The Effect of Joint Deformations on the Nonlinear Behavior of Retrofitted Reinforced Concrete Structures

In traditional frame analysis, beam-column joints are assumed as rigid and designed only for gravity load, yet they experience significant shear deformations and contribute significant story drifts during earthquakes. Although retrofitted reinforced concrete connection models are present in the literature for the finding of single assemblages; there is a retrenchment in the study of the full-frame analysis procedures simulating the nonlinear behavior of joints in addition to other expected failure. The objective of this study is to investigate the effect of joint deformations on the nonlinear behavior of retrofitted reinforced concrete structures by comparing the experimental study with the numerical study. Thus, two existing exterior beam-column joint retrofitting solutions: Carbon Fiber Reinforced Polymer (CFRP) and steel jacketing are selected for comparison. Mainly, selected retrofitting methods are compared under some specific failure parameters to investigate the best retrofitting method which enhances the failure of joints in the nonlinear zone under cyclic load imposed. In this paper, proper experimental study databases have been collected for a clear comparison of the proposed methodology. From the collected experimental study database, two exterior beam-column specimens with the same cross-section & reinforcement detailing and different retrofitting methods were selected to investigate the best option of joint rehabilitation. As per the result, the proposed strengthening solutions could partially upgrade the seismic capacity of the joints. Both the experimental study and numerical model shows that steel jacketing could enhance deformation and increase load-carrying capacities. But, the seismic capacity of the beam-column joint didn’t significantly affected by Carbon Fiber Reinforced Polymer wrapping. © 2023 American Institute of Physics Inc.. All rights reserved.