Shear Strength Evaluation of Diagonally Reinforced Concrete Coupling Beams with Steel Fibers

Abstract

This study evaluated the shear strength of a diagonally reinforced coupling beam with steel fibers subjected to cyclic loading through experiments. A total of seven specimens were examined using the amount of transverse reinforcement, concrete strength, and volume fraction of steel fiber as variables. The experiments showed that sufficient ductility and strength were ensured even when steel fibers were incorporated and transverse reinforcement was simplified. In particular, with a 2% volume fraction of steel fibers, the strength and ductility satisfied ACI 318-19 because steel fiber-reinforced concrete sufficiently replaced the transverse reinforcement to prevent buckling of the diagonal reinforcing bars. When evaluating the shear strength of steel fiber-reinforced coupling beams with regard to the ACI provision, the shear strength was predicted more accurately when the shear contribution of the concrete was considered and the diagonal reinforcement was properly confined.