Investigation on mechanical and microstructural properties of alkali-activated materials made of wood biomass ash and glass powder

The possibility of the application of biomass fly ash (BFA) as a precursor material for the synthesis of alkali-activated materials (AAM) is presented in this paper. Glass powder (GP) was tested as an additional substrate in a synthesis process. Different mixtures of samples were produced: four mixtures using only BFA for different NaOH concentrations and nine mixtures where BFA was partially replaced by the GP. Three different NaOH concentrations were applied here. Compressive and flexural strength after 7 and 14 days were performed. The microstructure and the chemical composition of samples were obtained. The results show that the compressive and flexural strength of materials increased with the increase of NaOH concentration and the decrease of the GP content in a mixture. The samples were also characterized by the high porosity with some voids and microcracks. The poorly dissolved BFA particles were also noted in a matrix. [Display omitted] •The biomass ash was used in a synthesis process of alkali-activated materials.•The glass powder was added as an additional source material.•An increase in mechanical strength was observed when the glass powder was added.•Samples had porous structure with some microcracks and voids.•Crystalline and non-crystalline phases were detected in obtained materials.