Corrosion of steel bars with respect to orientation in concrete

Corrosion of steel bars (main steel and stirrup) with respect to the orient ation in concrete is presented. A detailed study on macrocell and microcell corrosion of steel bars in concrete was conducted on horizontal and vertic al steels, depending on the casting direction. The horizontal steel was div ided into top and bottom halves. The study was conducted with chloride ions in concrete Water-cement ratios (w/c) were 0.5 and 0.7. The electrochemica l investigations, microscopic and physical observations of steel bars were performed. The laboratory investigations were verified with the long-term ( 23 year) exposure investigations on reinforced concrete beams. The study al so focused on the influence of stirrup on macrocell formation of main steel , and corrosion of plain and deformed steel bars. The study concludes that orientation of steel bars has a significant influe nce on macrocell and microcell corrosion of steel bars in concrete. Formati on of gaps under the horizontal steel's cause significant corrosion. Stirru ps play an important role in increasing macrocell corrosion of main steel. The deformed bar corroded more than fire plain bar.