HomeDiagramsDatabaseMapsForum About
     

Go Back   SkyscraperPage Forum > Discussion Forums > Engineering


Reply

 
Thread Tools Display Modes
     
     
  #1  
Old Posted May 15, 2015, 11:26 PM
M II A II R II K's Avatar
M II A II R II K M II A II R II K is offline
Registered User
 
Join Date: Aug 2002
Location: Toronto
Posts: 52,200
The 'living concrete' that can heal itself

The 'living concrete' that can heal itself


May 14, 2015

By Andrew Stewart

Read More: http://www.cnn.com/2015/05/14/tech/b...ers/index.html

Quote:
.....

The bioconcrete is mixed just like regular concrete, but with an extra ingredient -- the "healing agent." It remains intact during mixing, only dissolving and becoming active if the concrete cracks and water gets in.

- Jonkers, a microbiologist, began working on it in 2006, when a concrete technologist asked him if it would be possible to use bacteria to make self-healing concrete. It took Jonkers three years to crack the problem -- but there were some tricky challenges to overcome. --- "You need bacteria that can survive the harsh environment of concrete," says Jonkers. "It's a rock-like, stone-like material, very dry."

- Concrete is extremely alkaline and the "healing" bacteria must wait dormant for years before being activated by water. Jonkers chose bacillus bacteria for the job, because they thrive in alkaline conditions and produce spores that can survive for decades without food or oxygen. --- "The next challenge was not only to have the bacteria active in concrete, but also to make them produce repair material for the concrete -- and that is limestone," Jonkers explains.

- In order to produce limestone the bacilli need a food source. Sugar was one option, but adding sugar to the mix would create soft, weak, concrete. In the end, Jonkers chose calcium lactate, setting the bacteria and calcium lactate into capsules made from biodegradable plastic and adding the capsules to the wet concrete mix. When cracks eventually begin to form in the concrete, water enters and open the capsules.

- The bacteria then germinate, multiply and feed on the lactate, and in doing so they combine the calcium with carbonate ions to form calcite, or limestone, which closes up the cracks. Now Jonkers hopes his concrete could be the start of a new age of biological buildings. --- "It is combining nature with construction materials," he says. "Nature is supplying us a lot of functionality for free -- in this case, limestone-producing bacteria.

.....



Video Link
__________________
ASDFGHJK
Reply With Quote
     
     
End
 
 
Reply

Go Back   SkyscraperPage Forum > Discussion Forums > Engineering
Forum Jump


Thread Tools
Display Modes

Forum Jump


All times are GMT. The time now is 9:33 AM.

     
SkyscraperPage.com - Archive - Privacy Statement - Top

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.