Corrosion Behavior of Steel Bars Embedded in Fly Ash Concrete Deteriorated by Chlorides and Carbonation
Takao UEDA, Ryo OKA, Koichi ISHIBASHI and Masaru YOKOTA
Abstract:One of the main problems of fly ash concrete is reducing the resistance against carbonation of concrete due to consuming Ca(OH)2 by pozzolan reaction of fly ash. Then, admixing of fly ash into concrete may increase the corrosion risk of reinforcing steel embedded in concrete. In this study, the influence of fly ash admixed into concrete on corrosion behavior of reinforcement due to bothchloride attack and carbonation, was estimated by means of electrochemicaltechniques.The results showed that when the cause of corrosion was only chlorides, microcell corrosion rate could be reduced by admixing fly ash. However, when there was the act of carbonation, corrosion rate of reinforcing steel embedded in fly ash concrete was increased, compared with the case of non-fly ash concrete. Key Words:Fly ash concrete, Chloride induced corrosion, Carbonation, Half-cell potential, Polarization resistance