Utilização de cavaco metálico industrial como fibra na composição de concretos

Abstract

Concrete is one of the most widely used materials in civil construction and is essential for a wide range of projects, from small buildings to large infrastructures. Given its widespread use, the search for alternatives in its composition becomes an opportunity not only to improve its properties, but also to optimize the use of waste that would otherwise be disposed of inappropriately, causing an environmental impact. In addition, this practice can generate income for the producers of this waste, creating a beneficial solution from both an environmental and economic point of view. Metal chips, an industrial waste resulting from machining processes, are known for their high polluting potential. However, when incorporated into concrete, it can reduce the environmental impacts of this material and even contribute to improving certain mechanical properties of the construction. This type of metal chip, usually from the automotive industry and other metallurgical sectors, has characteristics that can act in a similar way to steel fiber, which justifies investigating its use as an additive in concrete. The main objective of this study was to evaluate the behavior of concrete when subjected to different volumes of metal chips, comparing it with the performance of steel fibers, especially with regard to the physical and mechanical properties of the material. The laboratory tests carried out included diametral compressive strength tests, one of the main parameters for determining the robustness of concrete under real loading conditions. The results of the tests indicated that the addition of metal chips to concrete, especially from the automotive industry, caused a significant reduction in the workability of the material, which ended up compromising the diametral compressive strength. This was because the presence of metal chips in the concrete interfered with the properties of the composite, making the mixing and application process more difficult, which in turn reduced the homogeneity and cohesion of the mass. In view of these results, it was concluded that, in order to implement metal shavings as an additive in concrete, it would be necessary to adjust the addition proportions to avoid compromising the mechanical properties. As the compressive strength did not achieve the expected results, a more in-depth environmental analysis was deemed unnecessary for the large-scale use of this waste in concrete. In summary, although metal shavings have the potential to improve the sustainability of concrete, the technical challenges associated with their incorporation must be overcome before their adoption is viable.