Flexural Behavior and Serviceability of Normal- and High-Strength Concrete Beams Reinforced with Glass Fiber-Reinforced Polymer Bars

This paper investigated the flexural behavior and serviceability performance of glass fiber-reinforced polymer (GFRP)-reinforced concrete (GFRP-RC) beams fabricated with normal- and highstrength concretes (NSCs and HSCs). The beam specimens measured 4250 mm long x 200 mm wide x 400 mm deep (167.0 x 8 x 16 in.). Three GFRP products with moduli of elasticity ranging from 48.7 to 69.0 GPa (7100 to 10,000 ksi) with sand-coated and helically grooved surface textures were employed. A total of 12 full-scale beams reinforced with GFRP bars and two reinforced with steel bars, serving as control specimens, were tested to failure in four-point bending over a clear span of 3750 mm (148 in.). The test parameters were: 1) type and ratio of the GFRP reinforcement; 2) surface configuration of the GFRP bars; 3) concrete strength; and 4) bar diameter. The test results were reported in terms of deflection, crack width, strains in concrete and reinforcement, flexural capacity, and mode of failure; they were also employed to assess the accuracy of the current deflection and crack-width prediction equations in the FRP-RC codes. The test results revealed that the crack widths were affected by the bar diameter and surface configuration while the deflections were not significantly affected. In addition, the bond coefficient k^sub b^ value of 1.4 was very conservative for both of the sand-coated and helically grooved GFRP bars in NSC and HSC. [PUBLICATION ABSTRACT]