Improvement of Shear Resistance of Unreinforced Masonry (URM) Walls made of Recycled Clay Bricks

Abstract

Buildings made with unreinforced masonry (URN) are one of the most common kinds of construction in the world. All of this building stock is vulnerable to destruction in the event of an earthquake due to its poor capacity to withstand lateral stresses. The experimental campaign on investigating the structural performance of masonry walls by conducting diagonal compression tests is described in this study. In the laboratory, three diagonal compression tests were performed on two specimens with nominal dimensions of 1.2 x 1.2 x 0.25 m. The major goal was to look at the structural behavior of two different types of masonry panels: unreinforced and reinforced. Mortar type used was type “O” and wall panels were built. A plain wall, a polypropylene strengthens on one side and the third was a polypropylene strengthen on both sides. Three diagonal compression tests were carried out completely according to the American Society for Testing and Materials' technical requirements (ASTM International). Material properties of masonry component materials were established for each panel prior to testing. The ultimate drift and ductility are two more parameters to consider while evaluating the behavior of URN. URM buildings are subjected to lateral loads as a result of seismic shaking, which cause lateral deformation of the structure. Ductility is described as a material's capacity to deform without rupturing, or, in the case of URM structures, the structure's ability to deform without collapsing. The decrease in stiffness was often noticed at load levels around the ultimate load, when the first crack forms but is unable to grow owing to the existence of external reinforcement. iv The testing findings revealed that the panel's shear strength is highly influenced by the mortar type (mortar strength), since the fractures spread through the joints without harming the bricks in all cases. The highest shear strength was achieved by W3-PP-2s, 0.376 MPa which was 4 times higher than the shear strength of the plain panel of W1. Additionally, W3-PP-2s achieved higher ultimate diagonal load of 159.424 kN. W3-PP-2s, on the other hand, had a lower deformation capacity and were more brittle than plain panels, with an ultimate drift ratio of 0.434.