Study on the Kinetics of Pozzolanic Reaction of Fly Ashes

In this paper, it has been presented that the amount of acid insoluble substance of fly ashes in fly ash Ca(OH) 2 H 2O system are measured by using the acid dissolution method. On this basis, the kinetic model of pozzolanic reaction of fly ash is established. Also, the kinetic parameters, reaction rate constant and activation energy, are obtained. The results show that the pozzolanic reactions of fly ashes conform to the Class I model of kinetics, and the activation energy may act as one of the indexes for evaluating the pozzolanic reactivities of fly ashes. At normal temperature, the afore mentioned kinetic indexes of Class I fly ash collected from selector are not better than those of Class Ⅱ ground fly ashes, but opposite at 80 °C.