Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Crushed wood is stronger than steel

nature.com

Post reply on HN
Print view View original

31–40 of 180 posts

Re: Crushed wood is stronger than steel

#31

Post by oldandtired »

Something1234 wrote: post #25
jacquesm wrote: post #8

Earlier quoted context omitted.

Engineered wood has been a thing for over 100 years. Wood has a lot of desirable properties that make it a good construction material (fire resistance for instance is much better than steel). This article is definitely missing the wood for the trees to some extent, but it is an interesting development and even if the gain isn't going to be quite as large as indicated and there are some serious questions about whether…

How is wood more fire resistant than steel? What are the metrics used for this?

See the comment above by phonon.

Re: Crushed wood is stronger than steel

#32

Post by HenryBemis »

I remember some time ago, watching an megafactories episode [1], about IKEA, and they described how they create durable, strong wooden frames, which they later using into making various furnitures. I am surprised there is no reference to that process, as I believe IKEA's has probably done 'a lot' of R&D on everything-wood (and probably disqualifies using $$$ criteria).

[1]: https://www.youtube.com/watch?v=vXI6Z3t6PDY

Re: Crushed wood is stronger than steel

#34

Post by gmueckl »

Something1234 wrote: post #25
jacquesm wrote: post #8

Earlier quoted context omitted.

Engineered wood has been a thing for over 100 years. Wood has a lot of desirable properties that make it a good construction material (fire resistance for instance is much better than steel). This article is definitely missing the wood for the trees to some extent, but it is an interesting development and even if the gain isn't going to be quite as large as indicated and there are some serious questions about whether…

How is wood more fire resistant than steel? What are the metrics used for this?

The key is that steel tensile strength goes down quickly as temperature rises. It softens dramatically long before it starts to melt. Wood does much better. My understanding is that wood weakens only by burning off on the surface. The unburnt core essentially seems to retain its mechanical properties for the most part.

Re: Crushed wood is stronger than steel

#35

Post by icegreentea2 »

tzahola wrote: post #13

Define "stronger"

The paper is behind a pay wall, but their figures and extended data stuff is free to view here: https://www.nature.com/articles/nature25476#extended-data

They say that their ultimate tensile strength of their material is ~600 MPa. Steel ranges from 250-2500 MPa.

Re: Crushed wood is stronger than steel

#36

Post by masklinn »

baud147258 wrote: post #26
phonon wrote: post #22

Earlier quoted context omitted.

> (fire resistance for instance is much better than steel). Specifically, steel melts/weakens in a fire, which can result in loss of structural integrity, while heavy timber will char and then very slowly burn. http://www.mace.manchester.ac.uk/project/research/structures... http://www.nzwood.co.nz/faqs/which-building-material-perform...

When the steel is inside concrete (in case of reinforced concrete), doesn't the concrete protect the steel? And since it's how most steel is used in construction, doesn't steel has an advantage here?

Concrete does provide some form of insulation as it has a fairly low rate of heat transfer. At the end of the day it'll still heat up though, and it's that heating up which weakens the steel, direct contact is not a requirement (there are specific methods like insulated concrete form which have higher fire resistance).

Re: Crushed wood is stronger than steel

#37

Post by nck4222 »

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…

>making it effectively thinner, lighter and stronger at the same time.

The article never says it's lighter, and the paper is behind a paywall. Interesting process none the less.

Re: Crushed wood is stronger than steel

#38

Post by waytogo »

Super interesting piece and as somebody who is interested in many things I appreciate such articles.

But seeing this on #1 feels a bit off on HN. Is there a slight possibility that the feed is sometimes curated (eg through different voting powers)?

Re: Crushed wood is stronger than steel

#39

Post by euroclydon »

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…

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.

Re: Crushed wood is stronger than steel

#40

Post by ryanianian »

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

They actually started the planning and final R&D! (That is before they realized that a slowly-melting ship isn't the most stable or sustainable solution to sea-travel and -defense.) https://en.wikipedia.org/wiki/Project_Habakkuk
Post reply on HN