HAMPDEN - On Friday, May 21st, the Maine Department of Transportation joined U.S. Senator Susan Collins; University of Maine researchers; Advanced Infrastructure Technologies (AIT) Bridges team members; industry partners; and state, local, and federal officials to celebrate the opening of the new Grist Mill Bridge in Hampden.
The 75-foot-long, single-span bridge carries Routes 1A and 9 over Souadabscook Stream. The old structure consisted of three bridges built on top of one other. The most recent of those bridges dated to approximately 1950.
The new bridge is the first in the nation to use fiber-reinforced polymer (FRP) tub girders called GBeams. The patented GBeam technology is the result of research and development at the UMaine Composites Center, which licensed the technology to AIT Bridges, the university's commercialization partner for this technology. Funding for the research was provided by the U.S. Army Corps of Engineers Engineer Research and Development Center (ERDC) and the U.S. Department of Transportation through the Transportation Infrastructure Durability Center led by UMaine. The GBeams used in the Grist Mill Bridge project were manufactured at the AIT Bridges facility in Brewer.
"Grist Mill Bridge is the result of a great partnership between the University of Maine, AIT Bridges, and federal and state transportation departments," said Senator Collins. "Working together, they have reached a milestone in advanced construction technology, while boosting economic growth and job creation here in Maine. As ranking member of the Transportation Appropriations Subcommittee, my priority is to improve our nation's infrastructure and ensure Maine's needs are addressed."
The GBeam technology is corrosion-resistant and designed to last more than 100 years with little to no maintenance. The composite girders are lightweight: they weigh as little as one-quarter the weight of steel girders. The GBeam technology is a promising, sustainable, low-cost alternative that is easy to install.
"The big draw here is durability," said MaineDOT Commissioner Bruce Van Note. "Time will not take quite the same toll on the composite tub girders in this bridge. We expect this structure will need less maintenance over time and may last 25 years longer than its conventional counterparts. At MaineDOT, we believe sponsoring this new technology now will yield long-term benefits for Maine taxpayers and travelers."
The University of Maine field-load-tested the Grist Mill Bridge with support from the MaineDOT and U.S. DOT. The bridge was successfully tested with more than 260,000 pounds of load carried by four MaineDOT trucks. The two-day testing provided baseline performance data allowing UMaine researchers and AIT Bridges to refine the GBeam design.
"This is an example of a University of Maine research-to-commercialization initiative helping to address infrastructure needs statewide and nationwide while providing hands-on learning experiences for students and jobs in Maine," UMaine President Dr. Joan Ferrini-Mundy said. "UMaine students at the Composites Center are members of tomorrow's workforce, providing their own contributions today and leadership going forward. All of this is made possible with state investments in research and development, and vision and support of the Maine Congressional Delegation and legislators."
Dr. Habib Dagher, executive director of the UMaine Composites Center said, "The R&D we are conducting at the Composites Center is delivering practical solutions to address our deteriorating infrastructure that is more durable, sustainable and cost-effective, and creating jobs right here in Maine. Thank you, Senator Collins, Commissioner Van Note, our partners at the U.S. Army Corps of Engineers, for your leadership in enabling this remarkable milestone. The Grist Mill Bridge showcases the real-world applications resulting from cutting-edge research in composite materials."
The many benefits of the composite GBeam technology are attracting interest from Departments of Transportation across the U.S. The technology is already planned to be used in bridge replacement projects in Washington, California, Florida, and Rhode Island.
"AIT Bridges is honored to commemorate this inaugural GBeam bridge alongside the University of Maine, Senator Susan Collins, and MaineDOT," said Brit Svoboda, chair and CEO of AIT. "The Grist Mill Bridge once again proves the viability and obligation to build more sustainable FRP composite bridges in Maine and the country. Adding the Composite GBeam Bridge System to the already successful GArch Composite Bridge System means AIT Bridges can provide a more comprehensive solution to the bridge industry."
The Grist Mill Bridge replacement was part of a project that included reconstruction and paving work on a nearly-two-mile-long stretch of Route 1A. The total cost for the project is approximately $9 million. The contractor on this project was T. Buck Construction out of Turner.
MaineDOT is already planning to use this GBeam technology again on the new Twin Bridge in Hampden. Construction of that project has already begun, and work is scheduled to be complete by June 2022.