Mechanical properties and mechanisms of fiber reinforced fly ash-steel slag based geopolymer mortar

Fly ash-steel slag based geopolymer was studied with the aim of recycling solid wastes, and developing a sustainable alternative to Portland cement. This paper studies the effects of fibers on mechanical properties of geopolymer. SEM and BET measurements were conducted to investigate the reinforcing mechanism. The results show that polypropylene fiber and basalt fiber can improve the mechanical properties at the late age, and steel fiber shows excellent toughening and reinforcing effects on geopolymer. SEM and BET results indicate that fibers could relieve the stress concentration, increase the specific surface area and significantly decrease the average pore diameter of geopolymer.