Effects of potassium-silicate, sands and carbonates concentrations on metakaolin-based geopolymers for high-temperature applications

• DOI: 10.1016/j.oceram.2022.100257
• Publication Date: 2022-04-21T16:53:18Z
• Authors: Paolo Scanferla; Ameni Gharzouni; Nathalie Texier-M...; Xavier Bourbon; Sylvie Rossignol
• Keywords: Metakaolin; Potassium silicate; Leucite

Geopolymers can be optimized to have interesting physical characteristics, which are influenced by the raw materials and additives utilized in their formulations. For this reason, various formulations of two metakaolin-based binders with filler additions different natures, i.e., sands carbonates, were tested. The aluminosilicate source used is a commercial metakaolin (Si/Al = 1.44). feasibility consolidated samples thermal behaviors evaluated. viscosity tests fresh geopolymer pastes indicated that setting times controlled potassium concentrations. evaluation stabilities was carried out before after heat treatment at 1000 °C means compressive tests. low concentrations showed mechanical strengths 16% greater (37–43 MPa) than geopolymers high concentrations, both treatment. exposure conditions did not influence final properties geopolymers. XRD analysis performed crystallization kalsilite found Different mechanisms during geopolymerization, specifically kinetic thermodynamic respectively, explain diverse responses room temperature, while presence differences temperatures. Hence, it possible develop fire-resistant controlling fillers.