Bond behavior of GFRP-concrete under long-term exposure to aggressive environments

The experimental results of the bond behavior between glass fiber reinforced polymer (GFRP) bars and concrete under several aggressive environments were studied. To give a comprehensive and comparative evaluation, a total 60 GFRP bar-concrete pullout specimens were divided into a control group and a treated group being immersed in tap water, alkaline and saline solutions for up to 270 days. The influences from aggressive environment, resin type and exposure period on the bond strength, together with the degradation mechanism and failure mode were explored. The time-dependent test results showed a clear decrease in the bond strength of treated group, with notably various degradation trends during different exposure periods. It is found that the saline solution induced the average bond strength loss of all corresponding specimens as 51.5% at 270 days, followed by alkaline solution (39.5%) and tap water (29.0%). © 2020 Japan Concrete Institute. All rights reserved.