基于SHPB与直剪装置的UHPC力学性能试验研究OA

In practical engineering,concrete structural members are subjected not only to compressive loads but also frequently to tensile and shear loads.Therefore,investigating the mechanical behavior of ultra-high performance concrete(UHPC)under various stress states and loading rates is crucial for structural safety design.In this study,quasi-static and dynamic compression,splitting tensile,and shear tests were performed on UHPC with and without steel fibers,utilizing a universal testing machine,a split Hopkinson pressure bar(SHPB),and a self-designed direct shear apparatus.The results indicate that the incorporation of steel fibers significantly enhances the mechanical properties of UHPC under both quasi-static and dynamic conditions.Furthermore,both types of specimens(UHPC with and without steel fibers)exhibit a significant strain rate hardening effect.Specifically,in the shear tests,although the presence of steel fibers and high strain rates alter the evolution characteristics of peak stress,they do not alter the failure mode,which remains as mixture fractures of type I and type II.