Corrosion Process of Reinforced Concrete by Carbonation in a Natural Environment and an Accelerated Test Chamber

Electrochemical impedance spectroscopy (EIS) was used to monitor carbonation front progress in plain and reinforced concrete beams in a tropical marine environment and an accelerated carbonation chamber. Manufacturing and exposure conditions notably affected the carbonation phenomenon. Passivity conditions, passive-active transition and activation of the concrete-steel interface were estimated. The EIS detected differential responses during the exposure time course caused by changes in environmental relative humidity. Relative humidity exercises an ohmic control that has a greater influence on the corrosion process than does carbonation of the concrete paste at the reinforcement level.