Reinforced concrete metallic structures corrosion, in the presence of chlorides

Using metallographic and electrochemical techniques it resulted that the ca rbon steel presents a high passivation tendency and in practice does not co rrode in Ca(OH), saturated solution. In the presence of chloride ions, of l ow concentration (0.005M-0.025M NaCl) the carbon steel also is passive and corrodes with a slow corrosion rates; although it appears pitting corrosion , this is produced at high potentials (+700mV divided by +650mV) which can not be achieved in service conditions; so, the metal can be considered stab ly. At high chloride ion concentrations (0.5M NaCl), the carbon steel from reinforced concrete presents pitting corrosion and is not surely.