Improved Abrasive and Acid Resistance of Geopolymer Concrete with Steel Fiber and Silica Fume

The effect of adding steel fiber and silica fume to enhance the abrasion and acid resistance of geopolymer concrete was investigated in this article through an experiment. First, the compressive strength and abrasion resistance of geopolymer concrete—type 1 (GC1) with four steel fiber types (short hooked, long hooked, short smooth, and long smooth) of volume fractions from 0 to 2 vol.% were investigated. The favorable content of steel fibers to enhance the compressive strength of the GC1 was more than 1.5 vol.%, with long fibers performing better than short fibers. Specifically, the long hooked fiber of 2.0 vol.% produced the best performance on compressive strength (41.3 MPa) and abrasion resistance (abrasion coefficient of 0.27 g/cm²). Second, the optimal amount of silica fume of 10% for replacing fly ash in geopolymer concrete—type 2 (GC2) resulted in the highest compressive strength (22.1 MPa). Under acid attack using H₂SO₄/HCL with 5% and 10% concentrations with immersion time, the compressive strength of the GC2 increased with increasing immersion time within 90 days, up to 44.0% using 15% silica fume. The specimen weight of the GC2 decreased with increasing immersion time within 120 days; using 15% silica fume significantly reduced the weight loss of GC2 from 1.69 to 0.68% compared to not using silica fume. The HCL was more corrosive than the H₂SO₄ in the same concentration. These findings of this study underscore the potential for using geopolymer concrete under the impacts of corrosive environments and abrasive loading.