[GSBN] Catalan vaults

Mon Dec 12 19:49:10 UTC 2011

Hi

 I also received this information from Auroville Earth Institute with some
information that could be useful for those interested on this matter:

** **

The most common stabilisers for soil stabilisation and particularly for
CSEB are cement and lime. The selection of one of them will depend on the
soil quality.****

** **

·       Cement stabilisation requires more sandy soils and the average
stabilisation is 5 % by weight of dry materials. Curing of blocks
stabilised with cement is 4 weeks. The principle is that CSEB should not
dry for 4 weeks.****

Best soils for cement stabilisation are considered to have these
proportions of components:****

15% Gravel (20 - 2mm) + 50% Sand (2 - 0.06mm) + 15% Silt (0.06 - 0.002mm) +
20% Clay (≤ 0.002mm)****

** **

·       Lime stabilization requires more clayey soils and the average
stabilisation is 6 % by weight of dry materials. Curing of blocks
stabilised with lime varies according to the quantity and quality of clay.
In general, blocks have to be kept humid for a week (covered with plastic
sheet, air tight) and then let to dry progressively.****

Best soils for lime stabilisation are considered to have these proportions
of components:****

15% Gravel (20 - 2mm) + 30% Sand (2 - 0.06mm) + 20% Silt (0.06 - 0.002mm) +
35% Clay (≤ 0.002mm)****

** **

Often soils have to be modified, either by sieving to remove coarse
particles, by adding sand to a soil that is too clayey or by mixing various
soils. The amount of sand and stabiliser to add depends on the soil
quality. It is therefore not possible to give a general recipe, as there
are infinite types of soils. The more stabiliser you had, the stronger the
blocks are but also costlier they become. Often we limit the stabiliser to
7-8 % of cement or 10 % lime, in order to optimise the ratio strength/cost.*
***

** **

I suggest you to visit our web site http://www.earth-auroville.com where
you have more information on earth architecture, earth technologies, soil
identification and our activities.****

** **

At your service for further information,****

Yours sincerely,****

** **

Mr. Satprem Maïni****

Architect – Director Auroville Earth Institute****

BASIN **South Asia** – Member****

UNESCO Chair Earthen Architecture – Representative for **Asia******

** **

******************************************************************

Auroville Earth Institute****

Auroshilpam, Auroville 605 101 – T.N. India****

Tel.: 0091 (0) 413 – 262 3064 / 262 3330****

Fax: 0091 (0) 413 – 262 2886****

Email: earthinstitute at auroville.org.in****

Web: http://www.earth-auroville.com

-------------------------------------------------------------

On Mon, Dec 12, 2011 at 7:40 PM, Van Krieken <vankrieken at gmail.com> wrote:

> The Auroville earth institute is doing an amazing work on vaults since
> many years. They also provide special equipments for producing the earth
> blocs.
>
> http://www.earth-auroville.com/auram_earth_equipment_introduction_en.php
>
> Sometime ago I asked them if it was possible to use lime instead of ciment
> (in the earth mix).
> They gave me some ideas regarding an ideal soil.
>
> The ratio soil/sand:**
>
> Note that clayey soils can be used by adding some sand to it. Very clayey
> ones will rather be stabilised with lime instead of cement and adding a
> little sand to it. The best soils for compressed stabilised earth blocks
> are sandier than clayey.****
>
> ** **
>
> We (at Auroville) consider that the best soil for compressed stabilised
> earth blocks has these proportions:****
>
> 10% Gravel (10 to 2 mm diameter)****
>
> 50% sand (2 to 0.06 mm diameter)****
>
> 15% silt (0.06 to 0.002 mm diameter)****
>
> 20% clay (below 0.002 mm diameter)****
>
> ** **
>
> Such a soil is difficult to find as such. It should often be modified by
> sieving and adding some sand if it is too clayey. If it is too sandy, no
> sand should be added.****
>
> ** **
>
> Adding sand and stabilising the soil depends on its quality. Therefore, it
> is not possible to give a general recipe, as soils are as different as
> human beings.****
>
>
> Mr. Satprem of the Auroville Earth Institute was also contacted regarding
> the use of lime as a stabilizer.  He confirmed that it is ok to use lime as
> a stabilizer,as already mentioned above, mainly for soil with more clay.
> For more detailed information regarding the use of lime as a
> stabilizer, you can also write directly to Mr.Satprem
> earthinstitute at auroville.org.in
>
> The Auroville Earth Institute www.earth-auroville.com which has a lot of
> information on earth construction.
>
>
> All the best
>
> Jorge Van Krieken
> Portugal
>
> On Mon, Dec 12, 2011 at 7:20 PM, John Swearingen <
> john.skillfulmeans at gmail.com> wrote:
>
>> Cratere, in Grenoble has done lots of work with blocks, and some vaults.
>>
>> John
>>
>> On Dec 12, 2011, at 11:12 AM, huffnpuff at q.com wrote:
>>
>> > Chris and All,
>> >
>> > I do remember perusing the info posted for the Catalan vaults and found
>> it most interesting. About a year ago I had an opportunity to attend a
>> charrette on Compressed Earth Blocks, hosted by Bernard Amadei at the U. of
>> Colorado. These CEB builders were meeting to discuss similar issues that we
>> SB builder types are/have experienced with acceptance, testing, codes etc.
>> Two fellows of particular vision and spirit were Satprem Maini from the
>> Auroville Institute, India
>> http://www.earth-auroville.com/vaulted_structures_introduction_en.phpand Jim Hallock, of icatis, USA
>> http://www.icatis.org/, both NGO's building with CEB's and Vaults/domes.
>> Both web sites are full of the work these two organizations have done and
>> are eye candy for anyone interested in vaults. If you visit the icatis site
>> you'll see they have teamed with George Nez and built at least one of his
>> 'thin shelled latex concrete' roof systems.
>> >
>> > Currently our local engineer and COSBA member Ian Smith and his wife
>> (both engineers) are on their honeymoon in India at the Auroville Institute
>> at a workshop on vaults. That's devotion...
>> >
>> > Mark Schueneman
>> > COSBA
>> >
>> >
>> > ----- Original Message -----
>> > From: "Chris Magwood" <chris at chrismagwood.ca>
>> > To: "with public archives) Global Straw Building Network (private" <
>> GSBN at greenbuilder.com>
>> > Sent: Sunday, December 11, 2011 9:55:05 AM
>> > Subject: [GSBN] Catalan vaults
>> >
>> > Hi all,
>> >
>> > The mention on this list some months back about Catalan vaults (or
>> > Guastavino vaults) sparked my interest, and we've now decided to forge
>> > ahead and build one as the roof for a buried, earthbag root cellar at
>> > Trent University.
>> >
>> > Does anybody have experience building these, or know of anybody who
>> > does. I'd like to try and hire in somebody to lead us in this build.
>> > It's a small structure (18 x 22 ft) so it won't be a long build, but I
>> > always like to have someone knowledgeable in charge when doing things I
>> > haven't done before.
>> >
>> > The budget for the project is not high, but I would be willing to try
>> > and cover travel costs, food, lodging and a bit of cash for the right
>> > person.
>> >
>> > Let me know!
>> >
>> > Chris
>> >
>> > --
>> > www.chrismagwood.ca
>> > www.endeavourcentre.org
>> >
>> > _______________________________________________
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>> > GSBN at sustainablesources.com
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>> >
>> > --
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>
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