Push-out performance of stud/channel steel connectors in UHPC for new precast concrete beam-slab connections

At present, the connection between the beams and slabs adopting composite layers is cast on-site, which is laborious and time-consuming. In this study, a new type of precast concrete (PC) beam and PC slab connection, which was connected by stud/channel steel connectors, was proposed to enhance the efficiency of prefabricated construction. Push-out tests were carried out on 5 PC beam-slab specimens connected with studs and 3 PC beam-slab specimens with channel steel connectors. The test variables were the connecting methods of beam-slab, the connector reinforcement ratio and the connecting width between two slabs. The failure process, load and slip of the beam-slab connection were recorded. Then, the slip behavior, shear capacity and shear stiffness of the PC beam-slab connection were analyzed. The results showed that the new type of PC beam-slab connection proposed in this study was an effective form for transferring force between the beam and slabs. Based on the push-out test results, the shear mechanism of connectors was analyzed and the calculation formulas for shear strength of stud/channel steel connectors were put forward. The calculated values obtained from the proposed formula demonstrated a strong correlation with the test results, providing an accurate measurement of shear strength of the new type of PC beam-slab connection. This study offers a reference for realizing the fast-full assembly construction of PC frame.