Experimental and Numerical Analysis of Steel-Block Shear Connectors in Assembled Monolithic Steel-Concrete Composite Beams

To study the shear behavior of the steel-block shear connector (SBSC) welded on a steel beam, eight push-out experiments were conducted, including two specimens with cast-in-place (CIP) concrete decks and six specimens with precast concrete (PC) decks. The principal parameters considered included loading path and casting method for the concrete deck. Through the experiments, the interface shear-slip curves and the governing failure mode of the SBSC in both CIP and PC decks under monotonic and repetitive loads were obtained. The comparison of shear behaviors between the shear stud group (SSG) and SBSC shows that the SBSC has a higher bearing capacity than the SSG, and the general failure mode is the local compression failure of the concrete deck. At the ultimate load, both kinds of connectors show great slip before failure and good ductility. A finite-element model was established and validated with the experimental results, which was then used in the parametric analyses. Parametric analyses on concrete compression strength, concrete tensile strength, SBSC width, SBSC height, and the diameter of transverse reinforcement were carried out. Following a comparison and analysis of the differences among the calculated, numerical simulation, and experimental results, a new calculation formula for the shear capacity of SBSC is proposed.