钢纤维高强混凝土的断裂韧性及缺口敏感性研究  

Experimental study on francture toughness and notch sensitivity of steel fiber reinforced high-strength concrete

作　　者：朱海堂[1] 张启明[1] 高丹盈[1] 王占桥[1] 

机构地区：[1]郑州大学水利与环境学院,河南郑州450001

出　　处：《四川建筑科学研究》2009年第3期173-176,202,共5页Sichuan Building Science

基　　金：国家自然科学基金(50678159);河南省高校科技创新人才支持计划(2008HASTIT027)

摘　　要：通过24组共72个尺寸为200 mm×170 mm×100 mm的楔劈拉伸试件的断裂性能试验,探讨了钢纤维类型及其掺量、切口相对深度等对高强混凝土断裂破坏形态和裂缝张开位移的影响,分析了高强混凝土和钢纤维高强混凝土的缺口敏感性。试验结果表明:钢纤维有效地改善了高强混凝土的断裂韧性,随着钢纤维体积率的增加,破断面更加曲折、粗糙,峰值荷载逐渐增加,Pv—CMODC曲线愈加丰满,断裂性能的提高愈加充分;随着切口相对深度的增加,破断面变得相对平直;钢纤维类型对钢纤维高强混凝土的Pv—CMODC曲线具有较为显著的影响,切断型钢纤维高强混凝土在试验后峰阶段表现出类似于金属性能的应力强化现象;高强混凝土和钢纤维高强混凝土的断裂韧度和断裂能均存在缺口敏感性问题。Through.the fracture test on the 42 specimens with the size of 200 mm × 170 mm × 100 mm under wedge-splitting tensile load, the impacts of the types and volume ratio of steel fiber, notch depth ratio on the failure toughness and critical crack mouth opening displacement （ CMODc ） of steel fiber reinforced high - strength concrete（HSC） were investigated, and the notch sensitivity of HSC and steel fiber reinforced HSC were analyzed. The research results show that the addition of steel fiber can significantly improve the fracture properties of HSC. As the increase of steel fiber volume ratio, the fracture interface of the specimens exhibit more sinuation and roughness, peak load （Pv） increase gradually, Pv--CMODc curve become more plumpness, hence the fracture properties increase adequately. With the increase of notch depth of specimens, the fracture interface of the specimens exhibit straightness. Dissimilar steel fibers have different degree influences on Pv-CMODc curve of steel fiber reinforced HSC, the postpeak of the Pv- CMODc curves of steel fiber reinforced HSC are similar to stress strengthening phenomenon of metal. The notch sensitivity of HSC and steel fiber reinforced HSC are substantiated also.

关 键 词：钢纤维 高强混凝土 断裂韧性 缺口敏感性 

分 类 号：TU528.572[建筑科学—建筑技术科学]