Considerazioni sugli effetti del weathering in rocce calcarenitiche utilizzate in monumenti di interesse storico artistico

In the last decade, the renewed interest in cultural heritage has encouraged researchers in various disciplines to study the technical properties of natural construction materials and the causes, processes and effects of weathering on exposed stone surfaces. For the ready availability, good workability and aesthetic and physicalmechanical characteristics of the many different varieties, calcarenite rocks have always been used with loadbearing and decorative functions, both for constructions of historic and architectonic interest, and in more basic buildings. The durability of these rocks, defined as the property of natural building stone to resist the weathering agents in the course of time and conserve its appearance and characteristics of strength, is however not the same in the different varieties, being controlled strongly by depositional fabric and diagenetic processes. In this context, the comparison between the analysis of the microfacies, decay patterns and physical-mechanical characters of different fresh and weathered varieties has made it possible to elaborate some considerations on the relations between fabric and technical properties of calcarenites and to evaluate qualitatively the effect of individual textural elements on the response of the stone to the weathering action.