Shear behavior of URM retrofitted with FRP overlays

A large inventory of older masonry buildings exists in earthquake-prone regions. In most cases these buildings contain shear walls constructed of unreinforced masonry. The majority of these buildings were built before any provisions for earthquake loadings were established. The failures and damages reported in recent earthquakes attest to the need for efficient strengthening procedures. The effectiveness of increasing the shear strength of brick masonry by epoxy-bonding fiber-reinforced polymer (FRP) overlays to the exterior surfaces was evaluated. The variables in the test included the strength of the composite fabric, fiber orientation, and anchorage length. The specimens were tested under static loading. The results showed that both the strength and ductility of tested specimens were significantly enhanced with this technique. The orientation of the angle of fibers with respect to the plane of loading had a major effect on the stiffness of the retrofitted system but did not affect the ultimate strength significantly.