Effect of Transverse Reinforcement Ratio on the Shear Strength of GFRP-RC Continuous Beams

A total of seven large-scale continuous concrete beams reinforced with glass fiber reinforced polymers (GFRP) bars and stirrups were constructed and tested to failure. One reference beam was reinforced with steel bars and stirrups and six beams were reinforced longitudinally and transversally with GFRP bars. Moreover, a three-dimensional (3D) finite element (FE) model was constructed to simulate the shear behavior of such beams. The beams had rectangular cross section of 200x300mm and were continuous over two spans of 2,800mm. The test variables include concrete strength and transverse reinforcement ratio. All test beams failed in shear near the interior support after significant moment redistribution. Also, the test results showed that no significant increase in the shear strength occurred when the shear reinforcement ratio increased by using a larger stirrup diameter. On the other hand, the FE models showed that increasing the transverse reinforcement ratio through decreasing the stirrup spacing is more efficient. Experimental and numerical results showed that the CSA/S806-12 code yielded better predictions compared with the ACI 440.1R-06 guidelines. (C) 2015 American Society of Civil Engineers.