Analysis of bond strength of adhesive mortars with different percentages of EVA exposed to hygrothermal cycles

ABSTRACT

The Ceramic Facade Coating System is traditionally composed of a set of layers adhered to each other, and the failure of any of these layers can lead to the appearance of pathological manifestations. The adhesive mortar is the main responsible for the adhesion of the ceramic tile and, thus, in order to attribute better characteristics to the adhesive mortars, traditionally, polymeric additives have been incorporated in their formulation. The most common polymeric additives used in the production of industrialized adhesive mortars are: ethylene vinyl acetate copolymer (EVA) and hydroxyethyl methyl cellulose (HEMC). Although these additives help in the performance of some characteristics of adhesive mortars, they are usually sensitive to high temperatures. In this context, the aim of this research is to analyze the tensile bond strength in which ceramic slabs were laid using adhesive mortars produced with three different percentages of EVA, after the system was exposed to an accelerated aging program. To this end, tensile adherence strength testing was performed. The results showed that the systems laid with higher percentages of EVA showed greater strength when exposed to room temperature, but also showed greater loss of strength after exposure to hygrothermal cycles when compared to adhesive mortars produced with a lower percentage of EVA.

Keywords
Ceramic Coating System; Adhesive Mortar; Accelerated Aging; Polymeric Additives; Adhesion Strength