Electrochemical Aspect of Protection Reinforced Steel Bar by Copper Coating via Modified Rolling Technique

This study investigates the corrosion resistance of copper-coated reinforcing steel bars embedded in concrete and exposed to a simulated marine environment for (28, 56, and 90 days) at temperatures of (298, 308, and 318 Kelvin). A novel thermal spray technique was integrated into the hot rolling process to deposit copper powder onto heated steel bars. The coated bars were characterized using X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive spectroscopy (SEM/EDS), and atomic force microscopy (AFM), revealing a dense, uniform microstructure with reduced surface roughness (63.99 nm) and increased particle density (〖30.2 ×10〗^6 particles/mm²) compared to the uncoated steel bar. Electrochemical measurements demonstrated a substantial decrease in corrosion current density (I_corr) for the coated specimens (〖1.11×10〗^(-7) A/cm² at 298 Kelvin), along with the highest protection efficiency (92.29 %). Electrochemical impedance spectroscopy (EIS) further confirmed the enhanced performance of the coated bars, with a superior total impedance resistance of 30,192 Ω.cm² and Warburg resistance of 18,320 Ω.cm^2, compared to uncoated ones (17,561 Ω.cm² and 9,363 Ω.cm^2), respectively. These results highlight the potential of copper coatings as a viable solution for extending the service life of reinforced concrete structures in aggressive environments.