Utilização de rejeito de rochas ornamentais na fabricação de concreto simples para a construção civil

Abstract

The ornamental stone industry in Brazil is one of the largest in the world, with constant growth year after year, guaranteeing itself strong in the competitive market, directly collaborating in the improvement of human lives with the generation of new jobs. However, there is a significant production of tailings arising from the processing of these rocks which are, sometimes, improperly deposited in places that interfere with the environment, directly or indirectly, in the short, medium or long term. The usage of ornamental stone waste in the manufacture of soil-cement bricks comes as an alternative to mitigate the environmental impacts caused, as is already the case in the ceramic and glass industries. Its main differential is the unnecessary burning process for the manufacture of blocks, since they are molded and pressed, thus, eliminating the generation of CO₂ and other gases or particles that could be released into the atmosphere. Thus, this work aims to evaluate the physical and mechanical properties of simple concrete samples, produced with tailings from the processing of marble/granite. Residue physical characterization tests, slump tests, and compressive strength tests were performed. Subsequently, the specimens were molded in cylindrical molds in the dimensions of 10 cm x 20 cm, with the replacement of the conventional fine aggregate by marble rejects at the levels of 5%, 10%, and 15% of weight. Finally, the mechanical properties were determined at the curing age of 14 days. It was observed that, despite the decrease of workability there were no significant changes in the mechanical properties of the specimens incorporated with the marble residue, and the values obtained to satisfy the normative parameters.