Tuesday, January 19, 2016

Progress with clay

I am not going into pottery.

I want to know about clay to make better
-thin bricks and tiles
-rammed earth walls.  Clay is the best binder, the more i know about clay.....
-clay based paints.
-mortars.  Roland helped me to understand clay and lime is my friends.

And why not I think Nashesha (daughter) and I could make some pottery.

I am trying different methods to get a purer clay.

Mixing , settling, mixing, screening, drying..........

Eventually i get a sticky clay.

Adding some sand makes it more workable.

Back to making doradangos (on right)

Monday, January 18, 2016

Some more rammed earth walls

Now i dig a 60x60 foundation ditch.  Do a rammed earth fill with 5% lime.  first 40cm lift of rammed earth has lime and the last 20cm has a pointed "cap"  It will be too much maintainence to keep that limewashed so i will put brick cap.

this section we also made the joints vertical and did not split the bonds.  I think this is a better method.

This is three coats on white parts the dark part is only one coat.

 this section was done after a period of rain and we were impatient for the earth to dry out before ramming.  Notice all the cracking due to shrinking becuase of excess water.

Monday, January 11, 2016

Improving single brick vaults

On the  two vaults currently in progress we had issues with the individual arches  separating .  Although this is always an issue, in a whole vault it might happen 1-2 times, but with these it was daily.

 Dickson was getting frustrated on both.  build an arch and then it pops out, or seperates several arches back.  Always on wet work.

Steel toed boots and helmets are your friend.

This was happening on these buildings:

(1)  Kiln Roof,  5.3m (16ft) span .  a fairly high arch of 160cm rise

(2)   Garage/ grain store,  4.3 m span, as flat as we dare 10% rise in width ( or 45cm rise).  I would not go any flatter on a roof.  Both vaults  are built with " not so well burnt"  bricks.

In the first building we thought it was due to vibrations from heavy trucks passing on the road 10m away. 
 On the second building we thought first it was poor clay mortar, then vibrations on reinforcement rods, then flatness of the arch.

The solution that worked is a sudo (?) cohesion method.

Just like with cohesion or timbral method to add layer(s) to the vault. WE laid them face side down in a clay mortar and filled the extrados later

 The first vault we did after many arches, better to do as soon as you can add another brick

 Another layer laid as stretchers does several things.  
-Ties the first layer while constructing so we dont have an arch popping
-greatly increases the rigidity of the vault.
- increases the cost
-increases the building time slightly, although when arches are popping and we are redoing it could be faster.

Purely for looks I would build tile catalan vaults.  Tile on the ceiling looks better.  The first course is slow and expensive as you are using gypsum to glue each piece.

This method gets similar rigidity and strength.

I can really bang on the kiln vault.

So why didn't it happen on this big vault?

I suspect:
-steepness of the vault
-following each day with a cement plaster on top of the vault.
-slower adding a vault line ( as you have to do one at a time, one each side of the groin vault.

Tuesday, January 5, 2016

Making Clay

I am embaressed to say I dont know what my soil type is that I use to make clay bricks, rammed earth walls.

I have been playing around and seperating and have reached this far.

which means I have clay but not sure about 50%.  Is it silt or not so good clay.  In the picture above this is after seperattion and long soaking.  What is left is clumps that done disolve, however i can really work them and i get a similarly sticky clay.

  Work in progress.

Monday, January 4, 2016

Lime white wash of rammed earth walls

Learning lime white wash.  Does wonders to the rammed earth walls.  

 Thinking of this cap on the wall.