用于硫铝酸盐水泥混合材的试验研究

Study on admixture for sulphoaluminate cement

通过混合材活性指数实验,初步筛选出了可用于硫铝酸盐水泥混合材的两类材料:一是石膏类材料,如天然二水石膏、硬石膏及脱硫石膏、氟石膏等;二是石灰石类材料,如天然碳酸钙岩等。其中,以活性指数匹配结果最佳的硬石膏为混合材,研究了硬石膏硫铝酸盐水泥物理及力学性能。结果表明,通过硬石膏掺量的调整和养护制度的设定,可使硬石膏硫铝酸盐水泥达到稳定的膨胀或收缩值;并且随着硬石膏的掺入量增加,水泥初凝终凝时间逐渐延长,pH值逐渐降低,抗压强度呈先增后减趋势。此外,介绍了磷石膏低碱度硫铝酸盐水泥及石灰石硫铝酸盐水泥的一些研究成果。

Two kinds of admixture that can be used in sulphoaluminate cement were screened out by activity index experiment, one kind was gypsum-material like natural dihydrate gypsum, anhydrous gypsum, fluorogypsum, ete, the other kind was limestone-material like natural calcium carbonate, etc. And physical and mechanical performance of anhydrous gypsum sulphoaluminate cement were studied by using anhydrous gypsum which activity index was the best. The results show that by adjusting the adding rate of anhydrous gypsum and the curing system, stable expansion and shrinkage value of the anhydrous gypsum could be reached, and with the anhy- drous gypsum added, the early set time prolonged, the pH value decreased and the compressive strength showed a trend of first increase and then decrease. Futhermore, the research aehivements of low pH value phosphogypsum sulphoaluminate cement and limestone sulphoaluminate cement were introduced.