石膏基胶凝材料与砌块的配比优化及性能研究

以建筑石膏为主要原料,掺入适量的硅酸盐水泥和石膏晶须制备石膏基胶凝材料及砌块,基于Minitab中的"混料设计"原理,确定了石膏基胶凝材料的最佳配比;通过掺入有机硅憎水剂,提高了石膏基胶凝材料及砌块的耐水性。结果表明:石膏晶须能降低石膏基胶凝材料及砌块的表观密度,且可以水化生成二水石膏,与其它轻质材料相比,可有效减少石膏基胶凝材料及砌块的强度损失。以建筑石膏52.2%、硅酸盐水泥27.4%、石膏晶须20.4%,外掺3%有机硅憎水剂制备的600 mm×500 mm×100 mm实心石膏砌块,表观密度可降到965 kg/m^3,断裂荷载为3260 N,软化系数为0.65,符合JC/T 698—2010《石膏砌块》的要求。

Study on ratio optimization and properties of gypsum based cementitious materials and blocks

In this paper,building gypsum is used as the main raw material,and appropriate amount of Portland cement and gypsum whiskers are used to prepare gypsum based cementitious material and block. Based on the "mixture design" principle in Minitab,the optimum proportion of gypsum based cementitious material is determined. The addition of organosilicon hydrophobic agent improves the water resistance of gypsum based cementitious materials and blocks. The experimental results show that gypsum whisker can reduce the apparent density of gypsum based cementitious and block,can be hydrated to form dihydrate gypsum. Compared with other lightweight materials,it can effectively reduce the strength loss of gypsum based cementitious and block. The apparent density of 600 mm×500 mm×100 mm solid gypsum block prepared by gypsum 52.2%,Portland cement 27.4%,gypsum whisker 20.4% and 3% organosilicon hydrophobic repellent can be reduced to 965 kg/m3,the fracture load is 3260 N and softening coefficient is 0.65,which meets the requirements of the standard JC/T 698-2010 "Gypsum block".