Nanotubes and Dams

name         Elsie R.
status       educator
location     MO

Question -   Can nanotubes be used in the
construction of dams and levees?
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Hi Elsie,

Carbon nanotubes exhibit, as you may have heard, very high
tensile strength. But tensile strength is basically useless
in the construction of dams and levees, which are subjected
mainly to compressive stress. In compression, carbon
nanotubes have very little more to offer than traditionally
used materials such as concrete.

Regardless, the use of carbon nanotubes in any sizeable
structure is impractical, since they are little more than
laboratory curiosities at this time, and have only been made
in very small quantities. Cost is another factor. The related
but less exotic material, carbon fiber, which also excels in
tensile (but not compressive) strength, is currently
available but is very expensive. Once material made of carbon
nanotubes is commercially available, it is expected that it
will be far more expensive still. A dam-sized structure made
of this material would probably bankrupt the country! Also
note that materials like carbon fiber and carbon nanotubes
are made from oil. The amount of oil needed to make a dam,
made from this material, would be astronomical! So the best
material for this application is still good old concrete.

Regards,

Bob Wilson.
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The cost of such a construction material would be out of sight. At 
present, nanotubes and nanotechnology is very new. No one knows what 
applications might be found, but at the present state of 
development, dams and levees would not be very practical.

Vince Calder
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