Characterization of surface corrosion of reinforcing steel in cement paste by low frequency impedance spectroscopy
✍ Scribed by Ping Gu; Yan Fu; Ping Xie; J.J. Beaudoin
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 662 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0008-8846
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✦ Synopsis
Surface corrosion of reinforcing steel embedded in cementitious materials containing chloride ion is described by characteristic change of impedance spectra. Phase angle shift, surface impedance and capacitive responses, recorded at very low frequency (100Hz-10mHz), are demonstrated to be very sensitive to surface corrosion processes. Information that is difficult to obtain by traditional dc techniques is provided. It was found that longer immersion of specimens in chloride ion solution results in a more significant decrease of the phase angle.
A modified equivalent circuit model considering surface corrosion of the steelcement interface was constructed to simulate the steel surface oxidation behavior. Circuit parameters can be used to explain the experimental results in a qualitative way. The low frequency impedance technique appears to be a very useful nondestructive method for assessing reinforcing steel corrosion. 232