Mapping of Atmospheric Corrosion of Steel in Southeast India Using Inverse Distance Interpolation Technique

Reinforced concrete and steel structural elements undergo premature degradation and lose strength primarily due to corrosion. Corrosion is an electrochemical phenomenon and its severity depends on several environmental factors. Experimental data on the corrosion of steel is important for making engineering decisions toward improving the service life of civil infrastructures. No recent dataset on atmospheric steel corrosion in an Indian coastal environment is found to be available in the literature, and hence this research attempts to address some of the literature gap. This paper presents an experimental study conducted to determine the corrosion rate of TMT, high-chromium steel, and stainless steel rebars exposed in actual coastal and inland regions for a period of 1 y. The site locations were located in southeastern parts of Tamil Nadu state in India. Based on the first-year corrosion rate, the corrosion rate after extended exposure (10 y) was determined based on ISO 9224 recommendations. The atmospheric steel corrosion map of Tamil Nadu state was developed using inverse distance interpolation technique. Microstructural studies indicated the formation of lepidocrocite (γ-FeOOH) phase composition in the rust products collected from coastal regions.