Effects of incorporating colloidal nano-silica and metakaolin on mitigating alkali-silica reaction

Alkali-silica reaction (ASR) is a critical durability concern, as it can reduce the service life of structures and increase carbon emissions due to the need for early repair or replacement. In this study, the effects of incorporating colloidal nano-silica (CNS) and metakaolin (MK) to mitigate ASR have been investigated. The results show that the incorporation of CNS and MK effectively suppressed the ASR in mortar. As the CNS content increases from 4% to 6%, ASR induced length expansion decreases by 58%. On day 16, the CH content in the sample containing 10% MK and 2% CNS was 48% lower than that of the reference sample. Moreover, on day 16 following the alkali-silica reaction, the compressive strength of both the MCNS-6% and MMK10CNS-2% samples were approximately 45% higher than that of the reference sample.