The result shows, for this composite cement system, retarding action of dihydrate gypsum is more obvious than that of anhydrite, meanwhile, anhydrite tends to cause setting time short and water needed increased.

• 结果表明：二水石膏对该种复合体系水泥的缓凝作用比硬石膏明显，硬石膏易引起复合体系水泥急凝和需水量增大。