Utilização do rejeito de minério de ferro na camada de revestimento primário em estradas mineiras

Abstract

ABSTRACT On open pit mine roads, it is common to use materials available in the mine itself for pavement construction. The study of the properties of materials is essential to reduce the appearance of defects and optimize operating costs. The choice of materials for the structural layers of the pavement, based on the use of materials available in the mines themselves, plays a crucial role in the durability and performance of the tracks. In this context, this dissertation carried out a detailed analysis of the physical and mechanical properties of the samples collected at the Segredo Mine, through laboratory tests. Empirical pavement design methodologies were used to determine the thickness of the primary coating layer, applying the CBR and DNIT methods. The defects found along the surface of the roads and the agents responsible for them were also analyzed. The results obtained indicate that, despite the frequent maintenance of the roads and the application of water sprinkler, the roads of the Secret Mine have several irregularities in the pavement surface, due to the intense traffic of trucks. The analysis of the properties of the materials revealed that they are poorly graded and uneven, which compromises the compaction process and reduces the bearing capacity of the pavement layers. The mineralogical composition of the samples also indicated the presence of kaolinite, which can affect the stability of the material. In addition, the design methods used, such as the CBR and DNIT, proved to be inadequate for the specific conditions of Minas Gerais roads, evidencing the need for adjustments or new methods to improve pavement design practices.