To make the repairs, the CFC used GFRP composite shells of two semi-circle shapes with a tongue-groove joint to encase the corroded steel columns. First, the team power washed the steel columns to remove rust. Next, they removed two feet of dirt and debris below the mud line to establish noncorrosive portions of steel bents and encased the composite shells there. They sealed the bottom of the shells with special epoxy concrete to block the water coming up from pressure and capillary action and pumped in self-consolidated concrete. Finally, they wrapped the outer part of shells with GFRP wraps and finished by painting the wrap.
The team finished the repairs in three weeks in March, and the rehabilitation was fully completed in May. The repairs brought the bridge back to its original design capacity at just a fourth of the price of conventional construction costs and are expected to last for the rest of the bridge’s lifetime, according to reports from the CFC.
This project proved to be unique for both the USACE and GangaRao. Until now, the USACE had never used such composite materials to repair aging civil works infrastructure. GangaRao, also a professor of civil and environmental engineering at WVU, says he has conducted bridge beam rehab and viaduct rehab projects, but never a bridge pile repair.
The new ventures paid off; in June, the USACE announced that the team received the 2014 Engineering Excellence Award for the Great Lakes and Ohio River Division. The award recognizes excellence in sustainability, design, construction and innovation throughout the division’s area of operations, which includes 17 states.
“It really was a group effort among the engineers and tradesmen throughout USACE, professors and graduate researchers with West Virginia University and the grant-making agencies that made this innovation possible,” says John Clarkson, a member of the project team from USACE’s Huntington District. “It pays to partner.”