Performance of Iron Ore Tailings/Cement Composite at High Temperatures: Inconbustibility

Abstract

Objective: This study aims to evaluate the performance of an iron ore tailings/cement composite at high temperatures, used in brick manufacturing. Specifically, it investigates the non-combustibility of the material and its structural integrity after exposure to intense heat, with an emphasis on compressive strength and the economic and sustainable viability of this composite.   Theoretical Framework: The research is based on concepts of sustainability in civil construction and the reuse of industrial waste. The literature highlights the synergy between iron ore tailings and Portland cement, resulting in materials with good durability and non-combustibility. Previous studies indicate a reduction in environmental impact and the economic feasibility of using these composites as substitutes for traditional materials, in addition to the importance of maintaining structural strength under extreme conditions.   Method: The adopted methodology involves the manufacture of test specimens using CP V-ARI cement and iron ore tailings, molded and cured according to Brazilian standards. Non-combustibility tests are conducted in a muffle furnace at 750°C, measuring temperature variation, smoke emission, and mass loss. Additionally, compressive strength tests are conducted before and after heat exposure to assess material degradation.   Results and Discussion: The results indicate that the composite exhibits satisfactory non-combustibility properties, with an average mass loss of 3.1%, well below the permissible limit of 50%. However, a significant loss of 67.5% in compressive strength was observed after exposure to high temperatures. The discussion contextualizes these results, highlighting the need to optimize the composition to minimize strength loss, although non-combustibility remains a positive aspect.   Research Implications: Practical implications include the potential use of the composite in environments subject to high temperatures, as a passive fire protection measure. Theoretically, the research contributes to the understanding of the behavior of cementitious composites with industrial waste under extreme conditions, suggesting directions for future studies and applications in civil engineering and sustainable construction.   Originality/Value: This study makes an original contribution by exploring the specific combination of iron ore tailings with cement at high temperatures, providing new insights into its applicability and limitations. The relevance of the research lies in the potential reduction of environmental impact and the promotion of sustainable practices in civil construction, as well as enhancing fire safety in buildings.