Fly ash is an industry by-product of thermal power factories that is broadly utilized in the concrete industry. This research shows a framework for evaluating the hydration heat, reaction amount, and strength progress of cement–fly ash binary composite. First, we conducted an experiment to study the isothermal hydration heat of fly ash composite paste with assorted fly ash contents and temperatures. According to the experimental outcomes of cumulative hydration heat, the coefficients of a kinetic reaction model of fly ash were determined. Furthermore, the reaction amount of fly ash was calculated using a fly ash reaction model. We discovered that the reaction of fly ash is considerably improved at elevated temperatures. The reaction amount of fly ash decreases with the growing content of fly ash. Second, in line with the reaction amount of fly ash and cement, we developed a straight-line equation for evaluating the strength progress of binary composite. The strength progress model applies to a number of water-to-binder ratios and fly ash substitution ratios. Summarily, the suggested hydration–heat–strength model is helpful for understanding the material style of fly ash concrete.

Keywords: Fly ash, Hydration heat, Reaction degree, Strength, Model