Corrosion Monitoring of Steel Reinforced Concrete Structures Using Embedded Instrumentation

Civil structures such as bridges and dams are extremely large construction efforts costing millions to billions of dollars and spanning several years. In the United States alone, repairs for corrosion damage to federal bridges are estimated at $50 billion annually. The high costs of corrosion due to replacement and premature failures mandate the need for integrated in-situ NDE systems. These NDE systems should provide information based on changes in the structure's corrosion condition to affect timely maintenance interventions. In this paper, a fully embeddable corrosion monitoring instrument incorporating all required electrodes and signal processing electronics will be demonstrated. The embedded corrosion instrument (ECI) approach allows for a higher signal to noise ratio and more accurate and repeatable measurements. Onboard measurements of LPR, OCP, resistivity, temperature, and chloride ion concentration will be demonstrated. Digital communications within an embedded local area network are performed using the SDI-12 industry standard protocol. Sensor results from laboratory and field studies will be shown that highlight the relevance of the multiple sensor approach and the communications capabilities.