GFRP-Bonded RC Beams under Sustained Loading and Tropical Weathering

Synopsis: A study on glass FRP-bonded RC beams subjected to sustained loading under tropical weathering is reported. Beams were observed for long-term deflections and cracking due to sustained loading over different periods of time, after which they were unloaded and subsequently tested to failure. Beams subjected to outdoor tropical weathering for six months showed 8% larger deflections and 15% larger crack widths compared to those kept under ambient laboratory condition. Under accelerated weathering in a chamber, similar increase in deflections and crack widths were observed. Also, after six months of accelerated weathering, the ultimate flexural strength was about 17% and 12% less for beams bonded with uniand bi-directional glass FRP laminates, respectively, compared to the un-weathered reference beams. The failure mode changed from concrete crushing to FRP rupture with weathering period, indicating the deterioration of FRP laminates. The effect of weathering was more detrimental in the presence of sustained loads.