Metakaolin-based geopolymer mineral particulate composite design for higher strength and thermal stability

This research targets to produce new composites from a highly reactive metakaolin-based geopolymer matrix reinforced with natural particles for use in sustainable ceramics, building and construction. Commercial waterglass and added mineral particles were optimized for geopolymer composites to provide higher strength, stability, and durability. The design method implicated higher flexural strength of one type of commercial metakaolin, one commercial waterglass formulation, a single-low-energy geopolymer processing, and seven types of added mineral particles. The particulate reinforcement formulations added to the geopolymer matrix were: (1) 20 wt% chamotte and 40 wt% Prairie fine sand; (2) 20 wt% chamotte and 40 wt% Quikrete medium sand; (3) 20 wt% chamotte and 40 wt% Quikrete fine sand; (4) 20 wt% ball-milled fine sand; (5) 20 wt% ball-milled fine sand and 40 wt% Quikrete fine sand; (6) 20 wt% ball-milled fine sand and 40 wt% Prairie fine sand; (7) 10 wt% ball-milled fine sand and 50 wt% Prairie fine sand. Potassium metasilicate Kasolv 16 with 11 M of water, Metamax metakaolin, reinforced with 20 wt% ball-milled fine sand, and 40 wt% Prairie fine sand (BF20PF40) resulted in the highest strength geopolymer composite. BF20PF40 also yielded lower mass loss, higher packing density, and better thermal stability.