Behavior of grouped stud shear connectors between precast high-strength concrete slabs and steel beams

This study aims to examine the interface shear behavior between precast high-strength concrete slabs with pockets and steel beam to achieve accelerated bridge construction (ABC). Twenty-six push-out specimens, with different stud height, stud diameter, stud arrangement, deck thickness, the infilling concrete strength in shear pocket (different types of concrete), steel fiber volume of the infilling concrete in shear pocket concrete and casting method, were tested in this investigation. Based on the experimental results, this study suggests that the larger stud diameter and higher strength concrete promoted the shear capacity and stiffness but with the losing of ductility. The addition of steel fiber in pocket concrete would promote the ductility effectively, but without apparent improvement of bearing capacity or even declining the initial stiffness of specimens. It can also be confirmed that the precast steel-concrete composite structure can be adopted in practice engineering, with an acceptable ductility (6.74 mm) and minor decline of stiffness (4.93%) and shear capacity (0.98%). Due to the inapplicability of current design provision, a more accurate model was proposed, which can be used for predicting the interface shear capacity well for specimens with wide ranges of the stud diameters (from13 mm to 30 mm) and the concrete strength (from 26 MPa to 200 MPa).