Tag Archives: self-repairing materials

Self-healing concrete made by including bacteria

Concrete is incredibly tough under pressure – that’s why it’s so critical in buildings and roads.  But it’s not so strong under tension – you can pull it apart much easier than you can crush it, which leads to cracks in concrete that sees a lot of temperature changes and/or heavy use.  Steel rebar is used to reinforce the stuff and make it last longer, but the cracks still appear and grow over time.

Enter a calcium carbonate-producing bacteria.  Dormant spores, along with some bacteria food, were mixed into concrete.  When the resulting block was cracked, the bacteria woke up because of the newly-available oxygen from the air and started producing calcium carbonate (which is what makes up limestone), repairing the crack.  Once the crack had closed up, the bacteria went back into hibernation mode.  Clever, right?  It wouldn’t last forever, of course, but it could still extend the lifetime of concrete in a number of applications.


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CES continues(!), sunflower-inspired solar-thermal systems, and many other things



  • The US military’s drone war in Pakistan is back online, despite the tensions created by “friendly” fire incidents.
  • Stealth tech keeps getting more and more elaborate.  This article in PopSci talks about a fluid cloak for submarines, and this one about low-heat-signature tanks.





  • A new photovoltaic solar system is being tested, in combination with a greenhouse, that will allow light through the panels in the winter, when the plants need it, and convert some of it to energy in the summer, when they don’t.
  • I mentioned incentives yesterday, here’s another example:  Conservationists are getting increasingly agitated about the increased rate of whaling these days; legal processes don’t seem to work, and illegal ones (Sea Shepherd, for example) don’t have much effect either.  So one bright fellow suggested that whaling be governed by quotas like the ones that some countries have set up for catching fish – whalers would have to bid for the right to catch whales, except that in this idea, conservationists would be able to bid as well in order to keep the whalers from catching so many whales.


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