Intrados strengthening of brick masonry arches with different FRCM composites: Experimental and analytical investigations

This paper examines the structural behavior of masonry arches strengthened at the intrados with fabric reinforced cementitious matrix (FRCM) composites. Textiles made of poliparafenilenbenzobisoxazole (PBO) and carbon fibers are considered. The experimental results are compared with those obtained on unstrengthened arches and arches strengthened with a carbon fiber reinforced polymer (CFRP) composite. The arches tested are analyzed with the approach of the limit analysis of the collapse mechanisms. For the FRCM strengthened arches the maximum fibers strain has been assumed equal to the maximum strain attained by the fibers during double shear bond tests previously performed, while for the FRP strengthened arches the maximum fibers strain has been assumed equal to the debonding strain evaluated according to the CNR (Italian National Research Council) guidelines. The employed approach allowed to accurately estimate the collapse load of the arches strengthened with FRP material, while the collapse loads of the arches strengthened with FRCM materials evaluated based on the results of the double shear tests underestimate the failure loads of the arches.