SHEAR STRENGTH OF CONCRETE BEAMS REINFORCED WITH GLASS FIBRE REINFORCED POLYMER (GFRP) BARS

摘要

The current paper presents the experimental results of the shear strength of concrete beams reinforced with GFRP bars without transverse reinforcement. Ten large scale simply supported beams with four point monotonic loading were tested to determine their shear capacity. The test variables were shear span to depth ratio, reinforcement ratio and depth of beam. The test results were analysed and presented in terms of crack and failure patterns, cracking and ultimate loads, GFRP and concrete strains. It was observed that the shear strength decreases with increasing shear span to depth ratio, a/d. Similar trends were observed for beams with the same a/d ratio but higher beam depth, d. However, the decrease in the shear strength with increasing the depth is less significant. On the other hand, the shear strength decreases with increasing the reinforcement ratio for beams with depth 350 mm; whereas the strength increases with increasing the reinforcement ratio for beams with depth 500 mm. Canadian Standard for shear design of FRP reinforced concrete beams (CSA S806-02) gives unconservative result for one of the beams with a/d equal to 3.5 and effective depth, d, equal to 305 mm.