机制砂全再生粗骨料混凝土的力学性能

Mechanical properties of fully recycled coarse aggregate concrete with manufactured sand

为探究骨料类型、水灰比与石粉含量对机制砂全再生粗骨料混凝土力学性能的影响,制备了不同石粉质量分数(5%、10%和15%)和不同水灰比(0.50、0.37和0.32)的全再生骨料混凝土试件.以72个立方体试件用于抗压强度试验,72个圆柱体试件用于弹性模量试验.结果表明,合理的石粉含量能有效提高再生骨料混凝土的力学性能,但在不同的水灰比下,最佳石粉含量存在差异;当水灰比和石粉含量双因素交互作用时,水灰比为0.32、石粉质量分数为15%的再生混凝土力学性能达到最优.构建了机制砂再生粗骨料混凝土抗压强度、弹性模量与水灰比、石粉含量的关系模型,计算结果的标准差与离散系数均不超过5%,模型精度良好.研究成果可为提高再生骨料混凝土力学性能及其工程应用提供理论依据.

To investigate the influence of aggregate type,water-cement ratio,and stone powder content on the mechanical properties of concrete with manufactured sand and fully recycled coarse aggregate,we prepared specimens of fully recycled aggregate concrete with different stone powder mass fractions(5%,10%and 15%)and various water-cement ratios(0.50,0.37 and 0.32).A total of 72 cubic specimens were used for compressive strength tests,and 72 cylindrical specimens for elastic modulus tests.The results indicate that an appropriate stone powder content can effectively enhance the mechanical properties of recycled aggregate concrete,but the optimal stone powder content varies under different water-cement ratios.When the water-cement ratio and stone powder content interact,the mechanical properties of recycled concrete are optimal at a water-cement ratio of 0.32 and a stone powder mass fraction of 15%.Moreover,a relationship model between the compressive strength and elastic modulus of concrete with manufactured sand and fully recycled coarse aggregate and the water-cement ratio&stone powder content was established.The standard deviation and dispersion coefficient of the calculated results do not exceed 5%,indicating good model accuracy.The research results can provide a theoretical basis for enhancing the mechanical properties of recycled aggregate concrete and its engineering application.