The effect of carbonation curing on depth-wise carbonation gradient and compressive strength development read more 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 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 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 read more 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.