I decided to make a paper model to cast in sand using the adaptive formwork technique. I chose to use the digital site information from my studio project and make it in scale 1:500. The final model would then be approximately 70*50 cm. I used a type of 300 gram paper to cut each height level and the same type of paper for the 2mm height difference for every curve. The model was then assembled using tape.
For casting with every level in the correct height I cut out several mirrored sections from the site to support the paper model from the bottom of the bounding box. The thought was that I would use these sections to level the sand underneath the model to get everything in the right height. This didn’t turn out well because the sand didn’t hold to this grid of sections.
I therefore shaped the sand through pushing and shaking the sand underneath the paper model, this method was not precise, but it seemed to hold the shape of the model well enough. I used a very coarse aggregate to fill the model, to make sure that the concrete slurry would filter all the way to the bottom. The size of the aggregate was roughly 10mm. For the slurry I used 0,75 part of water for 1 part of cement, in total 7 kg of cement.
I think that the paper was to thin for the size of the model. It was to difficult to shape an area of 50*70 cm of sand underneath a model. The edges of the model was to thin, so it bended, also because the aggregate was so large that it didn’t shape the model from the inside. For the recipe for the slurry I think that I could have used less water since the aggregate was larger than in the previous assignment.
We made two separate moulds. One origami with sharp edges and one with rounded and doubled curvature. Both were made with thick paper.
When we mixed the cement we noticed that it was way too thick to get in between the larger aggregate. Hence, we added more than the doubled amount of water. With 2 kg cement and 1,2 kg water we agreed that the mixture was a flowable enough and could sink through the coarser aggregate. We still had to carefully mix the aggregate with the slurry inside the paper models, and we also shook the whole container as much as we could, so that the paper models would not be deformed.
The resulting models shows that the slurry still didn’t fill the models enough. The origami model lost its lower part, however the edges came out as sharp as the paper model. The larger model came out somewhat deformed. Part of the model lacked cement altogether. We expected that the aperture would still hold, but the finer aggregate in this part filled with cement anyhow, perhaps the paper broke somewhere in the middle.
For this assignment I tried to cast in a medium with higher viscosity than water. I found that tapestry glue might shape the concrete without any other formwork. The glue mixture was made according to the instructions for putting up wallpaper, so it was quite thick. The concrete would sink slowly, I poured it in different parts of the container to see if this would create a variety of shapes. Some of it would just sink to the bottom, but when I poured the concrete slower, the lesser weight would make it float in the glue mixture.
Top view of the glue and the non cured concrete
One of the shapes
Our group chose the topics hydrostatic pressure and mixed material.
We built a mold of mdf board to which we attached a piece of stretchy fabric, and on top of that a piece of knitted fabric. We poured/stuffed the concrete mix into the mold so that the gravity would shape the finished model.
The pattern showed, but not as much as we expected. We didn’t find the perfect balance between the hydrostatic pressure and the stretchiness of the textile.
For the mixed material assignment, we attached a less stretchy textile between two wooden boards. Underneath these were attached wooden sticks to fix the concrete in the desires size. Our purpose was to stitch the finished piece of concrete to two pieces of wood. To make holes in the concrete we fixed shorter wooden sticks with duck tape, as shown in the picture, and then poured the concrete into the mold. When the concrete was cured we stitched the finished piece together.
Both the fabric and the wooden sticks were easy to remove.
Group 5 – Maria Johansson, Marieke van Dongeren, Johan Wallhammar
3rd picture – from left to right:
Mix 1 – more sand: coarser, no flow
Mix 2 – more water: more wet, flows easily
Mix 3 (picture 2) – blue pigment: almost oily,we accidentally mixed the sand in before the pigment
Mix 4 – red pigment: nice and red
Mix 5 – black pigment: also oily – but mixed the right way (first cement+pigment – then sand)
We hit each mould against a steady surface to fill the moulds completely, and to get the air bubbles out. It did not work with the firstmix which was to stiff.
Both mix 3 (blue) and mix 5 (black) turned out slightly oily – as if the pigment did not quite mix with the cement.
We changed the proportions so that each mixture was 500 grams (the calculations by hand).
A “rauk” is a rock formation formed by abrasion. Abrasion is a mechanical process created by the friction of smaller particles moving against a rock. The rauks are created when the surrounding sea erodes rock rising out of the sea due to the land uplift. This mechanical process of sea erosion only leaves a solid core of limestone. Rauks are common along the coast of the island of Gotland but can also be found on the island of Öland.
image source: http://mapio.net/pic/p-23729186/
made by: natural phenomena
The Pythagoras tree is a fractal invented by the Dutch mathematics teacher Albert E. Bosman in 1942. This set belongs to a type of fractals called L-systems. L-systems are a type of fractals that may resemble branching patterns, such as in plants, biological cells, blood vessels, etc.
The mathematics behind fractals began to form in the 17th century by the work of the mathematician and philosopher Gottfried Leibniz. A fractal is a mathematical set that makes a repeating pattern at every scale creating an expanding symmetry. If the repetitions are exactly the same on every scale it is called a self-similar pattern. Many patterns in nature shows some form of statistical self-similarity, and can be approximated by using fractals.
image source: http://www.marekfiser.com/Projects/AnimatedPythagoras
invented by: Albert E. Bosman
fabrication process: fractal