Hillman Composite Beam
A super-strong bridge beam
Hillman Composite Beam main
When John Hillman subjected his bridge beam to load tests, it handled a hydraulic press’s 145 tons of maximum force with ease. The Hillman Composite Beam (a winner of our 2008 Invention Awards) weighs one third as much as concrete competitors—saving 20 percent on shipping and installation costs—and can hold 50 percent more weight. The beam gets its strength from within. A concrete arch supports the weight above it, and a steel plate running lengthwise prevents the arch from collapsing. A plastic shell wards off corrosion. The first bridge built with the beams opened in August in Illinois. Next up: a 540-foot bridge in Maine, and licensing deals in Canada and Europe. hcbridge.net
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from Kent, WA
You don't really know about new technology like this until it has been in the field for 40 years, but this sure looks good. Nothing is mentioned about cost compared to conventional pre-stressed concrete spans, but I've seen a lot of projects that would have been affordable if not for the difficulty and expense of bringing in a crane strong enough to position the beams. This is especially true in remote rural areas, where a smaller crane or even a hydraulic loader might be all that is available.
A precast Filigree system seems similar to this type of beam. A U-shaped reinforced precast beam is placed across the span. Then a void material is placed inside the precast beam. The final step is to place a concrete topping. For the Hillman beam, the precast is replaced with a steel plate and the concrete topping is replaced with a concrete arch.
One of the main problems with the filigree system, and may eventually be a problem for this type of beam, is that in exposed conditions, water finds a way into the interior and fills the void increasing the weight and causing invisible damage to the beam (rust). Obviously in this case, the beam is protected with a plastic shell. But is it unlikely that the shell will not be damaged by sunlight and thermal expansion?
Kudos to another creative way to span a distance.
THat is freaking awsome. I cant belive that it can hold 145 tons with ease. Im not a construction worker but I know thats alot.
I like the idea. But I'm a bit confused. "A concrete arch supports the weight... steel plate... prevents the arch from collapsing... plastic shell wards off corrosion."
Where's the composite part of this thing?
composite :
1. made up of disparate or separate parts or elements; compound.
The arch/bridge support is made of different materials, therefore, it is a composite of sorts.
Looks great but there's one thing I don't get: What would the measurements (beam weight, installation costs, etc.) be if this new composite beam were designed to handle the same weight (not 50% more) as the concrete competitors it is being measured against? Am I missing something? T