【摘要】 介绍了水泥基材料的水化动力学模型。根据实验测定的水化放热数据,采用模型给出的积分和微分方程,对水泥基材料的水化反应中的3个基本过程即结晶成核与晶体生长(NG)、相边界反应(I)和扩散(D)进行了表征,得到反应速率常数K、反应级数n和表观活化能Ea等动力学参数以及各反应阶段的反应速率与反应度的关系。计算得到的各阶段的反应速率曲线能较好地分段模拟由量热实验得到的胶凝材料实际水化速率dα/dt曲线。观察3个阶段的相互关系,可对水泥基材料复杂的水化机理进行解释。水泥基材料的水化反应存在两种不同的历程:NG–I–D或NG–D。在水化初期NG是控制因素,随着水化程度提高,逐渐转由I或D控制反应。更多还原

【Abstract】 A kinetic model is introduced for the hydration of cementitious materials. Based on the model and the measured hydration emission heat under isothermal condition, integral and differential equations are derived to simulate the three basic processes in the hydration of cementitious materials: nucleation and crystal growth (NG), interactions at phase boundaries (I) and diffusion (D). The kinetic factors such as reaction rate constant K, reaction exponent n and apparent activation energy Ea are determined. The relationship between the reaction rate and the degree of reaction is discussed at different stages of reaction. The derived reaction rate curves compared well with the hydration rate of cementitious materials obtained from the measured hydration emission heat. An understanding to the complex hydration mechanism of cementitious materials is provided by studying the connection among the three processes. There are two different approaches for the hydration reaction of cementitious materials: NG–I–D and NG–D. NG dominates in the early stage of hydration. I or D becomes the dominating factor gradually as the hydration degree increases.更多还原