硫铝酸盐基促强减缩剂与硫铝酸盐水泥对比分析

将硫铝酸盐基促强减缩剂(SP-SRA)掺入到基准水泥中,并且按一定的比例设计了硫铝酸盐熟料-硬石膏-基准水泥的配合比,对宏观性能、水化过程、微观产物进行了对比分析.结果表明:掺SP-SRA的水泥各个龄期抗压抗折强度均高于硫铝酸盐熟料-硬石膏-基准水泥三元体系;掺SP-SRA的水泥早期水化放热速率大于硫铝酸盐熟料-硬石膏-基准水泥三元体系;XRD结果表明,掺SP-SRA的水泥水化生成的AFt(三硫型水化硫铝酸钙即钙矾石)含量多于三元体系生成的AFt,钙矾石的微膨胀性使得水泥石结构更加致密,有利于提高水泥石的强度,硫铝酸盐熟料-硬石膏-基准水泥体系有明显的AFm(单硫型水化硫铝酸钙)生成,即部分AFt转化成AFm.

Comparison of Sulphoaluminate-based Strength-promoting and Shrinkage-reducing Admixture with Sulphoaluminate Cement

The sulphoaluminate-based strength-promoting and shrinkage-reducing admixture(SP-SRA) was added into the standard cement, and sulphoaluminate clinker-anhydrite-standard cement was designed according to a certain proportion.By comparing the macro-performance, the hydration process and the micro-products of the two systems, the conclusions were drawn.The results show that the strength and the hydration heat release rate of the standard cement with SP-SRA is higher than the ternary system of sulphoaluminate clinker-anhydrite-standard cement, XRD show that the AFt content of the standard cement with SP-SRA is more than the ternary system.The expansibility of ettringite makes the structure of cement stone more dense, which is helpful to improve the strength of cement stone.There is obvious AFm formation in the sulphoaluminate clinker-anhydrite-standard cement system, that is, part of AFt is transformed into AFm.