, were found to be damaged as the result of ASR. Some of the earlier examples of structures recognised as being damaged by ASR are described, and the particular types of aggregate combinations involved are examined. An attempt is made to assess the current extent of the occurrence of ASR in the UK and to analyse the scale of damage typically found; some unusual examples are included. Guidance and specifications developed in the UK to minimise the risk of ASR in future concrete construction are explained in detail, and the prospects of developing an adequately predictive test are fully discussed. Finally, critical consideration is given to the most recent advice on diagnosis, the appraisal of affected structures in the UK and the possibilities of management or repair. The outlook is concluded to be generally encouraging, but some newly discovered aspects, including the important role of externally derived alkalis, are briefly considered.
