铁尾矿砂用于混凝土细集料的试验研究

为探索铁尾矿砂用作混凝土细集料的可靠性，将不同比例的铁尾矿砂与天然砂混合制备铁尾矿砂混凝土，进行了铁尾矿砂颗粒级配调整、混凝土稠度和强度试验研究。结果表明：随着铁尾矿砂取代天然砂取代率的提高，其细度模数逐渐增大，过粗颗粒逐渐增多，级配曲线逐渐偏向右下角。选取一定比例的天然砂与铁尾矿砂混合后，颗粒级配得到明显改善；当铁尾矿砂的取代率为50%时，混凝土拌合物的工作性良好，达到了预拌混凝土大流动性的施工要求；掺入铁尾矿砂的混凝土28 d抗压强度高于普通混凝土，且随着尾矿砂取代率的递增，混凝土28 d抗压强度也递增，但劈拉强度表现出递减趋势。

Experimental Research on Iron Tailings as Concrete Fine Aggregate

Aiming at studying the feasibility that iron tailings are taken as aggregates to prepare concrete, experiments on the adjustment of particle size distribution, concrete mixture consistence and mechanical strength, which using different proportion of iron tailings replace natural sand. The results reveal that the proportion of coarse iron tailings of large particle size distribution is bad, particle size distribution dramatically improved when select a certain percentage of natural sand mixed with iron tailings sand. When iron tailings replacement ratio was 50%, the workability of concrete mixture is very good, conforming to the requirements of the construction of concrete big liquidity. Adding iron tailings concrete 28 d compressive strength is greater than the ordinary concrete, with the increase of the tail sand, the 28 d compressive strength also increases, the splitting tensile strength decreases.