Influence of fiber reinforcement on the strength and durability of high strength geopolymer concrete with multi component precursors

Abstract This study investigates the influence of steel and polypropylene fibers on the strength and durability properties of high strength geopolymer concrete (HSGPC) such as 60 MPa and 80 MPa. The geopolymer concrete developed by using multi component precursors like fly ash, GGBS, silica fume and alccofine activated with an alkaline solution at a sodium silicate to sodium hydroxide ratio of 2.5, an alkaline activator to binder (AA/Bi) ratio of 0.38. Geopolymer concrete is brittle in nature, to overcome the brittleness, steel fibers (ST) were incorporated at the dosage of 0.25%, 0.50%, 0.75% and 1.0%, and polypropylene (PP) fibers at the dosage of 0.15%, 0.25%, 0.35% and 0.45% by volume of concrete. Mechanical properties, including compressive, splitting tensile, flexural strengths were evaluated along with durability parameters such as water absorption, sorptivity of HSGPC (with and without fibers) at the age of 7 and 28 days under ambient curing. The results indicates that the inclusion of fibers significantly enhance both strength and durability characteristics of HSGPC. Based on the strength properties, a good performance was observed at 0.75% ST and 0.25% PP fiber dosage in HSGPC. Fiber incorporation improves the strength behaviour, reduced water penetration, and increased UPV values, indicating the enhanced internal compactness and matrix integrity of HSGPC.