Processing techniques of recycled aggregates

Abstract

Three essential components of every modern-day growth are preservation of natural aggregate resources, green construction, and the safeguarding of the environment. One such endeavor is the incorporation of recycled aggregate (RA) in concrete. Because of the issues with its strength and durability, the use of RA is typically limited to inferior load constructions. With appropriate management and effective processing methods, the application can be expanded to high-strength concrete. In the present manuscript, the current C&D waste management practices adopted by various nations are highlighted alongside different in-action legislations are thoroughly reviewed for developing an understanding about the basic elements involved in the debris management. In addition, some of the latest and novel recycling approaches are investigated such as autogenous cleaning method, air and hydraulic jigging technologies, and advanced dry recovery system. To investigate the nature of RA processed from aforementioned technologies, the inherent properties of aggregates such as specific gravity, water absorption, density, and abrasion values alongside microstructure performance through scanning electron microscopy (SEM) are comprehensively reviewed and presented. Based on the extensive investigation, it is recognized that effective C&D waste management can be accomplished using certain techniques such as circular procurement and green construction. Furthermore, there is a requirement for specified processing methods that enhances the physio-chemical properties. Also, the surface morphology can be improved using combined crushing and ball milling approaches. Overall, it is recommended to implement vertical shaft crushing and ball milling for the development of fine RA whereas for the coarse RA fractions, multistage jaw crushing and advanced dry recovery (ADR) system are some of the finest processing approaches. © 2025 Elsevier Ltd. All rights reserved.