Reconceptualizing Quarry Stone Fines as Strategic Secondary Resources for Low-Carbon Concrete Infrastructure in Africa: A Circular Economy Systems Approach

The rapid expansion of infrastructure across Africa has intensified the extraction of natural aggregates while simultaneously generating large volumes of quarry stone fines that are commonly treated as waste. This dual challenge reflects a broader structural inefficiency within construction material systems, where valuable secondary resources remain underutilized. Grounded in circular economy principles, this research programme seeks to reconceptualize quarry stone flours not merely as aggregate substitutes, but as strategic secondary resources capable of supporting low-carbon, resource-efficient concrete infrastructure in African contexts. The programme integrates materials science, civil engineering, and sustainability systems thinking to develop a coherent framework for the responsible upcycling of stone flours in concrete production. Experimental investigations on the physical, fresh-state, mechanical, and microstructural performance of stone flour-based concretes will be conducted at the fellow’s home institution and partner laboratories. The STIAS residencies will be dedicated to higher-level synthesis: comparative analysis across geological contexts, development of design principles for aggregate substitution, lifecycle-oriented performance interpretation, and interdisciplinary engagement with circular economy and infrastructure policy discourses. By moving beyond isolated material testing, the research aims to generate transferable knowledge, decision-support guidelines, and scholarly outputs that inform both engineering practice and sustainable infrastructure policy in Africa. The programme contributes to strengthening African-led scholarship on circular construction materials while laying foundations for scalable, environmentally responsible concrete systems suited to future urbanization and climate resilience challenges.