Experimental tests on typical masonry of Messina area (Italy) retrofitted with CAM: A full scale arch

The present paper focuses on an in-situ testing programme recently developed in the Messina area, Italy, aiming at the assessment of the in-plane shear behaviour of traditional masonry structures 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, for its texture (bond) 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 transverse connection improvement. The CAM system, which uses masonry ties and active confining of masonry allows one to realise a 3D pre-tensioned tying system which is able to compact stones and mortar and improve the masonry mechanical characteristics. A full scale arch was cut from an ancient building and in-situ tests were carried out. First, the arch was horizontally in-plane loaded until first cracking appeared, then it was reinforced with CAM and re-loaded until failure. The results of the experiments carried out have highlighted the advantages in using CAM, specially its ability to provide a large increase in terms of strength and ductility.