Portland Cement Mortars Using Iron Ore Tailings As A Partial Substitute For Sand Fractions

Objective: Investigate the potential of iron ore tailings (IOT) from the Fundão Dam failure as a partial replacement for sand, in all its fractions (fine, medium-fine, medium-coarse, and coarse), in mortar production. Theoretical Framework: Mining is essential for the Brazilian economy but generates large volumes of waste with high environmental impact. The Mariana and Brumadinho disasters highlight failures in tailings management and the need for sustainable solutions. Method: Mortar samples were produced with 5%, 10%, 15%, and 20% IOT substitutions relative to the total mass of fine aggregate. Compressive strength tests were conducted at 7, 14, and 28 days. Failure plane analysis was performed to identify predominant failure types. Results and Discussion: Samples with 5%, 10%, and 15% IOT showed higher compressive strength than the reference sample. The 15% substitution was the most efficient, balancing strength, workability, and sustainability. The 20% substitution reduced strength and workability, indicating a limit for IOT incorporation. Research Implications: The study demonstrates IOT's potential as a sustainable alternative in mortar production and enables new applications for mining waste, promoting a more sustainable approach in civil construction. Originality/Value: The research explores the use of IOT as a raw material for mortars. It provides experimental evidence on the technical feasibility of partially replacing sand with tailings and proposes a sustainable waste management solution, combining mechanical performance with a positive environmental impact.