Investigation of Dirt Pickup of Facade Coating from the Color Appearance View Point

Buildings façade is one of the most significant factors to make the city concinnity; for this reason, special attention should be paid to aesthetics and cleaning them from pollution. The uncontrolled expansion of urban population growth in the world is the main cause of serious environmental problems and pollution in cities. In the construction industry, chemical, fungal and bacterial contaminants and also airborne particles are major environmental pollutants that directly affect on the building façade. This article review the various coatings used on the building facade, such as antibacterial and antifungal coatings, self-cleaning coatings and hydrophobic coatings, for increasing the age of color appearance and dirt resistance of the façade. Furthermore, various methods of measuring dirt-pickup of coatings have been investigated. Colorimetric methods are used to evaluate and measure dirt-pickup of the samples. The purpose of measurement is to select a suitable coating with ideal dirt resistance, to be used in various applications to maintain cleanliness and prevent discoloration of coatings over time.