Wednesday, April 03, 2013

speaking of rammed earth workshops

As has been shown time and again on this blog, it not necessary to use pneumatic tampers or rammers to build a rammed earth wall, but if you decide to go that way you will need something to power them.

Perhaps a compressor that carries its own form-ply and walers?






This is  Al Nichols' home-brewed, street-legal earth (and snow) compressor in use at his rammed earth wall building workshop last spring. Al built it from recycled materials and off-the-rack parts from Princess Auto  at a cost of around $1200 CAD, which is about a month's rental on a comparable machine.



Al's workshop was quick and dirty, fast and loose. No slide show, no feelings talk, just action.
  
 The sand and gravel was delivered to the site pre-mixed.

 Gnarly old tamper.

Yes, that formwork is being erected on the cold, hard ground. There is no footing, there is no foundation, nothing below grade.

Form-ply clamped on to a 2x10 (or 12"?) end panel along with some walers.

 Then wooden wedges were tapped between the pipe and the end panel for more stability.

More wedges down below to get things "levelled."

 How's this making everyone feel?


I'm sensing a sharp intake of breath in the coastal regions...

 And the form is ready to fill. Yes, we are looking skeptical.

There was a ratio at work here; 15 shovels of soil to one of portland cement or so? It was not presented as an exact science. Sometimes we threw in a bit of pigment.

 
We came back the next day to remove the forms. Despite my misgivings about the forming system,  a fine, sturdy wall embedded with a whimsical glow in the dark star was revealed.

 




After one year in a snowy Canadian winter it shows no sign of spalling or frost heave, nor has it fallen over.

4 comments:

JAL? said...

This is a hydraulic tamper. It runs on gas, solar or bio-diesel.

Adam Preble said...

I can understand doing these concept walls in workshops since it gets the basics down. I was wondering if it was practical to do these walls like this, one chunk at a time, in segments? I was pondering rammed earth for a sound wall. The wall would have to go along for something like 200 feet, and upwards of 8 feet high. Are there any techniques towards approaching that manegeably?

Adam Preble said...

I can understand doing these concept walls in workshops since it gets the basics down. I was wondering if it was practical to do these walls like this, one chunk at a time, in segments? I was pondering rammed earth for a sound wall. The wall would have to go along for something like 200 feet, and upwards of 8 feet high. Are there any techniques towards approaching that manegeably?

Rammed Earth said...

Take a look at what was done in Chad:
http://rammedearth.blogspot.ca/2008/10/worlds-longest-contemporary-rammed.html

The simply attached the formwork to the wall section previously built and rammed the next section right onto it.

This can be done vertically or horizontally, typically where formwork is scarce.