Influence of wood moisture content on the hardened state properties of geopolymer wood composites

Geopolymer wood composites (GWC) serve as an emerging green alternative to Portland cement wood composites in the construction sector. The wood's moisture content upon being introduced into the GWC formulation alters the content of water, which is one of the key factors influencing the strength and structure in the geopolymerization process. This study investigates the influence of initial wood moisture content on the material properties of GWC. The prepared GWC were made using 20 wt% wood flour with five different wood moisture contents (i.e. 1, 12, 27, 60 and 90 wt%). Generally, the GWC had structurally bound water, free water and cell wall water; the latter two waters can evaporate with time or temperature. Forming GWC with wood of a higher moisture content led to 30-wt% of the initial water being structurally bound. Density and compressive strength of the GWC were higher when using dry wood while porosity was reduced.