Seismic performance of masonry strengthened with steel strips

Strengthening of unreinforced masonry structures to improve their seismic performance is getting attention of civil engineers across the world. In this study, laboratory tests were carried out to investigate the seismic performance of unreinforced burnt clay masonry wall panels strengthened with externally anchored steel strips. Six masonry panels having an aspect ratio of 0.7 were constructed. First masonry panel was unreinforced reference specimen and remaining specimens were strengthened with steel strips using different steel ratios and mesh patterns. Three specimens were strengthened with steel strips on one face and two specimens were strengthened with steel strips on both sides. All the specimens were tested under lateral cyclic loading at constant axial pressure to determine seismic performance. The test results revealed a significant improvement in energy dissipation, ductility and lateral strength of strengthened masonry wall panels. The main contributing factors in performance improvement were 1) amount of steel reinforcement, 2) mesh pattern and 3) single or double side application of steel strips. The proposed steel strips strengthening technique is quite simple and economical which involves external application of steel strips and does not alter the mass significantly. The simplicity, cost effectiveness and efficacy of the technique can help the local designers and engineers to enhance seismic performance of existing masonry structures.