Geopolymer production through partial substitution of metakaolin for red ceramics

Abstract Red ceramic (RC) waste originates from the production, use, and demolition of ceramic construction materials. In an effort to mitigate the environmental impact of these activities, there is a growing need for studies focused on the reutilization of such materials. Due to its aluminosilicate-rich composition, red ceramic can serve as a precursor for production of geopolymer binder. Therefore, the objective of this study is produce geopolymers using metakaolin (MK) replaced progressively by red ceramic waste. Five formulations were developed under ambient curing conditions, varying the precursor concentrations, and subjected to mechanical property tests, as well as microstructural analysis using XRD and FTIR techniques. The results demonstrate the feasibility of using red ceramic in geopolymer production, showing improved mechanical properties at 28 days when the mixture contains up to 30% red ceramic and exhibits a Si/Al ratio of 1.92. Additionally, increasing the concentration of red ceramic can extend the initial setting time by up to 75 minutes and reduce the geopolymer's fluidity by 27.85%.