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:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/4163061
• Authors:
  • Puri, Sunil
  • Moser, Daniel E
• Publication Date: 2007-4

Language

• 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

• TRT Terms: Ground penetrating radar; Nondestructive tests; Posttensioning; Radiography; Scanners; Slabs
• Uncontrolled Terms: Strand
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 01046897
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 25 2007 1:48PM