Concreto de alto desempenho (CAD) com utilização de rejeito magnético de minério fosfático.

The pursuit of sustainable materials provides motivation for using magnetic tailings as an aggregate in the concrete production, which is the most used material in civil construction and is originated from the mixture of binder, water and aggregates. This study developed three dosages of high-performance concrete (HPC), one reference and two with partial replacement of the fine aggregate by a material with similar granulometry - magnetic tailings derived from the phosphate rock beneficiation process in Araxá-MG. The aim was to improve the pore structure of concrete by optimizing the particle packing of granular materials and incorporating a mineral admixture (silica fume), as well as adjusting the workability using a chemical admixture (superplasticizer). The properties of the concretes were evaluated using the tests: compressive strength, water absorption, specific mass and durability against sulfuric acid attack. The compressive strength increased with the increase in the proposed replacement percentage. All concretes had good durability, and the proposed replacement reduced the vulnerability of the concrete to acid attack. Regarding the specific mass, all concretes were classified as normal. The concrete dosage methodology applied was effective, producing high-performance concrete with the incorporation of magnetic tailings. [ABSTRACT FROM AUTHOR]