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.