Experimental Response of Rubble Stone Masonry Walls Retrofitted with Basalt Textile Reinforced Mortar under Compressive-and-Shear Load

Abstract

Seismic events recently occurred in Europe highlighted the vulnerability of unreinforced masonry structures, representing the majority of the built heritage, to earthquake-induced loads. In particular, the in-plane capacity of shear walls under seismic loadings appeared sensibly modest, both in terms of strength and ultimate displacement, and their failure mode sudden and brittle. Textile Reinforced Mortar (TRM) composites proved to be a proper strengthening solution for the seismic upgrade of such walls. With the aim of gaining a deeper knowledge on the behavior of historical walls retrofitted with TRM and subjected to compression-and-shear, this paper summarizes the results of an experimental campaign characterized by quasi-static cyclic shear-compression tests. The specimens under study reproduced the rubble stone masonry typical of vernacular structures of the UNESCO historical district of Lyon (France). Specifically, the work concerns a full scale masonry wall tested under loading until the development of diagonal cracks and than repaired by a composite constituted by a basalt textile embedded in a lime mortar matrix applied onto the external surfaces as a plaster. The use of a lime mortar plaster to reinforce the structural element permits the development of a solution compatible with the historical substrate. Experimental outcomes revealed how Basalt TRMs succeeded in improving the response of damaged vernacular wall, both in terms of strength and displacement capacity.