The Use of Suitable Design Mix Proportion of Graphene Oxide and Fly Ash Additives in High-Density Concrete for Offshore Applications

Offshore structures like oil pipelines and concrete mattresses are constantly exposed to adverse environmental effects such as saline water infiltration, fisherman trawl, buoyancy effects and vibrations from sea waves. As a result, the deterioration and corrosion of structures in such an environment are often a major concern. Hence there is the need for developing environmentally friendly high-density concrete for potential application in offshore activities as well as mitigating some of the challenges of concrete in harsh environments. Against this backdrop, environmentally friendly high-density concrete was developed by partially substituting cement with fly ash and adding graphene oxide. Whereas the coarse aggregate content of the concrete was fully replaced with coated waste steel punching collected from construction sites. The dosage of fly ash varied from 20 to 50% and graphene oxide dosages of 0.013–0.053% were used. After 28 days of curing, an optimal density of 4282 kg/m3 for the high-density concrete mix with 20% fly ash and 0.053% graphene oxide dosages was obtained. Also, the optimal compressive strength of 37.90 MPa for the high-density concrete mix with 35% fly ash and 0.033% graphene oxide was obtained. The compressive strength and density results obtained in this study are significantly higher than the conventional concrete values from past literature. This therefore suggests that the combined use of graphene oxide and fly ash has shown significant compressive strength improvement and density of high-density concretes which will be suitable for offshore applications.