Incorporação de resíduos de carvão vegetal em argamassas cimentícias

Abstract

Construction systems require significant amounts of natural resources, however, these are already beginning to present problems regarding the impacts caused by their extraction. The incorporation of agroindustry’s residues, such as charcoal, to cement composites can present solutions to minimize such problems and to take advantage of by-products from other sectors. In addition to being renewable, charcoal has great agricultural and industrial potential. Based on this assumption, the present study aimed to evaluate the potential of the use of charcoal waste (RCV) in partial replacement of fine sand (by volume) on the properties of mortars. For that, tests were carried out to evaluate the physicochemical composition of the RCV and to analyze its pozzolanic potential, without previous beneficiation. Mortar specimens (CP) with RCV were made at 0%, 10%, 20% and 30% in relation to the fine sand, in the water / binder ratio of 0.55. After the cure time of 7, 28 and 60 days, the CPs were analyzed by means of the techniques of resistance to axial compression, tensile strength by diametrical compression, scanning electron microscopy (SEM) combined with X-ray dispersion spectrometry (EDS), X-ray diffraction (XRD), water absorption, apparent porosity and specific mass. The results showed that although the RCVs do not present themselves as pozzolanic materials, their incorporation is feasible, which is confirmed by analysis of variance (ANOVA), where the statistical indices are significant for the 20% content in substitution for fine sand, which produced mortars with compressive strength values around 28 MPa, higher than the reference ones. These results contribute to research that confirms the feasibility of including these residues in cementitious matrixes, which can add value to a material until then without perspective of use. The inclusion of RCV in addition to reducing the waste disposal to the environment makes possible the minimization of non-renewable materials used in construction, contributing to the sustainable development of the sector.