NONDESTRUCTIVE TESTING METHODS TO DETECT VOIDS IN BONDED POST-TENSIONED DUCTS

The use of post-tensioning in bridges provides durability and structural benefits to the system while expediting the construction process. However, there is considerable interest to determine whether a tendon duct is properly filled with grout or not. Implementing nondestructive testing can be vital to the integrity of the structure because loss of post-tensioning can result in catastrophic failure. The purpose of this work was to develop and validate a nondestructive testing and evaluation method that can be used in the field to detect internal concrete conditions such as voids and cracks in grouted tendon ducts during bonded post-tensioned applications. These are three techniques that were evaluated in this research effort: Impact Echo (IE), Spectral Analysis of Surface Waves (SASW), and Ultrasonic Tomography Imaging (UTI). Based on the results from all three tests, the authors suggest that the IE scanning test should be used to evaluate the internal condition of the grouted duct. Impact echograms may also be used as a way to present the results since the plot provides more information in IE frequency data. The image results from UTI showed locations of both ducts clearly in all three cases. Unfortunately, the images did not show details inside the ducts. It is concluded that scanning IE tests show the most promise for assessing internal grout conditions of the steel duct. For a plastic duct, it was more difficult to identify grout conditions due to partial debonding conditions between the plastic duct and concrete wall.

• Corporate Authors:

  University of Florida, Gainesville

  School of Building Construction, P.O. Box 115703
  Gainesville, FL  United States  32611

  Florida Department of Transportation

  Haydon Burns Building, 605 Suwanee Street
  Tallahassee, FL  United States  32301

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Muszynski, L C
  • Chini, A R
  • Andary, E G
• Publication Date: 2003-5-30

Language

• English

Media Info

• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 135 p.

Subject/Index Terms

• TRT Terms: Air voids; Cracking; Ducts; Grout; Nondestructive tests; Posttensioning; Spectrum analysis; Tendons (Materials)
• Candidate Terms: Impact echo tests; Spectral analysis of surface waves
• Uncontrolled Terms: Ultrasonic tomography imaging
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00962188
• Record Type: Publication
• Report/Paper Numbers: Final Report
• Contract Numbers: BC 354-49
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 28 2003 12:00AM