Metakaolin-based geopolymer matrix formulations for higher strength and thermal stability

Abstract The need for sustainable and high-performance construction materials has led to the development of novel geopolymer matrices. This project aims to create an optimized, highly reactive, metakaolin-based geopolymer matrix for sustainable construction materials. The study involved mixing and optimizing commercial alkali silicates and metakaolin to enhance strength, stability, and durability. The goal was to maximize the flexural strength of the geopolymer matrix using one type of commercial metakaolin (MK), seven commercial waterglass formulations with varying water content, and a single, low-energy geopolymer processing method. The findings show that geopolymer matrices with charge-balancing potassium ions and 11 mol of water, and two formulations with charge-balancing sodium ions and 13 mol of water, resulted in the highest strengths (5.9–7.7–8.1 MPa on average), lower porosity, and reduced thermal degradation. These findings have practical applications in reducing the environmental impact of traditional construction materials. By utilizing metakaolin and commercial alkali silicates, the research enhances the mechanical properties of the geopolymer and promotes the use of industrial by-products. The low-energy processing method aligns with sustainability principles by minimizing energy consumption. The resulting geopolymer composites exhibit superior strength, durability, and thermal resistance, making them suitable for sustainable ceramics and construction materials. This research contributes to the development of eco-friendly construction solutions, promoting a sustainable and resilient built environment. Its significance lies in its holistic approach to optimizing geopolymer matrices for enhanced performance and sustainability.