Behavior of Continuous Concrete Beams Reinforced with FRP Bars

Abstract

Continuous concrete beams are commonly used elements in structures such as parking garages and overpasses which might be exposed to extreme weather conditions and the application of de-icing salts. Therefore, the use of the non-corrodible fiber reinforced polymer (FRP) bars in these types of structures is beneficial. However, due to the linear-elastic behavior of FRP materials up to failure, the ability of such materials to redistribute loads and moments in continuous beams is questionable. To date, unlike simply supported structures, very few experimental studies investigated the behavior of continuous concrete beams reinforced with FRP bars. Due to the lack of research, recently published design guidelines for FRP-reinforced structures provided limited provisions regarding continuous beams. The objectives of this research are to investigate the behavior of continuous concrete beams reinforced with carbon and glass FRP bars and provide design guidelines to predict the failure load and failure location. This paper presents the experimental results of two reinforced concrete beams with rectangular cross section of 200×300 mm continuous over two spans of 2800 mm each. One beam was reinforced with CFRP longitudinal bars while the other reinforced with GFRP bars. Both beams were reinforced with steel stirrups and provided with different reinforcement configurations at critical sections. Beams were tested under concentrated monotonic loads applied at the mid-point of each span. It is concluded that the FRP-reinforced concrete beams were able to redistribute the connecting moment over the intermediate support. Also, the Canadian code CSA-S806-02 could reasonably predict the failure load of the tested beams; however, it fails to predict the failure location.