Alkali-silica reaction (ASR) in the alkali-activated cement (AAC) system: A state-of-the-art review

Abstract Although alkali-activated cement has received worldwide attention due to its lower energy consumption and environmental impact than that of traditional ordinary Portland cement (OPC), high alkalinity activators generally used for activation may cause ASR deterioration and limit its commercial use. This paper reviews the development of knowledge on ASR in alkali-activated mortars or concretes. Apart from the influence of aggregates, activators, and binders, the applicability of existing test and mitigation methods which were developed based on OPC system are also discussed. Overall, compared to low-calcium AAC system, high-calcium system and hybrid system are more likely to suffer from ASR-induced expansion. Effect of binder chemistry, aggregates properties, dosage and silicate modulus of alkali-activators on the performance of ASR in AAC system are interdependent to each other. However, there still exist many questions on the ASR behavior in the AAC system, and this needs more studies to comprehensively and systematically investigate them to understand the fundamental mechanism of ASR in the AAC system and bridge the knowledge gaps.