Analysis of hydration kinetics and strength progress in cement–slag binary composites

Abstract

Slag is an industry by-product of steel-making factories that is widely found in the concrete industry. This study shows a framework for evaluating the hydration heat, reaction amount, and strength progress of cement–slag binary composites. First, a test is conducted to measure the isothermal hydration heat of slag composite paste at various temperatures. Based on the experimental results with cumulative hydration heat, the coefficients of the kinetic reaction type of slag were determined. In addition, the reaction quantity of slag was calculated utilizing a slag reaction model. It is found that the reaction amount of slag is significantly improved at elevated temperatures. The reaction quantity of slag decreases with an increasing content of slag. Second, using the reaction quantity of slag and cement, a straight-line equation is created for evaluating the strength progress of binary composites. The strength progress model applies to a number of slag substitution ratios and curing temperatures. The hydration-based strength model shows better analysis results than maturity-based models.