Using Concrete to build space ships...

>
> Concrete is an excellent building material. it is strong, offers
> excellent radiation protection and we have allot of experience
> working with concrete. We understand it physical properties and
> limitations. As man continues to move into space, we will also use
> concrete when appropriate.
>

Concrete has notable limitations.

You say it is strong - this is a bit misleading.

It is only strong in static compression.

It is weak in tension, and for varying loads.

Also, it has unpredictable crack propogation properties.

For these reasons it is not used in light weight pressure vessels,
nor in any structure which has a significiant tensile load.

It is also very poor for use in applications where there is lots of
vibration, or the load changes frequently. Concrete is brittle, and
its cracks propagate in unpredictable ways.

These problems can be mitigated somewhat by using pre-stressed
reinforcing rods or mesh. To make concrete bridges tolerant of
earthquakes, for example, complicated helical reinforcing rods are
used.

Light weight pressure vesels are usually made from metallic
materials. Sometimes they are made from composite material, e.g.
Kevlar or Graphite.

Crewed spacecraft are made of presure vessels.

Best regards,

Charles F. Radley