Investigating water absorption and mechanical properties of fly-ash-slag-based geopolymer mortar reinforced with hemp and glass fibers

Geopolymer materials are also called green materials since they are not as harmful as producing cement and they keep the environment safe because the synthesis of geopolymers does not release toxic gases that pollute the air instead these materials utilize industrial waste substances in their production consequently, they are considered cost-effective and environmentally friendly. Moreover, the geopolymer properties outperformed traditional cement as a result, it is a possibility that geopolymers could replace conventional cementitious materials. However, geopolymers are brittle and have a fragile breakage hence, they require reinforcement to enhance their strength. In this study geopolymer mortar was synthesized by the combination of fly ash class F and GGBFS (slag) with NaOH concentration of 10M and the solution of sodium silicate and reinforced with two types of fibers which are untreated hemp fiber and glass fibers in addition to the curing conditions were ambient curing. Untreated hemp fibers were used to maintain the fiber's strength and to avoid the degradation of the natural fiber by pre-treatment processes. The outcome of the experiment indicated that untreated hemp fiber is a promising natural fiber, and the self-treatment of the fiber did not damage the fibers' structural integrity hence, the strength of the mortar increased.