Alterações superficiais em calcários expostos a nevoeiro salino

Limestones used in buildings on the seashore results in their exposure to the marine aerosol that usually occurs in this area. The study of salt mist influence on such stones is important because of the degradation observed in some limestones exposed in the Portuguese shoreline. Accelerated ageing tests were performed on samples of the following limestones: “Cabeça de Veada”, “Semi-Rijo do Arrimal”, “Creme Fátima”, “Moca Creme”, “Moleanos” and “Azul Cadoiço”. Those tests, simulating the atmospheric conditions existing on coastlines where salt mist occurs, showed that open porosity plays an important role on the limestones’ alteration process. Among the studied limestones, “Azul Cadoiço”, “Moleanos” and “Moca Creme” samples, for which the lowest open porosity values were obtained, also revealed the lowest degradation degree. EPMA images obtained on the limestones surfaces documented this occurrence.