Extrados strengthening of brick masonry arches with PBO–FRCM composites: Experimental and analytical investigations

Fabric-Reinforced Cementitious Matrix (FRCM) materials are becoming increasingly suitable for strengthening of historic masonry constructions but only few experimental studies are still available concerning their application on structural elements. In the paper, the structural behavior of masonry arches strengthened at the extrados with a poliparafe nilenbenzobisoxazole (PBO) fabric reinforced cementitious mortar composite is investigated through an experimental and analytical approach. The experimental tests were performed both on unstrengthened and strengthened masonry arches in order to evaluate the contribution of the strengthening material in terms of maximum load and post-peak behavior. The failure mechanisms were also analyzed and discussed. Beam tests were carried out in order to evaluate the bond capacity of the FRCM–masonry interface. The tested arches were analyzed using the approach of the limit analysis of the collapse mechanisms, which was able to accurately estimate the experimental collapse loads.