[GSBN] Compression (Digest, Vol 50, Issue 1)
ArchiLogic at yahoo.ca
Tue Jun 2 18:41:04 CDT 2015
On Tue, 02 Jun 2015, André de Bouter <contact at lamaisonenpaille.com> écrit
> I'm looking for is a cheap, secure and rapid way to compress the SB
> walls 'a whole lot', that can, preferably, be reproduced on building
> sites. And if possible in a way that one can predifine the compression
Cher Squeezit de Bouter;
When a massive concrete bridge deck has collapsed and emergency personnel
want an easy, safe and economical means to jack it up in order to rescue
people trapped underneath, an "air jack" made by simply gluing up a piece
of EPDM sheet to make a pillow that can be slid into a narrow space as
little as a mere centimetre (before inflation) and then inflated, works
Some simple arithmetic demonstrates how effective this method can be:
I typically inflate the tires in my "dog bike" (an MTB-style) to about 40
pounds per square inch (psi) (~ 275 kiloPascals (kPa), which is less than
half the pressure of that typically used for road bike tires and easy to
do with even the crappiest of manual tire pumps.
Looking at a 2-string bale wall (bales laid flat), a nominal 18 inches
wide (0.45 metres),
40 psi x 18 inches (width) x 12 inches (length) = 8540 pounds of pressure
applied per lineal foot of wall.
That is to say, if one used a tube inflated to 40 psi to apply pressure to
the top of a bale wall, you would be applying 8540 lbs pressure to each
one foot length of wall (~ 125 kN/m).
I'll let you figure out how many straps or steel roads and at what
frequency you'd have to use to achieve the same (if in fact you could do
it all with those devices in any reasonable fashion).
Pretty easy to show whomever needs to see, what the applied stress is,
when using an inflated bag or tube -- you just put a tire pressure gauge
on the valve.
Years ago (in the 1990s ?) Bob Platts utilised this principle to make a
system for pre-compressing bale walls as part of a CMHC (Canada Mortgage
and Housing Corp) research project I know that listmembers Habib Gonzales
and John Glassford have owned/used that proprietary product/system and
perhaps can offer some insights on how it could be improved or made
Bon chance, eh (?), mon ami.
=== * ===
Rob "Stronzo di Nord" Tom ADT1
Kanata, Ontario, Canada
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