We set out to make an organic free form shape cast only in different sizes of aggregate.
The result of the first test of aggregate and slurry mix. The straws helped the cement mix to go down in the aggregate and the slurry mix seamed to work so we went up in size for the final cast.
We used three different sizes of aggregate, very small which we sieved, middle size and quite large pieces for where we wanted the cement mix to go down.
We poured the cement mix in steps to make sure that it would go down in the aggregate, and built the shape in many layers.
We used the slurry mix we tested in the first experiment:
750 g cement
300 g water
15 g super plasticizer
The end result.
A piece fell of in the process of removing the cast from the bucket, we could have reinforced the shape with for example steel wire, or greased the bucket before we cast.
Otherwise the shape we got was what we set out do make. The different aggregate made it possible to make voids and the shape was quite easily controlled.
How to go forward.
The method of casting in only different aggregate is good since there is not much waste material, and you don’t need that much cement since it is such a large portion of aggregate.