This study presents the result of the corrosion monitoring with the use of monitoring sensors in various conditions. Experimental tests were carried out on reinforced concrete structures to verify the applicability of a multi-functional sensor. Single-functional sensors, which could measure potential and current, were also used to compare with multi-function sensor’s data. Measured factors were corrosion potential, resistivity, and corrosion rate. Results have shown, at least under the present testing conditions, that the multi-functional sensor plays an important role in an understanding of corrosion severity. In addition, corrosion monitoring data collected by these sensors were also analyzed. The results of these tests were as follows however, it is hard to judge the corrosion quantitatively.
3. Due to the fact that galvanic current could not be measured under small potential difference between anode and cathode, other criteria such as potential, corrosion rate, and concrete resistivity were needed to understand corrosion inclination.
4. It was difficult to judge corrosion accurately by using resistivity measurement. The resistivity measurement is a useful additional measurement to aid in identifying problem areas, and give the capacity of the concrete to allow corrosion.
5. In correlation between corrosion rate and potential, potential was decreased according to the increment of corrosion rate.
From the above results, when carrying out a survey of reinforced concrete structure by monitoring with corrosion sensor, it is hard to diagnose a corrosion problem with only one parameter which including some errors. Therefore, in order to minimize errors and obtain more accurate results, entire corrosion diagnosis should be applied. In other words, the application of multi-functional corrosion sensor to collect available information and minimize measurement problems can know the status of quantitative corrosion. 1. Reinforced concrete specimens were tested in four kinds of environmental conditions (Air, Fresh water, 3% salt water, 15% salt water). The more severe circumstance was (15% salt water, 3% salt water, Fresh water, and Air conditions), the more active inclination corrosion rate was.
2. Corrosion potential measurements could be a qualitative corrosion judgment