[Cob] Re: [SB-r-us] bales vs. cob vs. adobe

[SALAS]

Hi all.

Haven't posted in a while-busy with another school project in Deming, New Mexico.

I had this discussion with Tibbits and Levine at New Mexico Earth a few weeks ago, basically an attempt at making the distinction between the various terminologies and how or when they apply to earthen materials.  

Yesterday I picked up some clay material--100% clay from a local quarry that found some in their sand & gravel pit.  I'm making some test samples for an 800 ft long wall.

Here's the dilemma.  I mixed the clay material all by its self--it was so heavy and sticky, I felt that I had my hand in a bucket of Henry's roofing tar.  I mixed it with just enough water to roll out a foot long sausage about 3" inches thick.

Next I took some of our Rio Rancho blow sand--sand-caliche with only a trace of clay--->1%.  Oh, there was some 1/2" straw in it that had blown out of the dog's kennel.  I molded it into some what of a sausage about the same as the all clay batch.--kinda because it just would not bind together.  This stuff gets rock hard if it is packed down when still damp. but only the first 1/2" or so.

I cut the all clay unit into 4 pieces and then did the same to the blow sand unit.  I then combined 3 parts of the blow sand with 1 part of the clay and mixed it (3:1) until I could shape it and it would hold together--extremely well.

I now have 3 samples drying--1) is the 3:1 clay-blow sand mix, 2) the all blow sand remains and 3) the all clay remains.  By observing all 3, I will be able to adjust the mix for the production run.

I plan to mix the material in a 7 yd volumetric mixer and place the material in into forms that are 12" wide x 60" tall.  The plan is to place the material in 4" lifts by a length of 270 feet and the add an additional lift, wait a day or so and continue until finished.  Now here's the question,

1) is this formed adobe or formed earthen wall?
2) if I pad it down with my hands, is it puddled earth if I pull the form and leave my hand prints on the wall?
3) is it adobe, albeit a long one?
4) is it cob because it does have straw and meets the clay criteria?
5) none of the above

I plan to use the same materials with added cement-lime for the render--now is it ..............................

Paul Salas
Gen Mgr
SANCO Enterprises, LLC
PO Box 45741
Rio Rancho, NM  87174
(505)  238-0427
chansey at earthlink.net