混凝土断裂能测试方法研究

On the Method of Determining Concrete Fracture Energy

基于局部断裂能分布的双直线模型,推导出混凝土真实断裂能和受尺寸影响的断裂能的计算公式;并进一步通过分析四组不同尺寸试件的楔形劈裂试验数据,得出了不受尺寸影响的混凝土真实断裂能。本文为确定混凝土的断裂能提供了一种实践可行的测试方法。通过实验数据拟合,给出了断裂能非均匀分布的外部区域长度与试件尺寸的关系表达式。这对于在规范中规定测试断裂能的标准尺寸试件是有意义的。

Based on bilinear model for local fracture energy distribution along concrete ligament, relevant formulas for calculating real fracture energy and fracture energy taking into account size effects were deduced, respectively. Furthermore, through the analysis of experimental data taken from wedge splitting tests for four series of concrete specimen with different size and various crack depth, size-independent real fracture energy was finally derived. A feasible method of determining fracture energy is provided in this paper. Based on experimental data fitting, a expression relating transition ligament length, where local fracture energy presents non-uniform distribution, and specimen dimension was proposed. It is meaningful for specifying normal specimen dimension in fracture energy testing for criterion.