The National Academies

NCHRP Synthesis 20-05/Topic 55-01 [Active (Synthesis)]

State DOT Policies and Practices on the Use of Corrosion Resistant Reinforcing Bars
[ NCHRP 20-05 (Synthesis of Information Related to Highway Practices) ]

  Project Data
Funds: $55,000
Authorization to Begin Work: 4/27/2023 -- estimated
Staff Responsibility: Sandra Q. Larson
Research Agency: University of Delaware
Principal Investigator: Jennifer McConnell
Fiscal Year: 2024

Final Scope

Throughout the United States there is widespread use of deicing chemicals during the winter months to prevent the buildup of snow and ice on roadway surfaces and bridge deck slabs. While deployment of deicing chemicals is an effective strategy for maintaining safe, reliable, ice-free roadway surfaces, this practice can lead to chloride contamination in bridge components. Bridges can also be subject to natural sources of chlorides, particularly in coastal and marine environments where components may be exposed to seawater, spray, and mist. The affected bridge components include foundation, substructure, and superstructure elements. Chlorides migrate through the concrete cover and cracks and become concentrated at critical levels. As a result, corrosion of the reinforcement is initiated. This results in concrete spalls, costly repairs, and eventually replacement of bridge components.

To meet this challenge, we can design and construct bridges using corrosion resistant reinforcing bars, which will delay the onset of corrosion and the subsequent deterioration of bridge decks and other structural elements. Material producers have been meeting this challenge by developing bars with improved corrosion resistance by providing bars with different coatings, steel compositions, and alternate materials.

The objective of this synthesis is to document policies and practices used by state departments of transportation (DOTs) related to the use of corrosion resistant reinforcing bars.

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

  • Types of reinforcing bars used, including variations and grades. Examples might include, but are not limited to:
    • Black steel; 
    • Epoxy-coated steels;
    • Galvanized steels;
    • Steels with multi-layer coatings (e.g., galvanized plua epoxy);
    • Alloy steels, such as low-carbon chromium steel;
    • Various grades of austenitic, martensitic or duplex stainless steels;
    • Stainless steel cladded steels; and
    • Fiber-reinforced polymer with various incorporated fiber materials, such as glass, carbon, basalt, etc.  
  • Bridge components that utilize different types of corrosion resistant reinforcing bars;
  • Materials typically specified;
  • Concrete cover provided on bridge components in conjunction with alternate materials;
  • Types, strengths, and permeability of concrete specified for various reinforcing bars;
  • Timeframe DOTs have used for different corrosion resistant reinforcing bars, including how those bars performed, and how the agencies measured the performance (i.e., have agencies seen better performance from their bridge decks);
  • Conditions DOTs specified when using various corrosion resistant reinforcing bars, (e.g. material type, exposure, environmental conditions, bridge component);
  • Information on life-cycle cost analysis used to justify the selection of an alternate corrosion resistant reinforcement, including any parameters and assumptions;
  • What decision-making tools are used in the selection of corrosion resistant reinforcement;
  • Material availability of different reinforcement types;
  • Efforts to increase the use of corrosion resistant reinforcement;
  • Information on any benefits or challenges identified through construction implementation of these materials (e.g. bar field modification, contractor response to alternate materials);
  • Methods used for quality control certification of corrosion resistant bars;
  • Information on any challenges with dissimilar metals and materials;
  • Modifications to standard design practices utilized when specifying different corrosion resistant reinforcing bars (e.g., optimization or adjustments to account for differences in yield or ultimate tensile strengths, modulus of elasticity, etc.); and
  • Written policies that govern the application of the various corrosion resistant reinforcing bar types.

Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.

Information Sources (Partial):

TRB Staff (consultant)
Sandra Larson

Phone: 515-971-6329
Email: slarson@nas.edu

Meeting Dates
First Panel: September 19, 2023, Washington, DC
Teleconference with Consultant: October 25, 2023, 1-2 pm Eastern
Second Panel: June 6, 2024, Washington, DC, Keck Center

Panel Members

Mr. Tekeste Amare, Maryland Transportation Authority

Dr. Rodrigo Antunes, Florida Department of Transportation

Mr. James Corney, Utah Department of Transportation

Ms. Arielle Ehrlich, Minnesota Department of Transportation

Ms. Katherine Hoensheid, Michigan Department of Transportation

Mr. Eric D. Yermack, New Jersey Department of Transportation

Mr. Raj Ailaney, Federal Highway Administration (FHWA)

Dr. Nelson H. Gibson, Transportation Research Board




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