Traditionally, carbonation in concrete has been viewed negatively, particularly in reinforced concrete structures. In these cases, carbonation can lead to potential corrosion of the reinforcement, especially in systems with low portlandite content in high humidity environments. Carbonation is typically measured using various pH indicators, where exposed samples are fractured after a certain time, and the carbonation front is assessed. Furthermore, the increasing use of alternative binders necessitates the assessment of possible microstructural damage due to carbonation, and the consequences that this might have in non-reinforced applications. In recent years, carbonation is increasingly seen as an alternative for absorbing CO₂ from the atmosphere in existing concrete structures. Nevertheless, despite being the same phenomenon, new methods are required to measure the amount of CO₂ that existing structures can potentially sequester. Experimental evidence shows that knowing the carbonation rate and mix design are insufficient to determine the carbon capture potential. In addition to the carbonation rate, the degree of hydration and the degree of carbonation are critical parameters that must be considered. In this study, a hybrid system with variable contents of uncarbonated recycled aggregates was investigated. The microstructural changes caused by the carbonation process were monitored using destructive and non-destructive techniques to evaluate the potential damage. The carbon capture capacity was also evaluated in different parts of the (un)carbonated microstructure. Overall, the trend in the studied samples indicates that concrete mixes with low-quality recycled aggregates result in a greater carbonation rate than natural aggregates concrete. In addition, there are significant differences in the CO2 uptake per gram of binder, due to the old cement paste in recycled aggregates.