Wood Flour’s Effect on the Properties of Geopolymer-based Composites at Different Curing Times

Abstract

Fly-ash (FA) /wood-flour (WF) geopolymer composites (FWGCs) were prepared to investigate the influence of WF on the properties of FA-based geopolymer composites at different curing times. The crystallization, surface morphology, geopolymerization, interface analysis, and mechanical properties were characterized. The results indicated that the curing time exerted positive effects on the mechanical strength of the FWGCs. Noticeably distinct microstructures and mechanical properties were observed with different WF contents. The FWGCs with low WF loading (1 wt% and 5 wt%) presented almost unchanged or even improved mechanical properties compared to the pure FA-based geopolymer due to the existence of bonds between the WF and geopolymer matrix in the interface. However, the addition of WF to a higher content (10 wt%, 15 wt%, and 20 wt%) posted a negative influence on mechanical properties with insufficient polymerization of geopolymer and degradation of WF detected by morphology and elemental microanalysis. This study will facilitate a better understanding of the interaction between geopolymers and wooden materials, and serve as a basis for further research and applications.