Propriedades e microestruturas dos granitos e limestones do Ceará utilizados como revestimentos na construção civil.

Abstract

The texture, color and ease of application render limestones from Ceará competitive with granites as tiles for wall coverings and flooring applications. Granite patologies, enhanced in wall coverings and heavy traffic flooring have been intensely researched and interpreted as being due to mineral inter-grain micro-cracks with differing thermal dilation coefficients which originate during magma cooling and that are enhanced during carving and milling operations. Thus, microstructural characterization performed by accurate non-destructive essays would result in technological improvement and significant reduction in time and prospection, as product properties could be efficiently ascertained and their use technical and commercial use as tiles for wall coverings and flooring applications, could be estimated in advance. The aim of this work is to execute the microsctructures analyzes and the properties of limestones and granites from the state of Ceará to be used as tiles in wall and flooring applications. Limestones and granites were characterized by chemical analysis, X-ray diffaction, thermal analysis and scanning electron microscopy. Once characterized, their physical-mechanical properties were determined by apparent density, porosity, water absorption, abrasion resistance, compression, flexural and impact testing. Durability was determined with respect to chemical attack. Results evince that microsctructure greatly influences the mechanical properties of the materials investigated, particularly of the limestones. Material durability varied with sample nature and solvent employed but in general, limestones were more affected by chemical attack than granites and citric acid caused more alterations in limestones while hydrochloric acid attacked granites mores severely.