Impact of reduced graphene oxide on epoxy coatings and its effect on the flexural performance of reinforced concrete beams

Corrosion of reinforcement steel in concrete structures is a major challenge, particularly in harsh environments such as coastal and industrial areas, where durability is critical. Conventional epoxy resin coatings offer chemical stability but face challenges in maintaining long-term corrosion resistance under severe conditions. This study explores the application of reduced graphene oxide (rGO)-modified epoxy resin coatings for enhancing the durability and corrosion resistance of reinforced concrete beams. By varying the rGO content, we evaluated the adhesion, water absorption, and corrosion resistance of rGO/EC (reduced graphene oxide/epoxy resin coatings). Our findings indicate that an optimal concentration of 0.2 wt.% rGO significantly improves the corrosion resistance and impermeability of the epoxy coating, while maintaining strong adhesion. Microstructural analysis and coating performance tests confirmed these improvements, and a predictive model was developed to determine the optimal rGO concentration, showing strong agreement with experimental results. The flexural tests on rGO/EC reinforced concrete beams demonstrated comparable performance to standard reinforced concrete beams, with negligible effects on bending performance, crack spacing, and maximum crack width. This study provides valuable insights for the practical application of rGO/EC in enhancing the durability and longevity of reinforced concrete structures.