A Critical Assessment to the Performance of Alkali-Silica Reaction (ASR) in Concrete

Alkali-silica reaction is one of the most recognized deleterious phenomenon in concrete that results in excessive expansion, cracks, loss in mechanical properties and serviceability problems. This paper reports overview of alkali-silica reactivity (ASR) in concrete including background, chemistry behind ASR, factors affecting ASR, and symptoms of ASR. The aggregates susceptible to ASR were evaluated using field performance, petrographic analysis, aggregate mineralogy and the standard and modified methods of ASTM C 1260 and C 1293, and their modifications. Aggregate classifications into innocuous and reactive based on the stated mineralogy tests, and the expansion limits of the standard methods and their modifications were compared. The study demonstrated that none of the single method is an ideal approach to evaluate the alkali-silica reactivity of an aggregate, and a suitable combination of various methods can be utilized to better predict the potential ASR reactivity of an aggregate.