Cob: soil tests

[Matthew HALL(SED)]

ap615 at hotmail.com writes:
>The Hand Sculpted House mentions testing for enough sand by how it sounds 
>when you squeeze a handful next to your ear.  In addition to how it cracks 
>or doesn't crack. That's the first aural test I've heard of, and I do like 
>the idea of using all our senses.

Have you read 'Earth construction: a comprehensive guide' by Houben & Guillaud? There are all sorts
of these 'field' tests described in there, some sensory-type ones as well.

There is, for example, one that allows you to discern between different particle sizes by
tasting/chewing! 

According to the 'taste' test...sand goes 'crunch' with a 'disagreeable sensation, silt smooth and
is not disagreeable, whilst clay is like flour and no abrasive sensation can be felt.

>From an engineering point of view, we (in the UK) classify soil particle sizes as follows:
Sand = 2mm - 63microns
Silt = 63microns - 2 microns
Clay = less than 2 microns

Sizes vary from country to country
Regards
Matthew
____________________________________________________________________
Matthew Hall BSc (Hons) GradBEng
Centre for the Built Environment
Unit 9 Science Park
Sheffield Hallam University
Pond Street
Sheffield S1 1WB
England

Tel: +44 (0) 114 225 3200
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E-mail: M.Hall at shu.ac.uk
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