Abstract
The main purpose of this study was to evaluate the impact of the substrate type and water absorption on the properties of rendering mortars. A mortar was applied on ceramic and concrete blocks and on standard concrete substrate, which received superficial treatments with water repellent and silicon. This strategy was used to alter the water absorption without changing the roughness. The mixture, application, and cure of the mortars were kept constant, and the results indicated that there are considerable differences in the spreading and open-time of mortars depending on the surface treatment and substrate type; there were no statistical differences in the adhesion or permeability of mortars applied on the ceramic and concrete blocks, regardless of surface treatment, but the values were much lower than those observed on the standard concrete substrate; and even with a direct influence of the coefficient of water absorption on adhesion and permeability, a different tendency was observed for each kind of substrate, indicating that, while absorption is important, it is not the main variable influencing the performance of coatings.
Keywords:
Mortar; Substrat; Surface treatment; Adhesion and permeability
