Strut-and-Tie Model for Predicting the Shear Strength of Exterior Beam-Column Joints without Transverse Reinforcement

Abstract

This paper presents an analytical approach to predicting the shear strength of exterior beam-column joints without transverse reinforcement using a strut-and-tie model (STM). The proposed model contains a single diagonal strut with varied angle and width for modeling the shear behavior. Modeling analyses involve three approaches to determine the width and angle of the diagonal strut for the best prediction of experimental shear strength values. An experimental database of 25 exterior beam-column joints without transverse reinforcement and without confining out-of-plane members was developed to verify the accuracy of the model predictions. The presented analyses reveal that existing models may overestimate the shear strength of referenced joints and, therefore, highlight the need for a better fitting model. The discussions include a comparison of predicted joint shear strength values with existing experimental results using three different formulations. Moreover, the discussions examine existing code requirements and the reliability of the presented STM in comparison with code regulations. Concluding remarks supported by statistical measures highlight the fitness of the STM to safely predict the shear strength and identify the optimum approach to determining the model geometry.