Shear Strength Prediction for Fiber Reinforced Concrete Beams

Abstract

Discrete fibers are often used to increase the tensile and shear strengths of reinforced concrete. Influence of fibers on the behavior of shear critical members is quite significant, therefore, it is crucial to accurately estimate the fiber contribution to ultimate strength. In this study, first a comprehensive database of 446 FRC shear critical beams from 51 different experimental studies is compiled and nonlinear correlation analyses are utilized to identify the key parameters affecting the shear strength. Then, parametric equations are developed to obtain interfacial bond strength of fibers and shear strength of beams with different fiber types, volume fractions, aspect ratios and reinforcement detailing. Shear strengths corresponding to both shear and flexural failures are computed to verify the failure mode. Comparison of the predicted and experimental load carrying capacities indicates the improved accuracy of the prediction equation when compared to the code requirements and existing equations. Due to its applicability to FRC beams with different configurations, reinforcement detailing, fiber types and failure modes, the proposed method is feasible for integration into structural codes as a conservative and practical design approach. © 2025 Elsevier B.V., All rights reserved.