Comparative Study on the Efficiency of Retrofitting Reinforced Concrete Columns by Concrete, Steel, and Fiber Reinforced Polymer Jacketing

Abstract

Structural members experience strength deficiencies for a variety of reasons, including improper design, faulty construction, inspection, change in structure use, older constructions that were not designed for earthquake actions, and so on. To overcome this problem, strengthening structural members when found deficient is necessary, and it can be applied before the hazard or after the hazard. The research that has been conducted so far mostly focuses on the behavior and axial capacity of single reinforced concrete columns that have been individually jacketed with FRP, steel, and RC jacketing. However, practically, retrofitting will be conducted for all columns of a building as a frame. To widen this gap, a reinforced concrete frame was modeled and analyzed using the three jacketing methods considered in the study to compare and select the most efficient jacketing technique. This research is a comparative study, considering a symmetrical G+5 office medium-rise RC building under an earth quake load that is retrofitted with steel, reinforced concrete, and carbon fiber reinforced polymer jacketing; and RC columns under axial loads. The analysis program consists of a total of 20 specimen models using finite element software ABAQUS 6.14. The comparison was in terms of two critical parameters; story displacement and story drift for a retrofitted reinforced concrete frame. In conclusion, the analysis result showed that RC jacketing gives greater axial load-carrying capacity than CFRP and steel jacketing for both short and slender columns. For retrofitted frames, the maximum reduction in both story displacement and story drift is found for reinforced concrete jacketed frames as compared to the other retrofitting systems considered in the study.