铁尾矿基掺合料混凝土的抗压性能

Compressive properties of mixture concrete based on iron tailings

为实现铁尾矿、钢渣和磷渣等固废资源化,减少水泥用量,并减轻铁尾矿单独做掺合料时对混凝土产生的不良影响,基于高硅型铁尾矿,引入磷渣、脱硫灰和钢渣3种掺合料,研究了铁尾矿-磷渣-脱硫灰(IPD)体系、铁尾矿-磷渣-钢渣(IPS)体系和铁尾矿-钢渣-脱硫灰(ISD)体系混凝土的抗压性能,利用压汞法和背散射电子成像技术分别对混凝土内部的孔隙、界面过渡区进行测试分析.结果表明:IPD体系、IPS体系和ISD体系28 d抗压强度分别达到纯水泥混凝土的80.1%、92.4%和82.5%;加入掺合料后,骨料与水泥的界面过渡区更加密实,孔隙率得到了不同程度的降低,掺合料的填充效应得到了较好发挥,减轻了内部孔隙对混凝土的不良影响.

To realize the resource utilization of solid waste of iron tailings,steel slag and phosphorus slag,reduce the amount of cement and reduce the adverse impact of iron tailings powder as admixture on concrete,three admixtures of phosphorus slag powder,desulfurization ash powder and steel slag powder were introduced based on high-silicon iron tailings powder.The compressive properties of iron tailing powder-phosphorus slag powder-desulfurization ash powder(IPD),iron tailing powder-phosphorus slag powder-steel slag powder(IPS)and iron tailing powder-steel slag powder-desulfurization ash powder(ISD)concretes were investigated.Mercury injection test and backscattered electron were used to test and analyze the internal pores and interfacial transition zone of concrete.The results show that the 28-day compressive strengthes of IPD system,IPS system and ISD system respectively reach 80.1%,92.4%and 82.5%of that of pure cement concrete,and the interfacial transition zone between aggregate and cement is more dense after the addition of the admixture with reduced porosity to different degrees.The filling effect of the admixture is well exerted,and the adverse influence of internal porosity on concrete is alleviated.