Experimental evaluation of the seismic performance of retrofitted masonry walls

•New retrofitting techniques for improving in-plane seismic performance of URM wall are proposed.•Twelve full-scale masonry walls were tested.•The retrofitting techniques can greatly increase the seismic behavior of the URM wall.•The most suitable retrofitting method is selected by polymer coating material.•The polymer coating technique is simple and economical for implementation. Unreinforced masonry (URM) buildings are known as seismically vulnerable systems and require retrofitting. In this study, the in-plane seismic behavior of URM walls with and without an opening before and after retrofitting using different developed methods was investigated. Retrofitting methods involving a combination of metal laths, steel plates, connecting steel plates (CSPs) and polymer coating material were considered. Twelve masonry walls, including three non-retrofitted (as reference specimens) and nine retrofitted walls, were tested by subjecting the specimens to cyclic loads. The experimental study was carried out on full-scale specimens, which were tested simultaneously under the conditions of gravity and in-plane cyclic loads. The performance evaluation of each specimen was performed in terms of the lateral strength and deformation, hysteretic response, and energy dissipation. The double side retrofitting/upgrading approach substantially enhanced the lateral strength, displacement, and energy dissipation capacity of the test specimens. Furthermore, it was found that the specimens involving the combination of the polymer coating with the steel plates and CSPs could be an alternative method in terms of high energy dissipation capacity owing to the ultimate strength and displacement enhancement.