Cob: cob mix

[Shannon C. Dealy]

On Fri, 8 Nov 2002, GlobalCirclenet wrote:

> Technically the straw is not the key to brick strengh, but a tiny
> percentage of caliche containing lime, given the proper ratio of sand and
> clay, more or less. Straw usually helps keep brick from cracking when cured
> properly, but it does not bind particles together at all.

While you are correct that the straw does not contribute to the binding
strength, it is a major source of tensile strength in cob mixes.
Interestingly, the increased tensile strength provided by the straw
can also significantly increase the compressive strength of the dried cob
by helping to keep the sides from pushing out when compressive forces are
applied to the cob.

Shannon C. Dealy      |               DeaTech Research Inc.
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