钢渣对磷酸盐水泥基材料性能的影响机制

Effect and Mechanism of Steel Slag on Performance of Magnesium Phosphate Cements

研究了利用钢渣制备磷酸镁水泥基材料的可行性,分析了钢渣对磷酸盐水泥基材料的凝结时间、水化特性、力学性能及微结构的影响机制.结果表明:钢渣对磷酸盐水泥性能的作用规律与粉煤灰相似.掺10%钢渣时,因钢渣引入的CaO及水化生成的氢氧化钙,使得磷酸盐水泥凝结硬化加快,且钢渣自身硬度在一定程度改善了硬化水泥浆体抗压强度;随钢渣掺量增加,起胶结作用的水化产物减少,整个体系孔隙增加、结构疏松,游离氧化钙还会使磷酸盐水泥基材料性能出现劣化.钢渣掺入在浆体中并未观察到新的水化产物,但较高掺量下体系微裂纹增多.

This work investigated the feasibility of reusing steel slag as raw materials in preparing magnesium phosphate cement （MPC）. The effect of steel slag on the setting time, hydration process, mechanical properties and microstructure of prepared cements was determined. The results show that the influence of steel slag on the performance of magnesium phosphate cement exhibits a similar trend as that of fly ash. The addition of 10% steel slag would accelerate the hardening of prepared cement due to the presence of CaO and the formed calcium hydroxide. The hardness of steel slag would also increase the compressive strength. With increasing the steel slag substitutional level, the content of hydration products would decreases, while the porosity increases and micorstructttre become loose as a result. The hydration of f-CaO would do a detrimental effect on the mechanical properties of MPC. The hydration products detected in X-ray diffraction（XRD） patterns of steel slag blended MPC is the same as those of reference. However, there is more microcrack present in the hardened paste containing 40% of steel slag.