Evaluation of Shear Capacity Prediction of Concrete Beam without Transverse Reinforcement

Abstract

Unlike other failure modes like flexural failure, almost no warning occurs for structures at the onset of failing in shear. Therefore, it is important to evaluate the accuracy of the determination the shear capacity of reinforced concrete beams by different design standards. This study evaluates the accuracy of some of the equations proposed by different codes of standard. Moreover, in order to gain an understanding of how different parameters, such as concrete strength, shear span-to-depth ratio and amount of longitudinal reinforcement affects the shear resistance of concrete beams without transverse reinforcement. For this purpose fifty-six reinforced rectangular concrete beams without transverse reinforcement have been selected from different experimental studies by other researchers taking into account longitudinal reinforcement, compressive strength of concrete and shear span to depth ratio. The experiment result is used to evaluate the accuracy of the prediction of some building codes, i.e., ACI 318-14, 2011,Eurocode 2, 2004, Zsutty, 1971, and Niwa et al. 1987. It is shown that the shear strength predicted by Zsutty,1971 shows good agreement with the test results having a better correlation coefficient of 0.712, and a mean ratio of 1.941 in predicting the shear strength of the selected 56 test beams than EC2,2004, ACI 318 and Niwa et al.1987 with correlation coefficient of 0.569, 0.5035 and 0.661 respectively, which predict the shear strength conservatively. The parametric study is carried out using the commercially available finite element package ABAQUS 6.14. The parametric study has been restricted to concrete compressive strength (25, 35, 40 and 60), longitudinal steel reinforcement ratio (0.679, 0.905 and 1.13) and shear span to depth ratio (1.5, 2 and 2.6). The result of finite element for analysis indicates that as concrete compressive strength increase, the shear capacity of reinforced beam without transverse reinforcement was increased. Also, by increasing the amount of longitudinal reinforcement to some limit, the shear capacity of RC beam without transverse reinforcement was increased, and in contrast, when the ratio of shear span to effective depth increase, the shear capacity of beam decreased