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

Supplementary cementitious materials (SCM) are used in concrete to reduce expansion due to alkali-silica reaction. However, studies reported higher expansion in the field compared to that of laboratory samples. 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 38 degrees C, followed by 60 degrees C and 23 degrees C. The expansions of different sample shapes at different temperatures and times are compared, and the possibility of reducing the testing duration is examined.