A new non-invasive method for the seismic retrofit of rubble masonry using composite connectors

With the aim of developing a new method for enhancing the seismic performance of historic rubble stone masonry, a shake table investigation was carried out on a full-scale wall retrofitted with non-crossing carbon fibre reinforced polymer (CFRP) connectors inserted through the stones of the façade. The wall was built with the stones collected in a small village struck by the 2016–2017 seismic sequence in Central Italy and subject to natural earthquake records, applied in vertical and horizontal directions with increasing intensity up to collapse. The novel non-invasive system effectively prevented masonry disintegration and leaf separation, entailing a significant improvement of its seismic capacity with respect to an unstrengthened specimen tested for reference. The impact of the retrofitting work is minimised because the fair face of the masonry is preserved and the installation of CFRP connectors is performed only from outside.