Abstract Ground granulated blast-furnace slag (GGBS) is a widely used precursor in the development of geopolymer concrete (GPC) due to its high reactivity. While nanomaterials have been explored for enhancing GPC properties, the specific influence of nano-Al 2 O 3 (NA) on the mechanical and durability performance of GGBS-based GPC remains underexplored. This study investigates the effect of NA at dosages of 1, 2, and 3% as a partial replacement of GGBS, aiming to optimize the strength and durability of GPC. The highest strength was achieved with 2% NA, yielding compressive, split tensile, and flexural strengths of 57.36, 5.81, and 5.59 MPa, respectively, at 90 days of curing. Durability performance was examined by exposing the GPC to harmful chemicals like 6% HCl, 6% H 2 SO 4 , 6% NaCl, and 6% Na 2 SO 4 . The water absorption is reduced with an increase in the dosage of NA in concrete. This is due to the non-porous nature of the dense and compact NA-incorporated GPC. Microstructure analysis was conducted to evaluate the influence of NA at nano- and microlevels. The formation of the extra N–A–S–H gel after incorporation of NA resulted in an enhancement in the strength of GPC. The key novelty of this study lies in providing comprehensive insights into the role of NA in refining the pore structure, enhancing geopolymerization, and improving the chemical resistance of GGBS-based GPC. The findings highlight the potential of NA in producing high-performance, sustainable concrete for aggressive environments.
Sharma et al. (2025) studied this question.