Advancing a Circular Economy in Rigid (Concrete) Pavements: A Comprehensive Systematic Review of Recycled Materials and Sustainable Design Strategies

Due to excessive dependence on extraction and processing of raw materials with energy-intensive processes, rigid (concrete) pavements are under continuous stress to adopt sustainable practices. This is further compounded by environmental issues caused by increase in demand for transport infrastructure. In this regard, the circular economy (CE) can be described as a prospective paradigm, which promotes resource efficiency through material reduction, reuse, recycling, recovery, and redesign. The current review was conducted to evaluate the opportunities in the sustainable materials and design solutions towards the adoption process of CE in rigid (concrete) pavements. Following PRISMA, 242 studies were synthesized across materials, structural design, life-cycle assessment (LCA) and life-cycle cost analysis (LCCA). Findings were organized within a 9 R circular framework. Supplementary cementitious materials (SCMs) and recycled concrete aggregate (RCA) can conserve resources and reduce environmental burdens if used after proper treatment and incorporated in optimum dosages. Use of waste-derived and bio-based materials, i.e., crumb rubber (CR), rice husk ash (RHA) and sugarcane bagasse ash (SCBA) is can also be beneficial. Recycled materials reduce the flexural fatigue limit by up to about 22%. Thus, slab thickness and joint load transfer must be verified. LCA and LCCA show that circular pavements can be initially expensive but often cheaper over the whole life. Field sections confirm viability but several obstacles to adoption of CE such as absence of long-term performance data, absence of standardization hinder its adoption at scale. The overall conclusion is conditional, not absolute as benefits depend upon dosage, treatment, exposure and design of materials. An evidence-led, closed-loop framework linking materials, design, LCA/LCCA and policy is proposed. Wider adoption requires long-term field data, consistent LCA boundaries, performance-based specifications and supportive policy. The work advances SDGs 9, 11, 12 and 13.