Influence of reinforcement detailing on the behavior of beam-column joints reinforced with GFRP bars

Implementing the non-corrodible glass fibre-reinforced polymer (GFRP) reinforcement in reinforced concrete (RC) infrastructure is a viable alternative to avoid steel-corrosion problems. However, the behaviour of GFRP bars in tension-compression reversed cycles in RC frame structures has not been well investigated yet. Furthermore, the elastic-linear behaviour of the GFRP reinforcement up to failure makes the ability to dissipate energy of frame structures in seismic loading events questionable. Therefore, this study attempts to partially fulfill this gap by investigating the structural performance and ultimate capacity of concrete beam-column connections reinforced with GFRP bars. In this paper, four full-scale exterior beam-column joint prototypes were constructed and tested under simulated seismic load conditions. Specimens were reinforced with GFRP bars. The test variable is the beam end anchorage (increased column depth, beam stubs and headed bars) of the beam longitudinal bars within the joint. Test results are presented in terms of load-drift ratio relationship, ultimate capacity and mode of failure. The study concluded that using beam stubs or headed bars are viable solution wherever geometric constraints do not allow for deep columns