Enhanced Earthquake Performance of Existing RC Buildings Through Hybrid CFRP and Damper Retrofitting

Interest in applying hybrid retrofitting approaches to existing buildings is steadily increasing. In this study, an attempt was made to seismically retrofit an RC (reinforced concrete) building using CFRP (carbon fiber-reinforced polymer) and dampers. For this purpose, nonlinear time history analysis was performed. The placement of dampers in the RC frame required the use of panels. Panels do not interact with columns; however, the interaction between the panels and the beams was considered. First, the behavior of a single-story RC frame with panels was numerically analyzed using Abaqus 2017. Then, a typical old RC building was modeled in SAP2000 v26 under three configurations: its existing condition with hollow brick infill walls, a CFRP-retrofitted condition, and a condition retrofitted with a hybrid CFRP–damper system, in which lightweight concrete panels replaced the hollow brick infill walls. When the results were compared, the hybrid retrofitting approach with CFRP and Idrizi dampers reduced story displacement by 41.13–42.70% in the X direction and by 32.74–46.89% in the Y direction, on average. Base shear forces were reduced by approximately 31–33% in the X direction and 6–9% in the Y direction. Improvements were also observed in beam plastic hinge conditions. Thus, the hybrid approach was found effective for seismic retrofitting.