Effect of flexural reinforcement type and ratio on the punching behavior of RC slab-column edge connections subjected to reversed-cyclic lateral loads

Abstract

Three full-scale reinforced-concrete (RC) slab-column edge connections were constructed and tested to failure under a combination of gravity load and uniaxial reversed-cyclic lateral load. The main test parameters were the flexural reinforcement type [steel or glass fiber-reinforced polymer (GFRP)] and flexural reinforcement ratio [0.7 or 1.4%]. The performance of the connections was evaluated in terms of mode of failure, hysteretic response, stiffness, energy dissipation and strains in the reinforcement. It was demonstrated that GFRP-RC connections are able to safely achieve or exceed the minimum 1.50% drift capacity before punching failure with adequate deformability. The low modulus of elasticity and high tensile strength of GFRP bars allowed GFRP-RC connections to experience comparable reinforcement strains to those in the steel-RC counterpart. In addition, the linear nature of GFRP reinforcement resulted in lower stiffness degradation and lower residual damage in GFRP-RC connections compared to the steel-RC connection.