Granitic rocks and other rock types used as dimension stones become easily altered once exposed to the atmosphere in urban centres and this process can be accelerated depending on how polluted the atmosphere is. In order to define the specific effects on rocks, several different experiments were carried on covering mechanical and physical tests, after promoting artificial ageing caused by acid environments (HCl, H2SO4, HNO3), combined with freeze and thaw exposure. The rocks used in the experiments were: Monção, Vila Real, Castelo de Vide and Monforte granites and other undersaturated rocks (Gabbro from Odivelas and the Monchique Nepheline Syenite). The decrease of rock property values (in percentage) relative to the initial values and the quality factor Q were determined. This relationship indicates the degradation experienced by each rock under similar natural environments and the constrains for the rock uses. This type of data represents a quality warranty for the natural stone industry.
|Publication status||Published - 1 Jan 2010|