Welcome to ROSA P | Use of electrochemical chloride extraction and associated repairs to extend the beneficial life of reinforced concrete substructures. - 30841 | US Transportation Collection
Stacks Logo
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.
 
 
Help
Clear All Simple Search
Advanced Search
Use of electrochemical chloride extraction and associated repairs to extend the beneficial life of reinforced concrete substructures.
  • Published Date:
    2016-05-01
  • Language:
    English
Filetype[PDF-7.73 MB]


This document cannot be previewed automatically as it exceeds 5 MB
Please click the thumbnail image to view the document.
Use of electrochemical chloride extraction and associated repairs to extend the beneficial life of reinforced concrete substructures.
Details:
  • Publication/ Report Number:
    FHWA/VTRC 16-R16
  • Resource Type:
  • Geographical Coverage:
  • Format:
  • Abstract:
    One of the biggest causes of bridge deterioration is corrosion of the reinforcement in concrete structures. Therefore, repair

    techniques that mitigate corrosion and extend the service life of reinforced concrete are of great value to the Virginia Department

    of Transportation (VDOT). One such technique is electrochemical chloride extraction (ECE), which is a temporary in situ

    restoration method for removing chlorides from reinforced concrete structures that are deteriorating because of corrosion.

    The results of this study are based on historical and current data gathered during the evaluation of substructure elements in

    Virginia, i.e., the 5th Street Extended Bridge in Albemarle County and two I-95 bridges in Richmond, and on information from

    the literature about the earliest bridge substructure treated with ECE, i.e., the Burlington Bay Skyway in Burlington, Ontario,

    Canada,.

    Early ECE work on the Burlington Bay Skyway showed favorable results upon reassessment of the treated area after 9 years.

    With regard to the ECE-treated structures in Virginia, the study determined that if additional service life beyond that provided by

    ECE alone is desired, the structure must be protected against the reintroduction of chlorides to the repaired elements. Further, the

    use of ECE techniques should be accompanied by repair or removal of overhead deck expansion joints that exposed the concrete

    elements to salt-laden water and application of a waterproofing sealer such as silane, methacrylate, or epoxy to the substructure

    elements. ECE provided an additional 15 to 20 years of service life when a post-treatment silane sealer was also applied.

    The study also found that in the project specification, the criterion used for determining when to terminate ECE is often the

    amount of charge passed but difficulties in the field might result in unforeseen construction delays as a result of the attempt to

    meet this criterion. Therefore, contracts should specify that chloride concentration at the level of the reinforcing bar can be used

    as an alternative criterion for determining when the ECE is complete, particularly when treatment times become excessive.

    Specifications should also require that all ECE connections to the steel be completely removed or embedded after completion of

    the treatment and a highly resistive cementitious repair material should be used to patch any holes.

    Another valuable outcome from this study was the discussion on how combining electrochemical techniques, such as cathodic

    protection and ECE, could theoretically provide additional life beyond that provided by the use of one of these techniques alone.

    This study gathered baseline data to assess this option. The two I-95 bridges in Richmond, one over Hermitage Road and the

    other over Overbrook Road, should allow a comparison of how much galvanic anode cathodic protection can extend service life

    beyond that of ECE treatment alone.

    The study recommends that VDOT’s Structure and Bridge Division incorporate the lessons learned from assessing the

    restoration of the substructures of the 5th Street Extended Bridge and the two I-95 bridges. In addition, the Virginia

    Transportation Research Council should continue to monitor the I-95 bridges to determine the value of combining different

    electrochemical mitigation techniques to extend service life.

  • Funding:
  • Main Document Checksum:
  • Supporting Files:
    No Additional Files
No Related Documents.
You May Also Like:
Submit Feedback >