铁尾矿砂掺量对混凝土力学性能、耐久性及水化特性的影响研究

为探究铁尾矿砂掺量对铁尾矿砂混凝土力学性能及耐久性的影响，以唐山某铁尾矿砂为骨料，考察了不同铁尾矿掺量下混凝土的抗压抗折强度、抗冲击性能、抗渗性能以及水化特性。结果表明：①随着铁 尾矿砂掺量的增加，混凝土抗压强度与抗折强度均呈现先增大后减小的趋势，铁尾矿砂掺量为10%时抗压强度最大，铁尾矿砂掺量为20%时抗折强度最大；混凝土的冲击功及断裂吸收能量呈现先增大后减小的趋势，铁 尾矿砂掺量为20%时冲击功及断裂吸收能量取得最大值。②随着铁尾矿砂掺量的增加，混凝土的吸水率逐渐降低，而混凝土的碳化深度及渗透深度先减小后增大，当铁尾矿砂掺量为20%时混凝土的抗碳化性能及抗渗性 能最佳。③随着水化反应的持续进行，水化放热速率呈现增、减、增、减的变化趋势，但同一水化时间下混凝土的水化放热速率随着铁尾矿砂掺量的增大而减小；随着水化时间的延长，混凝土的水化放热量呈现不断 增大的趋势；铁尾矿砂掺量增加，同一水化时间下混凝土的水化放热量越小。

Research on Mechanical,Impermeability and Hydration Characteristics of Iron Tailings Concrete

In order to explore the influence of iron tailing ore addition on the mechanical properties and durability of iron tailing concrete， the compressive strength， impact resistance， impermeability and hydration properties of concrete with different iron tailing addtions were investigated by taking iron tailing ore from Tangshan as aggregate. The results show that: ①With the increase of iron tailing sand content， the compressive strength and flexural strength of concrete both increase first and then decrease. The compressive strength is the highest when the iron tailing sand content is 10%， and the flexural strength is the highest when the iron tailing sand content is 20%. The impact energy and fracture absorption energy of concrete tend to increase first and then decrease. When the iron tailing sand content is 20%， the impact energy and fracture absorption energy reach the maximum value. ②As the content of iron tailings increases， the water absorption of concrete gradually decreases. The carbonation depth and penetration depth of concrete first decrease and then increase. When the iron tailing sand content is 20%， the carbonization resistance and impermeability of the concrete are the best. ③As the hydration reaction continues， the heat release rate of hydration shows a trend of increase， decrease， increase， decrease， and decrease. However， the hydration heat release rate of concrete under the same hydration time decreases with the increase of iron tailing sand content. With the extension of the hydration time， the heat release of concrete hydration shows an increasing trend. With the increase of iron tailings sand content， the lower the hydration heat of concrete under the same hydration time.