Role of temperature on Alkali-Silica reaction and the efficacy of supplementary cementitious materials

Supplementary cementitious materials (SCM) are used in concrete to prevent expansion due to alkali-silica reaction. However, studies reported higher expansion in the field compared to that of laboratory samples, likely due to different exposure conditions. This paper investigates the effect of temperature on alkali release from aggregates, alkali leaching from concrete samples, and hydration and alkali-binding capacity of SCM. Aggregates contribute more alkalis to alkaline solutions at higher temperatures. Hydration of the tested cementing blends and their capacity to bind alkalis were highest at 38ºC, followed by 60ºC and 23ºC. The expansions of concrete cylinders at 60ºC are compared to those of the standard Concrete Prism Test.