Aging bridges are causing public safety and financial worries nationwide.

UNL bridge engineers are working to ease these concerns by developing better ways to renovate existing bridges and to build new ones that last a century or longer. A $2 million grant from the National Academy of Sciences' Transportation Research Board is funding this four-year project that could change bridge design coast to coast.

""One goal is to extend the typical lifespan of highway bridges from 75 years to 100 years or more,"" said UNL civil engineer Atorod Azizinamini. Increasing service life could significantly reduce costs.

Roughly 30 percent of the nation's bridges are structurally or functionally deficient. While replacing them would be ideal, that is far too costly for cash-strapped governments.

""Finding ways to extend the useful life of bridges using modern materials and construction techniques and technologies is more practical,"" said Azizinamini, who heads UNL's National Bridge Research Organization.

Azizinamini and UNL civil engineers Maher Tadros and Andrzej Nowak, also leading bridge experts, are collaborating with international bridge designers to study whether high-performance steel and concrete materials can be used for individual bridge components. These new-generation materials, some of which were developed at UNL, are more resistant to corrosion. Researchers also will identify new construction strategies to renovate bridges without causing major traffic disruptions and examine new methods for predicting a bridge's lifespan so governments can better plan for maintenance needs.

This research has the potential to set new standards for renovating and designing bridges with spans of 300 feet or less, the size of 95 percent of the nation's bridges. The team's findings will be included in construction guidebooks published by the American Association of State Highway and Transportation Officials.

""We are providing the design profession with the knowledge to do a better job in the future so bridges last longer and can be fixed with minimal cost,"" Azizinamini said.

Since 2006, UNL researchers have led an initiative to modernize bridges in the Republic of Korea, which is expected to invest $100 million to update its transportation infrastructure.

A consortium of industry, government and universities will develop a plan and conduct research for the Korean project. The National Bridge Research Organization, a division of UNL's Department of Civil Engineering, will be the liaison between U.S. and Korean researchers. Atorod Azizinamini, director of NaBRO and professor of civil engineering, will lead the project.

""The Republic of Korea sees UNL as the authority on bridge engineering, and as a result, they want to work with us,"" Azizinamini said."