Experimental study of PZ shear connectors in composite beams

Abstract

To investigate the shear bearing capacity performance of new type puzzled shaped connector (PZ shear connectors) in composite beams and offer a reference for the design of steel-concrete composite structures, a push-out test method was employed. This approach took into account various influencing factors, including the diameter and shape of the penetration holes in PZ shear connectors, the thickness of PZ shear connectors, and the presence and diameter of penetrating steel bars. Six sets of specimens were designed and fabricated, yielding load-slip curves. Static performance indicators such as bearing capacity, slip amount, shear stiffness, and ductility coefficient of PZ shear connectors were analyzed. Taking into account the inherent function of PZ shear connectors, a formula for calculating the bearing capacity of PZ shear connectors applied in general composite beams is proposed. The results indicated that the PZ shear connectors exhibited concrete shear failure, manifesting as through cracks during the failure process. The PZ connector did not yield or fail, while the penetrating steel bar yielded. Through analysis of the experimental results, it was found that increasing the shape and thickness of the through holes in PZ connectors increased the shear bearing capacity by 4.6 % and 10.6 %, respectively. Among the more important control factors, increasing the diameter of the through holes and steel bars in PZ bending connectors can respectively increase the bearing capacity by 16 % and 33.8 %. The shear stiffness and ductility of PZ shear connectors are satisfactory. The novelty of this study lies in the fact that the use of PK plates can facilitate the insertion and construction of steel bars and the proposed formula for the bearing capacity of PZ shear connectors aligns well with the experimental results.