Condition Assessment of Bridge Post-Tensioning and Stay Cable Systems Using NDE Methods

Visual bridge inspection of post-tensioning and stay cable systems is difficult because tendons are typically embedded in massive concrete (internal tendons) or opaque ducts (external tendons or stay cables). The current state of non-destructive evaluation (NDE) technology has limitations for evaluating the condition of bridge post-tensioning and stay cable systems for corrosion, section loss, breakage, grout conditions, voids, water infiltration, and tendon deterioration in the anchorage systems. However, technologies and innovative applications continue to advance. NDE technologies from other industries may have potential for bridge condition assessments, and NDE technologies applied in combination may also provide opportunities not yet realized. Further investigation is warranted. Corrosion, section loss, and breakage have impacts in the form of reduced safety and load capacity, costly rehabilitation actions, and traffic disruption. Therefore, condition assessments of post-tensioning and stay cable systems could allow bridge owners to take timely, proactive actions to mitigate or prevent further deterioration and unanticipated failure. The population of structures containing post-tensioning and stay cable systems continues to grow and age. Therefore, condition assessments of these systems are critical for maintaining public safety. The objective of this research is to develop inspection guidelines to assist bridge owners in selecting the most appropriate NDE method or combination of methods for assessing the condition of in-service post-tensioning and stay cable systems common in U.S. application. As a minimum, the inspection guide shall consider duct type and address the following conditions: corrosion, section loss, breakage, grout conditions, voids, water infiltration, and tendon deterioration in the anchorage systems and other difficult areas to inspect such as diaphragms and deviators, cable saddles, and inside strand bundles. In order to select the most appropriate NDE method for assessing a particular condition, multiple NDE technologies shall be considered and evaluated against a set of applicable and repeatable metrics to be developed under this research and tested using mock-up specimens. Accomplishment of the project objective will require at least the following tasks: Phase I--Synthesis on condition assessment of post-tensioning and stay cable systems using NDE methods - Task 1. Review relevant literature, ongoing research findings, and current practices to assess the condition of post-tensioning and stay cable systems using state-of-the-art bridge inspection technologies. This information shall be assembled from published and unpublished reports; contacts with academia, transportation agencies, industry organizations, bridge owners and contractors; and other domestic and foreign sources. Task 2. Assess the application of technologies from other fields such as offshore structures and nuclear power plants that could be used for post-tensioning and stay cable systems condition assessments. Task 3. Summarize and outline the condition assessment technologies including the advantages and disadvantages of each NDE method. Identify gaps in existing inspection technologies and propose approaches to fill these gaps. Task 4. Prepare Interim Report No. 1 that documents Tasks 1 through 3 and provides an updated work plan for the remainder of the project no later than 4 months after contract award. The updated plan must describe the process and rationale for the work proposed for Phases II and III. Phase II-- Metrics for NDE method evaluations and NDE testing procedures - Task 5. Develop metrics to evaluate NDE technologies for each condition assessment of post-tensioning and stay cable systems. Task 6. Develop testing procedures for each proposed NDE method including the design of mock-up laboratory test specimens to be used in Phase III for each condition assessment of post-tensioning and stay cable systems. The mock-up designs should replicate in-service condition and consider the scale effect, and typical tendon types and configurations on the accuracy of the results. Task 7. Prepare a detailed outline of the recommended inspection guidelines that includes each condition assessment with pertinent NDE methods, evaluation metrics, mock-up test specimens, and proposed testing procedures. Task 8. Prepare Interim Report No. 2 that documents Tasks 5 through 7 and provides an updated work plan for Phase III no later than 6 months after approval of Phase I. Phase III--Inspection guide development and final products - Task 9. Conduct the laboratory testing according to the proposed testing procedures approved in Phase II. Task 10. Prepare inspection guidelines for the various types of condition assessments of in-service post-tensioning and stay cable systems. The guidelines will be presented in a format suitable for consideration by the American Association of State Highway and Transportation Officials (AASHTO) Highway Subcommittees on Bridges and Structures and Maintenance. Task 11. Prepare a preliminary draft final report that documents the entire research effort. After consideration of panel comments, submit the revised final report. The Task 10 guidelines should be included as a stand-alone appendix.

Language

  • English

Project

  • Status: Completed
  • Funding: $650000.00
  • Contract Numbers:

    Project 14-28

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Dekelbab, Waseem

  • Performing Organizations:

    Texas Transportation Institute

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Hurlebaus, Stefan

  • Start Date: 20121129
  • Expected Completion Date: 0
  • Actual Completion Date: 20150528
  • Source Data: RiP Project 38246

Subject/Index Terms

Filing Info

  • Accession Number: 01547385
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 14-28
  • Files: TRB, RiP
  • Created Date: Dec 9 2014 1:00AM