Effect of curing in an arid climate on the properties of metakaolin-based geopolymer mortar

Abstract In this research, medium crude metakaolinic clay (MK, Algeria) was used as raw material for the synthesis of geopolymers. Geopolymer synthesis involved mixing metakaolin with alkaline activators, with silica fume incorporated in some formulations to enhance mechanical properties. Samples were subjected to control curing at ambient and solar conditions, and their compressive and flexural strengths were evaluated at 28 days curing age, with a compressive strength of 35 MPa and flexural strength of 10 MPa. Additional tests assessed by XRD and FTIR revealed that new crystalline phases were formed in the geopolymer samples stored under ambient and sun exposure conditions; the curing condition had a significant effect on the change in the strengths of the investigation. The results indicate that the performance of geopolymer mortars can be considerably improved, even in extreme conditions, by optimizing curing protocols and material compositions.