Modern Mechano-Chemical Procedure for Obtaining a High-Strength Geopolymer Composite

Replacing the usual alkaline solution with sodium metasilicate nonahydrate as an alkaline activator of alumina-silicate waste for the manufacture of geopolymers represents a recent technical solution for significantly increasing their mechanical resistance. The principle of this method was tested in an own version by the authors’ team of the current work. Coal fly ash, river sand, and silica fume (nano-silica) were solid precursors used in the starting material mixture. Under the conditions of pressing the geopolymer powder (made by the conventional method) at the axial pressure of 400 daN·cm-2, compared to its value of 1000 daN·cm-2 used by (Nishikawa et al., 2022), the level of resistance to compression and flexure reached values very high, superior compared to that of usual geopolymers.