STRENGTH ENHANCEMENT OF UNREINFORCED MASONRY WALLS USING FIBER REINFORCED POLYMER SHEET

Unreinforced masonry buildings represent a significant portion of the existing and historical buildings around the world. Recent earthquakes have shown the need for seismic retrofitting for these types of buildings. Various types of retrofitting materials for URM(unreinforced masonry buildings) such as shotcrete, ECC and FRPs have been developed. Engineers prefer to use many types of fiber reinforced polymers because these materials enhance the shear strength of the wall without expansion of wall sectional area and adding weight to the total structure. However, the complexity of the mechanical behavior of the masonry wall and the lack of experimental data from walls retrofitted by FRPs may problems for engineers to determine an appropriate retrofitting level. This paper investigate in-plane behavior of URM and retrofitted masonry walls using two types of different FRP materials to determine and provide information for the retrofitting effect of FRPs on masonry shear walls. Specimens were designed to idealize the wall of a low-rise apartment which was built in 1970s Korea with no seismic reinforcements; they have one aspect ratio. Retrofitting materials were carbon FRP and Hybrid sheets which have different elastic moduli and ultimate strain. Consequently, this study will evaluate the structural capacity of masonry shear walls and the retrofitting effect of an FRP sheet for in-plane behavior compared to the evaluation method for a reinforced concrete beam which was retrofitted by FRPs.