Mechanical properties of metakaolin-based geopolymers modified with different contents of quarry dust waste

Abstract

This study aimed to evaluate the effect of incorporating quarry dust waste on the mechanical properties of metakaolin-based geopolymers. Sodium silicate and sodium hydroxide were used as alkaline activators. Five geopolymer mixtures were prepared with 0%, 10%, 20%, 30%, and 40% addition of quarry dust on the mass of solids in the mixture. The compressive strengths of the mixes ranged between 44.8 and 59.5 MPa after 28 days of ambient curing. The incorporation of quarry dust into the mass of solids in the mixture had a direct effect on the compressive strength. The results of the immersion absorption and void index tests corroborate with the compressive strength test results. The X-ray diffraction analysis showed that the quarry dust acted mainly as an inert filler material, improving the structure of the geopolymer matrix by densification. Therefore, the results showed that the incorporation of quarry dust is feasible and contributes to the trend of producing sustainable geopolymers with improved mechanical properties. In addition, new applications for the produced materials, such as mortars for fixing tiles and ceramics on floors, were made possible by the incorporation of quarry dust.