作　　者： ; ; ;

机构地区： 广州大学土木工程学院

出　　处： 《东南大学学报（自然科学版）》 2007年第5期892-897,共6页

摘　　要： 采用分离式霍普金森压杆（SHPB）对纤维体积率为0～3％的钢纤维高强混凝土（SFRH—SC）进行了中应变率的冲击压缩试验．试验表明，应变率从阀值提高到90／s时，SFRHSC峰值应力增梧30％左右，弹性模量增幅50％左右，峰值应变增长幅度则是基体混凝土的2～3倍．集料－高强基体和钢纤维－高强基体的双重叠加效应，大大提高了基体的抗冲击强度和韧度，使SFRHSC试件在冲击荷载作用下呈现出“微裂而不散，裂而不断”的良好破坏形态，而在相近的冲击荷载下，基体混凝土试件成粉碎性破坏．根据试验结果建立了SFRHSC四参数率相关性本构方程，该方程同时考虑了应变率和应变对材料应力的影响． Impact compression experiments for the steel fiber reinforced high strength concrete （SFRI-ISC） at medium strain rate were conducted using the split Hopkinson press bar （SI-IPB） tesring method. The volume fractions of steel fibers of SFRHSC were between 0 and 3 %. The experiment results show that, when the strain rate increases from threshold value to 90/s, the maximum stress of SFRHSC increases about 30%, the elastic modulus of SFRHSC increases about 50%, and the increase in the peak strain of SFRHSC is 2 - 3 times of that in matrix specimen. The strength and toughness of the matrix can be improved remarkably because of the superposition effect of the aggregate-high strength matrix and steel fiber-high strength matrix. As a result, under impact loading, cracks may develop in the SFRHSC specimen however the overall shape of the specimen may remain virtually unchanged. As a contrast, under similar impact loading, the matrix specimens are broken almost into small pieces. On the basis of the experiments, the rate-dependent constitutive equations with four key parameters are established, which take both strain rate and strain effect on the material stress into account.

关 键 词： 分离式霍普金森压杆 钢纤维高强混凝土 中应变率 冲击压缩 率相关性本构方程

领　　域： [建筑科学]