Condition Assessment of Unbonded Post-Tensioning Strands: A Case Study Using Nondestructive Testing to Evaluate the Floor Slab of a Parking Structure

The authors discuss evaluation of post-tensioned floor slab in a Wisconsin parking structure using three nondestructive testing (NDT) techniques: ground penetrating radar, magnetic scanning, and x-ray radiography. NDT and limited destructive testing was used to evaluate embedded post-tensioning elements. Analysis showed floor slab embedded post-tensioned tendons and anchors at a construction joint, especially with unsheathed portions of embedded strands, were highly corrosion prone; post-tensioning failure might be evident if corrosion in proximity of post-tensioned slab construction joints, concrete distress, or slab vertical offset could be observed; while NDT can be valuable in embedded post-tensioning condition assessment, one method, ground penetrating radar, may not identify small gaps in strands; and severed strands, as well as, under the right conditions, small gaps, can be detected at shallow depths effectively through magnetic scans. An insert details parking structure evaluation and repair.

  • Availability:
  • Authors:
    • Puri, Sunil
    • Moser, Daniel E
  • Publication Date: 2007-4


  • English

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References; Tables;
  • Pagination: pp 60-64
  • Serial:
    • Concrete International
    • Volume: 29
    • Issue Number: 4
    • Publisher: American Concrete Institute (ACI)
    • ISSN: 0162-4075

Subject/Index Terms

Filing Info

  • Accession Number: 01046897
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 16 2007 3:38PM