Evaluating prestressing strands and post-tensioning cables in concrete structures using nondestructive methods.

Details

• Creators:
  Jensen, Elin ; Grace, Nabil ; Kumi, Samuel
• Corporate Creators:
  Lawrence Technological University. Dept. of Civil and Architectural Engineering
• Corporate Contributors:
  Michigan. Dept. of Transportation. Research Administration
• Subject/TRT Terms:
  • Prestressing
  • Posttensioning
  • Cables
  • Concrete bridges
  • Box beams
  • Corrosion
  • Debonding
  • Delamination
  • Flexural strength
  • Grout
  More +
• Publication/ Report Number:
  RC-1632
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  Lawrence Technological University
• Abstract:
  The objectives were to evaluate the ability of different NDE methods to detect and quantify ; defects associated with corrosion of steel reinforcement and grout defects in post-tensioning ; applications; and to evaluate the effectiveness of selected NDE methods to detect and quantify ; the deterioration. The study included side-by-side box beam bridges for evaluation of the ; condition of prestressing strands and web reinforcement. Decommissioned box beams were ; tested in the laboratory to relate the quantified deterioration to the measured residual flexural ; capacity. Also a segmental bridge was included for evaluation of the condition of the web ; reinforcement and post-tensioning ducts. Laboratory specimens simulated debonding and voids ; around steel reinforcement, loss of cross section area of steel reinforcement, and various ; grouting challenges. The NDE methods used were 1) ultrasonic testing for delamination/void ; detection; 2) electrochemical measurements for assessing the corrosive environment; and 3) ; magnetic flux leakage (MFL) to estimate loss of cross sectional area of embedded steel. ; Ultrasonic echo-pulse tomography was able to detect debonding of the steel reinforcement and ; to detect internal voids and delamination. The method was able to quantify the depth of the ; defect but not the defect length. Electrochemical testing isolated the areas with high chance of ; corrosion. The MFL pilot demonstration showed that MFL can detect changes in the area of the ; steel reinforcement in laboratory and field applications. Presently, the calibration overestimates ; the steel loss. There was good agreement between estimated beam flexural capacity based on ; NDE results and the measured capacity of full scale box beams.
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• Format:
  PDF
• Alternate URL:
  http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Appendix_AB_508398_7.pdf ; http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Part_3_508397_7.pdf ; http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Appendix_CD_508400_7.pdf ; http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Appendix_E_508402_7.pdf ; http://ntl.bts.gov/lib/56000/56700/56792/AppendixG_Model.xlsx ; http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Appendix_F_508403_7.pdf ; http://ntl.bts.gov/lib/56000/56700/56792/RC-1632_Part_2_508396_7.pdf
• Funding:
  2010-0293
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29662/dot_29662_DS1.pdf
• File Type:
  [PDF - 2.98 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:090f69831e43fe54ee2b4e3067c3beff14d9d730289d16ae522627c336a2e882