rammed chalk

I hope this is the right place to ask this, but I am thinking of building with rammed chalk when I build a place in sussex Uk. The nature of the site means that most of these walls will be below grade. Some will be built into a bank to the rear and I am thinking of adding a basement too.

I can find very little information of rammed chalk online and only brief mentions of it in books. I know that they added 10% clay to a wall that was built out of chalk near me, But this was an interior wall above ground. I am wondering if I could stabilise the chalk with geopolymer by swapping the clay for a pozzolan - like brick dust - and adding sodium silicate and sodium hydroxide. I have made a couple of samples which look promising but I am just guessing proportions.

Does anyone know of anywhere I can find information with building with chalk, rammed, stabilised, or making chalk based geopolymers?

Martin Hughes : The Book ''Cottage building in Cob, Pise`, Chalk, and Clay: A Renaissance 2nd edition is the only book I know of that specifically

deals with building with Chalk! Fortunately it is out of print !

This means you can find the book, read it online, or get a free eBook (47,169 free ebooks last count) from the Good People at Gutenberg.org

For this book :::--> http//www.gutenberg.org/ebooks/32048hint Highlight the BOLD part to open in the address window or as a Google Search

Hope this is timely and helps Big AL .. And a tip of the Hat to Judith Browning for finding and promoting Gutenberg.org A. L.

Hi Martin,

You can mix 100 parts by weight lime and 53 parts by weight sodium carbonate with kaolin or calcined clay with water and then after allowing that to react mix in your chalk and then ram it into forms and it will set to stone. I would chose to ram into forms that are different shapes so I would have no straight horizontal or vertical seams that can shift. The large monuments all across the world are built in this fashion and they resist earthquake really well. You only need about 3-10% clay chemical mix for the reaction to work.

Here is a funny video of guys dressed as Egyptians doing what you are attempting to do: http://www.geopolymer.org/wp-content/uploads/pyramid-eng.mp4

The video has a recipe you can try out. If you do it please post some photos, would love to see a version made with chalk. Should be a really white building.

Good luck,

Jason

Oh, a few more things you could try.

I have used fibres to reinforce my concretes they help to prevent cracking. With the alkalinity of a geopolymer you would need something resistant like PVA fibres. The alcohol molecule ensures they will bond with the mix whereas normal plastics will not bond. Basalt rebars are covered in epoxy and sand so you should get a good bond with them, so you could reinforce the building with this. Something I would like to try in the future would be to create two layers of geopolymer stone walls with basalt rebar connecting the two layers and then fill the hollow cavity with mineral foam so you can have a really well insulated wall that breaths, resists mould, and is very strong. And basalt fibers don't transfer heat well so they would make it strong without providing a path for heat to escape.

Jason

Martin And Jason : Here is a Simple Link to Basalt Rebars, With every ones permission I will make a new topic for Basalt Rebars with several links including a link
to our Forum Thread Geo-Polymers ! Here is a start Big AL

http://cleantechnica.com/2014/11/06/neuvokas-basalt-rebar-lighter-stronger-cost-steel/

or

Basalt rebars

My only thought is that, however strong and stable it is, it will have the insulating power of r-1 per foot of thickness. That's about as low as it goes.

Maybe you don't need insulation in your application...


Finest regards,

troy

Thank you Al!

And Troy you are correct there. The walls would have to be very thick.

That is why someday I hope to try it with a mineral foam layer in the middle to help with that. It has a good R value. Or he could put a layer on the outside of rock wool and plaster over it. They do that to a lot of old buildings around here. Makes the windows a little more recessed but warms the house. Either way I sure want to see what he comes up with.

One company in the UK makes geopolymer foam by adding a little aluminum to the mix and the reaction makes hydrogen which expands the mix to a foam and later the hydrogen migrates out of the foam.

Jason

Hi Martin,

I hope you are well, and that your endeavours with chalk building have been successful. I am an architecture student in the UK and I am research building methods using chalk. I was wondering if you ever found the answer to the questions to posed here 10 years ago.