超缓凝是高性能混凝土技术中的一个重要内容。本文对酒石酸钾钠、氧化锌、柠檬酸糖蜜缓凝减水剂等几种常用级凝剂在高掺量情况下的缓凝性能进行了研究。试验表明，糖蜜缓凝减水剂随掺量增加缓凝作用逐渐消失，当掺量达到0．5％时转而促凝；在高掺量情况下，酒石酸钾钠和柠檬酸有显著的缓凝作用，在掺加量较低时，以氧化锌的缓凝效果最为显著。除此之外还探讨了上述四种缓凝剂对水泥砂浆抗压强度的影响。 Ultra retardation is an important part of high performance concrete technology. In this paper, the retardation properties of several commonly used coagulants such as sodium potassium tartrate, zinc oxide, and citric acid-reducing and reducing water-reducing agent under high dosage were studied. Tests showed that the retarding effect of the retarder of the molasses retarder gradually disappeared with the increase of the content of the additive, and when the content of the additive reduced to 0.5%, the coagulation was converted to procoagulant; in the case of the high content, potassium sodium tartrate and citric acid were significantly slowed down. In the case of coagulation, the retardation of zinc oxide is the most significant when the blending amount is low. In addition, the influence of the above four retarders on the compressive strength of cement mortar was also discussed.