A new formula for the shear strength of exterior RC beam-column joints using headed bars

Abstract

In several cases where high quantities of steel reinforcements are needed at reinforced concrete (RC) beam-column joints, headed bars are employed as a solution to facilitate the placing of reinforcement bars. This paper establishes a new formula for the prediction of the shear strength of exterior RC beam-column joints where beam longitudinal reinforcements use headed bars. A database was collected, which contains most of available test data of exterior beam-column connections using headed bars and subject to quasi-static cyclic loading. First, influences of the key parameters for the joint shear strength of the connections were evaluated by using the collected database. Then, three most important parameters were chosen to develop a formula for the prediction of the joint shear strength. The accuracy of the proposed formula was evaluated by comparing the predicted joint shear strength using the proposed formula and that of 30 experimental exterior connections collected from different sources, and also with predicted values using two existing analytical models. This evaluation showed a better relevancy of the proposed model in predicting exterior joint shear strength, compared to the existing formulas.