Relation between mechanical properties of concrete and alkali-silica reaction (ASR); a review

Abstract Alkali-Silica Reaction (ASR), as a harmful internal reaction in concrete, produces deleterious gel, which occurs due to the reaction between the reactive silica in the aggregate and the alkalis of the pore solution. Because of having hydrophilic groups, imbibes water from surrounding to expand to greater volume. This expansion is not damaging as long as the ASR gel fills the cavities completely and exerts pressure to its surroundings. In addition, it can produce and extend the cracks when the conditions are favorable and the gel has a deleterious expansion. Generating new cracks and extending the existing ones can affect the consistency and solidity of the concrete, which could ultimately alter its properties. Therefore, in the cases which are susceptible to ASR, it is essential to investigate the effect of cracks on the mechanical properties of the concrete. The present study aimed to review the studies evaluating the relationship between ASR and the mechanical properties of the concrete. The results showed that ASR can significantly affect and reduce the properties of the concrete, but the amount of this reduction is not the same for different aggregates and mechanical properties due to the differences in aggregates reactivity and the nature of the test methods for mechanical properties (e.g., compressive, flexural, tensile strength). The findings indicated that modulus of elasticity and tensile strength have the highest susceptibility to ASR progress. In addition, the reduction has a good correlation with the expansion of mortar and concrete specimens in some properties of the concrete and can be considered as a good test method for evaluating the reactivity of the aggregates.