Concept Development and Evaluation of a New GFRP Reinforcement Geometry for Concrete Beams

In this paper a reinforcement system that utilizes unique geometries in order to improve reinforced concrete beam stiffness, shear strength, and reinforcement bond properties, as compared with conventional glass-fiber reinforced polymer (GFRP) bar-style reinforcement is introduced. The proposed GFRP reinforcement is formed into modular units intended for use in place of traditional flexural reinforcement. Prototype reinforcement units were manufactured and cast into eight concrete beam specimens. These specimens were tested and compared to similar specimens with conventional straight GFRP bars in order to document their behavior and assess the effect on beam performance of the new geometry under typical loading. Bond failures that occurred in the control specimens were not present in the prototype specimens. Ultimate shear capacity in one of the prototype variations was increased by 26% over the bar-reinforced control specimens. Flexural performance for one of the prototypes was also found to be comparable to the bar-style control reinforcements.