Influence of sodium-based activators and water content on the fresh and hardened properties of metakaolin geopolymers

Abstract

Article highlights An elevated water content can improve the fluidity of the pastes, however, it increases pore formation and detriments the strength. A surplus of alkali content decreases the fluidity, accelerates the setting, and increases the shrinkage and surface cracking of metakaolin geopolymers. The best performance is achieved with a water-to-solids = 0.51, and molar oxide ratios of Na2O/Al2O3 = 0.97 and SiO2/Al2O3 = 3.14.

Keywords

• Metakaolin geopolymer
• Rheology
• Compressive strength
• Setting
• Shrinkage
• Density