Experimental and Numerical Investigation on Stress–Strain Relationship of Graphene Oxide and Fly Ash-Based Concrete Under Axial Compression

Graphene oxide (GO) is a derivative of graphene and a promising material for application as nano reinforcement in cementitious composites. In this study, combined effect of GO and fly ash addition on constitutive stress–strain behaviour of concrete under uniaxial compression was investigated. The low dosage of 0.15% GO addition and cement replacement with fly ash at 10, 20, and 30 percentage by weight was considered in this study. The results demonstrated that adding 0.15% GO to concrete improved the compressive strength by 54%. The combined effect of GO and fly ash compressive strength at 7 days was higher than the control concrete demonstrating that GO can counteract the effect of fly ash on delaying strength development at early stage. From the experimental results, it is found that GO introduction along with fly ash replacement improved both strength and elastic modulus of the concrete, demonstrating significant synergy in hybridizing GO and fly ash into concrete composite. Further, to validate the experimental results, nonlinear numerical model was also developed for GO and fly ash-based concrete using ATENA-GiD. The nonlinear numerical model effectively predicted the behaviour under uniaxial compression and thereby tedious experimental investigation can be avoided. Further, it is observed that the findings of both the experimental and numerical analysis are in good agreement.