NEW DIAGNOSTIC METHOD TO DEFINE THE SALT DAMAGE SOURCE IN MASONRY

摘要

The crumbling phenomenon of the stones, produced by the stresses due to salt crystallization, inside infiltrated, is well known in conservation problems. Less known, instead, it is the crystal configuration type and the dimension of salts, and the crystallization evolution correlated to chemical, physical and mechanical parameters, that locally were obtained in the stone. Through monitoring of typical experimental conditions, opportunely selected, by means of the Acoustic Emission techniques, it has been possible to get useful information to the characterization of the crystallization phenomena. Besides, according to the Acoustic Emission spectrum, it has been possible to identify the crystal type during the growth, the stress state produced inside the material, and the following break-up. In this paper, we describe the investigation data about the evolution of the crystallization phenomena obtained using the methodology of the Acoustic Emission in laboratory tests. The obtained results show that it is possible to suggest a procedure for a high sensible and diagnostic method for the salt crystallization, useful for defining conservative interventions.