Alkali–silica reaction: Kinetics of chemistry of pore solution and calcium hydroxide content in cementitious system

This paper presents the results of the investigations on the chemistry of pore solutions, the contents of calcium hydroxide, and the expansions in mortars containing both reactive and non-reactive aggregates. In order to examine the effect of the temperature, experiments were performed at three different temperatures (23 °C, 38 °C and 55 °C).The compositions of the pore solution were measured at short time intervals for a period of up to 130 days in order to capture the kinetics of the chemistry of pore solution. The results showed that the changes in the concentrations of alkali ions can be best explained by the first order reaction. In addition, the proposed rate equation could reasonably simulate the changes in the actual concentrations of alkalis. Finally, the results in this paper suggest that the rate of the alkali–silica reaction in cementitious system containing highly reactive aggregate can be also expressed as the first order reaction.