Abstract:Based on Arrhenius equation, the apparent activation energy of calcium sulfoaluminate cement pastes were calculated from the heat of hydration cured at temperatures of 20, 30, 40, 50℃. The apparent activation energy of hydration reaction was calculated by exponential method and linear hyperbolic method, respectively. Meanwhile, the influence of high calcium fly ash and silica fume on the apparent activation energy of hydration reaction of calcium sulfoaluminate cement pastes were also investigated. The results show that the apparent activation energy of calcium sulfoaluminate cement calculated by exponential method and linear hyperbolic method is 4554 and 5544kJ·mol-1 respectively. By comparisons, the apparent activation energy calculated by exponential method is lower than that of the linear hyperbolic method in all samples. In addition, the apparent activation energy of cement composite system increases when the cement mix with 25%, 50% silica fume or 400% high calcium fly ash, but with the addition of 200% high calcium fly ash in the composite system, the apparent activation energy of the cement composite system decreases.