Performance characterization, reinforcement, and application of recycled concrete aggregates in cement concrete and asphalt mixture: A state-of-the-art review

Urbanization renewal leads to a significant generation of construction and demolition waste (C&DW), predominantly concrete waste. It has been widely used as a recycled concrete aggregate (RCA) in pavement to alleviate the shortage of natural aggregates. This study presents a comprehensive review of the processing technology, performance characterization, performance enhancement measures, and application of RCAs in pavement engineering. It indicates that RCAs possess distinctive characteristics, multiple interfaces, microcracks, low bulk density, high water absorption, and specific abrasion values, which restricts its high-quality utilization. Removing or strengthening wrapping mortar are effective measures for improving the physical and mechanical properties of RCAs. RCAs can replace natural aggregates in cement concrete pavement using reinforcement techniques essential for durability. In asphalt mixtures, RCAs can substitute up to 60% of the natural aggregate while maintaining acceptable pavement performance. Recommending early adoption of reinforcing techniques and optimization of grading and mix proportions in pavement engineering promotes RCA utilization, supporting C&DW treatment as a recycled aggregate and improving overall efficiency in the future.