Final Evaluation of Corrosion Protection for Bonded Internal Tendons in Precast Segmental Construction

Details

• Creators:
  Salas, R. M. ; Kotys, A. L. ; West, J. S. ; Breen, J. E. ; Kreger, M. E.
• Corporate Creators:
  University of Texas at Austin. Center for Transportation Research
• Corporate Contributors:
  Texas Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  Calcium Nitrite Corrosion Grout Joints (Engineering) Laboratory Tests Precast Concrete Protection Segmental Construction Tendons (Materials)
• Publication/ Report Number:
  1405-6
• Resource Type:
  Tech Report
• Geographical Coverage:
  Texas ; United States
• Corporate Publisher:
  University of Texas at Austin. Center for Transportation Research
• Abstract:
  In 1993, aware of unfortunate experiences in Europe in early non-epoxy segmental joints, Research Project 0-1264 was started with the main purpose of investigating the corrosion protection of internal tendons at segmental joints. This testing program was transferred to Project 0-1405 for long-term testing. Half of the thirty-eight laboratory specimens were autopsied after around four and one-half years of highly aggressive exposure and the preliminary conclusions were reported in 1999. The variables included were joint type (dry or epoxy), duct type (galvanized steel or plastic), grout type (3 grouts with differing additives) and level of joint compression (3 different levels). This report documents the final results, after the second half of the specimens were autopsied with over eight years of very aggressive exposure. The observed conditions after eight years caused a number of changes from the preliminary conclusions. Main among these observations were the presence of some strand corrosion (away from the joint) in epoxy jointed specimens, corrosion at one epoxy joint that was found to be incompletely filled with epoxy, and very extensive corrosion in the galvanized steel ducts. Autopsies confirmed that dry joints should not be used in situations where aggressive exposure may occur, that match-cast epoxy joints provide good corrosion protection, that gaskets in epoxy joints do not appear to be beneficial, that plastic ducts provide excellent corrosion protection and that good grouting procedures and materials are essential. The use of calcium nitrite had little effect on the onset of corrosion but did seem to provide enhanced long-term strand corrosion protection.
• Format:
  PDF
• Funding:
  0-1405
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:71f283a086aef2f4e44cb73a238c5f4ae60aeb5c3f85e7e61289804b37f98ddc77e63b0f37ca5044d0a7afd47f1ed87b63b18e129ca63bf9ba031768c8f98e6c
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/86212/dot_86212_DS1.pdf
• File Type:
  [PDF - 2.86 MB ]