NDTnet 1998 Aug, Vol.3 No.8

Abstract

According to Stern-Geary formula, Icorr = B/Rp, the corrosion current, Icorr, (corrosion rate ) is inversely proportional to the polarization resistance, Rp. Corrosion rate meter has been developed to evaluate the on-site corrosion rate of reinforcing bars in concrete structures. This device has the following features.

(1)	It works on AC impedance principle. It has a reinforcing bar connection, a reference electrode, an auxiliary electrodes and so on. It applies a small sinusoidal voltage, and the amplitude of the sinusoidal current response and the phase difference between the two signals are measured.
(2)	It adopts the polarization resistance obtained from the AC impedance measurements attwo frequencies to allow a short time measurement. Two frequencies are 10-1 Hz and 20-10 mHz.
(3)	It has a guard counter electrode to define the area of measurement.
(4)	It has a rechargeable battery to allow a portable operation in the field.

The corrosion monitoring by the use of the portable device was applied to the reinforcing bars for real concrete structures: concrete walls of an open channel at coastal district. Corrosion rates obtained from AC impedance values had an almost linear correlation with ones measured from corrosion loss. This newly developed corrosion monitoring device is able to be applied for the evaluation of the corrosion of reinforcing bars in concrete structures.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com