3 ms·

I am confused by your comment. Wood does not disintegrate in water if it stays out of contact with the air ?

jacquesm 11mo ago
Indeed, if it is just saturated in an oxygen poor environment it will last for a very long time. As soon as you expose it to air it starts to rot, and pretty quickly too. This effect is compounded by the mechanical effects of repeatedly shrinking due to drying out and then re-absorbing water again until the wood is saturated. More than you probably ever wanted to know about this subject: https://www.tandfonline.com/doi/full/10.1080/17480272.2025.2466104#d1e1074 https://www.tandfonline.com/doi/full/10.1080/17480272.2025.2... https://www.waternet.nl/en/our-water/groundwater/ https://www.waternet.nl/en/our-water/groundwater/ Lots of houses and other historical buildings in Amsterdam are having their foundation supporting piles replaced. This is a very challenging operation and highly specialized gear has been built to do the job, and with a minimum of vibration to reduce the chance of damage to the structure. They're called 'schroefinjectiepalen' in dutch (too many letters for Scrabble). The essential piece of kit is a tiny pile driver that gets lifted into the basement of a building and that then pushes hollow steel shells into the soil until resistance. Each shell is threaded, much like drilling rig piles from oil drilling, only much shorter, typically 1 to 2 meters in length. When the required resistance is met the shells are filled with grout, so you end up with an inside-out reinforced concrete post that once it has cured can be load bearing. There are also versions where the grout escapes the post and forms a shell around it and there are versions where there is more armoring inserted into the steel tube. Edit: finally found a good English language article: https://www.walinco.nl/g-grouts.htm https://www.walinco.nl/g-grouts.htm These little machines are quite the feat of engineering, some of them are so small they fit through a standard doorway. https://www.schroefinjectiebv.nl/wp-content/uploads/2019/11/IMG_2550.jpg https://www.schroefinjectiebv.nl/wp-content/uploads/2019/11/... Here is a picture of one under one of Amsterdam's theaters: http://funderingstechniek.com/foto/carre3.jpg http://funderingstechniek.com/foto/carre3.jpg
- Akronymus 11mo ago
  > They're called 'schroefinjectiepalen' in dutch (too many letters for Scrabble). I was about to comment that you could form it in multiple steps, but turns out, I forgot about the size limitation of the scrabble board/how many of each letter. Either way, that's some neat tech. Specialized machines for such "obscure" usages are pretty interesting. Partially because you just never even think about those existing until you hear of em.
  - jacquesm 11mo ago
    It's a very interesting subject. At first the judgement was 'it can't be done' and then some enterprising company came up with a very creative solution.
    - Akronymus 11mo ago
      And for me, I hadn't even thought of that being a problem, or wood being used for foundations, or... and so on. Just, so many chains of logic I probably will never even think about that lead to such neat tech which would be interesting to me. Makes one wonder what else there is.

Indeed, if it is just saturated in an oxygen poor environment it will last for a very long time. As soon as you expose it to air it starts to rot, and pretty quickly too. This effect is compounded by the mechanical effects of repeatedly shrinking due to drying out and then re-absorbing water again until the wood is saturated. More than you probably ever wanted to know about this subject: https://www.tandfonline.com/doi/full/10.1080/17480272.2025.2466104#d1e1074 https://www.tandfonline.com/doi/full/10.1080/17480272.2025.2... https://www.waternet.nl/en/our-water/groundwater/ https://www.waternet.nl/en/our-water/groundwater/ Lots of houses and other historical buildings in Amsterdam are having their foundation supporting piles replaced. This is a very challenging operation and highly specialized gear has been built to do the job, and with a minimum of vibration to reduce the chance of damage to the structure. They're called 'schroefinjectiepalen' in dutch (too many letters for Scrabble). The essential piece of kit is a tiny pile driver that gets lifted into the basement of a building and that then pushes hollow steel shells into the soil until resistance. Each shell is threaded, much like drilling rig piles from oil drilling, only much shorter, typically 1 to 2 meters in length. When the required resistance is met the shells are filled with grout, so you end up with an inside-out reinforced concrete post that once it has cured can be load bearing. There are also versions where the grout escapes the post and forms a shell around it and there are versions where there is more armoring inserted into the steel tube. Edit: finally found a good English language article: https://www.walinco.nl/g-grouts.htm https://www.walinco.nl/g-grouts.htm These little machines are quite the feat of engineering, some of them are so small they fit through a standard doorway. https://www.schroefinjectiebv.nl/wp-content/uploads/2019/11/IMG_2550.jpg https://www.schroefinjectiebv.nl/wp-content/uploads/2019/11/... Here is a picture of one under one of Amsterdam's theaters: http://funderingstechniek.com/foto/carre3.jpg http://funderingstechniek.com/foto/carre3.jpg

Akronymus 11mo ago
> They're called 'schroefinjectiepalen' in dutch (too many letters for Scrabble). I was about to comment that you could form it in multiple steps, but turns out, I forgot about the size limitation of the scrabble board/how many of each letter. Either way, that's some neat tech. Specialized machines for such "obscure" usages are pretty interesting. Partially because you just never even think about those existing until you hear of em.
- jacquesm 11mo ago
  It's a very interesting subject. At first the judgement was 'it can't be done' and then some enterprising company came up with a very creative solution.
  - Akronymus 11mo ago
    And for me, I hadn't even thought of that being a problem, or wood being used for foundations, or... and so on. Just, so many chains of logic I probably will never even think about that lead to such neat tech which would be interesting to me. Makes one wonder what else there is.