Cement hydration kinetics study in the temperature range from 15 °C to 95 °C

The heat evolution during the hydration of cement was examined by multiple calorimetric methods: isothermal , oscillating isothermal, as well as temperature scanning tests in the temperature range from 15 °C to 95 °C. The apparent activation energy ( E a ) of several different types of cements were all found to decrease significantly with temperature. Type of additives and water to cement ratio had little influence on the temperature dependence of E a . The correlation between E a and temperature may be mathematically simplified to a step function, where E a is a nonzero constant below a critical temperature ( T cr ) and reduces to zero above that temperature. The proposed model of E a was combined with a scale factor model to simulate the influence of curing temperature on the hydration kinetics of cement with significantly improved accuracy compared to an earlier model.