Durabilidade de argamassas alternativas aditivadas com resíduos de quartzito.

Abstract

The exploration and processing of quartzite as ornamental rock generate a large amount of residues that, when improperly discarded, cause serious damages to the environment, such as the contamination of fauna, flora, water resources and soil. In order to attack this problem, mining companies, researchers and government agencies have performed studies on the use of these residues as raw matter for construction. So, the present study has the objective of analyzing the durability of alternative mortar compositions blended with quartzite residues. The physical, chemical and mineralogical characterization of the quartzite residues was performed through the application of the following techniques: granulometric analysis by sieving and laser diffraction (AG); chemical composition by X-ray fluorescence (EDX); X-ray diffraction (XRD); chemical analyses of the extracts lixiviated and solubilized by atomic absorption. In the study of the durability of mortar samples blended with quartzite residues, we employed the following investigation methodologies: alkaliaggregate reaction (AAR); sulfate-attack resistance; natural aging (exposure to local environmental conditions) and quick aging (directed rain). The results indicated that the aggregates coming from the quartzite residues are innocuous with respect to the alkali-aggregate reaction, not being deteriorated when immersed in NaOH 1N solution. They were also reactive to the sulfate attack, presenting dimensional expansions when immersed in sodium sulfate solution. With respect to the natural and quick aging methods, the results reveal that the mortar samples blended with quartzite residues presented satisfactory durability, proven by the mechanical behavior and microstructure, which were similar to those of the respective conventional samples over the period of evaluation.