Seismic performance evaluation of reinforced concrete buildings with FRP retrofitted infill walls

Masonry infill walls are commonly used in many reinforced concrete (RC) structures, however such walls are not considered as structural elements. In practice, they have impact on resisting lateral loads that come from severe winds and seismic activities. Beside this, for strengthening the buildings having inadequate seismic resistance, in the recent years, fiber reinforced polymer (FRP) retrofitting technique was proposed for strengthening infill walls in RC structures. In this study, two, four, six, and eight story RC frame buildings with five and three bays in two plan directions were analyzed before and after retrofitting their infill walls using FRP composite sheets. To this aim, for all buildings, two exterior frames in different directions were investigated as bare frame, infilled frame, partially or fully FRP retrofitted infilled frame. Thus, a total of 32 different frame cases were evaluated through nonlinear pushover analysis. The response parameters obtained from the analysis of each case model were discussed comparatively to understand the contribution of the retrofitting technique used in the structures. It was observed that the performance state of the buildings could be upgraded efficiently by means of FRP sheets.