Long-term Performance of Reinforced Concrete Beams with GFRP Bars Subjected to Aggressive Environments

摘要

The use of fiber-reinforced polymer (FRP) bars in concrete structures has emerged as an alternative to traditional steel reinforcement environments and other applications where steel has shown greater vulnerability such as a coastal environment. Although the number of analytical and experimental studies on RC beams with FRP reinforcement has increased in recent decades, its long term performance is still questioned in comparison to the traditional steel reinforcement. This study presents the results and discussion of an experimental study concerning long-term behaviors of concrete beams (CB) reinforced with glass-FRP (GFRP) bars after accelerated aging in an environmental chamber at 46°C (115°F) with 80% of relative humidity up to 300 days. Two types (Wrapped/Sand-coated surface) of GFRP bars were used. Concrete beams (CB) were subjected to sustained loads and placed for different periods in the chamber that accelerates the effects of outdoor weathering. In all cases, the moment carrying capacity decreased and the deflection increased as a function of time when exposing in circumstances for accelerated aging. The increase in deflections was lesser for beams with a higher FRP reinforcement ratio. The residual flexural strength and ductility of the beams decreased with longer aging periods. Comparison of deformability factor for compression failures of CB-GFRP and CB-steel indicates that the values are not similar before and after exposing into accelerated aging.