关键词: 铁尾矿, 钢渣, 脱硫灰, 混凝土, 酸侵蚀, 抗压强度

Abstract: In order to improve the acid erosion resistance of concrete materials and realize the comprehensive utilization of bulk solid waste,concrete specimens were prepared with iron tailings,steel slag and desulfurized ash as admixtures,iron tailings and iron tailings waste rock as aggregate.The influence of cement replacement rate and waterbinder ratio on the 28 d compressive strength,mass loss,apparent deterioration and neutralization depth of concrete specimens after 60 d acid erosion were studied.The results showed that: ①When the waterbinder ratio is constant and the cement replacement ratio is 10%,the compressive strength of concrete specimens at 28 days is the highest,which is higher than that of pure cement concrete specimen.When the cement replacement rate is constant and the waterbinder ratio is 0.42,the compressive strength of the concrete specimen is the highest after 28 days.②When the waterbinder ratio is constant and the cement replacement ratio is more than 15%,the concrete specimen show strong acid resistance after 60 days of acid erosion.When the cement replacement rate is constant and the waterbinder ratio is less than 0.45,the concrete test blocks show strong acid erosion resistance after 60 days of acid erosion.③When the waterbinder ratio is constant and the cement replacement rate is 30%,the minimum mass loss could be achieved.When the cement replacement rate is constant and the waterbinder ratio is 0.42,the minimum mass loss can be achieved.All are less than the mass loss of pure cement concrete test block.④The compound admixture system makes the internal structure of concrete dense and pores refined,effectively hinders the erosion of acetic acid solution on concrete specimen,and reduces the neutral depth of concrete specimen.In general,concrete prepared by mixing iron tailings,steel slag and desulfurized ash has better acid erosion resistance than pure cement concrete.

Key words: iron ore tailings, steel slag, desulfurized ash, concrete, acid erosion, compressive strength