水化硅酸钙的形貌调控及其在水泥水化中的作用

Calcium Silicate Hydrate Morphology Control and Its Effect on Cement Hydration

采用化学沉淀法制备无定形、球状、针状、层状等不同形貌的水化硅酸钙(C-S-H),探究了表面活性剂十二烷基苯磺酸钠(SDBS)和十六烷基三甲基溴化铵(CTAB)与C-S-H形貌和结构之间的变化规律,研究了不同形貌的C-S-H对水泥性能的影响。发现当表面活性剂浓度大于临界胶束浓度(CMC)时,水泥水化热与水泥强度之间存在显著相关性。通过C-S-H形貌设计得到不同微观形貌的水泥制品,其增强效果由高到低依次是无定形、球状、针状、层状。该实验结果对于普通水泥的性能改善具有一定的指导意义。

In the cement industry,the morphological control of calcium silicate hydrate(C-S-H)and its impact on cement hardening and hydration are important research topics.This study investigated the impact of template agents on C-S-H morphology and structure.By using chemical precipitation,amorphous,spherical,needle-like,and layered C-SH with the template agents being sodium dodecyl benzene sulfonate(SDBS)and cetyl trimethyl ammonium bromide(CTAB)were prepared.An increase in SDBS concentration resulted in the transformation of the C-S-H morphology from disorderly to spherical,rod-shaped,and vesicular.When CTAB was used,an increased concentration resulted in the transformation of the C-S-H morphology from disorderly to spherical and layered.When the template agent concentration was greater than the critical micelle concentration(CMC),both the C-S-H crystallinity and CMC value decreased.The impact of different C-S-H morphologies on cement performance particularly cement hydration was also evaluated and analyzed.A significant correlation between cement hydration heat and strength was verified.Different microscopic C-S-H morphologies were used to design cement products,allowing the improvement of cement performance to varying degrees.Experimental results would provide an insight into the improvement of the performance of ordinary cement.