Sustainability Assessment and Performance Evaluation of Recyclable and Modular Concrete Incorporating Treated Recycled Fine Aggregates

This study presents a comprehensive sustainability assessment of Recyclable and Modular (R&M) Concrete incorporating treated Recycled Fine Aggregates (RFAs) derived from Construction and Demolition Waste (CDW). While conventional concrete remains a structurally reliable material, its dependence on virgin sand, high embodied energy, and associated CO₂ emissions make it environmentally and economically unsustainable in the long term. To address these challenges, this research evaluates the economic, environmental, and socio-technical feasibility of replacing natural sand with RFAs at varying levels (0%, 30%, 50%, and 100%). The assessment integrates direct material cost analysis, life cycle economic indicators, embodied carbon quantification, and socio-economic evaluation to provide a holistic understanding of R&M concrete’s viability. Experimental findings reveal that 30–40% RFA replacement delivers the optimal balance, achieving 10–15% cost savings per cubic meter, along with 11–17% reductions in embodied CO₂ emissions, 35% conservation of natural resources, and up to 45% landfill diversion. Additionally, the study highlights social co-benefits, including employment generation in CDW recycling supply chains and enhanced affordability for prefabricated modular applications. Although higher replacement levels (≥50%) negatively influenced mechanical performance and durability, pre-treatment techniques improved material quality and extended usability within structural-grade applications. Overall, the research demonstrates that R&M concrete, when optimized with treated RFAs, represents a technically sound, eco-efficient, and economically viable construction material. Its integration into modular construction systems offers a scalable pathway for advancing circular economy practices, resource efficiency, and sustainable infrastructure development.