Recycling contaminated wood into eco-friendly particleboard using green cement and carbon dioxide curing

This study proposed an innovative and low-carbon technology by using magnesia cement and CO2curing to transform contaminated wood waste into eco-friendly cement-bonded particleboards, which demonstrated excellent compatibility and value-added properties. The microstructure characteristics and cement hydration chemistry were revealed by mercury intrusion porosimetry and X-ray diffraction analyses. At the optimal water to cement ratio of 0.3, the particleboards contained the lowest total pore area (10.2 m2 g−1) and porosity (26.1%), thereby successfully complying with the International Standards of mechanical strength (>9 MPa) and dimensional stability (<2% swelling after 24-h water immersion). An integration of 2-h CO2curing facilitated carbonation at early stage and reduced the volume of mesopores and air pores, which contributed to strength development and carbon sequestration in the particleboards (8.78% by weight) helping to combat global warming. A subsequent 7-d air curing further enhanced the strength to outcompete those of 28-d air curing only, because rehydrated formation filled in capillary pores (reduced from 0.11 mL g−1to 0.03 mL g−1). Moreover, fire resistance and thermal stability were improved by the chemistry of magnesia cement and accelerated carbonation. The carbonated particleboards retained high strength and stable dimension after 1-h heating up to 200 °C.