Shear Capacity of Exterior Beam-Column Joints Reinforced with GFRP Bars and Stirrups

The demand for sustainable concrete structures with longer service life and lower maintenance cost has been driving the use of glass fiber-reinforced polymer (GFRP) reinforcement in new concrete structures. The behavior of GFRP bars under seismic loading in reinforced concrete (RC) frame structures has not been widely investigated. Furthermore, the ability of FRP-RC frame structures to dissipate energy in seismic events is still questionable due to the elastic-linear behavior of the FRP reinforcement. Very few studies have been conducted on the seismic behavior of GFRP-RC exterior beam-column joints, and none studied the shear capacity of joints. Therefore, this study attempts to partially fill this gap by investigating the shear capacity of beam-column joints reinforced with GFRP bars and stirrups. Six full-scale exterior beam-column joint prototypes (T-shaped) were constructed and tested under simulated seismic load conditions. Test parameters in this study included the concrete strength and the shear stress level in the joint. Diagonal shear failure in the joint exhibited in some specimens showed the significance of evaluating the shear capacity in the joint.