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Crushed wood is stronger than steel

nature.com

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Re: Crushed wood is stronger than steel

#141

Post by vanderZwan »

willvarfar wrote: post #19

People may also find Pykrete interesting https://en.wikipedia.org/wiki/Pykrete Its adding wood pulp to ice to make the ice much much tougher. It was invented by the epitome boffin Geoffrey Pyke, who proposed they build an aircraft carrier of it! https://en.wikipedia.org/wiki/Project_Habakkuk

So in the Dutch equivalent of Secret Santa, we have a tradition where the gifts are cheap, small and silly, but the giftwrapping should somehow be an elaborate prank. Does the US have something like that? Sounds like something people in college would do.

Anyway, I bring this up because friend of mine once decided to encase a small gift in the centre of a bucket full of pykrete.

The joke obviously would that the receiver would just have to wait for the thing to thaw because it was impossibly hard to break it. Then they discovered that somehow, the woodpulp in pykrete makes it extra insulating. On top of that, since it wasn't a flat slab but a roundish sphere (low surface area compared to volume), it didn't exactly absorb ambient heat quickly either. So that other friend apparently had to wait over a week before the thing was thawed enough break open.

Re: Crushed wood is stronger than steel

#143

Post by bdamm »

ZenoArrow wrote: post #137
monochromatic wrote: post #110

Earlier quoted context omitted.

There’s also stabilized wood. You basically fill all the space inside the wood with a hard resin. Small pieces are used for things like jewelry, knife scales, etc.

Your comment reminded me of a technique that guitar makers have been using in recent years, which is to make wood more stable by roasting it in a kiln (which removes the moisture from the wood, and supposedly increases its stability).

If by "recent" you mean developed about 200 years ago, then yes.

Re: Crushed wood is stronger than steel

#144

Post by jacquesm »

Serow225 wrote: post #133
euroclydon wrote: post #39

Earlier quoted context omitted.

Do you mind sharing a picture of this done right? The end grain wood floor pics I found on Google look mostly hideous to me.

I work at Red Wing Shoe Company, and our office has this type of flooring on the first floor: https://i.imgur.com/arWH5NR.jpg

That's gorgeous.

Re: Crushed wood is stronger than steel

#145

Post by jacquesm »

thatcat wrote: post #138
jacquesm wrote: post #127

Earlier quoted context omitted.

https://www.google.nl/search?q=butchers+block&client=firefox... Plenty of floor links already in this thread.

There are no links or threads related to axial compression. I guess your original post ment that it is compressed during use rather than constrution.

It can be either way. The 'during construction' bit is done using compacting hammers and then afterwards it is sanded down again to expose the grain, the pounding can splinter the topmost layer. And after the sanding the floor is nice and smooth, the pounding leaves it somewhat uneven because the wood isn't equal density everywhere.

You can drop a hammer head down on that stuff and it won't even leave a dent.

Re: Crushed wood is stronger than steel

#146

Post by ZenoArrow »

bdamm wrote: post #143
ZenoArrow wrote: post #137

Earlier quoted context omitted.

Your comment reminded me of a technique that guitar makers have been using in recent years, which is to make wood more stable by roasting it in a kiln (which removes the moisture from the wood, and supposedly increases its stability).

If by "recent" you mean developed about 200 years ago, then yes.

From what I've seen, it's become more popular recently (last 10 years).

Re: Crushed wood is stronger than steel

#147

Post by cbsmith »

jacquesm wrote: post #6

The most expensive wooden floors have the end grain exposed facing upwards and this is then compressed down, much like the top of a good quality butchers block. Those floors are just about indestructible. The heavier such floors are used the stronger they get! The wood in the article is compressed crosswise to the grain (so they get thinner rather than shorter), using the original planks as the raw organic material t…

The story does make a lot of references to previous work done, and even has a quote about how this method seems expensive and no better than existing methods.

It looks like the paper (https://www.nature.com/articles/nature25476) provides the detail you are looking for.

Re: Crushed wood is stronger than steel

#148

Post by twic »

Isamu wrote: post #88
jacquesm wrote: post #6

The most expensive wooden floors have the end grain exposed facing upwards and this is then compressed down, much like the top of a good quality butchers block. Those floors are just about indestructible. The heavier such floors are used the stronger they get! The wood in the article is compressed crosswise to the grain (so they get thinner rather than shorter), using the original planks as the raw organic material t…

There is still a street in Pittsburgh that is end-grain wood blocks. (In Shadyside, a short residential street.) They continue to treat it with tar. So I wonder if it was a similar idea.

There's a tiny amount left in London:

https://www.ianvisits.co.uk/blog/2015/01/10/the-time-when-lo...

This seems to be a topic which animates a certain kind of urbanist nerd (of whom Ian Visits is the prince):

http://www.roadswerenotbuiltforcars.com/wood/

http://www.endgrain.org.uk/history/

That last page is from some Welsh applied research project on using more endgrain wood for surfaces; there's lots more interesting material on that site.

Re: Crushed wood is stronger than steel

#149

Post by justinlardinois »

mcguire wrote: post #89

" Five layers of the material laminated together — just 3 millimetres thick in total — was able to halt a 46-gram steel projectile travelling at roughly 30 metres per second. [...] That’s much slower than the several hundred metres per second at which a bullet travels, says Hu, but it is comparable to the speed at which a car might be moving before a collision, making the material possibly suitable for use in vehicle…

Also, you _want_ a car to crumple on impact, so the passengers aren't taking the brunt of the force.

Re: Crushed wood is stronger than steel

#150

Post by gkanai »

brudgers wrote: post #86
jacquesm wrote: post #6

The most expensive wooden floors have the end grain exposed facing upwards and this is then compressed down, much like the top of a good quality butchers block. Those floors are just about indestructible. The heavier such floors are used the stronger they get! The wood in the article is compressed crosswise to the grain (so they get thinner rather than shorter), using the original planks as the raw organic material t…

none of those ever made it to very high levels of industrial adoption. Non-exotic methods of strengthening wood, made it to high levels of production in spades: plywood, oriented strand board, microlam and glulam beams, and medium density fiber board (MDF) are direct examples. Wood I-joists and plate connected wood trusses are less direct. From a functional standpoint, standardization of lumber grades is a social tec…

Fire treated wood is called 'shou-sugi-ban' in Japanese and is occasionally used in commercial and residential applications. Fire treated wood has the benefit of being naturally fire-resistant, insect resistant, and water/rot resistant while also being a natural treatment (as opposed to a man-made chemical treatment.)

https://shousugiban.org/

https://www.treehugger.com/sustainable-product-design/materi...

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