The aim was to create a fine concrete texture, looking like skin.
First the fine aggregate was poured into a frame. A layer of crinkled paper was put on top, and then the cast was filled with the coarse aggregate and filled up with the mix of cement and water.
unfortunately the concrete didn´t went all through the aggregate, so only parts of it came out with the skin-texture.
Probabely the mix was not liquid enough, or not shaked enough so it could reach the bottom of the course aggregate.
Diamond by Erika Vegerfors
In assignment 5 I chosed to cast a diamond. I model the diamond up in a 3D program. To extract the parts accurate, I used a laser cutter to help me erase the pieces from the carton I used as a mold. During the casting process, I received problems with the recipe we received the teachers and therefore did I a test, to investigate the best relationship between water and cement. I found out that 1 part cement and 0,7 parts of water is needed for the casting to work. In the final cast, I have just that relation. But, I belive that up to 0,9 parts of water would even work better.
Material : Cardstock paper
So to make my paper formwork, I found some geometric shape patterns online and used a thicker paper to make the forms with tape holding everything together. Because I did my assignment a little later than everyone else, I was able to read about other peoples experiences with the slurry mixture and adjust the amount of water I used so that it was more liquidy.
However, although the mixture was pretty thin, it clearly did not reach all the way through aggregate. The concrete only reached about halfway through on each of them. I’m thinking that it was because the aggregate I used was too small.
First step is to make the mold, by folding the paper into a pipe, using the method showing above. I choose the cardboard as the material, seems like it is strong enough in this size. My first try failed, as you can see in the right picture above, because the concrete won’t go through, not even a little bit. I think there are two reasons: not enough water and the paper pipe is too thin.
So in my second test. I adjusted the recipe, doubled the amount of water, so the mix turned out to be liquid like. And also, I re-folded the paper to make it less in height, but much more wide opened. This time, after adding the concrete, I can see it was going down slowly and then it stopped at some point. I guess it was turning into solid there.
In the result, you can see the concrete stopped approximately half way and due to this the cast also broke down from the middle.
We choose to work with cardboard to create a precise shape made out of “mountain” and “valley” folds. We wanted to work with a small shape to keep control over the materials and the shape. Too big of a size would probably become more unstable and also require a big amount of slurry and pebbles. Too small of a size could make it hard to make folds and also create a risk of slurry not entering all gaps.
We did not get a clear picture of what would be a good size and mix between peeblestone and slurry.
What is relevant sizes according to different sizes and shapes of mould shape?
Hanna-Thea Björö, Bisera Örn
I started with 3d modelling form, and than I tansferd design into paper. Buried the form in fine aggregate and unfortunatley the aggeregate I used to fill in inner part of the modl ws to fine, so in fact model broke in the thinesst part. Mix recepie worked fine. In order to fill the modl with slurry I pured it in little by little.
we decided to use paper folding as a technique to cast concrete for this assignment. we made 2 ‘eggs’: one of them is purely folded, but by forming it to an ‘egg’, some of the foldings are hidden inside the form, which might cause problems for the demoulding process if it gets stuck in the concrete. so we made another one, which is just held together by tape so it does not cause any marks on the inside. furthermore they had 2 different materials: one with a glossy surface, the other one is normal thick paper.
we also had the problem, that there was not enough >5mm gravel left, so we filled one ‘egg’ with normal concrete.
the gravel with glossy paper ‘egg’ turned out quite interesting, the concrete did not get completely down because the gravel was not big enough, but it created 4 columns on the top. the normal concrete with paper ‘egg’ was also fine.
For the form we used hard plastic to fold a diamond shaped form.
When mixing we realised it was too dry, so we added water little by little, eventually ending up with twice the suggested amount.
We thought that the slurry would be able to flow through the aggregate, but when we took it out of its form only the upper half had successfully been shaped after the form, the lower part was unfortunately not reached by the slurry.
1.I like the Aalto vase, so make the volume similar to it with the plastic film.
2.When I made the slurry as the recipe, it seemed very dry and cannot pour down at all. So I added more water little by little. Finally the weight was 500 g. And I added 15 g blue pigment.
3.Cause I didn’t find the right aggregate, and didn’t sieved it very well. When I poured the final slurry, it was just on the surface.
4.The result is it. I think the reason is that the size of the inside aggregate is not coarse enough for the flow of slurry.