A Comparative Study of the Structural Behavior of Concrete Beams Reinforced with Different Configurations of GFRP and Steel Bars

This study examined experimentally and numerically the performance of five concrete beams reinforced with longitudinal and transverse bars made of Glass Fiber Reinforced Polymer (GFRP) or steel. All beams had the same dimensions of 2700 mm in length, 180 mm in width, and 260 mm in depth. The beams were classified into two groups with different variables and compared with a reference beam reinforced with longitudinal and transverse steel bars. The first group consisted of two beams with longitudinal GFRP bars and no stirrups, varying the main reinforcement ratio. The second group comprised two beams with longitudinal GFRP bars and transverse GFRP or steel stirrups, varying the stirrup type. The results indicated that the beams with GFRP bars improved their flexural strength for different ratios but had limited shear resistance when using GFRP stirrups because increased deflection causes the number and width of cracks to grow, reducing the shear strength. All the tested beams exhibited linear elastic behavior until failure, with GFRP being more brittle than steel due to no yield point or plastic behavior in GFRP. The numerical simulation of the five beams using ABAQUS software showed good agreement with the experimental data obtained in the laboratory.