Improvement of unreinforced masonry wall panels shear strength using NSM CFRP strips

Abstract

The objective of the research reported here was to investigate the applicability of using near surface mounted (NSM) carbon fibre reinforced polymer (CFRP) strips as a retrofitting technique for improving the in-plane shear strength and displacement capacity of multi-leaf URM walls constructed using solid clay brick masonry. The use of this technique for repairing earthquake damaged URM walls was also investigated. Ten multi-leaf wall panels measuring approximately 1200 mm × 1200 mm were constructed using recycled vintage solid clay bricks and retrofitted using NSM CFRP strips with varying reinforcement ratios. These panels were loaded in diagonal compression, and the results were compared with those obtained from testing of nominally identical unretrofitted wall panels constructed using the same materials. In addition, four wall panels extracted from existing buildings were tested in an as-built condition and then later retested after being repaired using the NSM CFRP strip technique. Recent case-study projects that implemented the NSM CFRP technique are also briefly presented.