Recycled concrete aggregates derived from construction waste: potential applications in structural engineering

Abstract

DOI: https://doi.org/10.66195/mtu.2026.16.160

Large amounts of waste concrete have been accumulated during construction activities, posing substantial environmental and resource concerns for the sector. Recycling this garbage into recycled concrete aggregates (RCA) helps to promote sustainable and circular structural construction. This paper critically reviews the processing, classification systems, physical and mechanical qualities, durability performance, and structural behavior of RCA. The presence of adhered mortar causes increased porosity and reduced stiffness when compared to natural aggregates; however, recent advances in processing techniques, supplementary cementitious materials, and optimized mix design show that RCA concrete can achieve reliable structural performance. Practical case studies from buildings, infrastructure, and precast construction demonstrate the viability of moderate RCA replacement ratios in load-bearing systems. Limitations, including long-term durability, variability control, and conservative design provisions, are determined. The study highlights future perspectives focused on performance-based design, improved material processing, and integration of RCA within circular economy frameworks to support resilient and sustainable structural engineering.