Investigating the Code Requirements and Influential Factors on the Determination of the Percentage of Maximum and Minimum Shear Reinforcement for Reinforced Concrete Deep Beams

Due to the increasing application of concrete structures and concrete beams as significant components in various buildings, research on the factors and different codes in concrete deep beams is so crucial. Strut-and-tie is one of the most common techniques employed in the analysis and design of deep beams. Some regulations, including ACI and CSA, have expressed constant values for the minimum shear reinforcement of deep beams. In recent years, investigating the influence of various parameters on the shear capacity of beams and the minimum and maximum shear reinforcement has been claimed. In this study, an attempt has been made to examine the parameters, including the ratio of shear span to depth, the percentage of longitudinal reinforcement, concrete compressive strength, and their impact on determining the minimum and maximum percentage of the required shear reinforcement. For this purpose, 243 specimens of deep beams were modeled by using ABAQUS software, and nonlinear attributes of materials were considered. Moreover, using the minimum shear reinforcement required for a different amount of compressive strength, a comparison was carried out with the conditions of the stated codes. Using the model presented by Arabzadeh et al. for calculating the softening coefficient and practicing a novel formula to determine the density of the orthogonal shear reinforcement and presenting the diagram of the softening coefficient compared to codes, it can be concluded that the formula is capable of being used instead of the formula proposed by ACI codes.