Sustainable Corrosion-Resistant Coating on Rebar Embedded in RCC Structures Using Garlic Peel Charcoal

This study presents the development of a novel and sustainable anticorrosive coating for protecting rebars embedded in reinforced concrete structures, utilizing organic materials such as garlic peel charcoal and linseed extract as binders. These organic materials were combined with epoxy and a hardener to enhance corrosion resistance. Garlic peel charcoal was prepared by carbonizing 150 g of garlic peel at 400 °C for 4 h. The corrosion resistance of the coating was evaluated using electrochemical methods, including Tafel polarization, Nyquist plots, in NaCl-contaminated simulated concrete pore solution (SPS). Mechanical tests, including pullout tests, surface roughness tests, and impact tests, were conducted to assess the coating’s durability. Additionally, the coating’s functionality was examined using SEM and XRD analyses. The composite coating of garlic peel charcoal and linseed extract with epoxy and hardener (GLEH) demonstrated the lowest corrosion rate of 15 mpy after 90 days of immersion in SPS. XRD analysis revealed that garlic peel charcoal is crystalline in nature. The results indicate that the garlic peel charcoal contains organosulfur compounds, and the presence of self-healing agents in linseed extract contributes to a significant reduction in the corrosion rate, with a protection efficiency of 90.3% compared to bare mild steel.