Developing tension field action of embedded steel plates-Stiffened rebars composite reinforcement within concrete deep beams

摘要

For reinforced concrete beams, the shear failure mode is confirmed to occur in disturbed regions rather than in the Bernoulli region where stresses can be computed from the flexure formula. Thus, the provision of such regions with shear deficiencies is of great importance. In this study, a tension field system is suggested to embrace the inevitable concrete compression field originating within disturbed regions. Nine rectangular reinforced concrete beams dominated by disturbed regions are tested to verify the proposed shear reinforcement approach of the tension field concept. In this approach, the thin steel plate is embedded within shear span to resist shear strength in two different modes: with and without enhancement of reinforcement as stiffeners. All specimens were tested for failure using a four-point load testing arrangement. Test results demonstrate the feasibility of using embedded mild thin steel plate with and without ribs of rebars as tension field action against initiated concrete compression field action to upgrade the section shear capacity. As depicted by experimental results, the provided tension field system can remarkably upgrade the post cracking, stiffness, and ultimate shear capacity of the considered concrete beams. The stringer panel model is considered to verify and confirm strength improvement. The numerical solution is considered to investigate the proposed composite reinforcement provided within concrete deep beams using the concrete damaged plasticity model. The numerical investigation succeeded to depict the generation of tension field action within the suggested embedded steel plates-stiffened rebars composite reinforcement.