2nd International Conference on Multi-scale Computational Methods for Solids and Fluids ͳ MECHANICAL TESTS ON MASONRY WALLS Mustafa Hrasnica 1 , Naida Ademović 2 , Azra Kurtović 3 , Fadil Biberkić 4 , Senad Medić 5 1 Full Professor, Faculty of Civil Engineering, Institute for Materials and Structures, Sarajevo, BH, hrasnica@bih.net.ba 2 Assistant Professor, Faculty of Civil Engineering, Institute for Materials and Structures, Sarajevo, BH, naidadem@yahoo.com 3 Associates Professor, Faculty of Civil Engineering, Institute for Materials and Structures, Sarajevo, BH, azra_kurtovic@gf.unsa.ba 4 Senior Assistant, Faculty of Civil Engineering, Institute for Materials and Structures, Sarajevo, BH, fabingsa@bih.net.ba 5 Senior Assistant, Faculty of Civil Engineering, Institute for Materials and Structures, Sarajevo, BH, senad_medic@yahoo.com Abstract — The paper presents experimental study of behavior of unreinforced masonry walls. Different tests were performed. Wallets were tested in order to obtain compressive strength and modulus of elasticity of masonry. Cyclic shear tests were done on reduced scale and full scale unconfined walls. Quasi dynamic horizontal loading combined with vertical precompression was applied on both unreinforced and strengthened shear walls. Key-words — unconfined masonry walls, compressive strength, modulus of elasticity, cyclic shear. 1 Introduction Structural assessment of existing buildings is an important task for civil engineers especially in densely populated urban areas and older cities. The existing buildings in Bosnia and Herzegovina are traditionally built as masonry. Depending on the historical period and the art of building in specific regions, brick or stone masonry was applied [8]. Despite the fact that reinforced concrete structures prevail in the newly erected buildings, masonry structures are still built, with application of new construction materials. The analysis results of existing masonry structures lead very often to the conclusion that some art of rehabilitation is necessary [1]. Buildings were traditionally built as unreinforced masonry (URM) with wooden floors. The buildings erected after World War II generally have reinforced concrete floors. Both groups of buildings are relatively stiff and show generally limited ductile behaviour. Regarding seismic vulnerability classification (EMS) they belong to the classes B and C respectively [9]. It means that already for moderate earthquake intensities some important damages could occur. In the case of stronger earthquake motions heavy and very heavy damages, including partial collapse could be expected. These statements were unfortunately proven by strong earthquakes in the Western Balkan Region in the last 50 years; Skopje 1963, Banjaluka 1969, Montenegro Coast 1979 [7]. The first phase of the project to be implemented at the Faculty of Civil Engineering in Sarajevo envisages material tests of masonry components. Also, it will include construction of URM walls made of solid clay bricks and lime-cement mortar. Two full-scale wall models have been prepared. It is important to state that the walls have no vertical confinement, which became typical way of construction in the Western Balkan Region after Skopje Earthquake in 1963. The full-scale wall models without vertical confinement are tested under constant vertical load and cyclic horizontal loads. In the second phase of the project it is planned to apply several strengthening methods and to compare the wall behaviour with the unreinforced one. The main goal of the research project is to investigate the influence of the different strengthening methods on the structural behaviour of masonry walls under cyclic horizontal loading. Reinforced concrete coating will be applied having different types of reinforcement meshes, and then the strengthening with FRP and plastic meshes will be analyzed. The third phase of the project consists of numerical verification of experimental results which will be used to suggest practical guidelines for analysis of existing URM structures and implementation of strengthening procedures.