Skip to comments.Engineers Unveil, Test University's Innovative Bridge Girder System
Posted on 07/19/2018 10:59:51 PM PDT by Tolerance Sucks Rocks
The University of Maine unveiled an innovative, rapidly deployable bridge system July 12 at the Advanced Structures and Composites Center.
Engineers, Maine Department of Transportation officials, business leaders, investors, researchers, members from Advanced Infrastructure Technologies (UMaine's licensee for the original “Bridge-in-a-Backpack”) and staff attended the event, at which a bridge span was strength-tested in the laboratory using computer-controlled hydraulic equipment that simulates the heaviest highway truck loads.
The strength-test was conducted for the first time to prove the design modeling predictions, and demonstrate the bridge system can withstand the truck loading specified in the American Association of State Highway and Transportation Officials (AASHTO) Bridge Design Specifications.
The system, developed at the UMaine Composites Center, utilizes composite material girders and precast concrete deck panels to reduce the time and logistics to build a bridge.
The lightweight highway bridge superstructure can be built in 72 hours, a considerable improvement on the time it normally takes to build a bridge.
In addition to significantly reducing construction time and logistics, the new bridge girders are designed to last 100 years, and the precast concrete deck is designed to be easily removed and replaced. The bridge system can be used for highway bridges, pedestrian bridges and military applications. The design is targeted for short- to medium-span bridge applications, up to 80-ft. unsupported spans.
“Today's bridge test exceeded our expectations. The composite bridge withstood forces equivalent to more than 80 cars stacked on top of each other, and more than five times the HL 93 design load specified by AASHTO. The composite bridge girder exceeded twice the collapse strength of steel and concrete girders. Today was truly a remarkable engineering achievement made possible by research sponsored by the U.S. Army Corps of Engineers and the dedication and hard work of University researchers,” said Habib Dagher, executive director of the UMaine Advanced Structures and Composites Center.
“This bridge system takes advantage of the unique properties of both composite materials and precast concrete, and it is designed with construction logistics in mind. The bridge girders weigh only 1-2 tons for 40- to 80-foot spans, so that they can be erected with locally-sourced common rental cranes, making them easy to deploy in most locations.
“The unique girder shape was designed to be nesting and stackable. As a result, three to four bridges can be transported on a single flatbed. This bridge system continues the University of Maine's commitment to be a world leader in developing advanced, innovative solutions to address our nation's infrastructure challenges. We thank the U.S. Army Corps of Engineers for sponsoring the research work.”
“As the commercialization partner of the Center's composite arch bridge system, today's event allowed us to showcase this new technology with potential investors as well as DOT partners and executives. We're ready to go to market,” said Brit Svoboda, chairman and CEO of AIT Bridges.
U.S. Sens. Susan Collins and Angus King issued a joint statement about the bridge system test:
“We are delighted to see the University of Maine preparing to test yet another important innovation on July 12,” they said. “Maine, New England and our nation need innovative technologies that will accelerate bridge construction, reduce traffic disruptions, increase the lifespan of infrastructure, and decrease costs to the taxpayer. The private sector partners and DOT officials attending the test will help to ensure that such critical technologies are quickly brought to market. As longtime supporters of UMaine R&D, we applaud the University for its continued leadership in transportation and infrastructure innovation.”
Hope it’s better than the one at FIU.
Looks like the leaf spring stack on my truck.
They normally have an Achilles heel though: fire. Heat will usually weaken the composite quickly, unless it's a special epoxy and fiber material heat-cured at high temperature. But then your cost will go way, way up. Maybe they have a solution.
I wonder if the sun will accelerate or pull (dry out) epoxy/base liquid used to hold the mix together . I didn’t see in the article where the girders were weather tested (but they must have)
Sun. That was my first thought.
Well building it in 72 hours is a great thing but EPA permits will take 6 months.
“..but EPA permits will take 6 months.” Scratch that, 6 years.
Where are you seeing this?
A drawing would be helpful. The photo is not.
I’m the project manager on a small bridge that crosses a non-fish bearing irrigation return drain. It’s taken over 3 years from initial funding through permitting to be approved for construction. Our issue now is the final permits were issued in June but our designated in-water fish window is between July and August and the bid processes takes 2 months, so we won’t be building this year.
Now were trying to negotiate a “floating” fish window that would allow us to bid and build based upon our bridge delivery schedule. It takes about 4 months after bid award to receive the manufactured girders, otherwise we have to wait until next July...
How often do bridges catch fire?
It's not that it happens too often, but you have to consider the consequences and expense if and when it does.
That sure went down the memory hole, huh. Lots of articles that first week, and absolutely nothing since.
Are you looking at the yellow slabs near the top of the picture? Everybody in the picture is looking toward the left.
Composites don’t do well with impact damage, especially if the fibers crack.
One would hope. But, never assume.
Alex, I'll take "new math" for $500...
It's 110° today where I live. Was my first thought as well. Also, the quote from one of the engineers "Today's bridge test exceeded our expectations." was somewhat disquieting. I would think they'd have dialed in their expectations pretty close to reality, as we have a pretty good handle these days on material sciences for the most part.
The careful text books measure
(Let all who build beware!)
The load, the shock, the pressure
Material can bear.
So when the buckled girder
Lets down the grinding span,
The blame of loss or murder,
Is laid upon the man!
Not on the stuff-the man!
-The Hymn of the Breaking Strain by Rudyard Kipling
That's one. Cost is another.
Cheap, high quality, fast - pick two at most.
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