Durability of concrete containing carbonated recycled aggregates: A comprehensive review

The utilisation of carbonated recycled aggregates in concrete has been increasingly considered as an effective strategy for CO2 sequestration in the built environment and enhancement of concrete sustainability. Following up a pervious review on the role of carbonated recycled concrete aggregates in the mechanical properties of concrete, this paper presents a comprehensive review on the effects of carbonation treatment on the chemical compositions and physical properties of recycled concrete aggregates, as well as the role of carbonated recycled concrete aggregates in microstructure and durability-related properties including volume deformation, transport properties, chemical resistance, freeze-thaw resistance and fire resistance of concrete. A special focus is placed on the relationship between microstructure and durability-related properties of carbonated recycled aggregate concrete considering the effects of pre-treatment method, replacement level, curing age, water-to-binder ratio and quality of the original aggregates. The insights into the deterioration mechanism and strategies for improving the durability of carbonated recycled aggregate concrete are provided. This review summarises the recent advances in the field, followed by a discussion on the remaining challenges and opportunities for future research.