New UK guidance on the use of concrete in aggressive ground

Abstract

The UK guidance for specification of concrete in aggressive ground has been revised following the discovery of the thaumasite form of sulfate attack in the foundations to highway bridges in England in 1998. Interim advice was issued in the Report of the Thaumasite Expert Group in January 1999. Following consultation with industry, a new BRE Special Digest 1 was published in September 2001 (to replace Digest 363) and parallel amendments to the current BS 5328 were drafted. New concepts are introduced for ground assessment and concrete specification. Allowance is now made for the oxidation of sulfides in the ground and there is a new classification for the aggressive chemical environment. Concrete specification additionally takes into account the required structural performance level, the carbonate content of aggregates, and the need for additional protective measures. Compatible guidance is being put in place for the UK Highways Agency and for BS 8500, the UK complementary standard to the European Standard BS EN 206-1, which will replace BS 5328 in December 2003.