Analysis and design of FRP composites for seismic retrofit of infill walls in reinforced concrete frames

There is an urgent need to retrofit deficient mid-rise reinforced concrete (RC) frame buildings in Turkey. For this purpose, an efficient FRP retrofit scheme has been developed previously, in which hollow clay brick infill walls can be utilized as lateral load resisting elements after retrofitting. The main premise of this practical retrofit scheme was to limit inter-storey deformations by FRP strengthened infill walls that are integrated to the boundary frame members by means of FRP anchors. Based on the analytical model that was previously verified extensively by comparison with test results, a simplified model was proposed for use in displacement based design of FRPs for deficient RC frame buildings. FRP retrofit design and analysis of an actual deficient RC building located in Istanbul are presented herein both for the local design spectrum and Duzce ground motion. It was observed that the FRP retrofit reduced the damage induced to deficient columns by controlling story deformations. In this way, it was possible to satisfy the collapse prevention performance state in an efficient and economical manner.