A miniature device for in-situ measurement of concrete corrosion

The degradation of reinforced concrete infrastructure is a significant issue resulting from the corrosion of reinforcement, with various novel solutions being explored to address this issue. One possible solution is instrumented self-sensing infrastructure, which can provide real-time information necessary to ensure safe and reliable structures. A potential method of instrumentation is through accurate and timely measurements of the impedance within the pore space of cement to assess durability and sense structural changes in the concrete containing conductive filler. There are many different approaches to monitor concrete such as ground penetrating radar and infrared topography, however, most methods have serious limitations. Most devices come with a cost, are large, not able to provide real-time monitoring and require regular recalibrations to maintain accuracy. Electrical resistivity measurement was chosen because it's simple, accurate and able to detect corrosion before initiation. The work presented in this paper includes a low-cost aggregate-sized sensing mechanism suitable for embedding within concrete structures, designed with large scale deployments in mind. This will in turn ensure safer, more reliable structures, reducing maintenance costs and allowing civil engineers to make informed decisions about infrastructure health without a premium price. This paper presents the steps through which this device is designed and implemented, and then discusses the results obtained.