钢纤维高强混凝土断裂性能的试验研究

Testing Research on the Fracture Property of High-strength Concrete Reinforced with Different Types of Steel Fibers

通过18个尺寸为200mm×170mm×100mm的钢纤维高强混凝土和素高强混凝土楔劈试件拉伸试验,研究了钢纤维类型、体积率对高强混凝土断裂韧度(KIC)、断裂能(GF)、临界裂缝嘴张开位移(CMODC)和裂缝尖端张开位移(CTODC)的影响.试验结果表明,钢纤维体积率对高强混凝土的断裂性能有显著影响;与铣削型和剪切波纹型相比,切断弓型钢纤维对钢纤维高强混凝土断裂性能的提高更为显著,断裂韧度增益比分别提高了19.9%,25.2%,断裂能增益比分别提高了355.4%,148.0%,临界裂缝嘴张开位移增益比分别提高了163.3%,148.4%,临界裂缝尖端张开位移增益比分别提高了225.9%,935.8%.

By the wedge-splitting tensile test on eighteen specimens of steel fiber reinforced high-strength concrete(HSC) and plain high-strength concrete with the size of 200 mm×170 mm×100 mm, this paper investigates the impacts of the type of steel fiber and fiber volume ratio upon the stress intensity factor ( K _(IC)), fracture energy( G _F),critical crack mouth opening displacement( CMOD _C),as well as critical crack tip opening displacement( CTOD _C) of HSC.The test results indicate that the influence of fiber volume ratio on the fracture property of HSC is more obvious. In comparison with the milled steel fiber and waved steel fiber, the addition of bowed steel fiber to HSC increases its fracture properties more notably:the increment ratio of K _(IC) is increased by 19.9% and 25.2%, G _F 355.4% and 148.0%, CMOD _C 163.3% and 148.4%, and CTOD _C 225.9% and 935.8%, respectively.