h a l f b a k e r yAlas, poor spelling!
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So,
concrete. good compressive, poor tensile strength.
idea: to give concrete directional microstructure.
how?
using a ferromagnetic component of the mixture,
exposed to
a magnetic field to which it will align.
Make it better?
ok. Coat the ferromagnetic material in a cement
reaction
retarder (sugar usually) possibly with a slow release
agent,
like shellac.
Palaeomagnetism
http://en.wikipedia...wiki/Paleomagnetism
[vfrackis, Jan 03 2013]
[link]
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This would be an amazing, revolutionary new building
material right up until the point somebody realized that
this is what pre-stressed rebar is for. |
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Having it couched as such might temper my derision,
certainly. |
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How is this "directional microstructure" supposed to help? |
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I know it's difficult to imagine, but some people actually
believe that order is better than chaos. |
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//How is this "directional microstructure"
supposed to help?// |
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I'm not saying the idea would work, but imparting
a "grain" to an otherwise amorphous material is
useful. |
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A lot of our construction technology is based on
beams and columns, where strength in one
direction is much
more important than strength in another*. Thus,
if
you are going to reinforce concrete beams with
some sort of fibre, you want the fibres aligned
along the beam; if they're randomly orientated, a
lot of their tensile strength is wasted. This, of
course, is why conventional pre-stressed or
reinforced concrete beams have the tensile
members predominantly along the long axis. |
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(The rest of it is based on shells, where strength
in two directions is more important than strength
in the third.) |
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directional micro structure would help to realize new
properties. I read of a metallurgy project in which the
atomic structure of particular materials was atom by
atom manually aligned the results were "new"
characteristics
previously unknown to science like incredible strength
or hardness. The one example I remember as standing
out was I think aluminum or zinc (not sure) became
diaphanous after the process was completed.
It was cool stuff |
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That said I think all concrete has a directional micro
structure that is aligned to the earths magnetic field
already.
One of the ways that they(they =geologists) know that
the earths
magnetic poles have in the past flipped (measurably
approximately every 600,000 years) is that molten
rock that solidified within a particular magnetic field
had a different magnetic signature than others or
something like that, it was a significant discovery way
back in the 20th century |
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I see this being useful where a foundation needs to
hold up a house or other weight, but also needs to
be flexible during floods or frost heaves. It could
bend temporarily and not break, all while staying rigid
in the other direction. Houses of the future thank
you. Also I have heard of instances where they infuse
plastic into concrete to keep it flexible, but that's in
all directions. |
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