Effect of FRP wrapping in seismic performance of RC buildings with and without special detailing : a case study

The results of a numerical investigation into the efficiency of glass fibre reinforced polymers (GFRPs) in improving the seismic performance of an 8-storey moment resisting reinforced concrete building are presented. In order to assess the effect of the transverse reinforcement, the building is detailed with different levels of transverse reinforcement representing well-confined and poorly-confined conditions. Although GFRP wrapping of columns at critical regions is the main retrofitting technique considered in this study, the effect of increasing the beam ductility on the seismic performance of a structure is also evaluated for the code-compliant building. The retrofitting strategy aims to provide both columns and beams with more ductility and energy dissipation instead of increasing the lateral strength. The load-displacement curves obtained from pushover analysis of the frames are then used in the seismic assessment using a capacity spectrum approach (the N2 method). The results confirm that GFRP wraps is capable of improving the seismic performance and ductility of the poorly-confined structure substantially, compared to the original structure. However, it was found that using FRP composites in order to increase the ductility of code-compliant building only, was not that effective.