Photocatalytic Performance of White Cement Mortars Exposed in Urban Atmosphere

Abstract

The objective of this study was evaluation of the photocatalytic performance of the addition of n-TiO2 in white cement mortars in terms of the light reflection (evaluated by CIE L*a*b* scale) and reflectance of the mortar surfaces exposed to solar radiation in an urban environment. Are produced specimens of 1.2m × 1.2m with n-TiO2 additions of 1%, 5%, and 10% concerning to the total dry powder mass.The performances of the specimens were then compared with two sets without n-TiO2,painted and unpainted, and these were used as references. To conduct an in-situ experiment, the mortars were mixed and applied by a mason. After 41 months of exposure and washing of the specimens, the painted mortars and the mortars with the addition of different n-TiO2 contents exhibited a statistically equivalent reflectance under exposure to solar radiation. All specimens exhibited color differences resulting from: (i)the accumulation of dirt on the surface; (ii) an increase in the surface roughness of the specimens; and (iii)a decrease in rainfall over the duration of exposure.