[Greenbuilding] adobe question

[Alan Abrams]

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they had an adobe house on HGTV last night and the guy showed how he made
his blocks and he added asphalt emulsion to the mix ????

I thought adobes were all natural materials
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Back in the seventies, in the Espanola Valley of NM, I built my first house
with adobes; a 600 sf cottage using about 2000 bricks.  (I carried them 100
at a time in my '61 Ford half ton until I bent the rear axel on the
washboard road, thenceforth 75 at a time.)  They were made a mile up the
road using the local hardpan soil shoveled into a tag-along mortar mixer (by
some unnamed alembristas, working for the local patron for the summer).  I
think I paid $0.15 a brick.  

The mix included some chopped straw and nothing else.  The 10"x14"x3 1/2"
thick sun dried bricks could be held waist high and dropped to the ground
(usually) without breaking.  I made the mortar on site from a similar mix,
sans straw.

There was a more "formal" operation down the highway toward Santa Fe;
someone had a battered ready-mix truck--no longer road worthy, and an
ancient Farm All with a front end loader.  They had two mixes; one, a
natural mix as described above, and one with something like 2% asphalt
emulsion and no straw, AKA "stabilized" adobe.  The alternate mix was for
BIA contracts for homes on the Pueblo reservations; govt regs called for the
asphalt additive and no organic material.  I never used them, but understood
they would not pass the waist-high test--the straw gives the bricks tensile
strength.  OTOH, they are supposedly more resistant to rain.  

AA