Compressed stabilised earth blocks.

[daftlad]

Eh I hear you say.

While I was away I did a week course on the afore mentioned technology and they seem pretty good, a few points.
1/ Only use 5% cement rather than 13% used in concrete blocks.
2/ Most of the material is available free on site.


Not all soil is capable of being used for CSEB but as long as there is a bit of clay and silt (sand and gravel can be added) then you should be OK.
I know that Rammed earth without the stabiliser (cement or lime) is coming back into use a bit more but unstabilised compressed soil is not weather or vermin proof.
The place where I did the course is actually using stabilised earth for foundations with only 5% cement and they actually get nearly as much rain as we do, all be it in the form of 2 monsoons (July and November)

The compressor is a development of the Cinva Ram which was developed in Columbia.
http://www.google.co.uk/images?um=1&hl=en&tbs=isch:1&q=cinva+ram&sa=N&start=20&ndsp=20
I know lots more stuff so if you have any questions I would be happy to share.

[noelsquibb]

Yup

20:1 is the mix I used for my 'cob' barn
I mixed it wet like concrete though, so the compaction was simply a bit of poking with a stick ....

Didnt have a large group of hangers on to mix place or compact, so had to make it all managable by one person.

The stabilised earth found is good and confirms my comments regarding how little loading there is on a strip footing.

The cement bound compressed earth blocks will probably be as strong as a celcon / thermalite block.

Oh sorry

you wanted questions ....


eeerrr

do you think manual rammed earth block production would be cost effective in the UK ?
do you think a building inspector would sign off your house extention if you used em to build it ?
do you think a building surveyor would comment on their use if you ever felt the need to sell said house ?

[daftlad]

I've been contemplating your post for a while.
The blocks we made were specified as being half the compressive strength of conventional fired bricks, but twice as strong as "country fired bricks" (a bonfire under a pile of hand made bricks) the usual building brick in India (it uses more wood than India can spare).
I don't see why they can't be regarded as a common building material like thermalite or concrete.
I understood that making bricks with a wet mix like you did could lead to cracking, did this happen?
I also can't see why they can't be cost effective if labour could be decreased by using a paddle mixer, normal mixers just make a load of mud balls in the mixer.
I think the blocks are excellent, look at this webpage to see what they are doing with them.
http://www.earth-auroville.com/?nav=menu&pg=vault&id1=33&lang_code=en
Looking at the pictures, if you were a building surveyor would you comment on them as being inferior, I wouldn't?
Oh and do you like the health and safety (sandals and wooden scaffolding with no boards). 
ta ta

[Billy]

Knowing this country I think someone somewhere would want a certificate or two.  Two blocks from each batch kept for a thousand years might do the trick but I doubt it, if it aint got a CE mark and been tested, nah mate can't do it see........

Billy.

 

I do so love India me.

[Rick O Shea]

To some extent the rammed earth build is very old technology Noel Squibb's cob barn is rammed earth technology. Cob buildings have been common  in rural  Devon for  over 100 years.  I do not really see why a proper building inspector (not one employed by a Local Authority with a GNVQ in Media Studies)  should not pass these blocks, as they are just rammed and compressed earth on a smaller scale. I wonder if  you could get a certificate from an architect, and there are independent building inspectors who might be a bit more sensible.  It may prove to be a bit more tricky if the building might be the subject of a mortgage, but even then........   

If you look at the aerodynamic technology a bumble bee cannot fly! any yet well all know it can. Straw bale buildings theoretically can't be build but they can and are.

Using rammed earth blocks, providing the roof is good and the floor drainage is good I don't see why there should be a problem, In GB  you  might have to use a lime based rended so that they can breath.         

[Baz]

You say you went on a course, which implies a degree of organisation. I think you should get the organiser of the course to contact the Building Research Association to make a formal statement that can be presented to planners etc. I would expect there is already some kind of formal statement on the subject somewhere. Perhaps the professional body for Architects or Surveyors has something official. It can't be the first time the question has been asked.

[daftlad]

It all depends on the soil. But,
If you posted the dude a bag of soil he would tell you if it was suitable or what to do to it to make it suitable (add sand etc)
The dude is a French architect who was trained at CraTerre which is an institute in France specifically engaged in building with earth.
Part of the course was soil testing which involved washing it to see how much gravel, sand, silt and clay there was in the soil. We did this by washing out the silt and clay and seeing what was left, clay is greasy on the hands where as silt isn't. Once these tests are carried out some blocks are made (without cement) and left to see if they crack.
The compactness of the block is also tested by applying a force of (I think) 5kg per cm2 and seeing if it deflects more or less than 6mm, if less then the block is good.
I probably wouldn't build with blocks, I would use rammed earth with maybe a few blocks above door ways, it just seems easier, and I would try to build internal walls without the cement.
ta ta
Oh... Rick The oldest rammed earth building in France is a library, apparently it is particularly good at storing ancient books because the humidity and heat is so stable.

[desperate]

Earthing smearthing.............just can't leave it alone can you?

Desp

[daftlad]

Earthing smearthing.............just can't leave it alone can you?

Desp

Oi Plumber..
   

 

[djh]

There are several different types of item being discussed (e.g. [1], [2]):

Earth blocks, or rather unfired clay bricks, are available commercially: Sumatec or Ibstock Ecoterre, for example. These products have specs and loading figures.

Homemade blocks are something different, because they haven't been tested and the quality control is likely very suspect. You can make them and use them for non-load bearing internal walls but I think it would be an almighty uphill struggle to get approval to use them in a loadbearing application, although CAT have built a toilet block from them[3]. I've heard they can also be very time consuming to make.

Clay lump, cob and rammed earth building have a long tradition and can be used. I don't know what the rules are, but presumably an established practitioner [4] would know.

Compressed stabilised earth blocks, which is what daftlad originally started the thread about, have cement added to strengthen the blocks. They are widely used around the world [e.g. 5].


The problem with using all of these materials for loadbearing work is that they all involve local soil of unknown properties, so every batch will need testing, or else be hugely overspecified. If you centralise manufacture so the material is consistent, you're basically back to a regular brickworks. So I think the obstacle is likely to be getting bits of paper to satisfy the designer & the professional indemnity, building control, insurance and mortgage companies. If you can avoid the need for a mortgage etc and/or find somebody with prior experience, you may get somewhere. The links show it can be done but I don't think it's likely to be straightforward.

Personally, I'd be willing to use them for internal non-loadbearing walls, to add thermal mass and hygroscopic capacity.

[1] http://www.cat.org.uk/information/pdf/EarthBuilding.pdf
[2] http://www.scotland.gov.uk/Resource/Doc/156686/0042109.pdf
[3] http://www.cat.org.uk/media/media_content.tmpl?startat=11&endat=20&subdir=media&sku=MEDIA_ATEIC/
[4] http://www.simmondsmills.com/services_page.php?id=2
[5] http://www.unhabitat.org/pmss/listItemDetails.aspx?publicationID=2736

[daftlad]

Personally, I'd be willing to use them for internal non-loadbearing walls, to add thermal mass and hygroscopic capacity.

Cheers djh for the links, lots of interesting reading.

I would be willing to build loadbearing walls because I have made these blocks and they are good and strong (not scientific but still....) and soil testing really isn't that hard, once you know you have good soil or can make good soil by adding sand or whatever you can be confident you will have good blocks.
The architect I did the course did, built some amazing domes, arches and three story buildings (see link above)
ta ta

[daftlad]

I was sent this PM and think it deserves my answer in public

4000 concrete blocks in the average size house at a cost of ?? .75p each = £3000.00?? and another £3000.00 to lay them.

Such a very small part of a house build........tried and tested and stood the test of time.  Even less money if timber was used and easier to put up.

Why bother with what you are doing?? the savings are tiny and the work huge.

A HUGE amount of the earths energy is currently going into building for cement that is fossil fuels, the same for bricks. In India the cut down tons of trees to fire "country fired bricks".
It's not all about the money, in fact money has nothing to do with it, if finance is the only yard stick then we are in a pretty sorry state, maybe we are toast?
We need to get away from doing things the cheapest way and start thinking how to do things the best way.

ta ta

[billi]

Personally, I'd be willing to use them for internal non-loadbearing walls, to add thermal mass and hygroscopic capacity.

Me too 

in generall i can not see cement and soil as a marriage .

Billi

[daftlad]

Another PM

Daftlad i am sorry i have mislead you...........i understand entirely "why" you would do it as i do read your posts, but my point was or points was.......

The energy used as regards the Earth's resources would be small in comparison as they are mass produced and made from just another kind of "earth" in this case sand and gravel instead of soil.  The amount of cement saving is not that fantastic as cement has to be used in your "Earth blocks". Sand and gravel  is easily found (energy usage) and lies just beneath the material that you are using, infact after using your earth blocks the material you dont want to use is going to be left exposed is it not?

Also timber being carbon neutral and having a life which will exceed yours and mine and requiring minimum labour and requiring no cement so...........do you see my points now??

I am not sure what else I can say, concrete block 13% cement, CSEB 5%. 40% of energy worldwide goes into buildings and of that 20 percent goes on construction.
Earth does not need transporting to site.

There may be a little confusion in which earth is used, it is the subsoil (clay and sand) not the topsoil.
billi, why do you think clay and cement is not a good marriage? It is the same in a brick built house..? (well not the same but similar)
ta ta

[dhaslam]

According to the Department of Energy, U.S. cement production accounts for 0.33 percent of energy consumption—lower production levels than steel production at 1.8 percent and wood production at 0.5 percent.

The above is a quote from
http://www.cement.org/manufacture/man_fuels.asp

OK it might be a little  worse than that and also Co2 is produced in the process  but it still isn't going to make a lot of difference eliminating most of the cement from buildings.    Using clay instead of sand isn't much of a saving either if both come from the local area.