Influence of waste glass on the microstructure and strength of inorganic polymers

Abstract The influence of the addition of waste glass, derived from spent fluorescent lamps, on the microstructure and strength of fly ash or fly ash/blast furnace slag-based inorganic polymers was studied through microstructural, spectroscopic, and compressive strength analyses. The results suggest that the degree of polymerization of the activated mixtures decreases as the amount of waste glass added to the synthesis mixtures increases. This finding is most likely due to the considerable increase in the overall SiO 2 /Al 2 O 3 molar ratio. The strength followed the same trend. The addition of slag to the synthesis mixtures appears to be beneficial because the compressive strength was improved compared with other mixtures activated with the same sodium hydroxide solution but with no slag. The negative effect caused by increasing the overall SiO 2 /Al 2 O 3 molar ratio through the addition of waste glass seems to be diminished when a sodium silicate solution is used as an activator.