Evaluating the binder performance and biocomposite applications of thermally reactivated wood-wool cement panel waste

This study addresses a research gap in upcycling complex organic-mineral residues by investigating the thermal reactivation of sanding dust (SD) generated during the production of wood-wool cement panels. Its novelty lies in establishing a low-temperature pathway that recovers hydraulic capacity without triggering CO₂ release from carbonated phases. The research design involved heating raw SD at 450 ℃ for five hours - a temperature selected to maximize portlandite dehydration while remaining below the 600 ℃ decarbonation threshold - followed by comprehensive chemical, mineralogical, and physical characterization (XRD, TGA, SEM). This reactivated binder was then utilized to produce novel, low-density biocomposites using manufacturing-line waste as filler. Major findings confirmed that heat treatment reduced average particle size from 29.21 μm to 19.11 μm and successfully restored hydraulic activity, increasing binder compressive strength from 1.59 to 13.05 MPa. The resulting biocomposites achieved compressive strengths up to 185 kPa and a low thermal conductivity of 0.068 W/(m·K) with a density of 369-415 kg/m³. These results indicate that 450 ℃ serves as an optimal "thermal window" for this waste, effectively transforming industrial residues into functional secondary raw materials for sustainable building insulation.