Application of protective products to "Noto" calcarenite (South-eastern Sicily): a case study for the conservation of stone materials

Noto is an important Baroque urban center insouth-eastern Sicily, which was completely reconstructedafter the severe earthquake of 1693. Most of its monumentsand historic buildings were built in Pietra di Noto stone, apale cream calcarenite, quarried in outcrops located near thecity. This stone, still currently used as building material, isundergoing many forms of alteration and degradation, whichcause significant damage to monuments. In this study, threecommercial protective products were tested on some Notocalcarenite samples from quarries, with the aim of assessingtheir protective effectiveness. In particular, petrographicanalyses by optical microscopy were carried out for texturalcharacterization of the stone materials. Capillary waterabsorption, porosimetric and colorimetric procedures, UVradiation and salt crystallization aging tests were performedto better evaluate interactions between protective productsand substrate.