Role of Reinforcement in Concrete Ring Deep Beams

The role of reinforcement in ring deep beams with horizontal curvature is studied. The study consists of six ring deep beam specimens, including a conventionally reinforced reference specimen and five specimens in which flexural and web reinforcement were varied. In the second and third specimens, horizontal and vertical web reinforcement were omitted, respectively, while in the fourth specimen, both were omitted. In the fifth and sixth specimens, top and bottom flexural reinforcement were reduced and omitted, respectively. Conclusions illustrate that vertical web reinforcement has a greater effect on load capacity compared to horizontal, and both have a greater effect than upper and lower flexural reinforcement. Moreover, depending on the experimental failure modes of the tested specimens, analysis using STM, ACI 318-19 is considered logical and safe despite its reservations. Therefore, a model has been proposed to predict load capacity by taking the effect of web reinforcement and the torsional moments.