Investigation on Performance Enhancement of Fly ash-GGBFS Based Graphene Geopolymer Concrete

In this study, the properties of fly ash and ground granulated blast furnace slag (GGBFS) combination based
geopolymer concrete containing graphene oxide are investigated. The effects of graphene oxide (GO) addition and
GGBFS inclusion on the compressive strength, modulus of elasticity of geopolymer concrete were investigated in
this paper. The scanning electron microscope (SEM) was conducted to provide a thorough insight into the
microstructure's characterization. Rapid chloride permeability test (RCPT) was also conducted to estimate the
chloride ion resistance of graphene-modified geopolymer concrete. The experimental data revealed that the geopolymerization products were detected to be extra compact, and the inside porosity was decreased due to the inclusion of GO. However, enhanced compressive strength can be achieved in the geopolymer concrete after the incorporation of GGBFS, and this effect is more prominent for containing GO. The SEM images indicated that graphene oxide altered the morphology of geopolymer concrete from a porous nature to a significantly pore filled morphology with increased compressive strength. Besides, better relationships were established between the compressive strength, modulus of elasticity, and RCPT; these relationships fitted reasonably well with the other predictions. The experimental results depicted that 3% addition of graphene oxide with 30% GGBFS replacement produced an increase in compressive strength and modulus of elasticity values by 38.51% and 28%, while the chloride ion permeability by 65.44% respectively compared to mix without graphene oxide.