Experimental Analysis Of Two Unreinforced Masonry Walls Under Cyclic Loads, And Its Retrofitting Through CFRP

This article presents a comparative experimental study of two unreinforced masonry walls: one made of perforated bricks (285 mm x 185mm x 130 mm) and the other of threshing bricks (190 mm x 90 mm x 50 mm). The Masonry walsl were constructed with standardized Turkish bricks in a rectangular steel frame supported by pinned uprights and built over a distance of 1200mm in length by 1500mm in height. The main objectives of this work are to study the behavior of structural unreinforced masonry under seismic actions and how it can be made more resistant to these effects. To achieve this goal, lateral cyclic loads are applied to the walls in plane. This application of forces had caused damage characterized by cracking. The natural excitation of the unreinforced masonry walls is determined through Operational Modal Analysis (OMA), and the dynamic characteristics of the structures emerged in the form of vibrational modes and natural frequencies. Their data recording is made before and after the application of cyclic loading. The reinforcement to fill the cracks is carried out using layers of CFRP with epoxy resin. A comparative analysis of the natural frequencies from undamaged wall to damaged points out a decrease in damaged walls (more than 20%) and a rise of 10% of frequencies between damaged vertical brick wall compared to the damaged coated CFRP-reinforced walls. These results of laboratory tests are compiled and compared in order to evaluate the seismic effects and the solutions that the CFRP brought in the reinforcement of the walls.