Title: Performance of Lightweight Self-Consolidating Concrete Beams Reinforced with Glass Fiber-Reinforced Polymer Bars without Stirrups under Shear

Author(s): Shehab Mehany, Hamdy M. Mohamed, and Brahim Benmokrane

Publication: Structural Journal

Volume: 120

Issue: 1

Appears on pages(s): 17-30

Keywords: beams; design codes; glass fiber-reinforcing polymer (GFRP) bars; lightweight aggregate (LWA); lightweight self-consolidating concrete (LWSCC); load deflection; shear failure and cracking; shear strength; shear strength predictions; strain

DOI: 10.14359/51737229

Date: 1/1/2023

Abstract:
Integrating glass fiber-reinforced polymer (GFRP) bars into lightweight self-consolidating concrete (LWSCC) would effectively contribute to producing lighter and more durable reinforced concrete (RC) structures. Nonetheless, the shear behavior of GFRP RC structures cast with LWSCC has not yet been fully defined. This paper reports experimental results on the behavior and shear strength of LWSCC beams reinforced with GFRP bars. The beams measured 3100 mm (122.05 in.) long, 200 mm (7.87 in.) wide, and 400 mm (15.75 in.) deep. The test program included six beams reinforced with GFRP bars and one control beam reinforced with conventional steel bars for comparison purposes. The test variables were the reinforcement type and ratio and concrete density. The experimental results indicate that using LWSCC allowed for decreasing the self-weight of the RC beams (density of 1800 kg/m3 [112.4 lb/ft3]) compared to normalweight concrete (NWC). All beams failed as a result of diagonal tension cracking. Increasing the axial stiffness of the longitudinal GFRP reinforcing bars improved the concrete shear capacity of the LWSCC beams. The test results of this study and the results for 42 specimens in the literature were compared to the current fiber-reinforced polymer (FRP) shear design equations in the design guidelines, codes, and literature. Applying concrete density reduction factors of 0.8 and 0.75 in the ACI 440.1R-15 and CSA S806-12 shear design equations, respectively, to consider the influence of concrete density achieved an appropriate degree of conservatism equal to that of the equations for NWC beams.