Steel Bridge Durability: Weathering Steel and Corrosion Protection Resources

Proper selection, design, detailing, and maintenance of corrosion protection systems are important considerations for the long-term performance and durability of steel bridges.

Uncoated weathering steel (UWS) is one option available to bridge owners and engineers. Its successful application depends on several factors, including environmental exposure, bridge location, detailing, drainage, and maintenance practices.

The Short Span Steel Bridge Alliance (SSSBA) would like to thank the National Steel Bridge Alliance (NSBA) for helping compile some of the following technical resources. These publications provide research findings, design guidance, best practices, and specifications to help bridge owners and engineers make informed decisions regarding weathering steel and other corrosion protection systems.

Corrosion Protection and Durability Resources

NSBA Corrosion Protection and Durability Resources

NSBA maintains a collection of technical resources addressing corrosion protection and durability for steel bridges.

The resource center provides information on commonly used corrosion protection systems, including painting, galvanizing, and metallizing, as well as additional technical guidance and publications.

These resources support the evaluation and selection of appropriate corrosion protection systems based on project requirements, environmental conditions, and long-term performance considerations.

Explore NSBA Corrosion Protection and Durability Resources

AGA Galvanized Design Guide

A new resource is also available from the American Galvanizers Association (AGA).

The Hot-Dip Galvanized Steel Bridge Design Guide is a comprehensive resource that offers bridge owners, engineers, and designers with practical guidance on the use of hot-dip galvanized (HDG) steel in bridge applications. It covers the full lifecycle of galvanized steel bridges – from design and detailing to fabrication, construction, inspection, maintenance, and repair – serving as a go-to reference for implementing durable, cost-effective corrosion protection systems.

View the Hot-Dip Galvanized Steel Bridge Design Guide.

Uncoated Weathering Steel – Technical Guidance and Research

NSBA Uncoated Weathering Steel Reference Guide

National Steel Bridge Alliance (NSBA) | 2022

The NSBA Uncoated Weathering Steel Reference Guide, initially published in 2022, provides designers and bridge owners with information on site and location considerations, design recommendations, structural design, detailing, and maintenance when specifying weathering steel.

Numerous studies have contributed to the best practices identified in the reference guide.

View the NSBA Uncoated Weathering Steel Reference Guide

Weathering Steel Performance Data Collection

Federal Highway Administration (FHWA)

This FHWA-sponsored research addresses the performance of uncoated weathering steel bridges through two parallel efforts:

1. A field evaluation program of bridges, accompanied by laboratory analysis of field samples, selected using a statistically driven process.
2. A statistical analysis of the performance and associated environments of all known uncoated weathering steel bridges in the United States.

As a result, researchers provided quantitative recommendations for two environments of concern, coastal environments and highway overpasses with heavy deicing agent use on the underpassing roadway.

View the FHWA Weathering Steel Performance Data Collection Report

Study of Corrosion Performance of Weathering Steel Bridges

Connecticut Department of Transportation (CTDOT) | 2021

This study reviews the current state of practice for implementing weathering steel bridges in Connecticut, followed by an evaluation of a large group of weathering steel bridges throughout the state.

The research focuses on three potential causes of corrosion:

1. Environmental Effects: Proximity to the coast, rivers, and wetlands.
2. Vehicle Effects on Overpasses: Spray from trucks and trains.
3. Detailing: Corrosion caused by bridge details, such as leaking deck joints.

Key Findings

Researchers found that virtually all structures showing significant end corrosion were more than 30 years old and had end-of-deck details that are not recommended by current guidelines. The study also found that there was not overwhelming evidence of corrosion issues associated with salt spray from roadways below. Based on these findings, the authors concluded that there was no need to curtail the use of weathering steel, provided that current recommended practices are followed.

View the Connecticut DOT Study of Corrosion Performance of Weathering Steel Bridges (PDF)

AASHTO/NSBA Steel Bridge Collaboration – Corrosion Protection Specifications

The AASHTO/NSBA Steel Bridge Collaboration Task Group 8 – Corrosion Protection focuses on the functions, operations, requirements, and activities necessary to achieve consistent quality in steel bridge coatings.

The task group is responsible for the following publications:

S8.1-2014 – Guide Specification for Application of Coating Systems

View S8.1-2014

S8.2-2017 – Specification for Application of Thermal Spray Coatings

View S8.2-2017

S8.3-2022 – Hot-Dip Galvanizing Specification

View S8.3-2022

The AASHTO/NSBA Steel Bridge Collaboration welcomes participation from individuals and organizations interested in advancing steel bridge practices.

Learn More About AASHTO/NSBA Steel Bridge Collaboration Meetings

Supporting Informed Decisions on Steel Bridge Durability

The Short Span Steel Bridge Alliance encourages bridge owners, engineers, and other transportation professionals to use these resources to better understand appropriate applications for weathering steel and other corrosion protection systems, apply current best practices, and support the long-term durability of steel bridges.

For additional information on durability, please visit the SSSBA’s dedicated resources page.