PROPOSED FORMULA AND COMPARISON OF SHEAR STRENGTHS OF REINFORCED CONCRETE BEAMS UNDER VARIOUS CODES

Abstract

 In the paper, the shear strength calculations were carried out in accordance with the SNI 2847:2019, ACI 318M-19, EN 1992-4, NZS 3101.2, and CSA A23.3 to predict the shear strength data from the literature. The number of data used for validation involved 129 experimental concrete beams to generate the predicted shear strengths of the corresponding various beams. After the predicted shear strength results were obtained, the next step was to compare the results of the predicted shear strength using these five available formula codes against the results of the experimental concrete beam test. This study focuses on the investigation of normal-strength and high-strength concrete beams. The comparisons were made to determine the predictive test strength based on which formula has the closest shear strength prediction to the experimental test results. A proposed formula has also been introduced to obtain a more optimal shear strength prediction. The results indicate that NZS 3101.2 provides better results compared to the other five formulations among the codes. In contrast, CSA A23.3 is the most conservative formulation. The newly developed formula is [0.66l(r_w)^1/3(f_c¢)^0.53+(N_u/6A_g)]b_wd, which modifies the ACI formula, to improve the prediction and maintain it on the safe side of the majority, and the proposed formulation improves the prediction compared with others.