Title: Eco-friendly corrosion prevention using waste powder coatings for carbon steel in aggressive concrete environments

Authors: Salah Galal; Ahmed Elshami; Hazem F. Khalil; Moustafa F. Bakr

Addresses: Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt ' Housing and Building National Research Centre, Dokki, Giza, 1770, Egypt ' Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt ' Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt

Abstract: In the concrete industry, corrosion inhibitors are frequently used to slow down the rate at which steel corrodes when exposed to harsh conditions. Waste powder coating (WPC) was assessed in this study as a protective coating for carbon steel in concrete-like solutions (highly alkaline, pH 12.5) with and without chloride contamination (NaCl), and acidic conditions (HCl). The effect of WPC as a corrosion-preventing coating was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). SEM and EDX methods were used to confirm that WPC was coated on the surface of carbon steel. The results of the potentiodynamic polarisation analysis showed that the inhibition efficiency increased to 69.15% in the presence of WPC, leading to a decreased corrosion rate of 0.009 μm/year. This effect is attributed to the presence of WPC on the carbon steel surface, as confirmed by SEM analysis. EIS studies revealed that the inhibition efficiency was increased due to the presence of WPC, in agreement with potentiodynamic polarisation findings. Results indicated that WPC significantly inhibited carbon steel corrosion in all tested environments (highly alkaline, chloride contaminated, and acidic solutions) which making it a promising and sustainable approach to protecting carbon steel from corrosion in concrete structures.

Keywords: carbon steel; corrosion; coating; waste powder coating; WPC; corrosion prevention; chloride-contaminated concrete pore solutions.

DOI: 10.1504/IJEWM.2026.155916

International Journal of Environment and Waste Management, 2026 Vol.40 No.4, pp.363 - 383

Received: 29 Jan 2025
Accepted: 30 Jun 2025
Published online: 26 Aug 2026 *

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