Shear Strength of Concrete Beams Reinforced with FRP Bars: Design Method

Abstract

Synopsis: ACI Committee 440 has proposed a design approach for evaluating the concrete contribution to the shear resistance of FRP-reinforced concrete beams that accounts for the axial stiffness of FRP longitudinal reinforcement. Recent shear tests conducted on beams longitudinally reinforced with different types and ratios of FRP bars indicate that the current ACI 440.1R-03 shear design approach significantly underestimates the concrete shear strength of such beams. This paper presents a proposed modification to the ACI 440.1R-03 shear design equation. The proposed equation was verified against experimental shear strengths of 98 specimens tested to date, and the calculated values are shown to compare well. In addition, the proposed equation was compared to the major design provisions using the available test results. Better and consistent predictions were obtained using the proposed equation.