| 摘要 |
PURPOSE:To perform the accurate diagnosis of corrosion, by a method wherein high frequency and low frequency AC currents are applied between a reinforcing bar and an electrode for diagnosing the corrosion of concrete and the real part values of respective AC impedances are calculated. CONSTITUTION:Two kinds of high and low frequency AC currents are respectively independently applied between an electrode 6 for dianosing the corrosion of concrete and a reinforcing bar 2 by an AC current applying apparatus 5. The voltage response between the reinforcing bar 2 and the electrode 6 at this time is monitored by an AC potentiometer 11 and converted to AC impedance from the phase shift of an input signal and an output signal and the ratio of the amplitudes of both signals by a frequency response analyzer 12. Then, the real part of the AC impedance is used as the factor of corrosion diagnosis. Further, the real part value when the high frequency current is applied corresponds to the ohm resistance between the electrode 6 and the reinforcing bar 2, and, further, the real part value when the low frequency current is applied corresponds to the sum of the ohm resistance between the electrode 6 and the reinforcing bar 2 and the resistance relation to the corrosion speed of the interface of concrete 1 and the reinforcing bar 2. Therefore, the real part value at the time of high frequency is subtracted from the real port value at the time of low frequency and, when the value obtained is large, corrosion-free condition is judged.
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