通过在水泥基材料中加入矿物掺合料硅灰,利用差示热膨胀测试方法对其热膨胀率进行了研究,结果表明:掺入硅灰的水泥石热膨胀率变化趋势与纯水泥石相似,均表现为随着温度的升高先增加后显著降低的规律,而硅灰的加入使水泥石在高温时产生比纯水泥石更大的收缩。借助于TG-DTA和XRD测试手段,对掺加硅灰后水泥石的热膨胀性能变化规律进行了机理分析,得出硅灰的掺入形成了大量C-S-H凝胶,高温作用下凝胶脱水使其体积明显收缩的结论。 The thermal expansion coefficient of cement admixture was calculated by differential thermal expansion test. The results show that the change trend of thermal expansion coefficient of cement stone with silica fume is similar to that of pure cement, As the temperature increases first and then significantly reduce the law, and the addition of silica fume cement paste produced at high temperatures than pure cement larger contraction. By means of TG-DTA and XRD test, the mechanism of thermal expansion of cement stone mixed with silica fume was analyzed. The results showed that a large amount of CSH gel was formed by silica fume incorporation, and the gel dehydrated under high temperature The volume was significantly reduced conclusion.