建筑石膏的复合磷酸盐缓凝剂及缓凝型膨胀剂

Setting compound phosphate retarder and reduced type expanding agent for building gypsum

在研究建筑石膏的复合磷酸盐缓凝剂基础上，探讨了缓凝型膨胀剂对建筑石膏凝结硬化性能和膨胀性能的影响．碱金属磷酸盐与建筑石膏作用后使料浆ＰＨ 值升高，液相呈碱性，处于碱性环境中的铵盐在建筑石膏水化热的促进下产生ＮＨ３ 气，推动料浆膨胀．

Based on the investigation into the setting retarder with compound phosphate of building gypsum,the paper discusses the effect of the reduced type expanding agent on the expanding and hardening properties of building gypsum.The PH value of building paste increases due to the reaction between the alkali phosphate and the paste and ammonia phosphate in alkali liquid phase produces ammonia gas and the gas makes the paste expand under hydration heat of building gypsum.