玄武岩纤维编织网的网格尺寸对混凝土拉伸性能的影响

Effect of Grid Size on Tensile Performance of Basalt Textile Reinforced Concrete

为研究网格尺寸对玄武岩纤维编织网增强混凝土(BTRC)拉伸性能的影响,进行了不同网格尺寸的4组48个试件的BTRC薄板单轴拉伸试验,分别从宏观和细观尺度分析BTRC薄板的破坏模式。在分析过程中采用ACK模型验证BTRC薄板拉伸的本构关系方程,并通过有限元模拟对结果进行对比验证。结果表明:BTRC薄板在拉伸荷载下呈明显的应变硬化特点;BTRC薄板的破坏模式为典型的脱黏破坏,且网格尺寸越小,纤维编织网与混凝土之间的黏结性能越好,单裂缝开展的细小裂纹越多;玄武岩纤维编织网不会改变混凝土的开裂强度,却能明显地提高其极限抗拉强度;编织网的网格尺寸越小,有效受力纤维束越多,抗拉强度越高。

In order to study the effect of grid size on the tensile performance of basalt textile reinforced concrete(BTRC),BTRC sheets with different grid sizes were subjected to uniaxial tensile tests.The failure modes of BTRC sheets were analyzed from macroscopic and mesoscopic scales.In the analysis process,the ACK model was used to verify the constitutive relation equation of the BTRC sheet tension,and the results were compared and verified by finite element simulation.The results show that BTRC sheets exhibit obvious strain-hardening characteristics under tensile load.The failure mode of BTRC sheets is a typical debonding failure,and the smaller the grid size is,the better the bonding performance between the textile and concrete is,and the more microcracks develop by a single crack.The basalt textile cannot significantly improve the cracking strength of concrete matrix,but can effectively increase the ultimate tensile strength.The smaller the grid size of textile is,the more effective fiber bundles are,and the better the tensile strength is.