可溶性氯盐对掺不同结构聚羧酸减水剂水泥浆体流变性的影响

摘要

Polycaiboxylate comb-like copolymer (PC) hag been widely used to prepare high-fluidity and self-compaction concrete under low water/cement ratio on account of exceptional dispersion capability and less slump loss. However, due to big variation of the raw material sources in China, big slump loss and pump blockage problem frequently occur during using of polycarboxylate water-reducer. In this article, polycarxylate water-reducer with different molecular structure was synthesized in the laboratory. Effect of soluble salt chloride on rheologicaL performance of PC with different molecular structure was researched. The result showed that influence of salt chloride having sodium ion and calcium ion on shear stress and apparent viscosity of cement paste was similar. But shear stress and apparent viscosity of cement paste increased remarkably,when aluminum chloride was added.%聚羧酸梳型共聚物(PC)具有良好的分散能力和流动度保持能力,因此被广泛应用于低水灰比条件下配制大流动度、自密实混凝土.但由于我国混凝土用原材料地域差别大,在聚羧酸减水剂的使用过程中经常会出现坍落度损失大、堵泵等问题.在实验室合成具有不同分子结构的聚羧酸梳型共聚物,较为系统地研究了可溶性氯盐对掺不同分子结构聚羧酸减水剂水泥浆体流变性的影响.试验研究表明,含有一价钠离子和二价钙离子的氯盐对体系剪切应力和表观黏度的影响大致相同,而三价铝离子氯盐的加入则会显著增大体系在相同剪切速率下的剪切应力和表观黏度.