Assessing the Eco-Efficiency of High Recycled Content Pavement Solutions: An Evaluation of the Mechanical, Durability, and Environmental Impacts

The growing demand for sustainable pavement materials has increased interest in using recycled concrete aggregate (RCA) as a substitute for natural aggregates. However, the mechanical, durability, and environmental performance of roller-compacted concrete pavement (RCCP) incorporating very high RCA contents (≥75%) remains poorly understood, particularly when combined with hybrid steel fiber reinforcement. This knowledge gap limits the practical adoption of high-RCA RCCP in infrastructure applications. To address this gap, this study investigates the eco-efficiency of RCCP produced with 75% RCA and different steel fiber systems, including industrial (ISF), recycled (RSF), and hybrid (HSF) combinations. Mechanical performance was evaluated through compressive, tensile, and flexural testing, while freeze–thaw durability was assessed under extended cyclic exposure. Environmental impacts were quantified through a cradle-to-gate life cycle assessment (LCA), and a multi-criteria decision analysis (MCDA) was applied to integrate mechanical, durability, and environmental indicators. The findings show that although high-RCA mixtures exhibit reduced mechanical performance due to weaker interfacial bonding, HSF reinforcement effectively mitigates these drawbacks, enhancing toughness and improving freeze–thaw resistance. The LCA results indicate that replacing natural aggregates and industrial fibers with RCA and RSF substantially reduces environmental burdens. MCDA rankings further identify HSF-reinforced high-RCA mixtures as the most balanced and eco-efficient configurations. Overall, the study demonstrates that hybrid steel fibers enable the development of durable, low-carbon, and high-RCA RCCP, providing a viable pathway toward circular and sustainable pavement construction.