Issues on Design Shear Strength of RC Deep Beams

TLDR: In this paper, a simple analytical expression is proposed for limiting the design shear strength of RC deep beams, by considering following facts: the effect of size, tension reinforcement and limitations on compressive strength of concrete result in either overestimation or high underestimation of beam shears with a/d ratio ranging between 1.0 and 2.0.

Abstract: In this paper, a simple analytical expression is proposed for limiting the design shear strength of RC deep beams, by considering following facts. The maximum shear strength equation of ACI code is same for both concentrated and uniformly distributed loading cases. The effect of \( \frac{a}{d} \) needs to be accounted for properly. Second, the effect of size, tension reinforcement and limitations on compressive strength of concrete result in either overestimation or high underestimation of shear strength of beams with a/d ratio ranging between 1.0 and 2.0. The proposed equation is validated with the test data of 413 deep beams segregated from literature and design provisions of various codes. The proposed model overestimates only, a meagre fraction, 5% of the collected data, whereas the ACI 318-14 code equation overestimates 18.4% of collected data.