水泥浆体的显微图像和质量随时间变化的测量与分析

用光学显微镜和电子天平相结合的方法，在室温（约290K）、1个大气压、相对湿度约45%的条件下，对水泥浆体的显微图像和质量进行了实时的测量.结果表明，水泥的水化反应可以划分为4个过程：1）0至t1（=8.3min）的I过程，水泥浆体的约化亮度I s随t近似线性增加，同时约化质量m随t线性减小；2） t1至t2（=27.9min）的II过程，Is随t快速近似线性增加，同时m随t线性减小；3）t2至t3（=46.3min）的III过程，随时间t的增加，m先快速、然后缓慢下降到稳定值， Is几乎不变；4）t3以后的VI过程，m和Is不随t变化.水泥浆体质量减少是因为其中水的挥发，其颜色变淡是因为其中CH的形成. t1之前CH的形成率较低，而t1至t2是CH形成率较快的时期， t2之后已经基本没有CH形成.因此， t1、t2分别表征的是诱导期、加速期的结束.从t2至t3时期，浆体中水仍有少量挥发，但已经不再有CH的生成. t3以后，浆体水分挥发得极少，也不再有CH的生成.

The Microscopic Image of Cement Paste and Quality Measurement and Analysis of Change with Time

Integrating light microscope with electronic balance, the microscopic image and mass of the cement paste were measured in real-time under one bar pressure and 45%RH （relative humidity） at room temperature （about 290K）. The result shows that hydration reactions of the cement can be divided into four processes： 1） process-I appears from 0 to t 1 （=8.3min） where the reduced luminance （I） of the cement pastes increases, while the reduced mass （m） decreases with time;2） process-II starts from t1 to t2 （=8.3min）, and during which I goes up rapidly meanwhile m declines with time; 3） process-III emerges between t2 to t3 （=27.9min） where m drops first rapidly and then slowly to a steady value, but I almost keeps constant with time;4） process-IV arises after t3, and both I and m do not vary with time. Combining the knowledge about hydration reaction of cement with the author’s some new ideas, it was proposed that I originates from evaporation of the water, while the fading color results in the form of Ca（OH） 2 （CH）. In the process-I, the formation of CH is at low rate, but the formation rate comes faster during the process-II, and there is no formation of CH after the process-II. So, t1 and t2 expresses, respectively, the end of the initial period and acceleration period. From t2 to t3, a little water of cement still volatilizes, but no CH generates. There is little water to volatilize and CH also does not form after t3.