Influence of Substrate Characteristics on Behavior of Applied Mortar

Abstract

A facade coating that still has wide applicability is mortar render, whether it is made with lime or cement, whether it is a predosed composition or traditionally made in situ, and whether it is applied in new constructions or for rehabilitation purposes. In fact, this type of coating is very versatile, easy to execute, and inexpensive. Whether the characteristics of a mortar are declared by the manufacturer or established by the user, they are normally determined in the laboratory in accordance with the relevant standards using specimens with recommended dimensions. But when applied to real substrates, will these mortars maintain their characteristics, or will the characteristics of the substrate have a significant influence on them? What will this influence be? Will a porous substrate have more or less influence than a nonporous one? The research carried out at the University of Coimbra in collaboration with the University of Porto and the National Laboratory for Civil Engineering (LNEC) set out to answer these questions. To carry out this experimental campaign, three types of substrates and three types of mortars were selected. The different mortars were applied to the different substrates. All the substrates and mortars were characterized before and after application on the substrates. A comparative analysis of the obtained results was made and it was possible to confirm that the substrates influence mortar characteristics and that this influence varies depending on the type of mortar.