缓凝剂对高胶凝性水泥水化硬化的双临界影响效应

对比不同种类水泥,研究了缓凝剂（蔗糖及葡萄糖）对高胶凝性水泥水化硬化的影响。结果表明，高胶凝性水泥对缓凝剂表现出敏感的反应特性,在合理掺量范围内,使缓凝效果加强,在非正常掺量下,使异常凝结特性加剧,并且掺量范围较传统水泥更窄。水化热也表现出双鞍峰现象,在合理掺量下,水化放热被有效延缓、降低,随着掺量的增加,第一峰被加剧,第二峰被明显削弱,当掺量达一定值时,第二峰的测试时间已经消失,凝结时间表现为促凝,因此,这类缓凝剂对水泥的水化、硬化存在双临界效应,这种效应在高胶凝性水泥中表现更为突出。

Double-critical effect of retarders on the hydration and hardening process of cement with high cementing property

The influences of retarders(sucrose and glucose) on hydration and hardening process of cement with high cementing property(HCC) through comparison of different kinds of cements are studied.The results show that the reactions between retarders and cement with high cementing property are more sensitive than common cements.The setting retarding effect and the abnormal setting characteristic are strengthened when at reasonable dosage and unreasonable dosage respectively.The range of reasonable dosage in high cementing property cement is narrower than that of in common cement.The hydration heat of HCC demonstrates the saddle phenomenon,i.e.the first peak of hydration heat is enhanced and the second peak is retarded and reduced greatly when retarders at reasonable amount.But when the dosage is beyond the reasonable amount,the second heat peak disappears during the testing age and the paste setting is very quickly.So this kind of retarders makes cement hydration and hardening process show double-critical effect,especially in the HCC.