Strength development and thermal stability analysis of carbonation-cured red mud-based cementitious materials

초록

Accelerated carbonation curing shows great promise for cutting carbon emissions in construction by using high- alkalinity industrial by-products. This study focuses on red mud as a cement additive to enhance CO2 capture and mechanical properties during carbonation curing. The synergistic effects of adding limestone and blast furnace slag were also analyzed. The thermogravimetric analysis measured carbonation product content and CO2 uptake, while microscopic techniques examined the hydration and carbonation processes of red mud-based materials. Mechanical properties and phase changes were tested at high temperatures (200 degrees C, 500 degrees C, and 800 degrees C) to evaluate thermal stability. Key findings include: (1) red mud significantly boosted carbonation rates and CO2 uptake; (2) limestone and blast furnace slag provided extra nucleation sites, improved Ca2+ diffusion, and influenced N-(A)-S-H gel formation, enhancing strength and CO2 uptake without slowing carbonation; (3) fully carbonated materials maintained high structural integrity below 500 degrees C, with compressive strength peaking at 200 degrees C. A carbon footprint analysis revealed that utilizing red mud effectively lowers carbon emissions in building materials, supporting the development of green construction solutions.

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