Shear Behavior for High Strength Concrete Beams with Steel Fibers

The current study reviews and synthesizes more recent studies about the shear action of steel fiber and high-strength steel rebar-reinforced high-strength concrete (HSC) beams. The beams act as the transfer point of loads and resistors for both flexural and shear forces in concrete structures and also play an essential role in the shear behavior. It has been shown from the literature that the presence of steel fiber (in different forms, volumes, and aspect ratios) affects the mechanical behaviour in concrete such as crack-bridging, ductility, and shear resistance. Optimal fiber types and weights (typically around 1–2% by volume) have been found to enhance performance, and crimped fibers frequently have better shear stability than hooked-end fibers. The shear strength improvement is attributed to factors such as fiber geometry, quantity of fiber and rebar, concrete compressive strength, span-to-depth ratio, and aggregate type. When stirrups may be displaced via fiber use, the hybrid mix of fibers and conventional reinforcement usually results in better shear–ductility. Even though predictive models have advanced, the existing code equations generally do not guarantee precise estimates for shear strength of the HSC beams with fibers, which underscores the importance of future studies and improved models that consider fiber type and other necessary parameters.