Effect of Different Confinements on High-Strength Steel Fiber-Reinforced Concrete (SFRC) Beams

High-strength concrete is extensively used in the construction industry due to its higher stiffness and modulus, but it is inherently brittle. In order to reduce its brittle behavior, steel fibers are being used to increase their application in the construction industry. In this experimental study, a fixed volume fraction (V-f = 1.5%) of steel fiber was used in the concrete, whereas the type of confinement (steel tube and carbon fiber-reinforced polymer CFRP strip) was varied. Five high-strength concrete beams with and without steel fibers strengthened with different confinements (steel sheet and CFRP) were cast and evaluated for flexural performance. (Four-point loading tests were done here.) Conventional steel was used for reinforcing concrete as it has the same lateral and longitudinal strengths. The high initial cost of steel tubes is compensated by eliminating the cost of formwork required for casting regular concrete members. For conventional reinforcement, a balanced steel ratio was used. All specimens were tested under monotonic loading. The tested structural elements showed good plasticity and increased flexural capacity. The improved ductility and energy absorption capacity of the members indicate their promising use in building structures.