Bond behavior of trm systems and reinforcement of masonry arches: Testing and modelling

The paper addresses the results of experimental and analytical investigations on composite systems able to reduce structural vulnerability of arches. Two composites, consisting of a PBO (propylbenzodioxole) fibre textile or a carbon fibre textile coupled with a cement-based matrix, are considered. Experimental results on bond capacity between composites and bricks and on the structural behaviour of unreinforced and extrados-reinforced 1:2 scale masonry arches, tested under vertical load, are presented. The global load slip law deduced from double-shear tests is employed to predict the load displacement path followed by an arch reinforced at the extrados through the two composites. The analytical model, which exploits stationarity of potential energy of acting forces, is validated through the experimental results on the reinforced reduced scale arch. Results show how the initial response is tackled by the model. The procedure could be refined and extended to other curved elements (e.g. pointed and ogee arches, vaults and domes) and loading conditions. A further improvement may come from the use of test results on convex surfaces, it being known that the bonding behaviour is improved with respect to that on plane surfaces.