Carbonated recycled materials for property enhancement in cement-based materials: a review

Abstract

Recycled concrete materials, including recycled coarse aggregates, recycled fine aggregates, and recycled powder, are essential for a circular economy. However, their incorporation into cement-based composites often reduces mechanical and durability performance due to high porosity and residual mortar. To address these limitations, various modification strategies have been developed, with mineral carbonation emerging as a promising technique. This process involves exposing recycled concrete materials to carbon dioxide to form calcium carbonate within the pore structure, which densifies the matrix and enables carbon sequestration, providing dual benefits for material performance and environmental sustainability. This study reviews the application of mineral carbonation to recycled concrete materials and discusses its potential for sustainable use in cement-based materials. The paper begins with a comparative overview of representative modification techniques, including mechanical, thermal, and chemical approaches, highlighting their respective strengths and limitations. It then elaborates on the reaction mechanisms associated with mineral carbonation. Afterwards, the effects of carbonation on recycled concrete material properties, the performance of concrete incorporating these materials, and the associated environmental benefits are summarized. Finally, the paper concludes by identifying research gaps and proposing future research directions for broader implementation in sustainable construction.