铁尾矿砂对磷酸镁水泥砂浆性能的影响

Effect of Iron Tailings Sandon Properties of Magnesium Phosphate Cement Mortar

由于铁尾矿砂大量堆积带来的环境问题以及河砂资源日益枯竭,探讨将铁尾矿砂代替河砂用于制备磷酸镁水泥(magnesium phosphate cement, MPC)修补砂浆。分析了铁尾矿砂替代天然河砂后对MPC砂浆流动度、凝结时间、强度和干燥收缩的影响规律,并利用XRD和SEM分析了影响机理。结果表明:相较于河砂,铁尾矿砂会造成MPC砂浆流动度降低,可以提高砂浆的抗折强度和抗压强度,但对砂浆凝结时间和干燥收缩影响相对较小;XRD和SEM显示铁尾矿砂对MPC砂浆水化产物基本无影响,但优化了砂浆体系的级配,提高了浆体和骨料界面黏结性能,从而提高了抗折和抗压强度。研究成果有助于促进铁尾矿砂的综合利用。

Due to the environmental problems caused by the accumulation of iron tailings sand and the depletion of river sand resources,it has become a trend to use iron tailings sand instead of river sand to prepare magnesium phosphate cement(MPC)mortar.In this paper,the effects of iron tailings sand after the replacement of natural river sandon the fluidity,setting time,strength and drying shrinkage of MPC mortar were studied,and the influence mechanism was analyzed using XRD and SEM.The results show that iron tailings sand can reduce the fluidity of MPC mortar and improve the flexural strength and compressive strength of the mortar,but it has relatively little effect on the setting time and drying shrinkage of the mortar.The results of XRD and SEM show that iron tailings sand have no obvious effect on the hydration products of MPC mortar,but the grading of the mortar system has been optimized to improve the interface bonding performance of cement paste and aggregate,and that improvs the strength of mortar.The research results contribute to promoting the comprehensive utilization of iron tailings sand.