Numerical Analysis of Reinforced Exterior Concrete Beam-Column Joints Retrofitted Using FRP under Cyclic Loads

Recent earthquakes worldwide have illustrated the vulnerability of existing reinforced concrete (RC) beam-column joints to seismic loading. Inadequate shear reinforcement in the existing beam-column joints, especially exterior ones, is believed to be the prime cause of failure/collapse of many moment-resisting RC frame buildings. Hence, effective and economical strengthening techniques to upgrade joint shear resistance in existing structures are needed. Retrofitting using FRP composites has grown in popularity over the last two-decade advantages such as fast and easy installation, high strength/weight ratio, and resistance to corrosion. In this study have been conducted a numerical analysis of 11 RC beam-column joints without FRP and strengthened with FRP in a variety of configurations under cyclic loads. The analyses are performed by ABAQUS finite element program and are calibrated with the experiments. A range of issues in joints, including maximum load, initial stiffness, energy dissipation, load-displacement hysteresis loops, stiffness-displacement curves, and energy dissipation-displacement curves, are investigated. The numerical results were in good agreement with the corresponding experimental ones. The results obtained from the numerical analysis in this study, similar experimental results demonstrated that externally bonded FRP reinforcement is a viable solution towards enhancing the strength, energy dissipation, and stiffness characteristics of RC joints subjected to seismic loads.