Localized upcycling of waste steel slag into building components: A sustainable building design and construction (SBDC) framework demonstrated in Yangxing Village

The decarbonization of the construction sector and the valorization of industrial solid waste are two sustainability challenges that are rarely addressed within a single, place-based design strategy. This study proposes and demonstrates a localized, waste-material-based framework for Sustainable Building Design and Construction (SBDC) that converts locally stockpiled steel slag—a high-volume by-product of steelmaking—into building components and site-specific architectural interventions. The framework is bounded deliberately: it is a design-research methodology for the localized reuse of a waste feedstock, rather than a standardized materials-engineering qualification of structural products. It was developed and tested through a case study of Yangxing Village (Shanxi, China), a settlement adjacent to one of the world's largest steelmaking complexes, where decades of slag disposal have driven soil erosion and landslides. The methodology integrates (i) characterization of the basic-oxygen-furnace (BOF) steel slag feedstock, drawing on plant data and the literature; (ii) two laboratory material routes—lithium-tetraborate flux fusion to obtain cast glass-like elements, and recycled-glass-powder-bound sintering to obtain slag bricks (optimal slag-to-glass mass ratio 3:1, fired at 1100 °C); and (iii) a computational, site-responsive design that deploys the resulting components as roads, retaining walls, and integrated roofs to arrest erosion while minimizing material-transport emissions. The work contributes a transferable, low-carbon model for rural waste valorization that couples circular-economy principles with context-specific design. Quantitative mechanical qualification (compressive and flexural strength, durability, leaching, and life-cycle assessment) is identified as the principal boundary of the present study and the priority for subsequent work.