Avaliação da eficiência do tratamento superficial de revestimento de argamassa com uso de endurecedores de superfícies.

Abstract

The addition of clay minerals to coating mortars in Brazil has been reported since the colonial period. During this time, in Salvador and the Metropolitan Region, there was a predominance of the use of this type of mortar in buildings. However, the empiricism adopted to establish the amount of clay minerals in the mixes and the lack of specific normative criteria for mortar dosage, to date, has generated a significant number of pathological problems in mortar coverings with the addition of clay minerals. Given this context, it is necessary to research methods to solve the pathologies that occur in mortar coatings. The objective of this study is to analyze the efficiency of surface treatment with liquid surface hardeners applied to masonry panels produced in the laboratory. To this end, a literature review was carried out in scientific databases (Scopus, Web of Science, Engineering Village and Science Direct) on the topic, in addition to the technical standards related to the study, which guided the preparation of the project. Regarding the analysis, characterization tests were carried out on both the materials used to obtain the mortar (cement, sand and clay mineral) and the ceramic blocks. Furthermore, a mortar dosage study containing clay additions was carried out, from which a reference mortar and two different groups with excess clay material were defined. Next, four masonry panels were made, one was used as a reference and hardeners were applied to the others. Regarding mechanical properties, the coatings were evaluated based on tensile adhesion, surface adhesion, scratch and impact resistance tests. Regarding microstructural evaluation, analyzes were carried out using optical microscopy, scanning electron microscope (SEM), in addition to X-ray diffraction (XRD). It was concluded that each product used presented a different performance, but in all cases the application of surface hardener promoted an increase in the adhesion resistance to surface traction and contributed to the partial waterproofing of the coating system, making it difficult for water to penetrate into the surface. substrate.