Four-Wheel Upgrade Drives Corrosion-Analysis Technology

Proceq’s Canin+ Corrosion Analyzing Instrument precisely locates areas of active corrosion–a chief culprit, when undetected, in reducing the life span of reinforced concrete structures–to effectively minimize corrective maintenance costs

Proceq’s Canin+ Corrosion Analyzing Instrument precisely locates areas of active corrosion–a chief culprit, when undetected, in reducing the life span of reinforced concrete structures–to effectively minimize corrective maintenance costs. In the face of decaying infrastructure, the launch of improved Canin+ with redesigned one- and four-wheel electrodes addresses the needs of construction firms and transportation agencies seeking ways to detect weakening concrete structures before disaster strikes.

According to Switzerland-based Proceq, Canin+ features the widest range of electrodes now available. Moreover, a completely integrated, waterproof measuring system and durable plug-in connection with robust cables allow wheel electrodes to function reliably in harshest site conditions. Besides the half-cell corrosion potential method implemented by electrode, the instrument can provide electrical resistivity measurements via Wenner probe.

The combination of resistivity and potential measurement increases the accuracy of information regarding rebar corrosion, product developers affirm. Among primary means of analysis, the half-cell corrosion potential method employs accurate field measurements of compromised rebar. Since corrosion of reinforcement steel in concrete is an electrochemical process, a potential field can be measured on the surface by the use of an electrode, known as a half-cell, and a high-impedance voltmeter. The Canin+ corrosion analyzing instrument thus highlights corrosion activity before rust becomes visible, providing early detection to avert unanticipated structural failure.

Secondly, the instrument is designed to measure concrete resistivity, because lower resistance at the matrix surface indicates a greater likelihood of reinforcement corrosion, plus an accelerated corrosion rate. While concrete resistivity can vary extensively, depending on local conditions and environmental influences, the electrical resistivity method has been proven empirically to give an estimate of the corrosion rate.

To meet variable customer needs, a choice of instrument probes is available. The Rod Electrode was developed to test areas less than 215 sq. ft. or hard-to-reach surfaces where using wheel electrodes is impractical. It also suits detailed measurements with a fine raster to accurately locate potential corrosion hotspots.

The 1-Wheel Electrode was designed for testing larger areas, typically between 215 and 1,076 sq. ft. The 4-Wheel Electrode offers a tool for fast testing of large areas. Its measuring speed can help reduce both time and cost, as in testing bridge decks, for example, without having to close the span for long periods.

Additionally, the Wenner probe measures concrete’s electrical resistivity for further indication of the probability of corrosion. It is best used for complementary diagnostics after testing based on the half-cell corrosion potential method is performed by rod or wheel electrodes.

Windows-based Canin+ ProVista software simplifies evaluation of measured data for fast and easy analysis, Proceq representatives note. It supports efficient documentation of measurements by transferring data from the device to a PC for display, editing and report generation.

The program generates a potential map, as well as relative frequency and cumulative frequency diagrams. The latter can be divided into four zones. A chipping graph then can be generated accordingly. Thus, statistical presentation provides a basis for efficient interpretation of half-cell potentials by the corrosion engineer.

The software allows the engineer to rotate and mirror files. Single potential maps can be combined to form a complete graph representing the total investigated surface area. Data can be exported easily to third-party software for further processing. Û www.proceq.com, www.canin-concrete-corrosion.com