Experiment_1 Pise structure
My own mini-pise structure.
To put my knowledge to the test I decided to construct my own pise structure.
Because I was building a relatively small rammed earth wall/column, I decided that I would not go through the trouble of drilling holes and clamping the sides from the inside. As shown on the photos below clamping the sides of the formwork from the outside required a lot more effort than expected.
-Maybe the amounts of clamps used tell the story by it self.
In my further casting experiments I will take this lesson with me.
The structure is made of 1 bucket of dirt to 2 handfuls of concrete. A splash of water is added after the dry materials are mixed. Because I used grey (normal) concrete the colour of my mixture was a bit more dark/greyish than the one I saw on site. However after the structure was completely dry (3 days +) it dried up to be a beautiful light red colour.
The formwork was made of plywood components; a new layer of formwork was added for every layer of dirt.
The shiny surface of the plywood guarantees that formwork can be easily removed leaving a smooth surface.
Possibilities within the pise system
The pise system does satisfy some of the requirements stated by my research question:
– It’s a vertical casting system
– The formwork panels are reused
– The same formwork elements can put together in various ways to produce customized elements
Even though the pise system is somewhat flexible and you are able produce double-sided elements. The system is quite limited when it comes to exploring the design potential in amorphous shapes. The systems rigid nature is primarily designed to produce perpendicular elements. These restrictions can be traced back to the formwork and the technique used when tamping the dirt. Most amorphous and vertical variations become impossible when having to compress the earth from above.
When working with rammed earth the tamping is an essential part of the technique. Obviously when working with concrete casting a different technique is employed and the tamping becomes excessive. Changing material and therefore part of the technique generates new possibilities for incorporating a far more flexible mould system. My further investigation will revolve around the possibilities and potentials of working with a flexible surface. However I would like to take with me some of the lessons learnt from working with the pise formwork:
– The interlocking mould panels make it very easy to hold the formwork in place.
– By using bolts to clamp the formwork together from the inside, minimal support structure is needed.