A new bridge project began last month in Fairfield, Vermont that uses new technology to reduce construction time, save money, and help the Vermont Transportation Agency start more projects that are backlogged across the state. The ‘Bridge in a Backpack’ technology is part of Vermont’s accelerated bridge program that incorporates quick building design and other innovations to speed up the bridge building process. The system was developed at the University of Maine Advanced Structures and Composites Center in response to Tropical Storm Irene that hit the region several years ago. Vermont engineers found themselves unable to quickly repair or replace the many bridges that were damaged by the storm. Rather than taking months to complete a bridge using conventional methods, the ‘Bridge in a Backpack’ technology allows a new bridge to be finished in weeks.
Workers began placing a series of hollow tubes over Wazner Brook in Fairfield, Vermont last week. After laying down the tubes, construction crews filled them with concrete and began laying a deck across the top. The tubes are made from a composite material that keeps out road salt and moisture to avoid any corrosion. The material is also much lighter than steel beams before it is filled with concrete so it reduces the need to transport heavy loads to the site. The Vermont Agency of Transportation expects the bridge to last for 100 years once completed and require very little maintenance.
The Bridge in a Backpack technology was first used in 2008 and that bridge has not required any maintenance. Since then, similar designs have been used in Maine, New Hampshire, Michigan, and Trinidad. This technology along with other innovations and policies has helped make Vermont’s accelerated bridge program successful. Several years ago over 30 percent of the state’s bridges were structurally deficient. That number has been reduced to 8 percent and many feel that the advanced bridge program played a key role in improving bridge quality across the state.