[Cob] cob shake test info

[Janet Standeford]

The problem here is that when you are in the middle of a wall, you cannot
wait for the cob to cure enough in a psi container!
You have to go by feel and all the preliminary tests such as determining
the strength through the snake test, etc.

It took my samples at least 3 months to cure enough to get a 350 psi? I
can't remember the exact number at the moment but it was load bearing.

Wet cob is not going to get anywhere near those numbers. It will simply
fall apart!

When you are racing weather, you can't take this kind of time to psi test
periodically. That would be insane.

On Thu, May 17, 2012 at 11:52 AM, dhowell at pickensprogressonline.com <
dhowell at pickensprogressonline.com> wrote:

> Ed,
>        Understood about quality control. I must point out concrete mixes
> from scratch in a wheelbarrow can also have vastly different strengths
> according to the amount of water used. Adobe bricks? New Mexico Earthen
> Building Materials code states, "each of the tests prescribed in this
> section shall be applied to sample units selected at random at a ratio of
> five units per twenty-five thousand bricks to be used or at the discretion
> of the building official." Five out of 25,000 seems like a pretty
> unrepresentative number for the whole. Quality control can be done by
> performing tests at the foundation, sill height, and lintel height of the
> walls. Did you know the adobe code allows a psi of 250 and one out of five
> can have a psi less than that? We're talking about the same material just a
> different building procedure. Their code is a good guideline, but some
> things are questionable, such as it requires concrete stucco which is an
> accident waiting to happen according to the Devon Earth Building
> Association. A healthy topic that must be discussed, don't you think?
> Damon
>
> On May 17, 2012, at 2:09 PM, Henry Raduazo wrote:
>
>         The problem might be one of quality control. When you are mixing
>> something in a large batching machine (like a concrete mixer) you have
>> large 3-5 yard batches which are perfectly uniform. When you have small
>> crews making 1/27th of a yard batches on a tarp asserting quality control
>> is a nightmare. Every crew can not make every batch the same let alone
>> getting the 5 or 6 different crews to make uniform batches.
>>        I have been able to make uniform cob batches by mixing one ton
>> batches on a concrete slab with a rototiller. That might satisfy a quality
>> control person, but getting such anal persons to accept hundreds of batches
>> made by half a dozen different crews might be expecting too much even if we
>> had a code that described the material in a way to differentiate acceptable
>> cob from unacceptable cob.
>>
>> Ed
>> On May 17, 2012, at 11:29 AM, dhowell at pickensprogressonline.**com<dhowell at pickensprogressonline.com>wrote:
>>
>>  Thanks Ron,
>>>        As I mentioned; "but no paperwork which building officials will
>>> accept."
>>>
>>>
>>>
>>> On May 16, 2012, at 8:17 PM, Henry Raduazo wrote:
>>>
>>>  but no paperwork which building officials will accept.
>>>>>
>>>>
>>>
>>
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