One of the main advantages of geopolymer technology is its capability to accommodate several types of waste that would otherwise be disposed of in landfills in the production of geopolymer materials. This study investigates the possibility of substituting proportions of fly ash, normally used for the synthesis of geopolymers, with recycled glass and red mud waste. Compressive and flexural strength testing, fracture toughness determination, SEM and FTIR analyses were performed. The results show that the compressive strength decreases as the amount of glass in the geopolymer increases, on the other hand, the addition of red mud seems to improve the mechanical behavior. Moreover, on substitution of fly ash with glass and red mud, the geopolymer demonstrates a similar performance in terms of fracture toughness and flexural strength properties. The results confirm that red mud and waste glass have the potential to partially replace fly ash in geopolymer synthesis, opening thus the possibility of using geopolymer technology to reuse such residues in technical materials.
Toniolo et al. (Sun,) studied this question.