Experimental tests on typical masonry of Messina area (Italy) retrofitted with CAM: Full scale panels

The present paper focuses on an in-situ testing campaign recently developed in the Messina area, Italy, aiming at the assessment of the in-plane shear behaviour of traditional masonry retrofitted with the innovative CAM system (a system of 3D pre-tensioned stainless steel ties). The typical masonry of Messina area, is characterised by low mechanical properties, both for its texture and for the bad quality of mortar, as well as lack of transverse connections. The high seismic risk characterizing the zone, amplifies the need for in-plane strengthening and improved transverse connections. The CAM system, Masonry Active Ties or Manufact Active Confining, allows one to realise a 3D pre-tensioned tying system which is able to compact stones and mortar and improve the masonry mechanical characteristics. Seven full scale panels were cut in-situ from ancient walls for shear-compression tests. One panel was used to evaluate the mechanical characteristics in compression of unreinforced masonry, the others were reinforced using a polymeric net immersed in the external plaster and tested using a range of mechanical characteristics of the CAM system. Ultimate capacity and ductility increase, as well as modification of the original failure mode, resulted from the CAM retrofitting system under shear compressive tests.