Relationship among the firing temperature, wetting properties and colonization of fungi on clay roofing tile surfaces

Abstract

The wettability of clay roofing tiles as a surface phenomenon plays a key role considering their deterioration process during exploitation. The experimental investigations in this paper were performed combining the data of the material-relevant parameters and the surface wetting properties in order to assess clay roofing tiles biodurability. The fungus Aspergillusniger was used as a model microorganism whose colonization and growth, during a period of 28 days on the tiles fired at two temperatures (900 and 1020°C), was analyzed. The paper confirms that the colonization of the tiles with the fungus goes through two stages: up to the 18 th day, based on the surface characteristics, and after the 18 th day when the textural characteristics (values of water absorption) are the dominant parameters.