An embedded multi‐parameter corrosion sensor for reinforced concrete structures

A prototype of an embedded corrosion sensor has been developed for assessing the corrosion status of reinforcing steel bar (rebar) in concrete. The integrated sensor unit includes an Ag/AgCl probe, a metallic oxide probe, a multi-electrode array sensor (MAS), and a four-pin (Wenner) array stainless steel electrode for chloride content, pH, microcell corrosion current, and localized concrete resistivity measurements, respectively. A stable solid probe was used as the reference probe in this unit to express the potentiometric measurement of chloride content and pH probes. In this study, the chloride and pH probes were calibrated in simulated pore solutions (SPSs) regarding temperature and pH fluctuations. The corrosion current results of the MAS probe in SPSs matched very well with those obtained by the linear polarization resistance technique, which was conducted on companion carbon steel specimens. A sensor prototype was embedded into a paste cylinder for long-term performance evaluation. Up-to-date results show that the sensor probes exhibit excellent sensitivity and reliability through 1 year of monitoring. Continuous monitoring in the laboratory for extended periods is underway.

[1]  Marta Castellote,et al.  Chloride threshold dependence of pitting potential of reinforcements , 2002 .

[2]  Bernhard Elsener,et al.  Non destructive determination of the free chloride content in cement based materials , 2003 .

[3]  Gro Markeset.  Critical chloride content and its influence on service life predictions , 2009 .

[4]  Y. Tan.  Wire beam electrode: a new tool for studying localised corrosion and other heterogeneous electrochemical processes , 1998 .

[5]  C. Andrade,et al.  Chloride threshold values to depassivate reinforcing bars embedded in a standardized OPC mortar , 2000 .

[6]  Y. C. Kim,et al.  Development of corrosion sensors for monitoring steel‐corroding agents in reinforced concrete structures , 2003 .

[7]  K.M.Z. Shams,et al.  Wireless Power Transmission to a Buried Sensor in Concrete , 2007, IEEE Sensors Journal.

[8]  B. Carkhuff,et al.  Corrosion sensors for concrete bridges , 2003 .

[9]  C. Giordano,et al.  Embeddable reference electrodes for corrosion monitoring of reinforced concrete structures , 2010 .

[10]  B. Isecke,et al.  Modelling of reinforcement corrosion – Influence of concrete technology on corrosion development , 2006 .

[11]  Alberto A. Sagüés,et al.  Characterization of Activated Titanium Solid Reference Electrodes for Corrosion Testing of Steel in Concrete , 1996 .

[13]  G. S. Duffó,et al.  Characterization of solid embeddable reference electrodes for corrosion monitoring in reinforced concrete structures , 2009 .

[14]  N. Sridhar,et al.  An In-Situ Galvanically Coupled Multielectrode Array Sensor for Localized Corrosion , 2002 .

[15]  G. Glass,et al.  The presentation of the chloride threshold level for corrosion of steel in concrete , 1997 .