中文摘要：

采用量热仪、X射线衍射仪、环境扫描电子显微镜、压汞仪分析了无水石膏及α-半水石膏对铝酸盐水泥为主的铝酸盐-硅酸盐混合水泥体系早期水化放热、浆体微结构演变等水化进程的影响.结果表明：无论何种石膏掺入后,三元体系的早期水化均有所加速,且集中于钙矾石的生成及其向单硫型水化硫铝酸钙的转变——水化30min内,浆体中均生成了一定量长度为1μm左右的短粗钙矾石晶体,并伴随首个水化放热峰的产生;而随后的8h内,另产生两个水化放热峰：掺无水石膏时,第2个水化放热峰源自无水铝酸钙和无水石膏的溶解以及少量钙矾石晶体的生成,第3个水化放热峰源自钙矾石的增长及其向单硫型水化硫铝酸钙的转变;而掺α-半水石膏时,这两个水化放热峰均与钙矾石的生成及增长有关.相比而言,α-半水石膏因溶解速度较快,与无水铝酸钙等的溶解速度相匹配,所以水化早期生成更多的钙矾石晶体,所得硬化浆体的孔隙率更低.

英文摘要：

This paper deals with the heat release and paste microstructure during the early hydration of calcium alu- minate cement-Portland cement-calcium sulfate （anhydrite or α-hemihydrate） blends by means of calorimetry, X- ray diffraction, environmental scanning electronic microscopy and mercury intrusion porosimetry. The results show that （1） when calcium sulfate is blended with the binder, the early hydration accelerates and is dominated by the formation of ettringite as well as the corresponding transition into hydrated mono-sulphate ; （ 2 ） in the first 30 mi- nutes of hydration, short and coarse ettringite in a length of about 1 p,m forms in the matrix, which leads to the oc- currence of the first heat evolution peak ; （ 3 ） in the following 8 hours, another two obvious heat evolution peaks occur, one resulting from the dissolution of calcium aluminates and anhydrite as well as the formation of etttingite in the paste with anhydrite, the other resulting from the growth of etttingite and the formation of mono-sulphate; （4） for the paste with a-hemihydrate, both of these two peaks are attributed to the formation and growth of etttingite; and （5） thanks to its rapider dissolution than anhydrite, α-hemihydrate matches well with the dissolution of calcium aluminate, so that the paste with α-hemihydrate contains more ettringite and exhibits lower porosity.