Re: Scientist Says Concrete Was Used in Pyramids

On Mon, 11 Dec 2006 07:42:28 GMT, Kendall K. Down
<webmaster@xxxxxxxxxxxxxxxxxx> wrote:

In message <nSZeh.182361$Fi1.83699@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
prd <X_header@xxxxxxxxxxx> wrote:

Strong enough to support the weight of the Great Pyramid, but too weak
for load-bearing arches? Do I detect a contradiction here?

In concretes stretch strengths and compression strengths are very
different.

I think you are forgetting that an arch is in compression.


It depends upon how well the shape of the arch conforms to that
required to support the load applied to it. The ancients had little
understanding of the mechanics of load bearing arches it it is likely
that parts of an ancient homogenous (cast) arch would have been in
tension. A masonry arch does not have this problem for the simple
reason that the joints do not support tensile forces.



Eric Stevens
.