Final Scope

In 2003, the National Association of Corrosion Engineers (NACE) estimated that the cost of corrosion to bridge infrastructure in the United States was approximately $8.3 billion annually. In a follow-up study in 2013, the global cost of corrosion was estimated to be US$2.5 trillion annually, which was equivalent to 3.4% of the global GDP. Ten years on, those costs are likely to have substantially increased. Corrosion deterioration of highway bridges significantly impacts the overall service life of the structures, which can lead to costly repairs for the bridge owners and high indirect costs and disruption for the users. The application of cathodic protection (CP) has demonstrated an ability to control corrosion and extend the service life of highway structures. Many state DOTs use CP in various applications, depending on their regional environments and experience with the technology, to preserve and extend the service life of structures.

Several different CP products, solutions, and applications are available for mitigation of reinforced concrete or structural steel corrosion, and new technologies are being developed each year. Highway structures throughout the United States are exposed to a wide variety of environments (e.g., a marine structure in coastal Florida, a bridge in Minnesota exposed to deicing chemicals) for which corrosion challenges vary. Therefore, DOTs use an array of CP solutions to maintain structures across a range of environments. The methods by which DOTs monitor these systems also varies.

The objective of the synthesis is to document (1) the different types of CP methods and their applications to mitigate corrosion in highway structures and (2) how DOTs implement and manage various CP systems.

Information to be gathered includes (but is not limited to):

• Which types of highway structures or components are protected by CP;
• Existence of CP standards and specifications;
• Existing CP methods and systems (e.g., passive galvanic systems, active impressed current systems, and other methods) used by the DOTs for highway structure applications;
• How DOTs are selecting and implementing CP technologies for highway structures;
• Challenges to successful implementation and installation of different CP technologies;
• CP systems management practices, including monitoring, data collection, analysis, interpretation, assessment and adjustment  or modification;
• CP long-term operation and planned maintenance practices; and
• Methods for quantifying and documenting CP performance.

Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs with significant experience in deploying CP, including example case studies. Information gaps and suggestions for research to address those gaps will be identified.

Information Sources (Partial)

A detailed literature search has not been undertaken, but relevant information is expected to be available through

• Association for Materials Protection and Performance (AMPP) (formerly NACE) committees and publications
• AASHTO TSP-2 Bridge Preservation Partnerships website
• Individual State DOT websites (design and operation policies, research, and development reports, etc.)

TRB Staff
Dr. Zhiye Li
Email: zli@nas.edu

Meeting Dates
First Panel Meeting: 02/11/2025 (In-person, in Washington, DC)
Teleconference with Consultant: 03/24/2025  (Virtual, via Zoom)
Second Panel Meeting: 11/18/2025 (In-person, in Washington, DC)

Panel Members
Kyle Henry Busch, Wisconsin Department of Transportation
Doug Cantrell, North Carolina Department of Transportation
Hongfen Li, South Carolina Department of Transportation
Thomas Ranck, Michigan Department of Transportation
Chengcheng Tao, Purdue University
Anshul Wankhede, California Department of Transportation
Eric D. Yermack, New Jersey Department of Transportation
Shri "Shrinivas" Bhide, Federal Highway Administration (FHWA)