Effect of colloidal nano-silica on alkali–silica mitigation

Alkali–aggregate reaction was first observed in the US during 1920s. In the last decades, several studies investigated the mechanisms of alkali–silica reaction in concrete and the extent of damage it may cause to the cementitious matrix. Research on alkali–silica reaction mitigation covers mainly the use of supplementary cementitious materials and lithium compounds. However, with possible change in coal burning regulations and fly ash shortages in some areas, it is important to investigate approaches to mitigate ASR that involves lower amounts of supplementary cementitious materials. Furthermore, current research has shown the potential enhancements to concrete microstructure through the use of nano-silica. In the current study, the effect of using nano-silica on the alkali–silica reaction will be investigated. Preliminary results show that nano-silica can help mitigate the effect of alkali–silica reaction.