外掺料对石膏基复合材料力学性能的影响

固体废弃物石膏的再利用和高强高性能石膏材料的开发一直是国内外学者研究的热点。以脱硫建筑石膏、水泥和矿渣为主要原料，掺加化学外加剂、化工废石膏和硫酸钙晶须，制备出石膏-水泥-矿渣复合材料。研究聚羧酸高效减水剂和柠檬酸缓凝剂、化工废石膏和硫酸钙晶须的掺量对该复合材料力学性能的影响。研究结果表明:聚羧酸高效减水剂和柠檬酸缓凝剂在石膏基复合材料中的最佳掺量分别为1.0%和0.08%。当煅烧化工废石膏掺量为12%时，石膏基复合材料的7 d抗折和抗压强度分别为3.7 MPa和12.0 MPa，其中抗压强度比空白样还高了0.1 MPa。当硫酸钙晶须的掺量增加到3%时，掺有煅烧化工废石膏的石膏基复合材料的28 d抗折强度为8.2 MPa，28 d抗压强度为31.5 MPa，其值和未掺化工废石膏和硫酸钙晶须试样的力学性能相当。 

Effects of Admixtures on Mechanical Properties of Gypsum Matrix Composites

The reuse of solid waste gypsum and the development of high strength and performance gypsum materials have always been the focus of domestic and foreign scholars. Gypsum-cement-slag composite materials were prepared by adding chemical additives, chemical waste gypsum and calcium sulfate whisker as main raw materials of desulfurization building gypsum, cement and slag. The effects of the content of polycarboxylic acid superplasticizer and citric acid retarder, chemical waste gypsum and calcium sulfate whisker on the mechanical properties of the composites were researched. The results showed that the optimum dosages of polycarboxylic acid superplasticizer and citric acid retarder in gypsum matrix composites are 1.0% and 0.08%, respectively. When the content of calcined chemical waste gypsum is 12%, the 7 d flexural strength and compressive strength of gypsum matrix composites are 3.7 MPa and 12.0 MPa, respectively. The compressive strength is 0.1 MPa higher than that of the control sample. When the calcium sulfate whisker content increases to 3%, the 28 d flexural and compressive strength values of gypsum-based composites with calcined waste gypsum are 8.2 and 31.5 MPa, which are equivalent to the mechanical properties of samples without waste gypsum and calcium sulfate whisker.