Effect of crack width and bar types on corrosion of steel in concrete

A study on the influence of crack widths and type of bars (plain and deformed) on corrosion of steel bars in cracked concrete is presented here. Microcell and macrocell corrosions of plain and deformed steel bars were investigated on 10 × 10 × 40 cm single crack specimens with crack widths of 0.1, 0.3, and 0.7 mm. Water-to-cement ratios were 0.3, 0.5, and 0.7. Electrochemical investigations were also conducted on 15 x 15 x 125 cm multicrack specimens with plain and deformed bars. For these specimens, water-to-cement ratios were 0.5 and 0.7 and crack widths were varied from 0.1 to 0.4 mm. After electrochemical investigations, chloride ions in concrete, corroded areas, weight losses, and pit diameters of the steel bars were investigated. The entire study was carried out in an artificially created chloride ion-induced corrosion environment. The study concludes that the relationship between crack widths and corrosion rate is observed at the very early age of exposure. Water-to-cement ratio and corrosion rate relationship is clearer than crack widths and corrosion rate relationship. Deformed bars are more prone to corrosion than plain bars.