A key factor in modern protection of historic buildings: the assessment of penetration of water-repellent polymers into porous stone-materials

摘要

From the 1960s on, the conservation of monuments and stone masonry has withessed an increasing use of polymeric products during restoration interventions. Actual penetration depths reached by different polymers within he porous stone matrix are supposed to be key factors in determining the efficacy of the treatments themselves (besides, of course, the chemical-mineralogical nature of the stone and the chemical-physical characteristics of the various polymers). This work presents some preliminary results obtained on specimens of Noto calcarenite treated with various polymric protective products. Samples were inverstigated with direct analytical methods (micro-ATR spectroscopy, SEM) in order to assess penetration dephths reached by polymers inside the stone while reducing to a miuimum the necessary manipulation of specimens. The obtained results highlighted the following trend in penetration depths for the various products tested: siloxcane product > partially fluorinated acrylic resin > acrylic resin. Moreover, data obtained allowed to establish direct correlation between long term efficacy of products and relative penetration depths.