Repair of damaged multiple leaf masonry: Assessment by the Acoustic Emission technique

Most historic centers in Italy are characterized by the presence of monumental buildings like churches and palaces, and also by a diffused built environment which itself constitutes an important part of the cultural heritage. The problem of safety of these historic masonry constructions started to attract increasing attention after the sudden collapse of ancient monuments happened in the last decades. In this work an experimental research has been carried out on three-leaf walls, using two stones of different characteristics trying to reproduce masonry typologies frequently used in Italian historic centres. Aim of the research was to understand the stress-strain behavior of this masonry under compression and shear actions and to find out suitable repair techniques. The application of the Acoustic Emission technique (AE), gave the possibility to interpret the damage mechanisms and to evaluate the effectiveness of the repair interventions, contributing to the determination of the most suitable methodology for their optimisation.