The effect of bulbar range on strength and behavior in block brick walls strengthened with expanded steel sheets

The earthquakes that have occurred in the past caused significant damages to numerous structures around the globe, which resulted in huge economic losses and took many lives. Therefore, in order to reduce the damages of structures exposed to a likely earthquake in the future, the damaged buildings, as well as those structures built with low standard, are required to be retrofitted and repaired. In this respect, different retrofitting techniques have been developed in the literature. For what concern the retrofitting and strengthening of the masonry walls, different materials (fibrous polymer strips, carbon fiber fabric, perforated sheet and expanded steel plate etc.) was considered using different methods. However, most of the available methods require too much time and their application is too costly, also during the strengthening process, the evacuation of the buildings is mandatory which makes them less practical. In this study, it is intended to imply more economical and practical method for strengthening infill was using externally-connected expanded steel plates. In this method, the retrofitting process is fulfilled by tying the infill walls from outside therefore the evacuation of the structures is not required The investigation is conducted by considering a total of five test specimens, where one of them is used as a reference and the other 4 are strengthened. The constructed specimens are then tested under monotonic diagonal loading. The retrofitting process simply began by attaching the expanded steel plates to both sides of the existing infill walls and these plates are then bolted to each other from both sides. It worth mentioning that the distance between the bolts is designated as the test variable. As a result, it was observed that the strengthened masonry walls with expanded steel plates behave as a composite material until the bolts reached their yielding capacities. In addition, the retrofitted specimens maintained their integrity up to the end of the experiment and their load bearing capacities were increased. Furthermore, mechanical properties of strengthened masonry walls such as their rigidity, ductility and energy dissipation was increased significantly and accordingly their behavior have been affected positively. Keywords: Vertical in filled brick walls with openings, rehabilitation, expanded steel plate, masonry building, monotonic diagonal loading