Experimental study of the effects of graphene nanoplatelets on microstructure and compressive properties of concrete under chloride ion corrosion

•Graphene improves the resistance of concrete to chloride attacks by densering microstructures of concrete.•Graphene reduces the brittleness of concrete during chloride corrosion.•Graphene retards the deformation of concrete during chloride attacks.•Graphene enhances the compressive performance of concrete. In a marine environment, chloride ingress has the most prominent effect on the durability of concrete. The effect of graphene on the microstructure and compressive properties of concrete subjected to long-term chloride ion corrosion was investigated in this study. The results showed that an increase of up to 20.92 %, 21.97 %, 19.13 %, 19.43 % and 17.81 % is achieved in compressive strength respectively due to the addition of 0.05 wt% graphene nanoplatelets (GNPs) after 0, 40, 80, 120 and 240 days of immersion in sodium chloride solution, compared with ordinary concrete. With an increase in chloride ion deterioration time, the dynamic elastic modulus of graphene concrete gradually increased. The SEM, XRD, compressive performance and chloride ion content test results of the two concretes show that graphene concrete has better and more stable chloride ion resistance than ordinary concrete.