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Senator Collins Attends Ribbon Cutting at Grist Mill Bridge in Hampden

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Hampden, ME - Today, U.S. Senator Susan Collins attended the ribbon cutting for the Grist Mill Bridge in Hampden and joined University of Maine engineers, Maine DOT officials, Advanced Infrastructure Technologies (AIT) Bridges and industry partners to celebrate the groundbreaking research behind the cutting-edge design.


The 75-foot single-span Grist Mill Bridge, which carries traffic over the Souadabscook Stream, is leading the country towards a sustainable, low-cost transportation system of the future.  It is the first in the nation to use fiber reinforced polymer (FRP) girders, called GBeams, designed and patented at the University of Maine Advanced Structures and Composites Center and licensed to AIT Bridges.


Last week, Senator Collins, the Ranking Member of the Transportation Appropriations Subcommittee, co-led a hearing on ways to increase the resiliency of our transportation infrastructure.  She invited UMaine’s Dr. Habib Dagher to testify about his cutting-edge research, including the G-Beam technology being used to reconstruct the Grist Mill Bridge.


“Grist Mill Bridge is the result of a great partnership between the University of Maine, AIT Bridges, and federal and state transportation departments.  Working together, they have reached a milestone in advanced construction technology, while boosting economic growth and job creation here in Maine,” said Senator Collins.  “As Ranking Member of the Transportation Appropriations Subcommittee, my priority is to improve our nation’s infrastructure and ensure Maine’s needs are addressed.  I was honored to invite Dr. Dagher to Washington last week to testify about how the Grist Mill Bridge design and other impressive examples of UMaine’s research and development can be utilized in infrastructure projects across the country.”


“This technology packs small, packs light, and can be deployed very quickly and easily,” said Dr. Habib Dagher, executive director, University of Maine Advanced Structures and Composites Center.  “The girders are designed to be stackable, which reduces transportation costs and lowers their carbon footprint.  One flatbed truck can transport enough girders for four 70-ft long bridges, that is four Grist Mill bridges on one stretch-bed.  The R&D we are conducting at the Composites Center is delivering practical solutions to address our deteriorating infrastructure that is more durable, sustainable, 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 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.”


“AIT Bridges is honored to commemorate this inaugural GBeam bridge alongside The University of Maine, Senator Susan Collins, and MaineDOT,” says Brit Svoboda, Chairman and CEO of AIT Composites.  “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 patented G-Beam technology results from research and development at the UMaine Composites Center, which licensed it 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 ERDC and the Federal DOT 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 located in Brewer.


The GBeam technology is corrosion resistant and designed to last over 100 years with little to no maintenance.  The composite girders are lightweight, weighing 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.


Because they are lightweight, common rental cranes could be used during installation.


The practicability of the GBeam technology is further enhanced by the bolt system that connects the girders to the concrete deck, allowing the deck to be quickly removed for future replacement after 50 years without jackhammers.  The girders are designed for 100-year life with little maintenance.  The ease of deck replacement after about 50 years will lower construction costs and minimize disruptive road closures.


The University of Maine field-load-tested the Grist Mill Bridge with support from the Maine DOT and Federal DOT. The bridge was successfully tested with more than 260,000 pounds of load carried by four Maine DOT trucks. The two-day testing provided baseline performance data allowing UMaine researchers and AIT Bridges to refine the GBeam design.


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.  In Maine, the technology will also be used in the Hampden Twin Bridge project that will begin construction in 2022. Girders for these bridges will be fabricated in Brewer by AIT and shipped from Maine to destinations across the country.