Geopolymers/alkali-activated binders and their composites have gained more and more attention around the globe because of their high early strength, outstanding durability, and minimal carbon emission during manufacture. This study examined how steel fibers affected geopolymer mortar’s microstructure and fracture behavior. The experimental procedure includes adding 1, 2, and 3 vf% of steel fibres to a mixture consisting of 20% silica fume modified GGBS-based geopolymer mortar. The results revealed that the addition of steel fibers led to a clear improvement in the fracture behavior of geopolymer mortar by retarding and preventing the growth of cracks generated by stresses. The results also showed significant improvement in the splitting tensile strength and bending strength of geopolymer mortar, particularly with the addition of low and medium steel fibers.

Geopolymer, Mortar, Steel fibers, Fracture, Composite.