不同仿钢纤维掺量对混凝土性能的影响

Influence of different steel fiber contents on properties of concrete

以赵石畔煤矿C60高性能井壁混凝土为研究对象,设置不同干湿循环次数不同仿钢纤维复合材料(FZ-SYS)掺量试验组,通过研究宏观裂隙形态、宏观破断形态建立数值计算模型,推导裂纹演化过程与本构关系,同时定义损伤度的概念。结果表明,基于PFC^(2D)的线性平行粘结模型,使用Clump命令模拟粗骨料,可以较好的还原出混凝土试件宏观规律,具有可靠的参考价值;数值模拟微观裂纹演化过程中,以拉裂纹为主,剪裂纹为辅的复合裂纹以偏转绕行粗骨料的形式发展,最终呈现“X”状典型破坏形态;在短期腐蚀向长期腐蚀转化的过程中,压密阶段扩大,非线弹性阶段减小,仿钢纤维掺量为1.0%时,峰值强度衰减缓慢,最大损伤度波动范围小。

We focused on the C60 high-performance shaft concrete of the Zhaoshipan coal mine.Different experimental groups were set up with varying dry-wet cycle frequencies and different amounts of imitated steel fiber-reinforced composite material(FZ-SYS).By investigating macroscopic crack and fracture morphology,a numerical calculation model was established.The evolution process of cracks and constitutive relationships were deduced,and the concept of damage degree was defined.The results indicate:Using the Clump command to simulate coarse aggregates based on the linear parallel bonding model of PFC^(2D) can effectively reproduce the macroscopic patterns of concrete specimens,providing reliable reference value;In the numerical simulation of the microcrack evolution process,composite cracks dominated by tensile cracks and supplemented by shear cracks developed in the form of deflection around coarse aggregates,ultimately presenting a typical“X”-shaped failure pattern;During the transition from short-term corrosion to long-term corrosion,the compaction stage expands,and the nonlinear elastic stage decreases.When the steel fiber content is 1.0%,the peak strength decays slowly,and the fluctuation range of the maximum damage degree is small.