Post-Tensioned Concrete Bridges
What's going on inside that bridge? You need x-ray vision to find out.
Myth: Post-tensioned (PT) concrete bridges are relatively maintenance-free.
Myth: PT concrete bridges have a 100-year service life.
Facts: Existing bridges and research have demonstrated that PT bridges require difficult, expensive monitoring and maintenance and can have service lives of as little as 30 years.
Many of these problems stem from corrosion, which can be difficult to detect in tendons that are encased in concrete. These bridges can have hidden corrosion and other internal damage that is not easily visible to a bridge inspector.
You need the facts. AISC has reviewed the existing literature to compile a summary entitled "Performance and Maintenance of Post-Tensioned Concrete Bridges" that summarizes industry concerns and research related to construction and service life, inspection, repairability, maintenance, long-term serviceability, and other uncertainties.
The combination of corrosion vulnerabilities, inspection difficulties that result in unreliable inspection data, and potential for deterioration that remains hidden increase the long-term maintenance needs and costs of PT concrete bridges.
Steel: The clear choice for easy bridge maintenance
Steel bridges have a proud history. They have connected communities over the course of decades or even centuries.
Steel bridges endure. Century-old icons such as the Brooklyn Bridge, the Golden Gate Bridge, and St. Louis's Eads Bridge have stood the test of time in harsh environmental conditions--and the materials, coatings, and fabrication techniques have come a long way since the erection of those landmarks.
With a steel bridge, what you see is what you get. Inspecting a steel bridge is generally cheaper and easier than inspecting a PT concrete bridge.
Steel bridges also have a significant advantage should that easier, more economical inspection find a problem. Individual steel bridge components can be replaced without permanently removing the bridge from service--a PT concrete bridge with the same issue may require complete replacement, with all the associated costs and downtime of a major construction project.
When replacement might be on the table for a whole PT concrete bridge, a steel bridge can be reinforced or individual components can be replaced without permanently removing the bridge from service.
Get the facts. Make the smarter choice. Choose steel.
Learn more about the benefits of structural steel bridges here.