Title: Flexural Behavior of Concrete Beams Reinforced with Glass Fiber-Reinforced Polymer (GFRP) Bars

Author(s): Houssam A. Toutanji and Mohamed Saafi

Publication: Structural Journal

Volume: 97

Issue: 5

Appears on pages(s): 712-719

Keywords: concrete; deflection; glass; reinforced concrete; reinforcement ratio

DOI: 10.14359/8806

Date: 9/1/2000

Abstract:
Concrete members reinforced with glass fiber-reinforced polymer (GFRP) bars exhibit large deflections and crack widths compared with concrete members reinforced with steel. This is due to the low modulus of elasticity of GFRP. Current design methods for predicting deflections at service load and crack widths developed for concrete structures reinforced with steel may not be used for concrete structures reinforced with GFRP. This paper presents methods for predicting deflections and crack widths in beams reinforced with GFRP. To use the effective moment of inertia for concrete beams reinforced with GFRP bars, the effect of the fiber-reinforced polymer (FRP) reinforcement ratios and elastic modulus of FRP were incorporated in the exponent m of Branson’s equation. In addition, an equation based on flexural stiffness of GFRP reinforced concrete was developed to predict deflections. Based on this investigation and those conducted by others, a theoretical correlation for predicting crack width was proposed. Six concrete beams reinforced with different GFRP reinforcement ratios were tested. Their measured deflections and crack widths were compared with the proposed models. The experimental results compared favorably with those predicted by the models.