Push-out tests of interfacial bond slip between H-shaped steel and ultra-high performance concrete

Abstract

The effects of steel fiber content, stirrup reinforcement ratio, cover thickness of ultra-high performance concrete (UHPC) and embedded length of H-shaped steel on interfacial bond performance were studied through pull-out tests of ten specimens. The crack development process and damage mode of the specimens were analyzed by the load-slip(P-S) curves obtained at the loading end and the strain distribution of the H-shaped steel web. A formula for characteristic bond strength of H-shaped steel and UHPC was established, and a constitutive relationship for bond slip was proposed. A finite element model based on nonlinear springs was established to simulate the bond-slip relationship and the whole process of loss of performance at the interface of H-shaped steel and UHPC. The results showed that the strain of H-shaped steel decreased gradually along its embedment length, and the amount of steel fiber content, cover thickness and embedding length had large influences on the ultimate bond stress.