【摘要】 利用铁矿尾矿(IOT)作为细骨料替代人造砂生产超高性能混凝土(UHPC),对于解决我国铁尾矿废弃物排放而引发的环境问题及天然砂资源缺乏问题具有重要意义。通过扫描电子显微镜(SEM)和压汞法(MIP)等多种测试方法,研究了不同比例的IOT替代人造砂(MS)对UHPC抗压强度、抗折强度、干缩率和渗透性的影响。结果表明:适当的IOT能显著提高UHPC的抗压强度、抗折强度、抗干缩和抗渗性;当IOT替代率为50%时,UHPC具有最优的强度和抗渗性,当IOT替代率为75%时,改性UHPC与传统UHPC性能接近;MIP和SEM试验结果表明IOT细颗粒能起到填充孔隙的效果。使用IOT作为细骨料生产UHPC,减少环境问题和成本的同时,还可以解决天然砂资源不足的问题。更多还原

【Abstract】 Using iron ore tailings(IOT) as fine aggregate instead of artificial sand to produce ultra high performance concrete(UHPC) is of great significance to solve the environmental problems caused by iron tailings waste discharge and the lack of natural sand resources in China. Scanning electron microscopy(SEM) and mercury injection method(MIP) were used to study the effects of different proportions of IOT on the compressive strength, flexural strength, dry shrinkage and permeability of UHPC. The results show that appropriate IOT can significantly improve the compressive strength, flexural strength, resistance to dry shrinkage and impermeability of UHPC. When the replacement rate of IOT is 50%,mortar has the best strength and impermeability. When the replacement rate of IOT is 75%, the performance of the sample is close to that of traditional UHPC. MIP and SEM test results show that IOT fine particles can fill pores. Using IOT as fine aggregate for UHPC production reduces environmental issues and costs while also addressing the problem of insufficient natural sand resources.更多还原