粗骨料和钢纤维对混凝土中裂纹扩展模式的影响

Influence of coarse aggregate and steel fiber on crack propagation pattern in concrete

以混凝土断面上粗骨料断裂分数作为评价手段,研究了粗骨料和钢纤维对混凝土中裂纹扩展模式的影响。研究结果表明:对于轻骨料混凝土和高强混凝土,裂纹的扩展模式主要是以穿过粗骨料的方式进行;对于低强混凝土,裂纹的扩展模式主要是以沿过渡区的方式进行。掺入钢纤维后,显著改变了轻骨料混凝土和高强混凝土中裂纹的扩展模式,使得部分裂纹的扩展由穿过粗骨料进行转变为沿过渡区进行;掺入钢纤维后,轻骨料混凝土断面上粗骨料断裂分数降低了39.6%,高强混凝土断面上粗骨料断裂分数降低了26.0%。

Abstract： Using fractured aggregate area ratio （FAAR） as evaluating parameter,the influence of coarse aggregate and steel fiber on crack prop- agation pattern in concrete were studied.Test results show that the crack propagation pattern in lightweight aggregate concrete and high strength concrete is mainly the pass through coarse aggregate type;and in low strength concrete, the crack propagation pattern is mainly along with the transition zone type.After the introduce of steel fiber, the crack propagation pattern of lightweight aggregate concrete and high strength concrete is changed notably,from pass through coarse aggregate to along with the transition zone.The calculation results manifest that the FAAR of lightweight aggregate concrete is lowered by 39.6 percent and the FAAR of high strength concrete is lowered by 26.0 percent after the introduce of steel fiber to concrete.