$2 million grant funds UNL research to help bridges last longer

University of Nebraska-Lincoln engineering researchers aim to find ways to make the nation's bridges last longer and to design new ones that last a century or longer with funding from a new $2 million grant.

With support from this four-year grant from the National Academy of Sciences' Transportation Research Board, UNL bridge engineering experts will identify technologies and designs to renovate existing bridges and develop guidelines for designing longer-lasting new bridges. It's part of a $150 million congressional initiative to improve the safety and performance of U.S. highways and bridges.

This research will focus on bridges with spans of 300 feet or less, which include 95 percent of the nation's bridges.

Aging bridges are a nationwide concern. The Interstate 35 bridge collapse in Minnesota in August raised public awareness of bridge conditions nationwide. Roughly 30 percent of U.S. bridges are structurally or functionally deficient, said Atorod Azizinamini, the civil engineering professor who will lead this research. Azizinamini, an internationally known bridge researcher, is director of UNL's National Bridge Research Organization, a division of the UNL-based Nebraska Transportation Center.

"The reality is, bridge maintenance and construction is a drain on governments already strapped for cash," he said.

While replacing all aging or deficient bridges would be ideal, the cost is prohibitive. Finding ways to extend the useful life of rehabilitated, replacement and new bridges using modern materials and construction techniques and technologies is more practical, Azizinamini said.

A highway bridge's typical lifespan is 75 years. This research aims to extend that service life to 100 years or more, Azizinamini said. Increasing the service life could reduce costs significantly. Researchers also will study improved methods for predicting a bridge's lifespan so governments can better plan for maintenance needs.

UNL civil engineering professors Maher Tadros and Andrzej Nowak, also leading bridge engineering experts, will collaborate with Azizinamini on this multidisciplinary project along with international consultants.

"This research has the potential to change U.S. bridge design from coast to coast," said UNL Chancellor Harvey Perlman. "This grant is evidence of our faculty's recognized expertise and reputation as leaders in bridge and transportation research."

Azizinamini said the team will study whether the new generation of high-performance steel and concrete materials can be used for individual bridge components. Corrosion, especially in bridge joints and bearings, is a leading cause of deterioration. These new materials are more resistant to corrosion caused by water, which occurs naturally over time, and to chemical de-icing agents.

The team also will identify construction strategies that could help engineers renovate an existing bridge without causing major traffic disruptions. Its recommendations will be included in construction guidebooks published by the American Association of State Highway and Transportation Officials.

"This research will have far-reaching benefits for both public safety and the economy," said Prem Paul, UNL vice chancellor for research and economic development. "Our bridge experts will be addressing this major concern about bridge infrastructure, which is important for Nebraska and the nation."

The project also has an educational component. Graduate students in civil engineering who assist with the research will have the opportunity to work with some of the world's top bridge designers and researchers, Azizinamini said. The UNL team will also work with international consultants and researchers from leading design and construction companies.

"The team that we have assembled has brought the best around the world to collectively solve a very challenging and important societal problem," Azizinamini said. "Through this project, we also hope to establish a new blueprint for conducting collaborative work."

Azizinamini said UNL's longstanding collaboration with the Nebraska Department of Roads helped position the university to win this project. This strong partnership has led to innovative road and bridge designs statewide.

The research will be conducted through the National Bridge Research Organization at UNL, which brings together UNL faculty, industry leaders and government agencies to research and develop bridge design technology. NaBRO is one of numerous transportation-related research programs collaborating with the Nebraska Transportation Center at UNL. The university established the center in 2006 to integrate and strengthen a wide range of transportation and safety programs on all four campuses under one umbrella organization.