Investigation of the effect of metakaolin substitution on physicomechanical properties of fly ash-based geopolymer mortars

Abstract

In this study, geopolymer mortar samples were prepared with metakaolin (MK) substitution in fly ash-based geopolymer mortar. A vibration table was used in the production of the geopolymer mortars, and the samples were shaped to 4 × 4 × 16 cm prismatic size. The samples were placed in a laboratory-type oven and subjected to thermal curing processes at different temperatures and times. After curing, the samples were kept in an open laboratory environment for seven days until the related tests. In conclusion, it was determined that NaOH molarity did not significantly affect the physical properties but significantly affected the mechanical properties. It was also observed that the strength values increased with an increase in MK replacement and curing temperatures. The mechanical properties of the samples are increased by decreasing the porosity of the samples with the MK substitution ratio. At the same time, the results also show that relatively high curing temperatures and extended periods of curing times are unnecessary for this type of production.