Cob: Codes Testing

[Alison Krohn]

I hope this is not addressed directly in the archives.  I breezed
through them and couldn't find exactly what I'm looking for.
I'm a landscape architecture professor and have been contacted by a
native Ukranian who wants to build what I would call formed cob for a
house in Moorehead, MN.  Needless to say, the local officials want
someone to sign off on his design.  NDSU has some architecture profs who
are interested in this method but are leery about this project.  My
concern is the local soil material.  It is fat clay with a high
shrink-swell rate (plasticity 25-50, CH silty clay according to the soil
survey).  These soils have toppled grain bins!  Am I right in believing
this is not a good material for earth-straw walls?  Anatoly made some
test bricks that our engineers will run compression tests on.  One of
them was amended with lime and or cement.  It was very light and seemed
very strong. I am inclined to think that this material would be better.
So here are my major queries to the list:
Do any states have codes for formed cob?
Shouldn't sand be added to the mix? 70% I believe I've read
What is the difference between forming this mix and rammed earth?
Rammed earth has no straw?
Which labs are approved for testing nonconventional materials in the
upper midwest?
Is there an experienced engineer or architect who'd be interested in
helping with this project?

The codes department also wants an R-value because MN requires a
threshold of energy efficiency for all homes, and fire resistance
although I question the official's common sense on this one.

Any assistance/advice/web pages will be greatly appreciated.

Alison