New Technologies for the Structural Rehabilitation of Masonry Constructions: Concept, Experimental Validation and Application of the CAM System

Old masonry structures are often characterised by irregular or double layer masonry, with lack of transverse connections. Besides requiring in-plane strengthening, they also need improving transverse connections. The ideal strengthening strategy would therefore be realised by a threedimensional tying system. The CAM system, Masonry Active Ties or Manufact Active Confining (patented by Dolce and Marnetto), is based on such idea. Ties are made of stainless steel ribbons and are pre-tensioned, so that a light beneficial pre-compression state is applied to masonry. Using special connection elements, a continuous horizontal, vertical and transverse tie system is realised, that improves the shear and bending in-plane and out-of-plane strengths of single panels and entire walls. The main characteristics of CAM are illustrated in the paper, along with its application potential, the setting up operation, as well as the first experimental results on both panels and columns.