ABSTRACT
The term ‘alkali-carbonate reaction’ (ACR) would appear to apply to a reaction between the alkaline pore solution in concrete and any aggregate made from carbonate rocks such as limestones or dolostones (dolomite rocks). However, the term alkali-carbonate reaction is really applied only to the reaction between certain argillaceous dolomitic limestones and the alkaline pore solution in concrete that gives rise to rapid expansion and cracking of concrete. In North America the ACR dolomitic limestones are of Ordovician age, but in the Sichuan Province of China, some are of Triassic age. RILEM considered the use of carbonate-aggregate reaction (CAR) instead of ACR, but the latter was too established.
