脱硫建筑石膏-水泥复合胶凝材料制备及性能

Preparation and Performance of Desulfurized Building Gypsum-cement Composite Cementitious Materials

以脱硫建筑石膏为基材、水泥为外掺料,加入减水剂制备得到脱硫建筑石膏-硅酸盐水泥复合胶凝材料,通过研究减水剂与水泥的类型及掺量、水泥掺入方式及制样养护工艺对复合胶凝材料力学性能和耐水性能的影响,确定最佳配合比和最佳制备工艺。实验结果表明:以水胶比为0.55、脱硫建筑石膏与42.5普通硅酸盐水泥的质量比为1∶0.18、萘系减水剂掺量为1%的配比进行制样,其中水泥采用经预水化2 h的方式掺入,采取先湿热养护6 h(温度为50℃,湿度为95%以上),后自然养护得到的复合胶凝材料综合性能优异,测得其7 d抗折强度、抗压强度、软化系数依次为5.6 MPa,18.8 MPa,0.81。

Desulfurized building gypsum portland cement composite cementitious material was prepared by adding water reducing agent and using desulphurization gypsum as base material and cement as admixture.By studying the influence of the type and amount of water reducing agent and cement,the mixing method of cement and the preparation and curing process on the mechanical properties and water resistance of the composite cementitious materials,the optimal mix proportion and preparation technology were determined.The experimental results show that the composite cementitious material has excellent comprehensive properties when the water binder ratio is 0.55,the mass ratio of desulfurized building gypsum and 42.5 ordinary portland cement is 1∶0.18,and the content of naphthalene series water reducer is 1%,in which the cement is mixed by prehydrated for 2 h,and then cured naturally after 6 h of wet heat curing(temperature of 50℃and humidity of more than 95%).The 7 d flexural strength,compressive strength and softening coefficient are 5.6 MPa,18.8 MPa and 0.81 respectively.