Professor, University of Wisconsin-Milwaukee, Milwaukee, WI
Graduate Student, University of Wisconsin-Milwaukee,
Pages: 13 Published: Jan 1996
Corrosion damage of steel in concrete structures is a major concern. NDE techniques based on variations in induced magnetic fields due to loss of steel have been shown to be an effective tool. This paper includes results from laboratory investigation, field tests, and numerical analysis based on this concept. Test specimens included reinforcing bars and prestressing cables with simulated flaws as well as flaws from real corrosion. Variations in the magnetic field were recorded as electrical signals that were characterized to aid in the detection of corrosion and evaluation of the condition of steel in concrete. It was found that the amplitude of the signals could be related to the extent of the corrosion. Loss of cross sectional area in bars and cables of approximately 3 percent could be detected by the technique. The results of a finite element analysis yielded a good agreement with those from the experiment. The technique offers significant capabilities for field assessment of the condition of steel in concrete structures.
corrosion, magnetic field, NDE, concrete, reinforcing bars, prestressing cables, signal processing, finite element analysis, laboratory tests, field tests
Paper ID: STP16971S