Ductility enhancement of geopolymer concrete columns using fibre-reinforced polymer confinement

Abstract

Geopolymer concrete is an environmentally friendly, green construction material. However, its use is constrained by its increased brittleness and lack of understanding of its behaviour under multi-axial loadings. Similar to ordinary portland cement concrete (OPC), the ductility of geopolymer concrete columns can be increased by lateral confinement and using fibre-reinforced polymers is one option in doing that. This research paper aims at investigating the effect of different confinements on the ductility of geopolymer concrete. Three different mixes with varying binder (fly ash and slag) and different curing conditions together with different levels of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) confinement were investigated in this research paper. FRP confined normal strength geopolymer concrete shows similar stress–strain behaviour when compared to that of high-strength OPC concrete When compared with the same level of confinement, CFRP confined geopolymer concrete marginally outperforms GFRP confined geopolymer concrete in 28-day compressive strength. However, ductility levels with GFRP confinement are better than those with CFRP confinement.