Diagnosing stone decay in built heritage. Facts and perspectives

Abstract

Stone and other materials used for the construction of historic buildings, memorial statues, gravestones and similar are exposed to weathering and polluting agents and, therefore, progressive decay. Such deterioration, whether physical, chemical or biological, involves mineral phases and their interrelationships (structure and texture). A review of the analytical procedures applied in scientific research on stone damage has revealed the need for appropriate tools and tests (each with a specific scope, depending on the extant damage) to identify decay processes and apply the correct "therapy", i.e. temporary and/or permanent protection (cleaning, protection, reinforcement, repair and/or replacement). A number of case histories of famous components of the Italian built heritage are discussed in the context of the use of integrated methodologies for researching decay in different kinds of stone.