高温后铁尾矿砂混凝土力学性能试验研究

Experimental Study on Mechanical Properties of Iron Tailings Sand Concrete after High Temperature

以铁尾矿砂细骨料取代率(0、25%、50%、75%、100%)为变化参数,完成了90个铁尾矿砂混凝土立方体试块在20~800℃下的高温试验。试验后观察经历高温后铁尾矿砂混凝土外观变化,测量其质量损失,分析高温后铁尾矿砂混凝土的残余抗压强度与经历温度间的规律,并给出建议公式。结果表明:随着温度的升高,质量损失率不断增大,800℃时的100%铁尾矿砂混凝土质量损失率达9.3%;随着温度的升高,残余抗压强度不断增大,800℃时的残余抗压强度损失率达78%;基于统计的铁尾矿砂混凝土残余抗压强度与经历温度间关系的建议公式,可为铁尾矿砂混凝土高温后的安全评估提供参考。

The high-temperature test of 90 iron tailings sand concrete cube test blocks at 20-800℃was completed with the replacement ratio of iron tailings fine aggregate(0、25%、50%、5%、100%).After the test,the appearance change of the iron tailings sand concrete after high temperature was observed,the mass loss was measured,and the law between the residual compressive strength and the experienced temperature of the iron tailings sand concrete after high temperature was analyzed,and the recommended formula was given.The results show that the mass loss rate increases with the increase of temperature,and the mass loss rate of 100%iron tailings concrete at 800℃reaches 9.3%.With the increase of temperature,the residual compressive strength increases continuously.The residual compressive strength loss rate at 800℃is 78%;the statistical formula based on the relationship between the residual compressive strength of iron tailings sand concrete and the experienced temperature can provide a reference for the safety assessment of iron tailings sand concrete after high temperature.