Influence of Shear Reinforcement on Reinforced Concrete Continuous Deep Beams

Abstract

This paper presents results from tests of 24 two-span reinforced concrete deep beams that were performed to study the influence of shear reinforcement on structural behavior. The main variables studied were concrete strength, shear span-to-overall depth ratio (a/h) and the amount and configuration of shear reinforcement. The results show that the load transfer capacity of shear reinforcement was much more prominent in continuous deep beams than in simply supported deep beams. The ratio of the load capacity measured and that predicted by the strut-and-tie model recommended by American Concrete Institute 318-05 dropped against the increase of a/h. This decrease rate was more remarkable in continuous deep beams than that in simple deep beams. The strut-and-tie model recommended by ACI 318-05 overestimated the strength of continuous deep beams having an a/h of more than 1.0. Horizontal shear reinforcement was always more effective than vertical shear reinforcement for beams having an a/h of 0.5. However, vertical shear reinforcement was more effective for an a/h higher than 1.0.