The erosion of granite surfaces. The cathedral of Évora as example

Abstract

ABSTRACT: The evaluation of the erosion in the stone surfaces of a granitic monument highlights the severity of decay due to the presence of salts. The method used and reported here integrates different but relevant information: besides the quantity of material lost by the stone surfaces, their hygroscopic behavior was evaluated in different humidity conditions, complemented by the characterization of the microenvironment where the erosion process takes place. The method used contributes to a better knowledge not only of decay but also of the behavior of these materials over one year, illustrating the dynamism imposed by the presence of salts as the most relevant factor of decay. How to modify the behavior of decayed stone materials is the great challenge of conservation actions.