Preparation and performance research of ecological concrete using waste wood

To mitigate environmental damage from mineral aggregate extraction, bio-based materials have garnered research interest as potential replacements for natural mineral aggregates. This work utilized waste wood as filler to prepare lightweight foam concrete with thermal insulation, low-temperature and corrosion resistance properties. The feasibility of using wood aggregate-based foam concrete (WFC) was explored in terms of dry density, softening coefficient, compressive strength, thermal conductivity, chloride ion permeability, freezing resistance, and sulfate attack resistance. Results showed that simultaneous addition of waste wood aggregate (WA) and foam effectively reduced WFC bulk weight and thermal conductivity while enhancing water resistance. However, the porous morphology of WA and foam caused the reduction of mechanical properties. In terms of durability, the addition of WA can increase the energy absorption capacity when WFC is subjected to expansion stress, reduce the damage to the structure, and have an inhibiting effect on the cracking of WFC caused by sulfate attack and freeze-thaw cycles. Nevertheless, WA's high water absorption loosened the matrix in WFC's interfacial transition zone (ITZ), increasing harmful pores and negatively affecting durability. In addition, in order to predict the mechanical properties of WFC and the resistance to sulfate attack, this study established a function model for the relationship between the compressive strength (Maintenance specimens of the same age and Specimen of sulfate attack) and the WA dosage. In conclusion, The use of waste wood for the preparation of WFC is more advantageous and sustainable than conventional foam concrete for the insulation of precast walls and coastal structures.