Seismic capacity of masonry infilled RC frame strengthening with expanded metal ferrocement

This research was to investigate the behavior of masonry infilled reinforced concrete frame strengthening with expanded metals under cyclic loading. In this study, a prototype frame was chosen from a three-story reinforced concrete building that was not designed for earthquake load. Three specimens were built to full scale of 1:1 ratio including, the reinforced concrete bare frame (BF), the brick masonry infilled frame (W) and the masonry infilled frame strengthening with an expanded metal sheet (W-SR). The specimens were tested under constant vertical load and cyclic lateral load. The infilled frame strengthening with expanded metal sheet (W-SR) provided the lateral strength, stiffness and energy dissipation capacity of 1.25, 1.26, 1.27 times those of the brick masonry infilled frame (W), respectively. An analytical model based on an equivalent strut was proposed for masonry infill panels. In this approach, the nonlinear behavior obtained from the masonry prism test results was employed to determine the lateral strength and stiffness of the masonry panel model. The hysteretic behavior of the infill panel and infilled frame was evaluated using a nonlinear structural analysis program, RUAUMOKO. The results of the hysteretic behavior were compared with the experimental results to validate the proposed model.