纳米偏高岭土对铁尾矿砂再生混凝土氯离子渗透性能影响研究

Effect of NMK on Chloride Penetration Resistance of IRC

为综合利用建筑固废,将铁尾矿砂(ITS)和再生粗骨料(RA)分别替代天然粗细骨料,同时将纳米偏高岭土(NMK)等质量替代水泥制作纳米偏高岭土增强铁尾矿砂-再生混凝土,进行氯离子渗透试验,探究纳米偏高岭土对铁尾矿砂-再生混凝土抗氯离子渗透性能的影响及改善机理。使用扫描电子显微镜(SEM)、压汞法(MIP)等分析纳米再生混凝土抗氯离子渗透性能,结果表明:(1)铁尾矿砂的掺入降低了再生混凝的抗氯离子渗透能力;(2)适配掺量的NMK能显著提高铁尾矿砂再生混凝土的抗氯离子渗透能力。

In order to comprehensively utilize construction solid waste,iron tailing sand(ITS)and recycled aggregate(RA)were used to replace natural coarse and fine aggregates respectively,and nano metakaolin(NMK)was used to replace cement to make nano metakaolin reinforced iron tailing sand recycled concrete(IRC).Chloride penetration test was conducted to explore the influence of nano metakaolin on the chloride permeability resistance of IRC and its improvement mechanism.Scanning electron microscopy(SEM)and mercury injection method(MIP)were used to analyze the chloride penetration resistance of nano recycled concrete.The results showed that:1)the inclusion of iron tailings decreased the chloride ion penetration resistance of reclaimed concrete.2)Suitable dosage of NMK can significantly improve the chloride ion penetration resistance of recycled concrete of iron tailings.