Utilização de rejeito de minério do cobre como agregado miúdo na produção de concreto

Abstract

A major concern with recent accidents involving tailings dams has again raised the urgent need for mining companies to adapt to the fate of ore tailings generated by their operations. In this context, the reuse of these materials in the construction industry shows itself to be an excellent alternative. In this research, it was evaluated the reuse of copper mining waste as a partial substitute for the small aggregates in the production of conventional concretes, aiming the evaluation of the mechanical performance of the concrete produced with this material, also if it is objective, to obtain a material destination sustainable for this material. Only in the mine where the material was collected, is there about 160 million tons of this material accumulated in the mine tailings basin, which shows that there is a considerable source of this material available for reuse. In the experimental program there were four study series: one reference composed of concrete without the addition of the tailings, and another three with 15%, 30% and 45% of substitution to the small aggregates, besides the use of two water ratios /cement. Fresh tests were carried out to evaluate the influence of the reject on the plastic properties of the concrete, and in the hardened state, test specimens were tested at 07 and 28 days for the axial compressive strength, diametral compression traction, traction in flexion and modulus of elasticity. The results obtained were statistically treated through analysis of variance (ANOVA) and proved for the substitution parameter of reject, there was significance. The results showed that the samples with substitution of tailings obtained good results, significantly increasing both the tensile strength and the compressive strength of the concrete when compared with reference series under the same conditions. Therefore, copper reject shows an excellent potential to be reused in the production of concrete, with respect to its effects on the mechanical properties of the concrete, in addition to achieving a more sustainable destination than today.