Influence of graphene oxide (GO) on thermo-mechanical performance of fly ash-steel slag based geopolymer composite: an experimental and numerical approach

This study demonstrates the feasibility of incorporating graphene oxide (GO) as an additive to enhance the mechanical and thermal properties of fly ash (FA) and steel slag (SS)-based geopolymer composites. A series of experiments and numerical simulations was conducted to evaluate the effect of GO on the material’s thermo-mechanical behaviour. Heat transfer in both solid and fluid domains was analysed using ANSYS Fluent, whereas structural deformation and stress distribution were evaluated through static structural analysis using ANSYS Mechanical. The results showed that adding GO reduced the setting time and flowability, while it enhanced the strength and microstructure. There was an increase in 32.5% strength for the GO-modified geopolymer along with an increase in the bulk density (2298 kg/m³), thermal conductivity (1.85 W/mK), and heat capacity (6.92 MJ/m³K). While subjected to thermal exposure, the GO-modified specimens showed lower thermal deformation by approximately 20% and limited thermal stress to around 2 MPa compared to the reference mix, as determined by numerical simulation. The enhancement in the developed geopolymer was due to the GO’s micro-filling, nucleation, and nano-reinforcement effects, which enhanced matrix densification and thermal stability. The findings of the study will contribute to the understanding of the influence of GO in geopolymer composites and offer valuable guidance for improving the low and high-temperature performance of FA-SS-based geopolymer composites containing GO in construction applications.