[HN Gopher] Thin, bacteria-coated fibers could lead to self-heal...
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       Thin, bacteria-coated fibers could lead to self-healing concrete
        
       Author : PaulHoule
       Score  : 53 points
       Date   : 2024-03-29 11:17 UTC (11 hours ago)
        
 (HTM) web link (theconversation.com)
 (TXT) w3m dump (theconversation.com)
        
       | ericskiff wrote:
       | Very interesting! I was curious how this related to Roman self-
       | healing concrete: https://news.mit.edu/2023/roman-concrete-
       | durability-lime-cas... and it seems like this is an entirely
       | novel method, where little capsules of bacteria break open when a
       | crack appears and then "heal" the crack through growth until they
       | consume their food stock.
       | 
       | Both the capsule (alginate-based) and bacteria are common and
       | safe
        
         | willmadden wrote:
         | It's the same idea, but instead of calcium carbonate leaking
         | out of quicklime in Roman concrete, it's done by bacteria.
         | 
         | The questions are if the bacteria will survive 50-100 years or
         | more in the real world, and if this can be done economically at
         | scale. My guess is no, it's more of a science experiment or
         | something to be used in niche applications.
        
       | beanjuice wrote:
       | https://www.sciencedirect.com/science/article/abs/pii/S09500...
       | 
       | They produce 60-80 milligram of calcium carbonate 'per fiber',
       | per 30 hours. I'm interested to know how they keep the bacteria
       | alive over time, through the concrete curing process (high
       | temperatures, high level of carbon dioxide, making any liquids in
       | the vicinity highly acidic), and how the bacteria remain viable
       | over time. Concrete we consider to last over decades, or a
       | century?
        
         | littlestymaar wrote:
         | > high level of carbon dioxide, making any liquids in the
         | vicinity highly acidic
         | 
         | Isn't concrete very alkaline by itself? Also where is the
         | carbon dioxide coming from?
        
         | marginalia_nu wrote:
         | Relatively common for bacteria to turn itself into an spore
         | form when it's unhappy with the environment. Can last that way
         | for a very long time.
        
       | Cthulhu_ wrote:
       | > if we work out the kinks and manage to bring it to the market
       | one day, could extend the life span of concrete.
       | 
       | If, could, one day; it sounds like one of many revolutionary
       | battery technology releases, and definitely not the first self-
       | healing concrete innovation either.
        
       | imhereforwifi wrote:
       | I'm curious why they are looking to make new concrete fixes.
       | Would using microplastics and bacteria in the current existing
       | concrete possibly help fix the current breakdowns of old
       | crumbling concrete? It could be a quicker and less bloated fix to
       | the current infrastructure issues.
        
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       (page generated 2024-03-29 23:02 UTC)