Non-destructive ultrasonic testings on a monumental structure of the historical center of Cagliari (Italy)

The Municipal Center for Art and Culture Exmà is an excellent result of the transformation of a mono-functional structure (the old abattoir of Cagliari) into a polyfunctional pole dedicated to art that has hosted major events since nineties. In order to monitor the conservation state of the building materials of this monument, mostly carbonate rocks, non-destructive ultrasonic analyses have been carried out since 2007. Ultrasonic data have been related to the physical and mineralogical-petrographic features of the investigated building materials, in order to correlate the elastic properties with their intrinsic ones. In situ ultrasonic investigations were performed on the outer walls of the main building of the monumental complex, subjected to various restoration works. The methodology used in this study proved useful to evaluate and monitor the weathering process, verify the effectiveness of the old restoration works and check the thickness of the weathered shallow part of the masonry by means of refraction techniques.