EXPERIMENTAL STUDY ON SHEAR AND TENSILE BEHAVIOR OF T-SHAPED EMBEDDED-NUT BOLTED SHEAR CONNECTORS IN PREFABRICATED STEEL-CONCRETE COMPOSITE BEAMS

To study the shear and tensile behavior of T-shaped embedded-nut bolted shear connectors in prefabricated steel-concrete composite beams, a total of four push-out specimens were tested to investigate the failure modes, load-slip curves and the shear capacity of bolt connectors by changing parameters including tensile strength of bolt and type of concrete. Shear and tensile push-out test and finite element numerical simulation analysis were carried out to ensure the correctness of the modeling method by comparing test results and numerical results. Numerical results were obtained to investigate the shear and tensile behavior of T-shaped embedded-nut bolted shear connectors through a comparison with existing research results. The push-out test results show that: the damage mode of high-strength bolts is the bending shear damage of bolt at the interface between the steel beam and concrete, the concrete around the root of the bolt is damaged by compression and the concrete plate is cracked and completely crushed. The shear behavior is mainly affected by the tensile strength of the bolt and the type of concrete, and the shear bearing capacity of bolted joints can be improved by increasing the strength of the bolt and adopting UHPC. Numerical analysis shows that: T-shaped embedded-nut bolted shear connectors are limited by the thickness of the concrete slab and the height of the inner nut, the concrete thickness between the nut and the inner nut is insufficient to provide sufficient pullout force, and its tensile behavior is insufficient under shear and tensile composite forces.