Experimental Study of Time-dependent Behaviour of Concrete Members Reinforced with GFRP Bars

This study presents the results and discussion of an experimental tests program in which 8 concrete beams reinforced with glass fibre reinforced polymer (GFRP) were maintained under a constant load for a period of 150 days. Two different ratios of reinforcement and two different levels of sustained load were used. The beams were instrumented and monitored to analyze the time-dependent behaviour due to concrete creep and shrinkage. The measured deflections are compared with those calculated using methodologies available for steel reinforced concrete structures as CEB procedure, as well as with ACI 440.1R-06 and CSA-S806-02 for FRP reinforced concrete structures. The comparisons of the theoretical and experimental long-term deflections indicate that CEB procedure gives reasonable predictions in all 8 beams. However, some differences can be found when ACI 440.1R-06 or CSA-S806-02 procedures are applied.