The Australian Standard accelerated mortar bar test (AMBT) method, AS 1141.60.1, adopts the expansion limits at two exposure periods to classify the alkali silica reactivity (ASR) of aggregate. This was a first step toward the use of ‘reaction kinetics’ or ‘rate of reaction’ to detect and classify alkali silica reactivity. The AS 1141.60.2 concrete prism test (CPT), on the other hand, uses a single expansion limit at one year to classify ASR. This paper examines the validity of the use of reaction kinetics, evaluated from the AMBT expansion data, to gauge and classify the reactivity. This may enable a better quantification of the degrees of reactivity and a more fundamental approach to ASR mitigatio
