Influência da adição de vidro moído e resíduo da produção de alumina eletrofundida nas propriedades de engenharia do concreto de cimento Portland

Abstract

The production of Portland cement accounts for a significant share of global CO₂ emissions, mainly due to the clinkerization process. In this context, incorporating industrial residues as supplementary materials in cement or concrete has become a promising strategy to reduce environmental impacts and promote sustainability. This study investigated the influence of adding ground glass powder and waste from the electro-cast alumina process (REA) on the engineering properties of Portland cement concrete. Mixtures were prepared with 10% cement replacement by each residue, followed by molding of test specimens subjected to compressive strength tests at 7, 14, and 28 days, pozzolanic activity tests, and microstructural analyses by scanning electron microscopy and X-ray diffraction. Results showed that REA contains extremely fine particles, including a nanometric fraction, favoring the filler effect and presenting low crystallinity, which is desirable for pozzolanic reactivity. The glass powder exhibited irregular geometry and micrometric particle size, leading to less efficient packing. Mechanical tests indicated that mixtures containing REA achieved higher compressive strength than the reference concrete, likely due to improved compaction and matrix densification. Conversely, mixtures with glass powder displayed lower strength values. In the pozzolanic activity test, both additions exhibited compatible behavior with supplementary cementitious materials, though with different intensities. Overall, REA showed greater technical potential as a concrete additive, while glass powder, although environmentally beneficial, requires granulometric optimization to achieve improved mechanical performance. The study reinforces the feasibility of reusing industrial residues to produce more sustainable concretes.