Reutilização de resíduos de construção civil e demolição na fabricação de tijolo cerâmico

Abstract

The losses caused by the waste of materials during the construction of a building are the main responsible for the generation of construction and demolition waste - RCD at the construction site. Recycling is an alternative to reduce the environmental impact of such waste, the use of waste materials within the site or outside specialized companies, makes materials that would be discarded with a certain financial and environmental cost return in the form of new materials and reinserted in the construction, improving even in the quality of the material, durability and resistance. The practice is advantageous in several ways: it reduces the chances of deposition in clandestine locations and helps to relieve pressure on increasingly saturated landfills. The ceramic products obtained with natural clays are very varied, showing reddish tones, mainly after burning. The development of Brazilian cities increases the consumption of building materials, consequently generating a large amount of construction and demolition waste (RCD). In the characterization of these, physical-chemical aspects were approached in order to analyze the consistency of clay and residue mixtures, the samples were characterized by granulometry, liquidity limit, plasticity limit, X-ray Fluorescence Spectrometry - FRX, Diffraction of X-rays - DRX. The characteristics of the clay are very fine granulometry, chemical and structural diversity (clay - Si (Silicon) with 57.8% and RCD - Si (Silicon) with 52.5%), easy dispersion in water, high plasticity and good homogeneity, so, for the preparation of a ceramic mass is recommended to incorporate a less plastic material, to improve the yield of the production and the workability with the raw material. The RCD consists mainly of quartz, that is, non-plastic material, a predominantly sandy material, facilitating the incorporation of the residue in the ceramic mass. In this work the incorporation of RCD in the ceramic mass was carried out to produce ceramic bricks, aiming to propose an option to reuse this residue and to economize the clay raw material. The experimental methodology used is based on the use of RCD as a non-plastic material, with a pre-established composition of 0 to 90% RCD. The RCD was crushed and mixed with clay and water (8%). The blend was pressed in a manual hydraulic press and dried for 24 hours in an oven at 110 ° C, being burned at 950 ° C. It was observed that all the specimens obtained values within the limits established by the technical norms. For mechanical resistance with 10% RCD composition, tensile strength was higher than 4 MPa, being considered the best composition. The results show that it is possible to use RCD to produce ceramic material, providing a good alternative for reuse and saving of natural resources. Key words: incorporation, construction and demolition waste, ceramic brick.