Subramaniam et al. Res. Trends Int. J. Technol. Innov., January - March 2026, 1 (1) : 63-71
1Department of Civil Engineering, National Institute of Technology, Tiruchirappalli, India; 2Department of Civil Engineering, Amrita Vishwa Vidyapeetham, Coimbatore, India
Article History
Accepted : 08 Mar 2026
Published : 28 Mar 2026
Publication Issue
Volume 1, Issue 1
January - March 2026
Page Number63–71
Geopolymer concrete is gaining attention as a low-carbon alternative to ordinary Portland cement concrete, but its long-term durability under aggressive exposure conditions requires further characterisation. This study evaluates the sulphate resistance of fly ash and ground granulated blast furnace slag (GGBS) based geopolymer concrete at three GGBS replacement ratios, immersed in 5 percent sodium sulphate solution for up to 180 days. The 50 percent GGBS blend retained 92 percent of its 28-day compressive strength after exposure, substantially outperforming a companion OPC control mix, which retained 76 percent.
Keywords - geopolymer concrete, fly ash, GGBS, sulphate attack, durability
Sulphate attack is a common durability concern for concrete structures in coastal and industrial environments, and alkali-activated geopolymer binders have been proposed as a more resistant alternative due to their distinct reaction chemistry compared to calcium-silicate-hydrate systems in OPC.
Geopolymer mixes were prepared with fly ash to GGBS ratios of 100:0, 70:30 and 50:50, activated with a sodium silicate and sodium hydroxide solution, alongside an OPC control mix of equivalent 28-day design strength. Cube specimens were cured for 28 days then immersed in 5 percent sodium sulphate solution, with compressive strength and mass change measured at 28, 90 and 180 days of exposure.
The 50:50 fly ash-GGBS blend retained 92 percent of its pre-exposure compressive strength after 180 days, compared with 87 percent for the 70:30 blend, 81 percent for the fly-ash-only mix, and 76 percent for the OPC control, with corresponding trends observed in mass loss and surface spalling.
Increasing GGBS content in fly-ash-based geopolymer concrete improves resistance to sulphate attack, supporting its use in aggressive exposure environments. Future work will examine chloride-induced reinforcement corrosion in the same mix series.
[1] Davidovits J., Geopolymer Chemistry and Applications, Institut Geopolymere, 2008. [2] Bakharev T., Resistance of geopolymer materials to acid attack, Cement and Concrete Research, 2005. [3] Provis J. L. and van Deventer J. S. J., Alkali Activated Materials, Springer, 2014.
© 2026 The Author(s). Published by IJEIA Editorial Office. This is an open access article under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
Karthik Subramaniam, Divya Menon (2026). Performance Evaluation of Geopolymer Concrete Incorporating Fly Ash and GGBS Under Sulphate Attack. IJEIA, 1(1), 63-71.