粗骨料形状对混凝土力学性质的影响

Influence of different shape of coarse aggregate on concrete mechanical properties

混凝土是一种力学行为复杂的多相复合材料。通过PFC2D模拟,对四种不同形状粗骨料混凝土试件的应力-应变曲线,破坏形态及破坏过程中的能量变化进行对比分析。结果表明:混凝土单轴受压开裂裂缝都是绕骨料产生的,粗骨料本身不发生破坏;混凝土的单轴受压强度与砂浆基质与粗骨料外边缘有效接触面积有关,非圆形骨料较圆形骨料的界面接触面积大抗压强度也高,对应的峰值应变也越大,应力应变曲线下降段也越陡些。

Concrete is a kind of multiphase composite materials whose mechanics characteristics are very complex.Four different shapes of the aggregate were simulated by PFC2D and concrete stress-strain curve of the specimens ,the failure pattern and failure in the process of energy change were analyzed.The results showed that the concrete under uniaxial compression cracking cracks were produced around the aggregate,the coarse aggregate itself damage did not occur.The uniaxial compressive strength of concrete relate to mortar matrix and aggregate outer edge of the effective contact area,the circular aggregate a circular aggregate interface contact area was large and strength was high,the greater the peak strain and the corresponding,decline period of stress and strain curve was steep.