Automated Chain Drag Testing

The chain drag test is commonly used in current practice for bridge deck evaluation due to its low cost and ease of use. It detects delaminations in bridge decks by dragging a chain over the concrete surface and listening to the dull or hollow sound. However, this method is subjective and lack of consistency. Interpretation of test results highly depends on the experience of inspectors. Ambient noise caused by traffic also affects the test speed and accuracy of results. Since the test results are directly analyzed in the field and defects are marked on site, there is no data saved for further analysis.This research project aims to address the above mentioned drawbacks by developing an automated chain drag test that integrates sensing, data processing, defect identification algorithms and automated positioning in one testing system. Acoustic signals generated by the dragging chain on concrete will be sensed by acoustic sensors (microphones) and further analyzed and recorded by a computer. Including a positioning system will enable real time visualization of tested areas and allow engineers to make quick assessment of bridge deck conditions. Data from the test can be saved for further analysis and used for comparison with past and future tests. The proposed automated chain drag testing system will significantly improve the test consistency and speed for bridge deck evaluation, and therefore reduce the traffic disruption and bridge closure. The goal of the proposed research project is to develop an automated chain drag testing system for rapid evaluation of concrete bridge decks. Specific objectives include: (1) Develop an acoustic inspection device for bridge deck evaluation based on the chain drag test. A microphone is used to collect sound signals generated from the chain drag test. Replacing human ears with a microphone will improve consistency of the test result interpretation, and reduce effects of ambient noises. (2) Build a system with multiple sensor channels that is capable to cover the half or full-width lane. (3) Integrate global positioning system (GPS) or laser positioning system to automatically track test positions and save time for documentation. (4) Develop signal processing and defect identification algorithms, and present the test results and position information in a map view.


    • English


    • Status: Active
    • Funding: $96871.00
    • Contract Numbers:

      SPR-P1(16) M041

    • Sponsor Organizations:

      Federal Highway Administration

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

      Nebraska Department of Roads

      1500 Highway 2
      Lincoln, NE  United States  68502
    • Performing Organizations:

      University of Nebraska, Omaha

      1110 South 67th Street, PKI 107C
      Omaha, NE  United States  68182-0178
    • Principal Investigators:

      Zhu, Jinying

    • Start Date: 20150701
    • Expected Completion Date: 0
    • Actual Completion Date: 20161231
    • Source Data: RiP Project 39673

    Subject/Index Terms

    Filing Info

    • Accession Number: 01569413
    • Record Type: Research project
    • Source Agency: Nebraska Department of Roads
    • Contract Numbers: SPR-P1(16) M041
    • Files: RiP, STATEDOT
    • Created Date: Jul 11 2015 1:00AM