Investigation on axial compression behavior of concrete columns wrapped with ferro-geopolymer composites

This study presents a comprehensive experimental investigation into the axial compression behavior of concrete columns strengthened with ferrocement jacketing using geopolymer mortar (GPM) and cement mortar (CM), considering both circular and square cross-sections. The work evaluates the effectiveness of ferrocement confinement reinforced with single and double layers of chicken mesh. The GPM binder was synthesized using industrial fly ash (IFA), ground granulated blast-furnace slag (GGBS), and an alkaline activator, offering a sustainable alternative to traditional cement-based materials. A total of twenty specimens, wrapped and unwrapped, were cast and tested under axial loading to assess load-deformation characteristics, failure modes, crack propagation, and confinement efficiency. The results show that ferrocement wrapping significantly enhances axial capacity and ductility, with double-layer GPM jacketing providing the highest improvement. Wrapped specimens exhibited delayed crack initiation, reduced spalling, and increased energy absorption compared with unwrapped columns. Durability assessments under saline exposure further confirmed that GPM-wrapped specimens experienced minimal strength reduction, demonstrating their suitability for marine and aggressive environments. Overall, the findings highlight ferro-geopolymer composite jacketing as a cost-effective, eco-friendly, and mechanically efficient technique for strengthening and retrofitting concrete structural elements.