Experimental Study of Interior Glass Fiber-Reinforced Polymer-Reinforced Concrete Slab-Column Connections under Lateral Cyclic Load

The feasibility of using fiber-reinforved polymers (PRPs) as internal reinforcement for a totally reinforced concrete (RC) structure immune to corrosion essentially pertains to strength, stiffness, and deformation capacity in resisting seismic loads has become questionable. Nevertheless, no experiments have yet been conducted on the punching-shear behavior of FRP-reinforced concrete (FRP-RC) slab-column connections subjected to lateral reversal cyclic loading. Consequently, current FRP-RC design guidelines and codes in North America contain no seismic provisions. This has been the main impetus to conduct the ,first-ever experimental study on the punching shear behavior of glass-FRP (GFRP) slab-column connections under the combination of gravity and lateral reversed cyclic loading. Four full-scale interior slab-column connections were constructed and tested to investigate the influence of flexural-reinforrement type (GFRP and steel bars), reinforcement ratio, and gravity load intensity on the punching shear performance. All test specimens were identical and measured 2500 x 2500 mm with a thickness of 200 mm. A column measuring 300 x 300 mm extended 700 mm at its center above and below the slab surfaces. The results revealed that the GFRP-RC specimens possessed adequate strength and deformation capacity against punching-shear failure during and after reserved lateral cyclic-load conditions. The GFRP-RC specimens achieved lateral interstory drift capacities over 1.50% satisfying the limits in CSA A23.3 and ACI 421.3R. The GFRP-RC specimens also had adequate drift-ductility indexes, dissipated energy, and connection stiffness. Moreover; the GFRP bar strains at the ultimate lateral-drift ratio were less than the guaranteed tensile strength by 42%. No rupture of the GFRP bars and bond failure or slip were observed during the test.