Effect of pre-conditioning on the carbonation curing characteristics of belite-rich cement paste

This study investigated the effect of pre-conditioning on the carbonation curing characteristics of belite-rich cement (BRC) paste. Before carbonation curing, the BRC paste was pre-conditioned under ambient dry and oven dry conditions, and its physicochemical and mechanical properties were subsequently evaluated. The highest compressive strength was observed when the moisture content before carbonation curing was approximately 50 %. The results suggest that CO₂ penetration alters the hydration mechanism of BRC paste and that pre-conditioning enhances both carbonation curing efficiency and overall physicochemical properties. Compared to untreated samples, pre-conditioned specimens exhibited higher compressive strength, primarily due to the removal of internal moisture, which increased the reactive surface area for CO₂, facilitated its rapid diffusion, and promoted more uniform carbonation. Furthermore, XRD, TG/DTG, and MIP analyses revealed that pre-conditioned BRC paste contained higher amounts of ettringite and calcite after 28 days of curing, further improving its physicochemical performance.