复掺铁尾矿和粉煤灰掺量对混凝土性能和微观结构性的影响

    Effect of Mixed Iron Tailings and Fly Ash Content on the Performance and Microstructure of Concrete

    • 摘要: 这是一篇陶瓷及复合材料领域的论文。采用不同掺量作用下混凝土的电阻率、抗压强度和氯离子迁移系数的变化规律,来评价混凝土的耐久性能。对不同铁尾矿掺量和不同粉煤灰掺量作用下混凝土的抗渗性能、力学性能、抗氯离子侵蚀性能进行了研究,以及分析了同时掺加不同比例铁尾矿砂和粉煤灰对混凝土性能的影响。结果表明:铁尾矿和粉煤灰掺量为30%时混凝土的抗压强度达到极大值。而粉煤灰掺量比例越大、铁尾矿掺量比例越小,混凝土的抗压强度、抗渗性能和抗氯离子侵蚀性能就越差,故在实际制备混凝土时应该采用大掺量铁尾矿砂、少掺量粉煤灰的配合比。随着铁尾矿掺量和粉煤灰掺量的增大,在同一水化时间作用下铁尾矿的水化放热速率和总放热量也呈现出不断减小的趋势,这说明了掺加铁尾矿和粉煤灰很大程度上降低了混凝土的水化放热速率和总放热量。随着铁尾矿掺量和粉煤灰掺量的增大,混凝土孔径分布曲线峰值点对应的孔径值也是不断增大的,但是增大的幅度却越来越小。

       

      Abstract: This is an article in the field of ceramics and composites. The changes of resistivity, compressive strength and chloride ion migration coefficient of concrete under different dosages are used to evaluate the durability of concrete. The impermeability, mechanical properties, and chloride ion corrosion resistance of concrete under the action of different iron tailings content and different fly ash content are studied. The effect of adding different proportions of iron tailings and fly ash on the performance of concrete is analyzed.The results show that the compressive strength of concrete reaches the maximum when the content of iron tailings and fly ash is 30%. However, the larger the proportion of fly ash and the smaller the proportion of iron tailings, the worse the compressive strength, impermeability and resistance to chloride ion corrosion of concrete. Therefore, in the actual preparation of concrete, a mixing ratio of a large amount of iron tailing sand and a small amount of fly ash should be used. With the increase in the content of iron tailings and fly ash, the hydration heat release rate and total heat release of iron tailings also show a decreasing trend under the same hydration time. This shows that the addition of iron tailings and fly ash greatly reduces the hydration heat release rate and total heat release of concrete. With the increase in the amount of iron tailings and fly ash, the pore size value corresponding to the peak point of the concrete pore size distribution curve is also increasing, but the increasing amplitude is getting smaller and smaller.

       

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