The Retardation Effect of Super-Retarding Polycarboxylate-Type Superplasticizer on Cement Hydration

In view of the problems existed in water reducing agent and the request of setting time for Large-scale projects and according to the study on modification of LK poly carboxylic acid water reducing agent, super-retarding poly carboxylic acid water reducing agent LKS was successfully developed, which has high water reducing rate, good slump retention ability and more than 20 h retarding time. The retarding time can be achieved by adjusting adding amounts of LKS. The effect of LKS on the setting time, hydration heat, rheological properties and zeta potential were system researched. the results showed that the super-retarding poly carboxylic acid water reducing agent LKS had good adaptability to cement and had no adverse effect on the cement. The retarding mechanism was discussed.