Corrosion detecting probes for use with a corrosion-rate meter for electrochemically determining the corrosion rate of reinforced concrete structures

摘要

A corrosion detecting probe is to be used in combination with an electrochemical corrosion-rate meter for performing on-site diagnosis of the corrosion rate of metallic reinforcement systems in concrete structures. After the probe is brought into surface contact with a concrete member, voltage/current signals are applied thereto and a series of calculations are performed to determine the polarization resistance directly about a confined concrete portion. The probe consists essentially of an external counterelectrode, a central counterelectrode, a central reference electrode and a pair of extra reference electrodes (sensors). A current applied from the external counterelectrode serves to repel the lines of current (resulting from a voltage signal first applied at the central counterelectrode) below the probe and within the confined concrete portion which is between the central counterelectrode and the external one. The pair of sensors located on the surface of the concrete make it possible to fix the operating conditions so as to confine the measured area for which a polarization resistance is to be calculated. The sensors are necessary as they provide a substantially accurate indication of when the measured area is sufficiently confined as a function of the electrical signal field effects resulting from the voltage signal applied at the central counterelectrode and the current applied to the external counterelectrode.