Title Influence of Initial CO₂Curing Duration on the Age-Dependent Properties of Cement Mortar
Authors 하상주(Ha, Sang Ju) ; 나형원(Na, Hyeong-Won) ; 형원길(Hyung, Won-Gil)
DOI https://doi.org/10.5659/JAIK.2026.42.5.369
Page pp.369-377
ISSN 2733-6247
Keywords Carbonation Curing; CaCO3; Cement Mortar; Long-Term Properties
Abstract TThis study evaluated the effects of varying initial CO2 curing durations on the physicochemical and microstructural properties of cement mortar. In the experiment, cement mortars subjected to CO2 curing for 3 days (C3d) and 6 days (C6d), followed by air curing up to 7, 28, 56, and 91 days, were compared with plain specimens cured in air for the same ages. Carbonation depth, water absorption, chloride penetration resistance, and compressive strength were analyzed. In addition, XRD, TGA, and SEM were employed to investigate the changes in hydration products and microstructural characteristics. The results showed that specimens subjected to CO2 curing exhibited superior performance in all test parameters compared with air-cured specimens. In particular, the 6-day CO2 curing condition demonstrated the lowest water absorption, the highest resistance to chloride penetration, and improved mechanical strength. These enhancements were attributed to the formation of CaCO3 through the carbonation reaction, which effectively filled pores and densified the microstructure. XRD and TGA analyses revealed a clear reduction in Ca(OH)₂ and an increase in CaCO3 depending on curing duration, while SEM images confirmed a more uniform and cohesive microstructure. These findings confirm that carbonation curing not only contributes to short-term strength development but also enhances long-term structural stability and durability of cement mortar.