Viability of Asphalt Mixtures with Iron Ore Tailings as a Partial Substitute for Fine Aggregate

Abstract

Dark colors aggravate the absorption and accumulation of heat in urban centers in the layers of asphalt coating. These problems can be minimized by incorporating materials that increase the albedo on these pavements. The use of waste in the industry has been encouraged, and an alternative is iron ore tailing (IoT), whose material comes from processing iron ore. The circular economy encourages a change in waste disposal after project decommissioning, encouraging the transformation, reuse, and recycling of waste. Therefore, this research investigated the influence of percentages of IoT in the contents (7.5%, 10.0%, and 12.5%) as a substitute for fine natural aggregate on hot asphalt mixtures’ mechanical and thermal performance. The statistical variance test (ANOVA) was used to validate the obtained data. An economic analysis concerning the costs of production and recovery of asphalt mixtures was carried out using the Present Net Value. Asphalt mixtures with IoT were evaluated with regard to the environmental aspect using the circularity index. Among the asphalt mixtures analyzed, the one produced with 12.5% was the most viable. The results showed a gain in mechanical performance concerning tensile strength, resilient modulus, fatigue, and permanent deformation of this mixture, as well as a reduction in production costs per kilometer of highway. The use of 12.5% provided a greater circularity and a reduction of the surface temperature of the pavement by 2.9°C. IoT is viable in constructing highways close to places that produce iron ore.