The use of iron ore tailings obtained from the Germano dam in the production of a sustainable concrete

The present work aims to identify the influence of the incorporation of iron ore tailings (IOT) obtained from the Germano dam in Brazil in substitution of sand fractions in concrete. The IOT was characterized through particle size distribution, specific weight, and mineralogical composition using x-ray diffraction (XRD). Moreover, a possible reactivity of IOT with Portland cement was investigated using thermogra-vimetrical analysis, the modified Chapelle test, XRD and by uniaxial compressive tests. It was observed that the used IOT has no pozzolanic activity for the studied particle size distribution. Sustainable concretes were developed using IOT fractions as natural sand replacement in 10, 20 and 30% by weight and characterized by compressive tests and a comprehensive pore size distribution analysis through micro computed tomography. The IOT inclusion resulted in a decrease of the pore sizes leading to an increase in the compressive strength of all studied concretes. Nevertheless, for high amounts of IOT incorporation the concrete workability is reduced due to its high surface area. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study found that incorporating iron ore tailings in concrete can significantly increase its compressive strength, but a high proportion of iron ore tailings can reduce the workability of concrete.