硫铝酸盐水泥对建筑石膏性能的影响

Effect of sulphoaluminate cement on properties of building gypsum

研究了硫铝酸盐水泥对建筑石膏物理力学性能的影响,结果表明:硫铝酸盐水泥有利于减小建筑石膏的标准稠度需水量,一定程度上降低了浆体初始塑性黏度;硫铝酸盐水泥具有加快建筑石膏水化进程作用,宏观上表现为凝结时间大幅缩短,塑性黏度迅速增大,对浆体的工作性起到负面影响;硫铝酸盐水泥对建筑石膏增强改性的临界掺量为20%,3d抗折强度从空白样的5.47MPa大幅提高到10.23MPa,3d抗压强度从空白样的11.59MPa大幅提高到22.36MPa;当龄期延长至28d,硫铝酸盐水泥对建筑石膏的增强效果表现出一定的倒缩现象;硫铝酸盐水泥增大了建筑石膏的体积密度,降低吸水率,大幅提高软化系数,耐水性得到显著改善。

This paper studies the influence of sulphoaluminate cement on the physical and mechanical properties of building gypsum. The results show that sulphoaluminate cement is beneficial to reduce the water requirement of the standard consistency of building gypsum and reduce the initial plastic viscosity of the slurry to some extent. The sulphoaluminate cement has the function of accelerating the hydration process of building gypsum,and the macroscopically setting time significantly shortened,plastic viscosity increased rapidly,and negatively affected the workability of the slurry,the critical amount of sulphoaluminate cement for building gypsum reinforcement modification was 20%,and the 3 d flexural strength increased significantly from the blank of 5.47 MPa to 10.23 MPa,the compressive strength of 3 d increased significantly from 11.59 MPa to 22.36 MPa. With the increase of age to 28 d, the enhancement effect of sulphoaluminate cement on building gypsum showed a certain shrinkage;sulphoaluminate cement increased the bulk density of the building gypsum,lowered the water absorption rate,greatly increased the softening coefficient,and the water resistance is remarkably improved.