[Cob] Re: How about another BC test, on sheer strength?

[Raduazo at aol.com]

In a message dated 12/12/2004 1:52:21 AM Eastern Standard Time, 
ocean at woodfiredeatery.com writes:
While we're on the subject of materials testing, another test I'm very 
interested in seeing done ...
    There is lots of testing on lots of things that needs to be done. Here is 
the DC area we have one young lady who is doing a test on earth floors 
(composition and finish) as her high school science fair project. She hopes to find 
if paper or straw gives a more impact resistant to surface an earth floor, and 
also which finish material will result in the most abrasion resistance and 
durability.
    I would like to see someone do a science fair project on wall finishes 
and weather resistance. It would be nice if someone would do a test to see if 
small amounts of cement actually improve wall strength. In one of the rammed 
earth books that I read it sounds to me like the builder put small amounts of 
cement in the mix to make the building inspectors happy rather than to improve 
strength particularly since the earth/sand/cement/water mix was made up several 
days before it was rammed into a form. I would like to see someone do a paper 
cob/bamboo roof test... And, if we think about it for a while I bet we could 
come up with a lot of other things that could use some study. Science fair time 
is just around the corner, but many of the really meaningful projects need 
lots of lead time for testing.
    Earth structures are ideal for testing because they are scalable, because 
the material is affordable and available to almost anyone who wants to do 
testing, because there are so many new combinations of materials and because 
there is so much that we do not know about one of the most common materials on 
earth, clay.
    If you have teenagers that need a science fair project to work on this 
year or next forget electronics or bioengineering. Five to ten percent of the 
earth's carbon dioxide is produced by the manufacture of cement. Some people say 
we can do nothing about global warming, Lets prove them wrong by researching 
mud.
Ed