STUDY ON SHEAR BEHAVIOR OF WEB-EMBEDDED U-SHAPED STEEL-CONCRETE COMPOSITE BEAM

The U-shaped steel-concrete composite beam has the advantages of high bearing capacity and good ductility, and its assembling construction technology also conforms to the current trend of assembly-type building structures. In this paper, nine web-embedded U-shaped steel-concrete composite beams (WUSCB) were designed with embedded connectors. The influence of parameters such as shear span ratio, concrete slab width, connector spacing and inclination angle, diameter of bottom longitudinal rebar, configuration of bottom studs and stirrups, depth-to-thickness ratio of steel web were considered. The specimen failure modes were analyzed and summarized. The mechanical properties such as shear capacity and ductility were analyzed based on the shear-deflection curves. The shear transfer mechanism of U-shaped steel web was studied based on the equivalent stress distribution in shear span. By using finite element software ABAQUS, a finite element model of WUSCB specimen was established and verified. Employing the finite element model, the four parameters including shear span ratio, concrete slab width, web depth-to-thickness ratio and bottom rebar ratio were analyzed. Based on the test results and finite element parameter analysis results, a shear bearing capacity design method of WUSCB was proposed. The method takes into account the contribution of concrete, U-shaped steel webs and bottom longitudinal reinforcements, and can be used to accurately predict the shear bearing capacity of WUSCB.