Evaluation of eco-efficient geopolymer using chamotte and waste glass-based alkaline solutions
Beatryz Cardoso Mendes, Leonardo Gonçalves Pedroti, Carlos Maurício Fontes Vieira, José Maria Franco de Carvalho, José Carlos Lopes Ribeiro, Nathália M. Albuini-Oliveira, Igor Klaus Rocha Andrade
Abstract
Geopolymers are binder materials that can be an alternative to replace Portland cement. They are considered less aggressive to the environment because of the lower emission of CO2 and use of energy in their production chain. This work aimed to manufacture a more eco-efficient product and recycle industrial waste, contributing to the solution of the disposal problem. Thus, this study evaluated the performance of alkali-activated pastes produced from industrial wastes in both phases, using chamotte as the precursor and waste glass (WG) as a component of the activating solution. The effects of molar concentration and WG content in the alkaline solutions were investigated. A factorial design of experiments was developed, considering three levels of molar concentration (8 mol/L, 10 mol/L and 12 mol/L) and four levels of WG content per 100 mL of solution (0, 5, 10 and 15 g). Physical and mechanical tests were performed, as well as the microstructural analyses using XRD and FT-IR techniques. The environmental impacts of replacing the traditional activator by the WG-based one were also assessed. The results showed that the WG content strongly affects the mechanical strength of geopolymers and the quality of the matrices, promoting a greater formation of geopolymerization products. Using an alternative activator can reduce 69.8% of the embodied energy and 78.0% of CO2 footprint compared to the traditional waterglass activators. Therefore, this study proved the sustainability potential and technical viability of using WG as an activator in chamotte-based geopolymer.