Impedance-based detection of corrosion in post-tensioned cables : phase 2 extension of sensor development.

Details

• Creators:
  Orazem, Mark ; Bloomquist, David ; Alexander, Christopher ; Chen, Yu-Min
• Corporate Creators:
  University of Florida. Dept. of Chemical Engineering
• Subject/TRT Terms:
  Bridge Cables Bridges Corrosion Posttensioning Sensors Spectroscopy Tendons (Materials)
• Publication/ Report Number:
  BDV-31-977-19
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Corporate Publisher:
  Florida. Dept. of Transportation
• Abstract:
  A proof of concept was established for a sensor capable of using indirect impedance spectroscopy to
  
  detect the existence of corrosion in post-tensioned tendons. This development was supported by a
  
  combination of bench-top experiments performed on synthetic tendons, bench-top experiments
  
  performed in synthetic grout pore solutions for the same steel used in tendons, and modeling used to
  
  interpret impedance measurements and to simulate the signals obtained by the sensor.
  
  This work showed that indirect impedance can be used to observe differences in the impedance and
  
  differentiate between active and passive steel. Sensitivity to localized corrosion was found to be greatest
  
  when a current injection electrode is positioned directly above the corroding metal. Since the polarized
  
  area of steel was found to be a function of both frequency and the condition of the steel, it will be difficult
  
  to extract detailed reaction kinetics from the indirect impedance measurement, but the measurement will
  
  identify the presence of active corrosion.
  
  Bench-top measurements performed for ASTM A416 steel in aerated simulated pore electrolytes at pH
  
  of 13.6 showed a porous electrode behavior with a low rate of corrosion. In the absence of oxygen, the
  
  porous electrode behavior was also observed, but the corrosion rate increased. Experiments performed at
  
  elevated temperature showed an increase in the corrosion rate. This work provides guidance for the
  
  development of future models for interpretation of indirect impedance measurements.
  
  
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:cdf705c9c7c5061fea251e50168c94a7e5a72f287f47753df39660b71a2b2f5b
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28121/dot_28121_DS1.pdf
• File Type:
  [PDF - 1.20 MB ]