Seismic performance of exterior beam-column joints reinforced with glass fibre reinforced polymer bars and stirrups

Concrete beams, slabs and recently columns reinforced with fibre reinforced polymers (FRP) reinforcements have shown considerable deformability under monotonic and fatigue loading. However, concerns still remain regarding the ability of FRP - reinforced concrete (RC) frame structures to dissipate energy in seismic loading events due to the elastic-linear behaviour of the FRP reinforcement. Furthermore, the behaviour of FRP bars in RC elements subjected to tension-compression reversals has not been well investigated yet. Therefore, this experimental study aims to investigate the feasibility of using glass FRP (GFRP) reinforcements in such structures. Four full-scale exterior T-shaped beam-column joint prototypes were constructed and tested under simulated seismic loading. The test parameters included the type of longitudinal and transverse reinforcement as well as the detailing of beam longitudinal reinforcement. The experimental results showed that under seismic-type loading, beam-column joints reinforced with GFRP bars and stirrups sustained more than 3.0% story drift ratio safely with no considerable damage.