Effect of Longitudinal Steel Reinforcement on Shear-Flexural Behavior of Hybrid GFRP/Steel-Reinforced Concrete Beams

This paper presents the experimental results on the behavior of concrete beams reinforced with a combination of glass fiber-reinforced polymer (GFRP) and steel bars under shear-flexural bending. A total of four reinforced concrete (RC) beams were manufactured and subjected to four-point bending tests, with a shear span to equivalent depth ratio (a/d) of 3.65. Different ratios of longitudinal steel reinforcement, ranging from 0 to 1.01%, were analyzed to study the effect of the longitudinal steel reinforcement ratio on the shear-flexural behavior of hybrid GFRP/steel RC beams. Based on the experimental findings, the failure modes, relations between load and deflection, and relations between load and strains in materials were analyzed. The results obtained revealed the significant influence of the longitudinal steel reinforcement ratio on shear-flexural strength of the tested beams. With an increase in the steel reinforcement ratio, there was a corresponding decrease in the angle of the critical shear crack, the quantity of cracks, crack spacing, and beam deflections.