Effects and mechanisms of component ratio and cross-scale fibers on drying shrinkage of geopolymer mortar

Abstract

This study initially examined the impact of varying component ratios on the drying shrinkage of geopolymer mortars. It further explored the drying shrinkage inhibition of cross-scale hybrid fibers, specifically carbon nanotubes (CNTs) and hooked steel fibers (HSFs). The findings indicate that increasing the content of granulated blast furnace slag (GBFS) or reducing the water-binder ratio and binder-sand ratio could effectively minimize the shrinkage of geopolymer mortar. The addition of fibers also had an inhibitory effect on shrinkage. Hybrid fibers exhibited better performance compared to steel fibers, and steel fibers performed better than CNTs. Finally, the mechanical mechanisms of fibers and aggregates on the shrinkage inhibition of geopolymer mortars was revealed and the drying shrinkage prediction models that suitable for fiber reinforced geopolymer mortars was proposed.