The US Army, seeking to embiggen its green image, has proudly announced the building of the world's first bridge made from recycled plastic and able to support heavy loads. To test the recycloplast bridge, troops drove a monster 70-ton Abrams Main Battle Tank across it. “This represents a ‘first of its kind’ event in terms of …
"The recycloplast bridges are also said to be corrosion resistant compared to other bridge materials, meaning that they need almost no maintenance."
Looks like they've never heard of UV degridation. Serves them right for employing accountants instead of materials engineers.
"The firm sees it as taking on many structural and building tasks in coming years, replacing "last-generation" materials, such as wood, steel or concrete".
Last time I checked, we'd only been using steel, wood and concrete for, oh, around 100 generations...
Hmm. What about....
Better stick it where the sun don't shine.
need no maintenance !!
you just look at some old cars with plastic bits on the outside
They crack dry go brittle !!
...may not be as strong, but sourcing them once the oil has run out isn't going to be an issue.
And plastic does have a habit of slowly degrading over time (especially in sunlight), so I bet the reduced maintenance cost savings turn out to be much less than anticipated.
Is it fire proof? How does it age when exposed to long periods of UV (sunlight).??? Is it lighter in weight?
Never mind that
It's hardly a huge demo is it given it's over a creek and you can't see the underlying support.....strangely most materials are able to hold a higher load over short spans than over long spans......lets see it over a real void - not jut a creek that you could have driven the tank over anyway ;-)
Structural steel for 100 generations? 2000 years? I don't think so. Swords yes, building not. Even structural *iron* is only 18th century.
But I would like to have seen a bit more of what the bridge was spanning as being track laying vehicle, it spreads the load out more than say a lorry with a few axles and therefore I wonder if it is mostly resisting shear forces at the ends rather then bending moments in the middle.
I still like the idea of it - something (else*) to use up all that dumped plastic.
*Thermal insulation made from recycled drink bottles seems to be getting common now.
I thought they were green already: Green tanks, green cars, green underwear...!
What a great idea!
Unlike the naysayers, above (and below, I suppose), I think this is a great use of plastic that seems most likely to end up in a landfill anyways. I agree that we should not source new petroleum products so that we can make more bridges, but as a recycling option, this sounds awesome. (Not being a materials engineer, I can only comment that I would hope that their engineers did consider the relative pros and cons of using such material.)
"The US Army, seeking to embiggen its green image"
Armies and ecology are diametrical opposites, there will NEVER be anything green about destroying landscapes, blowing up buildings, polluting the environment with lead, depleted uranium, etc.
That Abraham tank probably requires more fuel to cross that plastic bridge than my car does in a year.
The ONLY step to embiggen their green image they can take is permanently shut down all armies and weapon factories.
Ver nice but...
What happens to it at extreme temperatures like -30C+ does it go brittle? That would be funny :-/
Armies kill people, which is very green.
Already great recyclers
Aren't their tank shells made out of recycled uranium?
to see the lego version.
Come on, it can't be that hard building a plastic bridge which holds Optimus Prime can it ?
So, what's new?
For some time now there have been picnic tables made out of recycled plastic.
The local scrotes in the park haven't managed to wreck them - even with fire.
They don't break with a kick and have been there some time so the UV angle looks like it's been sorted, too.
US military a bit late on this one?
"...Armies and ecology are diametrical opposites..."
That's not entirely correct. The areas of the UK which have been used as firing ranges and closed to the general public for decades have turned out to be very successful nature reserves, providing habitats for various flora and fauna previously thought to be rare or extinct in the wild.
"...Armies and ecology are diametrical opposites..."
"The areas of the UK which have been used as firing ranges and closed to the general public for decades have turned out to be very successful nature reserves, providing habitats for various flora and fauna previously thought to be rare or extinct in the wild"
... and of course, teaching important life skills to badgers, such as how to avoid tracer fire...
And the award for biggest failure to read the article goes to...
@ Dale Richards - And the award for biggest failure to read.
Actually the fail could be all your own.
Jolyon Ralph is quite correct. The M1A1 Abrams uses depleted uranium (DU) ordinance in its anti tank and armour piercing munitions as well as in its own armour. The article only mentions the DU used in the tanks armour so his question is valid
DU is a byproduct of uranium enrichment and reprocessing or spent nuclear fuel taken from nuclear reactors
Has the word 'enlarge' been taken out of the dictionary without my knowledge?
Embiggen is a perfectly cromulent word.
Not so worried about UV
Is it flameproof?
If so, can they do a deal to supply Sweden's combat-bras?
as pointed out by lionel plastic rapidly turns brittle and cracks, this is due to UV radiation interacting with the polymers, theyd be lucky if it retained its integrity for a year nevermind any kind of long term use.
"timber needs expensive and potentially troublesome coatings or treatments."
Not suggesting that wood is necessarily a good choice, but there are more than a few timbers that require little or no preparation to be used in a battlefield situation - e.g. azobe or jarrah - although they are almost universally f*****g heavy (or rather dense and hence....) and so humping them about might be fun. Timber supports made from these can survive for surprisingly long periods of time submerged (tens -> several hundred years) whilst retaining usable engineering strength... and they don't have problem with pesky UV damage.
The only reason they want bridges made of plastic is so their own soldiers don't get hurt filming JDAM strikes from across the street to put on Youtube.
"Here it comes, here it..."
*sound of clapping, cheering and Sweet Home Alabama*
"Dude! What the fuck was that?"
@ AC 11:59
"Structural steel for 100 generations? 2000 years? I don't think so. Swords yes, building not. Even structural *iron* is only 18th century."
You might want to check with the Chinese. They were making ductile iron over 2000 years ago, and that's steel in all but carbon morphology.
Besides - I can't think of a more structural application than a spring-temper, impact-resistant, standalone spar of steel. Can you?
@Falanx - think it's just us now
*Structural*, FFS. The iron bridge, 18th c, remember. It's an article about bridges not swords or pots. Swords aren't structures, nor springs either. Cantilevers if anything, but STRUCTURALLY for a sword bronze is fine. WOOD is fine STRUCTURALLY for hand weapons.
Steel and iron are used in weapons for their use in hard edges or points against bronze, leather, even steel armor. And that's why primitive people would bother with producing these metals in very small lumps which is all they were capable of. Thats why weapons tend to be all tool steel or have high carbon edges. Not like bridges, which are not cutting tools but STRUCTURES.
Iron in lumps you could make buildings & bridges out of is 18thc. Industrial revolution? Remember? STEEL for builders is more modern still. A hundred generations is just wrong, sorry. I know you wish you hadnt said it now, but this is just sad.
Well, a large part of Rutgers was a WWI army base...
and a few of the buildings from that era are still in use!
What is a structure?
I think you are both wrong... a sword is certainly a load bearing structure, in the ultimately pedantic mechanics sense. But really, when someone talks about structural steel, they are going to be meaning the modern use of rolled I beams and such to build welded or riveted structures.
Heaviest ground vehicles?
Some of the trucks used in mining and axcavation make the M1 Abrams (and tanks of other nations as well) look puny by comparison.
There is a suburb locally (Hobart/Australia) where if they don't like you they burn down your House/Flat. About a dozen last year... The kids normally hop on to their roof to watch. I guess its their fun they normally set fires in the hundreds when bushfire season is in full swing.
Wheelie bins lit and rolled next to cars is prevalent in another suburb. My Grandfathers place was burnt down last night, standard sort of risk when unoccupied, sad.
Build one of these in this area and it'll get burnt just to see how well it goes up.
Umm... and when they want to remove the bridge...
Can you just melt the plastic and reuse it?
I'm pretty sure steel, and the like, melt quite nicely.