But can jet fuel melt crushed wood?
Crushed wood is stronger than steel
81–90 of 180 posts
Re: Crushed wood is stronger than steel
#82Earlier quoted context omitted.
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).
I have a technique I'd use to add heat resistance to steel. Only necessary If we lived in a doomed world where engineers didn't exist and I was asked to make steel more heat resistant. Cover steel beams in a relatively thick later of plaster of paris mixed with very find grain sand. I built a charcoal forge out of that material (I used quartz sand I got from a pool supply store) and it's ludicrously heat resistant. I…
They did a similar thing with spray on asbestos but this is obviously no longer an option.
Re: Crushed wood is stronger than steel
#83The 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…
Sorry to go on a tangent, but your comment reminded me of a book I read about the Chinese culinary culture pre-revolution. Chinese chefs had, and may still have, wooden cutting boards that were conditioned somehow such that they were as hard as stone. (There was also an implication that they resisted bacteria unlike normal wood boards when not scoured properly.) These boards were passed down from generation to genera…
Yes, many Chinese chefs and households still do use wooden chopping boards. I am not sure if the boards are as hard as stones, since there are many different kinds of stones. But thickness and the type of wooden do matter and will certainly make the wood very hard to crack (and to burn).
Here are some videos for the readers:
https://www.youtube.com/watch?v=oTNVDH6ZFLg
https://www.youtube.com/watch?v=isFTIHy7Duo
You will see pork bone chopping (beginning of the video), skin slicing (1:40), and meat grinding (5:30) in the second video.
Those are very typical boards in a restaurant's kitchen. The typical household chop board is a lot smaller and thinner, probably around 35" wide x 5" high. However, many families have moved away from wooden chopping board because plastic boards are easier to clean.
As far as resistance to bacteria, that will fall short with science. The passing down from generation to generation is a cultural effect. If you live with your in-laws, the board will of course be reused. Since wooden boards don't crack for years, yes, the board will be passed down. Butchers (Chinese and other cultures) use wooden boards because of the durability (Chinese chefs love chopping real fast with force). Real chefs prefer wooden chopping board (yeah, your famous Gordon Ramsay!)
Also, it is very common to see a butcher or a chef to stick the big kitchen knife on the side of the board tilted like the Leaning Tower of Pisa :-) The strength of a real butcher or a real chef can be so much more powerful than a MMA boxer.
EDIT: If you want a short English intro on this topic, https://www.youtube.com/watch?v=gDdoht0e1sg is solid.
Re: Crushed wood is stronger than steel
#84Earlier 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…
Portland is building a 5 story building with Cross Laminated Beams (all Wood, no steel structure). Its not this material, but is incredibly strong. A 12 story wood building is also being planned in Portland (mentioned in article) http://www.capitalpress.com/Oregon/20171005/nations-largest-...
NL has two wooden bridges that carry heavy traffic:
https://nl.wikipedia.org/wiki/Kr%C3%BAsrak
There is also some steel in there but the arch is entirely made out of wood.
Re: Crushed wood is stronger than steel
#85Earlier quoted context omitted.
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).
I have a technique I'd use to add heat resistance to steel. Only necessary If we lived in a doomed world where engineers didn't exist and I was asked to make steel more heat resistant. Cover steel beams in a relatively thick later of plaster of paris mixed with very find grain sand. I built a charcoal forge out of that material (I used quartz sand I got from a pool supply store) and it's ludicrously heat resistant. I…
If you use a clay like fire clay instead of plaster, it will be much more durable.
Re: Crushed wood is stronger than steel
#86The 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 technology that allows designing wood members with known engineering properties.
On the chemical front, pressure treated lumber increases wood's strength across a timeline. Fire treatment increases wood strength in a narrow set of circumstances.
Of these, plywood is clearly the most successful in terms of industrial adoption being used for aircraft, boats, and furniture among other things.
Re: Crushed wood is stronger than steel
#87The 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…
Sorry to go on a tangent, but your comment reminded me of a book I read about the Chinese culinary culture pre-revolution. Chinese chefs had, and may still have, wooden cutting boards that were conditioned somehow such that they were as hard as stone. (There was also an implication that they resisted bacteria unlike normal wood boards when not scoured properly.) These boards were passed down from generation to genera…
Bamboo cutting boards are often advertised as having anti-microbial properties. No clue if there's any scientific backing to the claim, though.
Re: Crushed wood is stronger than steel
#88The 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.
Re: Crushed wood is stronger than steel
#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 vehicles."
That's not how this works. That's not how any of this works. Nature?
A ballistic impact seems like a poor model for a vehicular impact. You don't want a car to resist impacts the way armor stops bullets. A large, slow projectile isn't a small fast projectile, but should be comparable. This section seems meaningless.
Re: Crushed wood is stronger than steel
#90Earlier quoted context omitted.
I have a technique I'd use to add heat resistance to steel. Only necessary If we lived in a doomed world where engineers didn't exist and I was asked to make steel more heat resistant. Cover steel beams in a relatively thick later of plaster of paris mixed with very find grain sand. I built a charcoal forge out of that material (I used quartz sand I got from a pool supply store) and it's ludicrously heat resistant. I…
If you use a clay like fire clay instead of plaster, it will be much more durable.
Hm, the fire clay I'm familiar with is extremely brittle once it has been through a heating cycle, do you have some specific kind in mind?
The stuff I know is more like glass.