Punching shear behaviour of GFRP-RC slab-column interior connections with high strength concrete and shear reinforcement

Abstract

This work deals with punching shear behaviour of flat plates reinforced with glass fibre-reinforced polymers (GFRP) reinforcing bars. Six full-scale reinforced concrete (RC) slab-column interior connections were constructed and tested to failure. Two variables were investigated; the flexural reinforcement ratio when high strength concrete (HSC) is used and the type of GFRP shear reinforcement (headed studs and corrugated bars) when normal strength concrete (NSC) is used. All specimens were tested under concentric shear force and unbalanced bending moment with a constant moment-to-shear ratio. Increasing the reinforcement ratio increased punching capacity and post-cracking stiffness for HSC connections. Both types of shear reinforcement increased the punching capacity and deflection of NSC connections. Test results were compared with the predictions of the available fibre-reinforced polymer (FRP) design provisions in North American codes.