Magnetic Flux Leakage Signal Characterization for Detection of Corrosion in Prestressed Concrete Girders

Employing the Magnetic Flux Leakage (MFL) concept as a non-destructive test method has shown success for detection of corrosion or other section losses in reinforcing or prestressing steel embedded in concrete. In this study, an MFL system consisting of a pair of powerful permanent magnets and a set of Hall-Effect sensors is used in conjunction with a data acquisition system to monitor the variations of magnetic field along the length of test samples simulating prestressed concrete beams. These test samples included corrosion-like flaws at various locations along the length. It was found that the relative position of flaws in the test samples played an important role for their detectability in the test samples. It is demonstrated that an MFL signal from a test presents a superposition of a set of signals produced by various contributing effects such as transverse stirrups, multiple flaws, and artifacts that may be present in the test sample. The combinatorial effects of relative distance of stirrups and flaws are analyzed in this study by simulation and the findings have shown good agreement with experimental results. Through such simulation, magnetic field variations in test samples were correlated with the location of stirrups and percentages of section loss for nearby flaws.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 9p

Subject/Index Terms

Filing Info

  • Accession Number: 01763418
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-03154
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 10:58AM