基于水化动力学模型的水泥基材料温度效应

为探究温度对水泥浆水化过程的影响，采用等温量热仪测试了水泥浆样品在20，30和40 ℃的水化放热量和水化放热速率，获得了水化度α和表观活化能Ea并利用Krstulovic-Dabic模型计算了相应阶段动力学参数K和n，探讨不同温度的水泥浆体的水化机理。结果表明，水化动力学参数随温度升高显著增大，水泥浆在20~40 ℃的水化表观活化能Ea为37.63 kJ/mol，且升高温度促进0~72 h内水泥水化度的增长。20 ℃下的水泥浆具有NG-I-D过程，而30 ℃和40 ℃下的水泥浆只具有NG-D过程，表明升高温度使水化阶段的持续时间缩短，且反应速率加快。研究可为水泥基材料在不同环境温度下施工时控制浇筑时间以及掌握强度的发展趋势，提供一定的理论依据。

Temperature Effect of Cement-Based Materials Based on Hydration Kinetics Model

The rates of hydration heat evolution and hydration heat of cement paste samples were determined at 20，30 and 40 ℃ respectively to investigate the effect of temperature on the hydration process of cement pastes by an isothermal calorimeter during 72 h. The hydration degree [α] and the apparent activation energy Ea were obtained，and the hydration kinetic parameters K and n were calculated according to the Krstulovic-Dabic models for the corresponding stages，revealing the hydration mechanism of the cement pastes at different temperatures. The results show that the hydration kinetic parameters increase significantly with the increase of temperatures，and the apparent activation energy Ea of the cement pastes is 37.63 kJ/mol at 20-40 ℃，moreover，a higher temperature promotes the cement hydration degree within 0-72 h. The hydration of cement paste has an NG-I-D process at 20 ℃，while the hydration of cement paste has only the NG-D process at both 30 ℃ and 40 ℃，indicating that the period of cement hydration was shorter and the hydration rate became faster with the increase of temperature. The research results can provide theoretical basis for site workers to control casting time and predicting strength during the construction of cement-based materials at various temperatures.