THE CIRCULAR BUILT ENVIRONMENT IN LUXEMBOURG: INTERDISCIPLINARY STUDIES FROM SUPPLEMENTARY CEMENTITIOUS MATERIALS TO POLICY AND STAKEHOLDERS

The transition to a regenerative sustainable model in the construction sector is one of the pathways to reducing negative impact and aligning with the United Nations Sustainable Development Goals. Cement production is a major environmental burden, contributing nearly 8% of global CO₂ emissions. This research explores circularity in the built environment through an interdisciplinary approach starting with material technology and specifically the potential of using secondary waste materials, particularly Gravel Wash Mud (GWM), as Supplementary Cementitious Materials (SCMs) to reduce reliance on ordinary Portland cement (OPC) and promote more sustainable construction practices. By repurposing industrial byproducts from gravel mining in the Greater Region (Luxembourg, France, Belgium, and Germany), this study aligns with circular economy principles that prioritize waste valorization and resource efficiency. The findings confirm that such materials, when thermally activated and incorporated as a partial cement substitute, enhance concrete performance while reducing its carbon footprint. However, despite the technical feasibility of such materials, their widespread adoption remains limited due to some challenges. Beyond material innovation, following into the interdisciplinary approach to assess the broader systemic factors influencing circularity in construction, it examines the role of policy frameworks, stakeholder networks, and industry dynamics in shaping the circularity landscape and sustainable material adoption. By mapping these interactions, the study identifies key barriers to change and proposes actionable strategies for fostering a regenerative circular economy—one that not only minimizes waste but also restores and revitalizes resources within the built environment. This research underscores the need for systemic transformation in construction practices, advocating for an integrated approach that combines material science, policy adaptation, and industry collaboration to drive meaningful progress toward a more resilient and regenerative future.