Publication

Abstract : The use of natural compounds derived from plant extracts offers an eco-friendly solution for preventing the corrosion of rebar in concrete structures. This study investigates the corrosion inhibition efficiency of Cassia fistula (CF) leaf extract on mild steel in NaCl-contaminated simulated concrete pore solution (SPS). The corrosion protection performance was evaluated using weight loss measurements, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). Surface analyses were conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM) to assess the protective film formation. The results revealed that at an optimum concentration of 5 % v/v CF extract, a maximum inhibition efficiency of 85.21 % (from weight loss) and 92.4 % (from PDP) was achieved, accompanied by a significant increase in charge transfer resistance (799 Ω·cm²). indicating strong barrier formation on the metal surface. SEM and AFM analyses demonstrated smoother and less corroded steel surfaces in the presence of CF extract. This work demonstrates the potential of Cassia fistula leaf extract as a sustainable and effective corrosion inhibitor for reinforced concrete structures, aligning with the demand for green and durable construction materials.