Interface shear behavior of shear connectors with constrained construction in composite plate

The problem of concrete cracking of composite structure ill decrease of the member stiffness, and become one of the important reasons restricting the application of composite structure. In order to solve this problem, a structural measure based on stud connector with constraint is proposed. The feasibility of using additional steel plates to help concrete tensile in negative bending moment region and the effectiveness of this structural measure to prevent concrete slabs from opening crack are verified by interfacial shear performance test. The results show that the stud connector with constraint structure can restrain the cracks within the range of 6 times the diameter of the stud, avoid longitudinal penetrating cracks of concrete slab, and give full play to the advantages of high compressive strength of concrete. The constraint measure can effectively improve the shear stiffness of the stud. It is proved that it is feasible to use additional steel plate to replace the concrete plate and the tensile steel bar in the negative moment zone, and the stud connector with constraint structure can reduce the amount of transverse steel bar. A formula for calculating shear stiffness of stud connectors with constraint structures is proposed, and a shear stiffness ratio-shear angle curve is proposed to evaluate material utilization efficiency and shear efficiency of connectors with different length-diameter ratios. It is suggested that the maximum elastic shear stiffness of stud connector with constraint measure. It lays a good experimental and theoretical foundation for the engineering application of this kind of shear connector.