Effect of reinforcement detailing on performance of composite connections with headed studs

•The effects of confinement of concrete were investigated.•The behavior of change in quantity and location of reinforcement for composite connection was studied.•The connection behavior in terms of strength, stiffness and ductility was investigated.•The connection shear stiffness as obtained from load-slip curve was estimated through bilinear idealization.•An energy balancing approach was adopted for bilinear idealization. The effectiveness of a composite connection lies in the adequate transfer of forces between the steel and concrete elements. The connection strategy adopted, determines the behavior of connection. This behavior of composite specimens connected using headed studs depends on various factors, such as, cross-sectional area and dimensions of shear connectors, material properties of connectors, grade of concrete, type of loads acting on the members and quantity and location of reinforcement in concrete slab. Current study addresses the effects of confinement of concrete by altering the quantity and location of reinforcement on composite connection. The behavior of connection was investigated in terms of connection bearing capacity, ductility and shear stiffness from load-slip curve. The shear stiffnesses of composite specimens were estimated through bilinear idealization of the obtained load-slip curves using energy balancing approach. The stiffness, strength and ductility of composite connections were found to increase with an increase in the percentage of reinforcement in the concrete layer. The distance between root of stud and first layer of reinforcement was found to be inversely related to strength and stiffness and directly related to ductility.