Investigation and Quantification of the Corrosion Behavior of Different Types of Reinforcing Steel

Abstract

The galvanic corrosion behavior of the different reinforcing •steel bars has been investigated and quantified through an indicator calculated through the current density measured in electrochemical accelerated tests. The steel coupling 35-35, 35-52, and 35-60 were embedded in concrete cylindrical moulds to provide three cover thicknesses 0.55, 3.75, and 5.75 em. The concrete grade was also varied where poor, normal, and silica fume concrete were used. Under all tested conditions, the couple 35-60 yielded the worst galvanic corrosion behavior while 35-35, 35-52 yielded a better behavior. Also, the 0.55 em thickness at any type of concrete was found to be insufficient to protect steel from corrosion.

Moreover, the sensitivity of weight loss percentages to the chemical composition of the solution in immersion tests was investigated. Two solutions were considered: solution I which consists of Ca(OH)2 with pH I2.6 and solution 2 of Ca(OH)2, NaOH, and KOH with pH !3.3. The ratio of weight loss percentage of solution I to the corresponding value of solution 2 ranged from I to 6 according to the tested conditions.