Circular Economy in the Construction Sector: Challenges and Opportunities in Luxembourg and the Greater Region

Concrete used in the construction sector is made with natural aggregates such as sand, gravel, and crushed stone, sourced directly from the region's nature. These aggregates are mixed with cement and water to create a durable building material. Until today, only primary materials, such as crushed aggregates or river gravel, have been used in the national production of concrete. The construction and demolition (C&D) sector in Luxembourg and the Greater Region generates significant landfill waste. While current reuse and recycling efforts are in place to help reduce waste, they result in downcycling materials, underscoring the need for a circular economy approach. However, Luxembourg's accessible local river sand reserves may be exhausted within the next two decades due to urbanization along the Moselle River, emphasizing the urgency for sustainable solutions in construction materials. This research will focus on improving material recovery from existing construction through optical surveys to assess quality and remove low-grade materials. If the removal of low-grade materials is not feasible, the focus will shift to integrating a circular economy approach by designing products with the end-of-life stage in mind during the deconstruction and demolition processes. This ensures that materials can be easily separated, reused, or recycled without degrading their quality. This approach minimizes the need for raw resources and reduces environmental impact. Additionally, the research will examine C&D waste processing logistics, comparing centralized and decentralized recycling facilities. Non-mobile locations may offer better quality control and economies of scale, while mobile equipment could reduce transportation costs and offer localized solutions. Identifying the optimal strategy is crucial for efficient recycling and consistent quality. By addressing these technical, economic, and logistical challenges, this study aims to enhance the integration of recycled materials into construction, reduce reliance on virgin resources, and contribute to sustainable development in Luxembourg and the Greater Region.