Morphology Analysis on Metakaolin/Dolomite Geopolymer under High Temperature Exposure

This paper presents the morphology of the metakaolin/dolomite geopolymer after being exposed to high temperature and compare the findings with the morphology that has not been exposed to the temperature. The geopolymers were exposed at temperatures from 200°C up to 800°C. The geopolymer was a constant mix of 90% metakaolin and 10% dolomite with 10 NaOH molarity, 0.8 solid to liquid ratio, and 2.0 by mass of alkaline activator. The morphology of geopolymer exposed to high temperature contains many pores and as the temperature rises, the pores become huge, and a higher quantity of pores can be observed. The surface analysis, compressive strength, and water absorption test were also done to support the findings. The compressive strength calculation was based on weight loss. The lowest compressive strength loss was at 200°C temperature exposure with 10.98%. Meanwhile, the highest compressive strength loss was at 800°C temperature exposure with 48.54%. In comparison, this metakaolin/dolomite geopolymer archive better properties compared to the concrete and metakaolin past studies.