The city of Hampden, Maine DOT and Innovative Infrastructure Systems (AIT) recently celebrated the installation of an progressive bridge and are awaiting the completion of the second bridge of its variety in the coming months.
The metropolis of Hampden, Maine DOT and Advanced Infrastructure Technologies (AIT) lately celebrated the set up of an impressive bridge and are awaiting the completion of the second bridge of its sort in the coming months.
The Grist Mill Bridge spans the Souadabscook Stream in Hampden and was heralded with a ribbon-slicing following the December opening.
“It truly is the first bridge of its sort in the globe,” mentioned Wendell Harriman II, AIT senior operations engineer. “It made use of our fiber reinforced polymer [FRP] girder, which is the main supporting structural aspect of the bridge. It really is a plug and enjoy girder that fits the similar envelope as precast or metal — common elements. We are capable to healthy it in just as you would any other classic supplies with the exception of it being an eighth of the bodyweight of concrete or metal.”
It’s not only significantly lighter, but it is also “upkeep-free,” requiring tiny or no maintenance for 100 years.
The FRP is non-corrosive, and since the completed floor of the structural element is integral to manufacturing, it isn’t going to will need to be painted, cleaned of rust or patched of any likely swelling.
“It withstands the check of time when it comes to Maine’s substantial use of highway salt, sand and other varieties of corrosive Mom Mother nature wants to produce,” Harriman explained.
The U-shaped FRP girder is known as a Gbeam — AIT shorthand for composite or CT Girder.
“AIT composites are providing several tasks employing FRP, not only the GBeam, but also factors: GBolts, GBar, GDecking,” reported Harriman. “There are a good deal of elements we can supply to other components of infrastructure and other areas of the building field. We obtained right here for the reason that we commenced in the bridge small business with the GArch, beforehand recognised as composite arch bridge process. The arch bridge only applies to 10 % of the nation’s bridge infrastructure and we preferred to be capable to help the other 90 p.c, but by changing to a small to medium span FRP girder, we could protect one more 70 % of the bridge market.
“So AIT, working with the Advanced Constructions and Composite [ASCC] group at the University of Maine, made the GBeam with the strategy of delivering a remedy to the nation’s infrastructure by designing a 100-yr structure bridge with no upkeep and comparative price engineering,” he said.
A important component of the structure procedure was guaranteeing the plug and enjoy girder applied common parts.
“We worked to ensure we ended up ready to style all over those regular programs devoid of having to make any big modification for installation of our composition. The gain to our structure will allow contractor T-Buck Building to modularize. They have been ready to set two beams at a time. In addition, we had utilities that were to be hung beneath this framework and they have been capable to consider the two beams and join all the cross customers and utilities and set as a person device. That was a reward below. Due to the fact it is so light-weight, we had been equipped to set modular models and utilities all at after and nevertheless be considerably lighter than a traditional bridge girder.”
Tools included a GMK 5275 crane, which Harriman noted seems like a “really strong” crane, but the five-axle, 275-ton crane desired outfitting only to its 175-ton potential.
“What that permitted the contractor to do was established the crane farther absent. So, there is not virtually as a lot preparation operate around the bridge framework but nonetheless a good deal of capacity for the double lift.”
Crews with CPM Constructors are now at do the job developing the Twin Bridge on SR 69 in Hampden. It also crosses the Souadabscook Stream. The $1.8 million bridge replaces the unique span crafted in 1950 and will broaden it from 25 to 53 ft.
“The SR 69 Twin Bridge is a prefabricated bridge unit [PBU] task,” Harriman mentioned. “We had double CT girders by precasting two girders below the concrete deck and setting it on the bridge foundation one PBU at a time. Location these units only calls for a small concrete closure placement. These PBUs can be created with a four-inch thick partial deck — a usual deck would be 8 inches thick. That allows these even lighter units to be established in put and the deck cast on leading.
“Fabrication will start out in June and the bridge will go under construction starting in July and we will be environment girders by the conclusion of August. The bridge opening is scheduled for November 2021.”
“Sustainability in infrastructure is turning out to be a policy prerequisite,” explained Gregory Nadeau, AIT board member, chairman, infrastructure ventures, and previous administrator, Federal Freeway Administration. “AIT Composites’ bridge making technologies is created of composite material, with no steel reinforcement, and it will not corrode. If you can make a bridge that will past around 100 years in a aggressive, cost-effective manner, it would make economic sense, environmental feeling and operational feeling.” CEG
