Recycled concrete tends to be increasingly investigated with respect to the environmental needs, such as resource depletion, circularity and lack of landfill disposal spaces. A naturally accelerated carbonation procedure by using atmospheric CO2 concentration level and a cyclic wetting and drying of the recycled concrete aggregates was applied. A two stages carbonation process was applied. The recycled concretes exhibited similar mechanical properties of the reference concrete or even better durability as compared to the reference concrete prepared with natural rock aggregates. The carbonation of the outer layer of the recycled concrete aggregates was achieved with a simple method that can be widely applied and is sufficient to significantly increase the properties of the recycled concrete aggregates.
Keywords: Concrete, Recycling, Aggregates, Acceleration, Carbonation.