The effect of carbonation curing on depth-wise carbonation gradient and compressive strength development of RCM was evaluated.The RCM mortars were carbonated for seven curing periods, complemented by a thorough investigation of carbonation degree, phase assemblage, and microstructural at varying depths.Results showed a significant increase in compressive strength, from 3.
3 MPa on Accessories the first day to 51.7 MPa after seven days and 63.5 MPa after 28 days of carbonation curing.
A notable gradient in CaCO3 concentration was observed, decreasing from 41.4% at the surface to 16.8% at 25 138 mm depths.
Additionally, the formation of CaCO3 polymorphs and Ca-modified silica gel in the surface layers was found to enhance microstructural density and impede CO2 penetration, while a higher prevalence of micropores was noted in the inner regions.These findings highlight the potential of optimizing the carbonation regime or employing internal carbonation methods to achieve a more homogeneous microstructure.