Quasi-brittleness is an important factor affecting the size effect of concrete, and the addition of steel fiber can effectively change this effect in concrete. The size effect on the fracture energy of steel fiber reinforced high-strength concrete was investigated in this paper. A total of 156 concrete single-edge notched beams (SENB) of various span-to-depth ratios, crack-to-depth ratios and steel fiber contents were tested to study the size effect of fracture energy of the high-strength concrete added steel fibers. The parameters of fracture in the boundary effect model (BEM) and size effect law (SEL) were deeply analyzed. The results show that the addition of steel fiber will generate significant influence on the parameter values obtained from both BEM and SEL. Based on the BEM, the relationship among G_f (experimental test fracture energy), g_f (local fracture energy), and G_F (fracture energy unaffected by specimen boundary) could be obtained. Thus, a method for analyzing the influence of steel fiber on G_F was proposed using small-size SENB specimens at laboratory. In addition, based on the SEL, the impact of size effect on the fracture energy was effectively mitigated by the addition of steel fibers in high-strength concrete to a certain extent.

准脆性是影响混凝土的尺寸效应的重要因素，并且添加钢纤维可以有效地改变混凝土的这种效应。研究了尺寸对钢纤维增强高强混凝土断裂能的影响。总共测试了156种跨径比，裂缝与深度比和钢纤维含量的混凝土单边切口梁（SENB），以研究高强度混凝土添加钢的断裂能的尺寸效应。纤维。深入分析了边界效应模型（BEM）和尺寸效应定律（SEL）中的断裂参数。结果表明，添加钢纤维将对从B​​EM和SEL获得的参数值产生重大影响。基于BEM，G _f之间的关系（实验断裂能），g _f（局部断裂能）和G _F（不受样品边界影响的断裂能）可以获得。因此，用于分析钢纤维的影响的方法ģ _˚F使用小尺寸SENB试样在实验室中提出的。另外，基于SEL，在一定程度上通过在高强度混凝土中添加钢纤维有效地减轻了尺寸效应对断裂能的影响。