三点弯曲下的钢纤维高强混凝土断裂能

通过100个尺寸为100mm×100mm×515mm的不同体积率的钢纤维高强混凝土切口梁三点弯曲试验,探讨了钢纤维体积率和裂缝相对切口深度对高强混凝土断裂能和作用力功的影响。结果表明,钢纤维改善了高强混凝土的断裂性能与延性。钢纤维高强混凝土断裂能增益比、作用力功增益比以及延性指数随着钢纤维体积率的增加而线性增加,随着切口深度的增加而降低;外力功对断裂能的大小起较大作用。在分析试验结果的基础上,建立了钢纤维高强混凝土作用力功和断裂能的计算公式。

Fracture energy of steel fiber reinforced high strength concrete under three point bending

Through the three point bending test on 100 specimens (dimensions of 100mm×100mm×515mm) of steel fiber reinforced high strength concrete with various fiber volume fractions, the effects of fiber volume fraction and the relative notch depth upon the fracture energy were detected and analyzed. The results show that the steel fiber can obviously improve the anti fracture property and ductility. The increment ratios of fracture energy, ductile index and ductility of the steel fiber reinforced high strength concrete increase linearly with the increase of the fiber volume fraction and decrease with the increase of the notch depth. The fracture energy of the specimens mainly depends on the work of external force. Based on the test results, the formulas for calculating the fracture energy and the work of acting forces were proposed.