黄河特细砂–机制砂混凝土力学性能试验研究

Experimental Study on the Mechanical Properties of Yellow River Ultra Fine Sand-Manufactured Sand Concrete

摘要: 为实现特细砂资源化高值化利用，采用特细砂替代部分机制砂，粉煤灰替代部分水泥制备特细砂混凝土。对比分析特细砂替代率与粉煤灰替代率对特细砂混凝土力学性能的影响规律。结果表明：特细砂混凝土抗压破坏模式为压剪破坏，劈裂抗拉破坏模式为脆性破坏。特细砂混凝土抗压强度与特细砂替代率呈负相关，劈裂抗拉强度与抗折强度随着特细砂替代率的增加呈先降低后增加再降低的变化趋势，特细砂替代率为30%时，特细砂混凝土劈裂抗拉强度与抗折强度最优。粉煤灰的火山灰效应可提高混凝土后期强度，且粉煤灰替代率对特细砂混凝土劈裂抗拉强度的影响程度要小于抗压强度和抗折强度。

Abstract: In order to achieve high-value utilization of ultra fine sand resources, ultra fine sand is used to replace some mechanism sand, and fly ash is used to replace some cement to prepare ultra fine sand concrete. Comparative analysis of the influence of the replacement rate of ultra fine sand and fly ash on the mechanical properties of ultra fine sand concrete. The results show that the compressive failure mode of ultra fine sand concrete is compression shear failure, and the splitting tensile failure mode is brittle failure. The compressive strength of ultra fine sand concrete is negatively correlated with the replacement rate of ultra fine sand. The splitting tensile strength and flexural strength show a trend of first decreasing, then increasing, and then decreasing with the increase of the replacement rate of ultra fine sand. When the replacement rate of ultra fine sand is 30%, the splitting tensile strength and flexural strength of ultra fine sand concrete are optimal. The volcanic ash effect of fly ash can improve the later strength of concrete, and the impact of fly ash substitution rate on the splitting tensile strength of ultra fine sand concrete is smaller than that on compressive strength and flexural strength.