Strength Modeling of Concrete Deep Beams Reinforced with Internal Fiber-Reinforced Polymer

Abstract

It is well-known that arch action in deep concrete members provides a beneficial increase in strength. However, while specific design code provisions are available for steel-reinforced deep members that account for this influence, current design code provisions for members containing internal fiber-reinforced polymer (FRP) reinforcement do not consider the capacity obtained from arch action. Strut-and-tie-based modeling approaches for FRP reinforced members were developed through the adaptation of existing models for steel-reinforced concrete deep members. When compared to test results for large-scale members with small shear span-depth ratios (a/d), the recommended strut-and-tie model (STM) is shown to be in better agreement than existing shear provisions for FRP-reinforced members. The proposed STM is also shown to accurately account for influences on capacity from the reinforcement ratio, reinforcement stiffness, and overall member height.