Bridges

Bridge made of steel

Steel Bridges Offer Durable, Cost-Effective Solutions

We need them to transport billions of tons in freight and millions of travelers  each year from coast to coast, yet the Federal Highway Administration (FHWA) estimates that over 25 percent of America’s more than 600,000 bridges are either structurally deficient or functionally obsolete. The ASCE Infrastructure Report Card 2017 graded the nation’s bridges with a “C+” and noted that one in 11 (9.1%) were designated structurally deficient in 2016, and more than one in eight (13.6%) were designated as functionally obsolete in 2016.

Repairing and/or replacing these bridges with modern steel bridge designs must be a national priority. Steel bridges offer owners practical design and accelerated bridge construction solutions that are durable, cost-effective and offer ease of maintenance and construction.

New technology like Press Brake Tub Girders (PBTG) provide an economical alternative for simple and short span bridge construction. These innovative yet simple models provide a long service life, require little maintenance, and are designed for accelerated project delivery.

The structural advantages of using steel include its high strength, durability, and light weight, which mean lighter foundations and lower erection costs. Steel’s strength also makes it highly resistant to extreme natural disasters, such as earthquakes. The 1994 Northridge, California earthquake destroyed the surrounding transportation infrastructure. However, 96 percent of the existing steel bridges were completely undamaged, even though they were designed using 1940s technology.

AISI is actively involved in developing innovative steel solutions to meet the nation’s bridge infrastructure challenges:

High-Performance Steels (HPS): Developed by member companies of AISI with the Office of Naval Research and the Federal Highway Administration, these steels have superior toughness and can be welded with little or no preheat. HPS steels can save up to 18 percent of a bridge project’s cost.

Weathering Steel: Recognized for its performance, economic and environmental benefits, the use of uncoated weathering steel typically provides initial cost savings of 10 percent or more, and life cycle cost savings of at least 30 percent over the life of the structure.

Short Span Steel Bridges: Most of the United States’ substandard bridges are short span structures. Falling within the 20’ to 140’ span range, short span bridges make up the largest sector in the national bridge inventory. Virtually every one of them could be replaced with durable, sustainable, economical steel. As a founding organization of the Short Span Steel Bridge Alliance, AISI is involved in the development of new technologies like press-brake-formed steel tub girder bridges, which save significant construction costs and time and provide an expected life service of more than 100 years. The web-based design tool eSPAN140 provides individualized project designs at no cost to bridge designers, with optimized steel solutions provided in minutes.

Research: AISI facilitates meetings to bring together the nation’s top experts to identify current and future design challenges, develop new technologies and advance best practices. AISI has three research committees — the Steel Bridge Task Force, Corrosion Advisory Group and Welding Advisory Group — that have made significant contributions over the years to advance steel bridge design and construction.

Design Aids: A useful library of design aids related to steel bridge design and construction.

Research Reports: Technical information related to steel bridge design and construction.

Awards: AISI recognizes significant contributions to steel bridge design and construction with the Robert J. Dexter Memorial Award Lecture and the Richard S. Fountain Award. The Robert J. Dexter Memorial Award Lecture recognizes new talent in the structural engineering community, and the Richard Fountain Award recognizes leadership in steel bridge research and outstanding efforts to advance AASHTO specifications.

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