Punching Shear Behavior of Bent-Shaped Web-Embedded Perfobond Strip Connectors in Composite Structures

Web-embedded shear connectors (WESCs) in steel-concrete composite beams (SCCBs) are gaining attention due to their potential to reduce structural weight, eliminate welding requirements, and decrease residual welding deformation. The punching shear behavior of WESCs is essential for their practical engineering applications. In this paper, a bent-shaped web-embedded perfobond strip connector (B-WPSC) was proposed. The punching shear behavior of the B-WPSC was experimentally investigated by varying steel rib types and transverse rebar layers. Subsequently, a parametric analysis was conducted to evaluate key factors influencing the punching shear behavior of the B-WPSC. A strut-and-tie model (STM) was established to estimate the punching shear capacity provided by the end-bearing effect of concrete. The analytical model was finally proposed to estimate the punching shear capacity of the B-WPSC. The experimental results demonstrated that the punching shear capacity is mainly provided by the transverse rebars. The punching shear capacity of the B-WPSC increases by 194.5% as the number of transverse rebar layers increases from zero to two. For specimens with double-layer transverse rebars, the initial stiffness of the B-WPSC with bent-shaped ribs is 27.5% higher than that with straight-shaped ribs. The concrete strength, transverse rebar diameter, and yield strength of the transverse rebar have significant effects on the punching shear behavior of the B-WPSC. The proposed analytical model can be used to predict the punching shear capacity of the B-WPSC.