The Feasibility of RCA Treatments Utilised in Asphalt Mixtures to Enhance their Properties and Performance: Narrative Review

Recycled concrete aggregates (RCA) can be utilised instead of virgin aggregates to produce hot asphalt mixtures. This contributes to solving the difficulty of construction waste disposal and mitigates the supply-demand dilemma associated with implementing the sustainability strategy. Nevertheless, the presence of cement mortar in the recycled concrete aggregate leads to changes in its mechanical and physical characteristics, posing a major challenge. Therefore, researchers investigated methods to mitigate the harm caused by this cement mortar through various treatments. This paper offers a narrative review of the feasibility of employing several treatments or techniques on recycled concrete aggregates to enhance the susceptibility of asphalt mixtures to fatigue, water damage, permanent deformation, and Marshall properties. Several treatments have been discussed, such as heating, coating, mechanical treatment, immersing RCA in chemical solutions, and the composite method. This review concludes that mechanical treatment is the most practical and effective, making it the most likely to succeed in practical application.