Cation leaching behaviors of carbonation-cured belite-rich cement paste

• Leaching is dominated by Ca and Si ions in BRC (Belite-rich cement). • Carbonation curing reduces the leaching of Ca and Si in BRC compared to air-curing. • Carbonation curing transforms Ca(OH)2 into CaCO3, enhancing the leaching resistance. • Fly ash mitigates early-stage Ca leaching, particularly with carbonation curing. This study examines the leaching behavior of major cations from carbonation-cured belite-rich cement paste under electrically accelerated leaching conditions. A series of experiments were conducted to evaluate how variations in carbonation curing duration and the incorporation of supplementary cementitious materials affect leaching resistance. Inductively coupled plasma mass spectrometry revealed that carbonation curing significantly suppresses early-stage calcium ion release and reduces total cation leaching by promoting the formation of stable CaCO 3 phases. Fly ash further improved leaching resistance by minimizing calcium leaching, while slag showed more complex behavior dependent on curing conditions. Physicochemical analysis results confirmed microstructural rearrangement and recrystallization of CaCO 3 into more thermally stable forms post-leaching. The results suggest that carbonation curing, especially in combination with appropriate SCMs, enhances the chemical durability of BRC paste by mitigating ion leaching and restructuring the pore network. These findings contribute to the development of CO 2 -absorbed sustainable cementitious materials with improved resistance to degradation.