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Researchers Make Bendable Concrete

CowboyNeal posted more than 9 years ago | from the flexible-roadways dept.

Upgrades 399

karvind writes "PhysOrg is reporting that scientists from University of Michigan have developed a new type of fiber-reinforced bendable concrete. The new concrete looks like regular concrete, but is 500 times more resistant to cracking and 40 percent lighter in weight. Tiny fibers that comprise about 2 percent of the mixture's volume partly account for its performance. Also, the materials in the concrete itself are designed for maximum flexibility. Because of its long life, the Engineered Cement Composites (ECC) are expected to cost less in the long run, as well." Michigan roads must make the perfect test cases for this stuff, and I look forward to their improvement.

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A keyboard? (4, Funny)

James_G (71902) | more than 9 years ago | (#12449149)

How quaint!

Re:A keyboard? (5, Funny)

Punboy (737239) | more than 9 years ago | (#12449179)

That would be SO much funnier if this were the right time period, if the article had to do with transparent aluminum, and if you had a scottish accent.

Re:A keyboard? (0, Offtopic)

James_G (71902) | more than 9 years ago | (#12449194)

You're right.. it wasn't concrete, was it? Must be tired. Oh well.. the quote struck me when reading the summary, so I figured, what the hell..

Re:A keyboard? (-1, Troll)

Anonymous Coward | more than 9 years ago | (#12449195)

shutup cunt

Buildings (5, Insightful)

antivoid (751399) | more than 9 years ago | (#12449151)

Now finally we can see buildings that bend and shift better under harsh weather conditions such as wind and rain.

The benefits of this extend greatly beyond that as well however.

It will be intresting to see where this goes...

concrete submarine (5, Interesting)

nounderscores (246517) | more than 9 years ago | (#12449163)

I wonder if this new concrete may enhance the concrete submarine [popularmechanics.com] programme for deep submersibles.

Being in something with a bit more toughness, and better tensile strenght might be more reassuring. A little less like going to sea in an eggshell.

Re:concrete submarine (1)

goonies (227194) | more than 9 years ago | (#12449316)

Acc. to your link, the subs already use kevlar reenforced concrete... like it says in the article above, this is not really new technology... we can do this for years... (breaktrough could be, to make it as cheap as or even cheaper than normal concrete)

Re:concrete submarine (0)

Anonymous Coward | more than 9 years ago | (#12449322)

Thats the coolest sub idea I've seen in a while

I'll take two.

Re:concrete submarine (0)

Anonymous Coward | more than 9 years ago | (#12449415)

I wonder how well those would hold up against ADCAP torpedoes?

Re:Buildings (1, Interesting)

kcelery (410487) | more than 9 years ago | (#12449242)

But when your house is on fire, those tiny fibres within the concrete block would lost strength when temperature go around 200 C. When the temperature went higher, combustion of the fibre would weaken concrete strength further.

Re:Buildings (5, Interesting)

Velk (807487) | more than 9 years ago | (#12449368)

How do you know that ? The article makes no mention of what the fibres are actually made of, let alone what their temperature response is. And how would they catch on fire if they are inside the concrete ? It would have to crack open to expose them to oxygen before that could happen, presuming that they are even flammable in the first place.

"Buildings that bend and shift " (1)

Quae (881525) | more than 9 years ago | (#12449254)

Don't go to the loo at the top!

Re:Buildings (4, Interesting)

Dead Kitty (840757) | more than 9 years ago | (#12449496)

buildings that bend and shift better under harsh weather conditions such as wind and rain

Although it's good for a structure to have some flexibility under periodic loading (earthquakes, winds, etc.), the U of M article mentions applications like expansion joints and roads. In an expansion joint, the component is expected allow displacement to reduce pressure on other parts. Just think about a simple bridge with 2 expansion joints on both ends. Temperature changes will cause the bridge to expand/contract. Rigid joints on either end would prevent the structure from deforming freely so there would be a lot of added stress. The amount of force to resist this expansion/contraction is huge, (Any second year civil engineering students can back me up with some numbers) thus the need for expansion joints. The joints themselves aren't doing any significant load-bearing.

Compare this to a building where much of the structure is supporting vertical loads (gravity). Imagine if a column was made from this stuff, nothing could depend on it for structural support due to its inability to resist deformation. So everything this column (or beam) is trying to hold up comes tumbling down. Just look at that video where the beam completely bends under the load.

Flex in structures is good in hurricanes and stuff, but it doesn't do much good if it can't even hold itself up.

Re:Buildings (1)

travellerjohn (772758) | more than 9 years ago | (#12449497)

You mean like wood.

The more things change, the more they stay the same

Roads? Hah (4, Funny)

nounderscores (246517) | more than 9 years ago | (#12449152)

How about a concrete jumping castle?

Re:Roads? Hah (1)

kfg (145172) | more than 9 years ago | (#12449213)

How about a concrete jumping castle?

And I thought living in a castle in the air was a bit inconvenient at times. I don't even want to think about what would happen to the china.

KFG

Re:Roads? Hah (1)

netcrusher88 (743318) | more than 9 years ago | (#12449323)

Jumping castle? How about a flying citadel?

Michigan Roads? You Mean Minefields! (1)

n3v (412497) | more than 9 years ago | (#12449154)

I've bent many a rim here...

Roads (5, Insightful)

Rosco P. Coltrane (209368) | more than 9 years ago | (#12449158)

Michigan roads must make the perfect test cases for this stuff

Except that roads crack because water infiltrates under the surface and freezes over. I don't know many material, even 500x stronger concrete, that can withstand the force of expanding freezing water.

I think the material is more targeted toward seismic-proof constructions.

flexible Roads (4, Interesting)

nounderscores (246517) | more than 9 years ago | (#12449167)

Maybe a flexible road may not be able to stop the water penetration, but might be able to return (or be pounded) back into its original shape? A small crack stays small, even after many ice expansion cycles, rather than turning into a massive pothole?

freezing water (5, Insightful)

Soulfarmer (607565) | more than 9 years ago | (#12449178)

If the material won't bend/stretch at all, it might shatter, this new elastic concrete supposedly kand bend at least a little, so it could withstand the freezing expanding water. At least I think that the freezing expansion is not enough to stretch the new concrete to it's limits.

Re:Roads (2, Insightful)

myowntrueself (607117) | more than 9 years ago | (#12449181)

"I don't know many material, even 500x stronger concrete, that can withstand the force of expanding freezing water."

Its flexible.

It doesn't need to withstand the force, it gives a little.

Re:Roads (1)

vought (160908) | more than 9 years ago | (#12449487)

It doesn't need to withstand the force, it gives a little.

Supertramp - Give A Little Bit Lyrics
Roger Hodgson & Rick Davies
--
Give a little bit (of your tensile strength)
Give a little bit (of your tensile strength) of your love to me
Give a little bit (of your tensile strength)
I'll give a little bit of my love to you
There's so much that we need to share
Send a smile and show you care
I'll give a little bit (of your tensile strength)
I'll give a little bit (of your tensile strength)
So give a little bit (of your tensile strength)
Give a little bit (of your tensile strength)

Re:Roads (1, Insightful)

DietCoke (139072) | more than 9 years ago | (#12449189)

"I don't know many material, even 500x stronger concrete, that can withstand the force of expanding freezing water."

Clearly you haven't experienced the joys of ice-cube trays.

Don't ask me how to apply that material to roads, though.

Re:Roads (2, Funny)

kfg (145172) | more than 9 years ago | (#12449236)

"Clearly you haven't experienced the joys of ice-cube trays."

What have Jell-O shots got to do with it?

KFG

Re:Roads (2, Funny)

vought (160908) | more than 9 years ago | (#12449492)

Clearly you haven't experienced the joys of ice-cube trays.

Don't ask me how to apply that material to roads, though.


Sure as I c'n set a wireless tower in the holler, I c'n say that there a'int no way to freeze the roads south of Virginny!

Re:Roads (0)

Anonymous Coward | more than 9 years ago | (#12449365)

The problem of water under a road is solved by using subdrains consisting usually of clean stone to outlet the water.

Re:Roads (1)

nippinout (713391) | more than 9 years ago | (#12449490)

The cracking is due to the ice entering cracks and freezing, thawing, and freezing again in the larger and propogated cracks.

To ensure good freeze-thaw strength, air entrainment is used to allow the ice to expand.

Cracked concrete is not always a bad thing! Concrete forms, when designed correctly, take into account cracking over its servicable life. When you are driving, look at the bridges you go under, there are cracks and chunks of concrete missing.

This is not unsafe. The concrete at the top of the beam is in compression (which we want), and at the bottom the concrete is in tension (which is a bad thing). BUT, that concrete in tension is only used as a cover to prevent rebar from rusting. Removing chunks of that tension concrete is not decreasing the overall strenght of the beam, as long as the steel rebar is not exposed.

Springs made out of concrete (3, Interesting)

LemonFire (514342) | more than 9 years ago | (#12449160)

I remember reading an article that talked about differenct concrete compounds, for example they had made a spring out of concrete.

-- Error: SIG not found.

Re:Springs made out of concrete (4, Informative)

MacroRex (548024) | more than 9 years ago | (#12449249)

There is also translucent concrete [slashdot.org] which works by having optical fibers mixed in.

Forget architecture. (1)

Blacken00100 (864342) | more than 9 years ago | (#12449188)

Imagine the BSDM^H applications! Seriously, though--interesting stuff. Curious as to how well it'd stand up under pressure.

Re:Forget architecture. (1)

Rosco P. Coltrane (209368) | more than 9 years ago | (#12449212)

Imagine the BSDM^H applications!

So it's a dead concrete?

Re:Forget architecture. (2, Funny)

geekboy642 (799087) | more than 9 years ago | (#12449302)

Well, it runs on toasters.

Concrete is just the next logical step.

In the long run... (0)

Anonymous Coward | more than 9 years ago | (#12449198)

means this is going to be really fucking expensive.

Remember asbestosis? (0, Troll)

elucubra (685819) | more than 9 years ago | (#12449199)

Tiny fibers in concrete seem very similar to compounds that used asbestos.
As the concrete is degraded these fibers will be released to the environment, and tiny fibers tend to make very good respiratory tract irritants (to say the least).
BTW, I bet demolition crews will hate the stuff...

Re:Remember asbestosis? (1)

Blacken00100 (864342) | more than 9 years ago | (#12449209)

Mesothelioma ambulance chasers will have a new field, then. Good for them. Capitalism in action.

Ob Simpsons (1)

DarkHelmet (120004) | more than 9 years ago | (#12449281)

Bart: But we want... More asbestos! MORE ASBESTOS!

Re:Remember asbestosis? (3, Informative)

Anonymous Coward | more than 9 years ago | (#12449292)

No, the only reason asbestos is damaging to lungs is that it
tends to form particles 0.5 to 1.4 microns in diameter, which is the range in which any paticulate matter is lung damaging and carcinogenic in nature. Asbestos is not mutagenic; any particles that form mainly in that size will cause lung cancer. It is a strange twist of fate that asbestos fibers disintigrate to particles that size, but it has nothing to do with fibers in general or their chemistry.

Re:Remember asbestosis? (1)

krypticide (589771) | more than 9 years ago | (#12449295)

Every breath you take is filled with micron-sized dust and more; just look at the dust in a typical carpeted house. The asbestos risk came more from its carcinogenic effects, than anything else.

Re:Remember asbestosis? (0)

Anonymous Coward | more than 9 years ago | (#12449379)

Its carcinogenic because of its particle size, not for any other reason.

Re:Remember asbestosis? (2, Informative)

Skadet (528657) | more than 9 years ago | (#12449304)

Concrete is already a very harmful substance in mix form, or when it gets dust-i-fied thru demolition, breaking, what have you:


Caution:
CONCRETE MIX contains cement-itious materials and may cause irritation to lungs, eyes and skin. Avoid contact. Use only in adequate ventilation. Do not breath dust. Wet mixture may cause burns. Wear suitable gloves, eye protection and protective clothing. In case of skin contact, wash thoroughly with soap and water. In case of eye contact, flush immediately and repeatedly with large quantities of water and get prompt medical attention. In case of difficulty breathing, remove person to fresh air. If difficulty breathing persists, seek medical attention

http://www.rapidset.com/ConcreteMix_data.asp [rapidset.com]

If anything, it'll encourage those who are at risk to use the protection they should be using anyway.

Re:Remember asbestosis? (5, Insightful)

King_of_Prussia (741355) | more than 9 years ago | (#12449312)

Why is this modded up?

Fiber reinforced materials have been around for years. Carbon and glass fiber reinforced polymers are used in many everyday applications without harm. The problem with asbestos was its crystal structure and cleavage planes, which enabled it to break down into very small (micrometer scale) fibers that were easily inhaled.

The above comment is about as insightful as saying "Cotton fiber? That seems eerily reminiscent of asbestos, better not wear clothes!" or "AIDS medicine? Wasn't thalidomide also orally available in pill form? Better not give it to pregnant women..."

concrete trampoline? (5, Funny)

wcitech (798381) | more than 9 years ago | (#12449200)

why? because nobody makes the first jump. (shameless matrix refrence)

Earthquake-proof buildings (4, Insightful)

Red Pointy Tail (127601) | more than 9 years ago | (#12449207)

Doesn't say in the article, but wouldn't this be useful in making buildings that would fare better in absorbing the shocks of an earthquake, instead of crumbling down?

Re:Earthquake-proof buildings (0)

Anonymous Coward | more than 9 years ago | (#12449237)

Either that or they'd be so flexible, downtown would be a mass of skittles swinging into each other.

Re:Earthquake-proof buildings (0)

Anonymous Coward | more than 9 years ago | (#12449279)

Meh, I want concrete golf shafts!

Re:Earthquake-proof buildings (1)

Aqua OS X (458522) | more than 9 years ago | (#12449336)

Agreed. That's the first thing I thought of. Flexible concrete sounds like a God send for CA.

Highways instead? (1)

helioquake (841463) | more than 9 years ago | (#12449341)

Would it make a better material for building elevated highways and bridges? It needs to tolerate both weak and strong vibrations (small cars and trucks) all day and night. It needs to be water-proof that cracks don't become serious issue, either.

Re:Earthquake-proof buildings (1)

mikael (484) | more than 9 years ago | (#12449518)

The problem with tall buildings is that they do have a certain amount of flexibility, which allows them to sway in an earthquake. The worst case scenario is when the building sways at the same frequency as the earthquake. Then the amplitude gets higher and higher until the building falls down. You're better off having an intelligent vibration dampening system by having a computer automatically move a large weight around near the middle of the building.

Like most of life's problems... (5, Funny)

Your Pal Dave (33229) | more than 9 years ago | (#12449208)

this one can be solved with bending - Bender Bending Rodriguez [wikipedia.org]

Origional News Source at U of M (4, Informative)

Kelerain (577551) | more than 9 years ago | (#12449219)

Why not link to the source at the U of M News Service:

U-M researchers make bendable concrete [umich.edu]

Technocrat.net [technocrat.net] had this article [technocrat.net] earlier today, and without the extra advertising.

interesting stuff!

Re:Origional News Source at U of M (1)

biobogonics (513416) | more than 9 years ago | (#12449344)

To me, the most interesting point is that this material is being tested as a replacement for expansion joints. This would allow more bridges to be paved with concrete instead of being covered by asphalt.

Michigan is in fact the ideal place to test this stuff. We have

1. Two seasons, winter and road construction.

2. State government that neglects roads and bridges until past the point of needing repair.
See recent news stories about chunks of concrete falling down on traffic under freeway overpasses, etc.

Concrete Roads (1)

nmb3000 (741169) | more than 9 years ago | (#12449223)

Michigan roads must make the perfect test cases for this stuff, and I look forward to their improvement.

Does anyone else here hate highways that are made with concrete? They have them here around Salt Lake with asphalt segments every now and then. Every time I go from concrete to asphalt I realize just how much quieter the car is and smoother the ride feels. It's almost painful to go back to concrete.

I guess concret must have some advantage if it's used all over, but it seems like asphalt is better for roads. It expands and contracts easier, and when a pothole forms in concrete it always seems to get real big and deep a lot faster than with asphalt. Not sure, but maybe all the salt they dump on the roads around here in the winter is bad for asphalt?

Re:Concrete Roads (4, Interesting)

inflex (123318) | more than 9 years ago | (#12449248)

Concrete roads are far more resiliant to wear than asphalt/tar roads, this means (generally) less repair work. This is a major factor when you're dealing with a massive arterial system.

Overall concrete roads and asphalt tend to work out the same in terms of costs (over a period of years), concrete being more expensive to lay but lower repairs and vice-versa for asphalt.

Re:Concrete Roads (4, Insightful)

inflex (123318) | more than 9 years ago | (#12449261)

I forgot to note that the "noise" that you're suffering is from the grooving they put into the concrete road. Without this grooving people would be crashing everywhere when it starts raining from aquaplaning (even the smoothest asphalt road will not be as slippery as a wet smooth concrete one).

Paul.

Re:Concrete Roads (4, Informative)

TheFlyingGoat (161967) | more than 9 years ago | (#12449328)

There's an alternative they're trying out in certain areas of Wisconsin. It's basically asphalt, but with a very high rubber content. They grind old tires into the asphalt. The net result is that it costs about the same to lay, and it can "heal" itself to some degree. The main concern is how safe it is when completely frozen, which is why it's only being tested in certain sections of freeway.

If it does prove to be a viable material to replace basic asphalt, it'll be great for Wisconsin drivers... we deal with slippery roads all winter then road construction in the spring, summer, and fall. If this can at least eliminate pothole patching, it'll pay for itself many times over.

To add on to the parent post.... (1)

AKosygin (521640) | more than 9 years ago | (#12449349)

Some roads are built with concrete as the foundation and asphalt is then laid on top. On some surfaces, the concrete is necessary to give the road strength for soft ground like areas where it is more sand like or is soft. Also roads that carry heavy trucks tend to have such a concrete base (if not plain concrete). Bridges must be concrete, but asphalt can be laid on top to make it "quieter". When they lay concrete or asphalt or both, the engineers decide based on environmental factors also, not just cost or because it is nice. Another major factor is distance to a major city or repair point. If a particular stretch of road is heavily traveled and is far from a city, concrete might be better as the constant repair costs of asphalt might prove to be expensive, compared to a one time fix.

Re:Concrete Roads: How about brick (3, Interesting)

StormyWeather (543593) | more than 9 years ago | (#12449409)

I see 150 year old brick streets in a lot of towns still. Seems like that's a pretty good building material for slower traffic too :).

Re:Concrete Roads (1)

SB5 (165464) | more than 9 years ago | (#12449303)

I live in Pennsylvania, which has the second worst roads in the country. I can tell the difference between asphalt and concrete.

Concrete is usually smooth, but noisy.

Asphalt has tends to get potholes from people just spitting on it. And from the "unique" weather we get in Pennsylvania, although New York, Ohio, Maryland, and the Virginias don't have a problem, with similar weather patterns.

They lay nothing but asphalt here and yes, when it is freshly laid, its nice and smooth, but it is the worst solution, since they have to relay it every 5-10 years on even the lightly used roads.

Re:Concrete Roads (1)

spectrokid (660550) | more than 9 years ago | (#12449438)

In Brussels, they just put a new kind of concrete instead of asphalt on one of the bussiest highway stretches. The manufacturor claims ith will hold maintenance-free for... thirty years.

Plastic or Elastic Bending? (5, Insightful)

zeromemory (742402) | more than 9 years ago | (#12449235)

The article fails to state whether the ductility of the concrete results in elastic (returns to its original shape when load is relieved) or plastic (stays in the shape you bent it) deformation.

One would hope for the former, since structures made out of this material may look strangely 'bent' over time if it readily undergoes plastic deformation.

And one last note: is this material going to be more cost-effective than steel?

Re:Plastic or Elastic Bending? (1)

Tomfrh (719891) | more than 9 years ago | (#12449453)

Like other ductile materials, it will be elastic at low stresses, and will become increasingly plastic as stress increases.

Structures are not generally designed to go fully plastic, and thus there is always additional elastic capacity to prevent unarrested plastic deformation.

Dunno about the cost-effectiveness. I dont suppose anyone really does yet.

Re:Plastic or Elastic Bending? (2, Informative)

zeromemory (742402) | more than 9 years ago | (#12449485)

Like other ductile materials, it will be elastic at low stresses, and will become increasingly plastic as stress increases.

True, but the most important factor in this case would be the lower yield strength (LYS), the point at which the transition from elastic to plastic behavior occurs. The article says very little about whether this concrete has a great LYS (deform elastically under everyday stress), or a small LYS (plastically deform even under little stress).

Re:Plastic or Elastic Bending? (1)

nippinout (713391) | more than 9 years ago | (#12449511)

It also fails to mention any study on creep and relaxation. When concrete fails the cement matrix crushes and the aggregate shears and crushes. I doubt such a flexible concrete would be used for a structure for uses such as an office building. Flexing under load may be within the limits of this concrete, but it isn't very comfortable.

Yes but... (4, Interesting)

qualico (731143) | more than 9 years ago | (#12449243)

...can it withstand the impact of a jet airplane?
And is it safe to inhale the fibers if said airplane makes a big ol' mess?

Re:Yes but... (5, Funny)

cablepokerface (718716) | more than 9 years ago | (#12449414)

...can it withstand the impact of a jet airplane?

No, but because of it's bendability, it can actually dodge incomming plains.

Flexon my Marchon (0)

Anonymous Coward | more than 9 years ago | (#12449458)

..can it withstand the impact of a jet airplane?

Was going to post this infamous "If only all metal were FLEXON"-ad that distraught New Yorkers found in their mailboxes when they came home on 911, but it was nowhere to be found... Good censorship job!

Concrete roads? (1)

flubbergust (818863) | more than 9 years ago | (#12449245)

We dont have that here and I never understood why you would rather use conrete than asphalt on roads. Well, I guess it could be that its cheaper but is it really better and safer?

Re:Concrete roads? (1)

Quae (881525) | more than 9 years ago | (#12449264)

Concrete makes a smoother ride.

Re:Concrete roads? (1)

zeromemory (742402) | more than 9 years ago | (#12449286)

We dont have that here and I never understood why you would rather use conrete than asphalt on roads. Well, I guess it could be that its cheaper but is it really better and safer?

One area where you can't use asphalt is on raised runways, like the elevated sections of freeways. Concrete might be more brittle, but its greatest quality lies in its resistance to compression. Unlike concrete, asphalt can't support tons of weight, so people don't make load-bearing structures out of asphalt.

This material might make the elevated sections of freeways safer. I don't see much use for it on regular roads, though.

Re:Concrete roads? (2, Interesting)

goonies (227194) | more than 9 years ago | (#12449362)

One area where you can't use asphalt is on raised runways, like the elevated sections of freeways.
Wrong!
you use concrete for the bearing construction and put asphalt on the road... thats how they do over here in Switzerland

Re:Concrete roads? (1)

Kamots (321174) | more than 9 years ago | (#12449366)

If there's any sort of heavy traffic, then concrete is a much better material for roads than asphalt.

Asphalt is a good material for lightly used roads. It'll deform under heavy loads though... go pick up a bit of broken asphalt, and you'll notice that it's not a solid.

However, the largest problem with a road in poor condition usually isn't what the surface is made of... but lies in poor preperation of the subgrade.

replacing 2% volume reduces weight by 40%? (2, Insightful)

Anonymous Coward | more than 9 years ago | (#12449258)

even if you replaced 2% of the volume with vacuum, you could only make it 2% lighter

how the hell do they come up with this 40% figure?

Re:replacing 2% volume reduces weight by 40%? (1, Funny)

Anonymous Coward | more than 9 years ago | (#12449305)

even if you replaced 2% of the volume with vacuum, you could only make it 2% lighter

how the hell do they come up with this 40% figure?


Negitive mass ...

Re:replacing 2% volume reduces weight by 40%? (1)

Skadet (528657) | more than 9 years ago | (#12449318)

If I understand TFA correctly, the fibers are 2% of the mix volume. This translates to a much larger percentage of total volume once the concrete dries.

Re:replacing 2% volume reduces weight by 40%? (3, Informative)

elliotjo (409448) | more than 9 years ago | (#12449339)

"Tiny fibers that comprise about 2 percent of the mixture's volume partly account for its performance."

The fibers are only one part of the improvement. The article also mentions replacing other major components in the concrete, including the bulk aggregate. Presumably the new components are also lighter and would account for the 40% reduction.

Re:replacing 2% volume reduces weight by 40%? (0)

Anonymous Coward | more than 9 years ago | (#12449411)

even if you replaced 2% of the volume with vacuum, you could only make it 2% lighter

how the hell do they come up with this 40% figure?


This would be true if u assumed the volume remained constant. I have not RTFA but if I remember my high school physics correctly,

Weight = Mass x Gravity.

If you add 2% of this stuff its possible the same mass can occupy a larger volume and yet have comparable structural strength. So you'd have the same "size" of concrete but it could weigh a lot less. All this is purely hypothetical to my understanding to this of course.
Either that or they weighed it on the moon ;-)

Re:replacing 2% volume reduces weight by 40%? (4, Informative)

valkoinen (81260) | more than 9 years ago | (#12449447)

The increased strength makes it possible to use less of it to build structures of similar strength. You need 40% less of the fiber concrete to get the same strength as the traditional concrete.

Re:replacing 2% volume reduces weight by 40%? (2, Insightful)

OneSmartFellow (716217) | more than 9 years ago | (#12449463)

Surely it depends upon which 2% is replaced. If it's the most dense 2% being replaced with a substance that is significantly less dense, then I suppose it is possible.,b.I agree though, unless these guys are using a concrete mix comprised of something other than cement, sharp sand and gravel, I find it hard to understand myself

What about me? (1)

dauthur (828910) | more than 9 years ago | (#12449275)

They say this concrete is plyable. Can it cushion my face hitting it at roughly 3 metres a second as I accidentally catch my foot in the spokes? Or is it mainly to be used to stand up to Boeing 777's in a 650 knot vertical dive? Either way, I don't want to have my face turn out more useless than Rambus... Ouch.

A little too late (2, Funny)

itsmekirby (858745) | more than 9 years ago | (#12449276)

The architects, contractors, and construction workers of the Petronas towers in Kuala Lumpur simultaneously shout, "D'oh!"

Re:A little too late (4, Interesting)

zeromemory (742402) | more than 9 years ago | (#12449313)

The architects, contractors, and construction workers of the Petronas towers in Kuala Lumpur simultaneously shout, "D'oh!"

From what I remember of watching a documentary on the construction of the Petronas towers, the primary concern of the engineers was the compressibility of the concrete -- each floor has to withstand the weight of the numerous floors above it. Flexibility was the least of their worries.

Furthermore, the two towers are located on a relatively 'soft' foundation -- they essentially 'float' on sea of soft land. The towers aren't anchored to the bedrock. Additionally, the bridge that connects the two towers is designed to allow the towers to move towards and away from each other. Thus, the towers stabilize each other and are quite flexible. According to the documentary, if you watch the water in the upper-level toilets on a windy day, you'll see it swooshing around.

Re:A little too late (2, Interesting)

rwjyoung (674310) | more than 9 years ago | (#12449441)

I didnt see the documentary you mention, but I was a civil engineer and I was in Kuala Lumpur when the towers were being built. The rumour was that one tower was built on the bedrock and the other tower was built on clay. From what we experienced of the geology under Kuala Lumpur I would say this was quite feasable. They had different teams of contractors building each tower, One French and one German (I think) and held a race on which tower went up the fastest. The tower on the bedrock won as the other tower had to stop every so often to allow the building to settle. The other rumour going around was that when they came to fix the bridge, the bridge was nearly half a meter to small due to the clay founded tower leaning. Half a meter sounds like a lot to me but I would be very suprised if the bridge fitted exactly as it was supposed too.

if only I had some bendable steel then i could (0)

Anonymous Coward | more than 9 years ago | (#12449284)

bendover and start a flappin my wings and a flyin with my flapable concrete wings attached to my flapable steel.

Chick0en Tonight.

This isn't new... (1)

d474 (695126) | more than 9 years ago | (#12449317)

...I believe the technical term for this is "Gray Rubber".

Stone bends, too (2, Informative)

Zog The Undeniable (632031) | more than 9 years ago | (#12449338)

The columns of some cathedrals - built before people understood roof trusses - are slightly but definitely bent if you sight along them. The percentage strain is very low, so they don't crack.

Like those portable cement dwellings (1)

kafka47 (801886) | more than 9 years ago | (#12449353)

Reminiscent of the "house in a bag" invention by those guys in the UK. Need a shelter? Just add water, and poof! There's your house.

TFA [wired.com]

/Kafka

Re:Like those portable cement dwellings (1)

Zog The Undeniable (632031) | more than 9 years ago | (#12449491)

Just add water, and poof! There's your house.

That would be Elton John's house, then?

demolition (1)

zobier (585066) | more than 9 years ago | (#12449373)

Is bendable concrete going to make it difficult to demolish structures built using it as the main material?

Dynamite, Anyone? (2, Informative)

zeromemory (742402) | more than 9 years ago | (#12449400)

Is bendable concrete going to make it difficult to demolish structures built using it as the main material?

I don't think buildings made out of this stuff will survive a large enough explosion. Besides, concrete is really easy to break apart and chip (hence why you need to use rebar frames for serious construction), so just whacking away with chisel-tipped jackhammer should work for small jobs.

Whatever happened to ... (1)

WindBourne (631190) | more than 9 years ago | (#12449404)

transparent concrete? I seem to recall something about that in /.

Only possible problems I see.. (4, Insightful)

Ice_Hole (87701) | more than 9 years ago | (#12449429)

How much does this road bend, also what kinda of deformation would we see from traffic. The current roads currently get grooves in them. But make a road that actually felxes, wht kind of effect would that have on the surface of the road? This to me would mean MORE maintaining the road, not less.

Also, what effects would this have on gas mileage of vehicles. If the road was givein way a little as say a semi or large vehicle was driveing over the road, to waht degree would it "sink" into the road? Would you be wanting to run more air pressure in the tires of the vehicle on these types of roads, to compensate for the flex inherant in this road? And over time, what effect would this have on gas. Another valuable resource.

Also, adding fibers into a road, could effect it's traction. Current roads, are rather random. If (through wear) all these fibers were to orientate themselves one way would this effect the grip these roads provided? Also, now does this fiber react after years of abuse, and oil contamination? If oil were to cause these fibers to swell, or if they were to absord it, I would imagine it would have negative effects.

But what the heck, it may just work. Imagine, no ccracks in the slab of your home anymore. All for only a few side effects (and probably 3x the cash).

- Ice_Hole

Earthquakes (1)

nmg196 (184961) | more than 9 years ago | (#12449435)

I wonder if this stuff could be used to make buildings more invulnerable to earthquakes. If the foundations and a couple of lower levels were flexible, maybe the building would just wobble rather than shaking itself to bits - the equivalent to putting suspension in a car?

Sliding fibres? (1)

icejai (214906) | more than 9 years ago | (#12449468)

The article doesn't mention anything about the stresses this concrete can take. It just says it looks exactly like concrete and cracks less.

I don't think this kind of concrete is the kind builders would want to make lower-level walls of very tall buildings with. Sure it can handle tensile stresses very well and is extremely flexible, but how will this "concrete" react to compressive stresses? Flexible concrete means less force is required to make it buckle and warp.

Will this concrete be appropriate for floors of condomunium and office towers? Will the concrete floor warp if a heavy copier is moved into the office, or if someone moves in a piano?

Maybe because it's lighter, concrete floors can be made thicker, and thus less prone to warping, but I really think something like this would be better suited in bridges, roads, houses, and maybe their foundations.

Concrete roads? (1)

tod_miller (792541) | more than 9 years ago | (#12449476)

?? I think this will have a great impact on space building, reading about crazy plastic/concrete/steel mixtures of materials in sci-fi and you will see.

This could be the start of pour your own space home!

rar.

Idea Terrorist deterrent (2, Funny)

delusrexpert (578176) | more than 9 years ago | (#12449477)

Headlines Plane hits building....

Today the newly launched Airbus [portalbrasil.net] was hijacked by an unknown group of radical loons just before 3.00pm EST. After the terrorists seize control of the cockpit they flew the plane into the side of the world tallest building 'the humgo ercto 'standing over 675m in height built in 2006 housed in a flexible concrete sheath. The building stood the attack, bystanders claim the plane hit the build folding into a pile of scrape metal. One claimed the building swayed a full football fields length as it took the blow. The bad news is as the ball of molten steel fell from the sky it took out the 3 Skyscrapers below ;(

Concrete overshoes (0)

Anonymous Coward | more than 9 years ago | (#12449495)

Great! Now instead of the concrete overshoes the mafia can go modern and use concrete running shoes!

This is about US engineering conservatism (2, Interesting)

panurge (573432) | more than 9 years ago | (#12449502)

If you read the article, you may realise that the point here is that the US lags the rest of the developed world in using engineered cement composites. Back in dead tree days, Scientific American had an interesting article on how restrictive building codes and fear of litigation was causing the US to lag behind in road and building construction because more modern materials could not be used.
This results in higher build and repair costs for roads and bridges and explains the poor maintenance of many US highways.

The article is essentially saying that, at last, someone is prepared to experiment with ECCs in the US on a small scale following a test in a difficult area. Meanwhile, advantage has been taken of these materials in the Far East for a number of years.
This is important because in many ways the US is becoming depressingly conservative. It is no longer a world leader in innovative building. Ford and GM have just seen their shares reduced to junk status as the Japanese and Daimler-Chrysler increase their share of the US auto market. And the whole IP/copyright thing is basically about trying to protect what you have rather than innovate and create new markets. If this little experiment is a sign that someone is getting brave enough to risk trial lawyers (my client tripped over a kerb as a result of using this unproven concrete technology...) perhaps it's a green shoot.

"the bridge is 40% lighter..." (5, Interesting)

Senor_Programmer (876714) | more than 9 years ago | (#12449508)

because the concrete is thinner, not because the concrete is lighter. This discerned from RTFA. We poured a pad for a picnic pavilion at the yacht club using concrete that is reinforced with polyethylene fibers. It allowed us to pour a large pad that will not crack without having to use tiebacks. Which brings to mind something I've often wondered about...

With concrete, when it's pre or post stressed in compression, it's much less likely to crack. Traditionally this is done by tensioning the steel prior to pouring or tensioning cable or rod 'tiebacks' after partial curing. Now this is very nice but... It should be possible to engineer a fiber that will shrink as it ages and bonds well as an aggregate. If the shrink time could be matched up reasonably well with the cure time of the concrete it would simplify many types of construction.
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