Concrete is incredibly sturdy when subjected to heavy compression, but suffers catastrophic cracking under strain--that's why it snaps so easily in earthquakes. But a scientist in Michigan has just perfected a new concrete mix that changes all that. It's bendy, and it can heal its own cracks--all it takes is a little rain.
The invention, by professor Victor Li of Michigan University, is a refinement of a research material dubbed "engineering cement composite" or ECC. His lab has been working to perfect this substance for 15 years. Unlike the ceramic behavior of "normal" concrete, the new ECC is a bit more like a metal.
Its amazing properties rely on a chemical and structural mix: In the resulting solid, tiny cracks do still form when the material is bent, but they remain tiny and don't connect up to each other. The cracks stay around 60 microns in size, allowing the solid to bend, and their propagation is halted by microscopic reinforcing fibers. Furthermore, the cracks are exactly the right size to allow moisture and air in when they form. After a short while to react, "spare" dry cement in the mix reacts with the available carbon dioxide and water to form calcium carbonate--a naturally strong material that then seals up the cracks.
That means the material can suffer bending and stretching loads that would utterly destroy plain concrete and even badly affect steel beams, and still remain firm. As Li puts it, the results were somewhat unexpected: "We found, to our happy surprise, that when we load it again after it heals, it behaves just like new, with practically the same stiffness and strength."
The implications of a bendable, self-healing concrete are somewhat incredible. Current architectural and civil engineering designs are strictly limited by the material characteristics of plain and steel bar-reinforced concrete. A totally new material could enable radically different building designs that couldn't be constructed using current materials. The earthquake-readiness of a building made with a bendable concrete structure could also be significantly enhanced. And the self-healing aspects have important ecological implications, giving infrastructure elements like bridges much longer life-spans, negating--or at least delaying--the need for expensive and eco-unfriendly rebuilds.
[via Physorg]
Related: Scientists Invent Scratch-Proof Paint
Related Stories: | Topics:Innovation, Technology, Design, Bendycrete, self-healing, concrete, ECC, engineering cement composite, structures, architecture, Victor Li, eco-friendly, Victor Li, Michigan University, Michigan, Science and Technology, Civil Engineering |
Email
Digg
StumbleUpon
Facebook
Buzz Up!
LinkedIn
Recent Comments | 7 Total
April 23, 2009 at 12:57pm by Mathew Glomit
Wow, the lives this could save in earthquake zones. Hopefully its cheap enough to viral the costs of ordinary concrete, otherwise cost cutting will exclude it.
Ed
MegaDroid
April 23, 2009 at 12:58pm by Mathew Glomit
Wow, the lives this could save in earthquake zones. Hopefully its cheap enough to viral the costs of ordinary concrete, otherwise cost cutting will exclude it.
Ed
MegaDroid
April 23, 2009 at 1:29pm by Kit Eaton
@Mathew. Yep--that's hopefully a spin-off. Considering it starts with fairly "normal" concrete, we can hope the price isn't too high.
April 23, 2009 at 9:20pm by Bernie Mabalot
We need to exercise proper cautions in adapting with a new tech., it still needs to pass the health implications for those who want to use it. Does it not affect us like asbestos in the long run? A chemically grown fiber like in fiberglass has a serious implication on those who breath it, the calcium carbonate that will be powdered and inhaled - a possibility of sealing your lungs, your family or your employee - its good but we need more safety precaution.
April 24, 2009 at 7:13am by Kit Eaton
@Bernie. A proper cautionary stance is sensible, and legally required too, of course. Not too sure about worrying about calcium carbonate though--it's already found in cement, and it's used as an antacid medicine.
September 26, 2009 at 2:27am by stephen marks
If they will use polished concrete floors than It will certainly help them to survive in the earthquake of 7.5 in the reactor scale. They are doing a great job to serve the humanity and if they will be succeeded than it will be a very helpful thing to sustain in the natural disasters.