Compressed stabilised earth blocks.

[daftlad]

Or.

"CEMENT kilns contribute more to the world's output of carbon dioxide than aircraft and could soon be responsible for 10 per cent of all emissions of the greenhouse gas. New calculations by an industry scientist reveal that cement manufacturers already produce 7 per cent of global CO2 emissions—almost three times previously published estimates—and that CO2 output is increasing faster from cement works than from any other industrial source."

Source
http://petekelsey.typepad.com/the_dirt/2008/02/cement-producti.html
Allegedly from a new scientist article.
Just goes to show you can't always believe what you read.
ta ta

Or
Cement manufacture contributes CO2 to the atmosphere when calcium carbonate is heated, producing lime and carbon dioxide. CO2 is also produced by burning the fossil fuels that provide the heat for the cement manufacture process.

It is estimated that the cement industry produces around 5 per cent of global man-made CO2 emissions, of which 50 per cent is produced from the chemical process itself, and 40 per cent from burning fuel to power that process.

The amount of CO2 emitted by the cement industry is more than 900 kg of CO2 for every 1000 kg of cement produced.

From the British Geological Survey
http://www.bgs.ac.uk/education/carboncapture/Anthropogenic.html

I think 5 percent is quite a lot considering it is only a one time use, it isn't like transport which is constant, once something is built, it is built, finished.
ta ta

[Rupert]

So you save a few percent of co2 on the cement used. Your little cement mixer will make up for that when making your earth blocks (approx 4000) and the only other saving is when you dig out the tens of tons or "earth" with a little shovel by hand.  Making concrete blocks is very efficient and done by an automated machine when the raw materials are added which are just "earth" in this case sand and gravel cheaply and efficiently extracted from the ground by diggers and loading shovels or if you want you could go and use a little hand shovel.

I can understand savings if using bricks but all you are really doing is making another kind of concrete block with less cement and doing it inefficiently by hand and maybe producing the same or more co2 in the process and also may be producing an inferrior product?

I think it is 20 kg per concrete block so you would have to dig up and mix by hand in a little cement mixer in excess of 80 tons for your earth blocks and probably more as yours will be denser so heavier.  I estimate this to be approx 40 digs or less with the digger bucket as apposed to approx 8000+ (many many more) with your little hand shovel, and that would be just to get it out of the ground never mind transporting it to the mixer, loading it, unloading it, putting into moulds etc.

If you want to save on co2 then use wood.

[DominicJ]

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.

Bees fly by flapping their wings, not by aerodynamic flight.
I'm not sure anyones said straw bale buildings cant be built, but I know of what thats been built with a wood fire / cob wall to heat and the things freezing all the time.

[billi]

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)

I just see no point in combining those two different materials that work against each other

I perhaps would understand to built blocks from shreddered hemp/straw and cement

But clay doesnot need any cement to built a house

http://www.lehmtonerde.at/english/w1.html

Billi

[daftlad]

So you save a few percent of co2 on the cement used. Your little cement mixer will make up for that when making your earth blocks (approx 4000) and the only other saving is when you dig out the tens of tons or "earth" with a little shovel by hand.  Making concrete blocks is very efficient and done by an automated machine when the raw materials are added which are just "earth" in this case sand and gravel cheaply and efficiently extracted from the ground by diggers and loading shovels or if you want you could go and use a little hand shovel.

I can understand savings if using bricks but all you are really doing is making another kind of concrete block with less cement and doing it inefficiently by hand and maybe producing the same or more co2 in the process and also may be producing an inferrior product?

I think it is 20 kg per concrete block so you would have to dig up and mix by hand in a little cement mixer in excess of 80 tons for your earth blocks and probably more as yours will be denser so heavier.  I estimate this to be approx 40 digs or less with the digger bucket as apposed to approx 8000+ (many many more) with your little hand shovel, and that would be just to get it out of the ground never mind transporting it to the mixer, loading it, unloading it, putting into moulds etc.

If you want to save on co2 then use wood.

I am sure there are more appropriate (less labour intensive) ways of making these in the west than a hand machine.
Personally I would try to avoid using stabiliser if I could (as with traditional cob). I also wouldn't use it for external walls because I would use something with better insulating properties, but I can't see why it couldn't be?
I believe that CSEB is a valid building material with many benefits over concrete. Wood is also a valid building material but if your building required thermal mass then something else would need to be used.

A forum member.
The reason I left your name in the second PM is to nudge you into discussing these things in public, why wouldn't you want to? Why should I reply to a PM from someone who seems to have made his mind up about earth building when others on the forum may be more open minded about the technique?
ta ta

[daftlad]

But clay doesnot need any cement to built a house

Yes, completely agree except for building arches and domes, not that I want to.
ta ta

[Baz]

I guess natural stone rolled off the fields surrounding the house is the most energy efficient.

[Rupert]

I am sure there are more appropriate (less labour intensive) ways of making these in the west than a hand machine.

Yes there is....A digger with a large bucket 1-2 tons or more each dig.  A loading shovel 6 ton bucket or more.  An industrial mixer for concrete. Concrete block laying machine (automatic)

All used to make concrete blocks using sand/gravel and cement.

Only other way i know of is a small cement mixer and a block mould what you fill with block mixture and then leave to set.

[Rupert]

I guess natural stone rolled off the fields surrounding the house is the most energy efficient.

Yes and very ecological but very labour intensive and stone men ask and get premium money for building with stone.

[djh]

CSEB is mostly used in third-world or developing countries where timber and stone are not available or are expensive, cement is expensive, labour is cheap, and often the climate is warm and there are heavy rainstorms and/or earthquakes etc. Combine these factors and CSEB emerges as a realistic alternative to pure timber, or concrete or earth for some or all elements of construction and also can be a basis for building small local businesses. So nobody argues (I hope) that it's the answer to every occasion but it can sometimes be a good answer.

It's not used widely in the developed world partly because the economics and regulations are different but also because there's a huge established industrial base that provides cheap concrete and fired clay bricks, as well as lots of other products. The good news is that some of the brick makers are now producing unfired bricks, as mentioned before, and the concrete makers use recycled aggregates and non-cement binders (flyash, ggbs etc) - http://www.sustainableconcrete.org.uk/main.asp?page=37

There's no right or wrong answer here. No competition to win.

If people are interested, read the links that have already been provided, or search for articles (cinva turns up a lot). This site - http://www.parryassociates.com/ - also has some background on the economics and on use in the UK in among its content.