铁尾矿微粉对大流态混凝土性能的影响研究

发布时间：2018-01-26 18:27

本文关键词： 铁尾矿微粉大流态混凝土强度耐久性和易性　出处：《混凝土》2017年11期 　论文类型：期刊论文

【摘要】：研究了铁尾矿微粉作为混凝土掺合料不同比例替代粉煤灰对大流态混凝土性能的影响。进行了混凝土和易性、强度、耐久性等一系列试验,结果表明:随着铁尾矿微粉替代粉煤灰的比例增加,混凝土的流动性降低,但铁尾矿比例不大于70%时,各组混凝土坍落度均在220 mm以上;混凝土强度随着尾矿微粉替代量的增大下降幅度不大,当铁尾矿微粉替代量为50%时,铁尾矿混凝土强度均与纯粉煤灰组相比下降幅度在5%左右;在耐久性方面,在铁尾矿微粉替代粉煤灰的量不大于70%,混凝土的抗碳化性能增强。铁尾矿混凝土抗氯离子渗透性能在铁尾矿取代粉煤灰量不大于50%之时;SEM分析结果也表明铁尾矿微粉颗粒在不大于50%比例替代粉煤灰时,在混凝土中堆积、填充作用效果较好,混凝土微结构致密。
[Abstract]:The effect of iron tailings powder as concrete admixture to replace fly ash on the performance of large-flow concrete was studied. A series of tests were carried out on concrete such as ease strength durability and so on. The results show that the fluidity of concrete decreases with the proportion of iron tailings replacing fly ash, but when the ratio of iron tailings is less than 70, the slump of concrete in each group is more than 220 mm. The strength of the concrete decreases little with the increase of the replacement amount of the tailings powder. When the substitution quantity of the iron tailings powder is 50, the strength of the iron tailings concrete decreases by about 5% compared with the pure fly ash group. In terms of durability, the amount of iron tailing powder replacing fly ash is not more than 70%. The resistance of iron tailings concrete to chloride ion permeation is enhanced when the amount of iron tailings replacing fly ash is less than 50%. The results of SEM analysis also show that when iron tailings powder particles replace fly ash with a ratio of less than 50%, they pile up in concrete, and the filling effect is better, and the microstructure of concrete is compact.
【作者单位】：北京建筑大学北京市绿色建筑与节能技术重点实验室;
【分类号】：TU528
【正文快照】： 0引言由于我国大规模的基础设施建设,混凝土用量持续增大,掺合料掺加比例随着外加剂技术的不断提高而越来越大。由于粉煤灰、矿渣粉等掺合料的地域分布不均,当前我国一些地区开始面临传统掺合料供应不足的问题。另一方面,尾矿是我国大宗固体废弃物之一,年产出量在十亿吨以上,

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