POCATELLO — Researchers from Idaho State University are leading an expert team that is studying how the Idaho Transportation Department can better protect its bridge decks, which are the surface that pedestrians and vehicles move across.

The study is expected to last three years, according to a news release from ISU. The team also includes researchers from East Texas A&M University, Boise State University, Kennesaw State University and the bridge engineering firm Marx & Arndt Engineering LLC.

Bridges in Idaho go through freeze-and-thaw cycles every winter that lead to cracked concrete and deicing salts that corrode steel. Water and other chemicals also eat away the reinforcement holding the bridge together.

"Bridge decks are among the most wear-prone parts of our infrastructure," Mustafa Mashal, principal investigator for the project from East Texas, said in the news release. "They bear the full weight of traffic while being constantly exposed to the elements such as moisture, chemicals and temperature extremes that work together to break down the deck materials over time."

Darren LaMay, technical engineer 2 at ITD's Bridge Design Office, said in the news release that the rehabilitation of concrete bridge decks takes up a significant portion of ITD's bridge preservation budget.

"Every time ITD needs to perform a bridge deck rehabilitation project, the traveling public is impacted greatly since the deck is literally the component where the rubber meets the road for all bridge travelers," LaMay said in the news release. "As a result, making the best decisions during design by gaining a better understanding of bridge deck performance through research will benefit everybody."

ITD currently uses a specialized concrete coating called polyester polymer concrete to protect its bridge decks. Researchers will compare this coating with other materials to see how they hold up to Idaho conditions. The research will take place at ISU's Structural Laboratory, which is the largest facility of its kind in Idaho.

"We're not testing materials in a vacuum," lead researcher Jared Cantrell said in the news release. "Every test is designed to reflect what these materials actually face on Idaho roads, including the temperature swings, repeated freezing and thawing, salt exposure and simulated traffic wear."

Visits to existing ITD bridges will give the researchers a chance to see how current overlays age under real-world conditions.

"We want ITD engineers to be able to look at a bridge, consider the local conditions and have a clear, confident answer for which approach makes the most sense," Tadesse Wakjira, assistant professor at Kennesaw State University, said in the news release.

Funding for this project comes from a $183,139 grant through ITD's Research Program. It is built on a longstanding partnership between ISU and ITD. Researchers at ISU have completed several bridge-related projects for ITD. Their findings have been incorporated into Idaho's infrastructure, such as the precast pier system that was implemented at the Fort Hall Interchange Bridge over I-15.