Thin Shell Concrete Structure: Experiment 01.01

Second prototyping attempt.

The left over form work after the concrete shell was released.

The pillowing result can be seen more clearly.

The edges are still rough.

Fabric impression on the concrete.

Second attempt using the same form work but using polyester latex, wire reinforcement, and properly waiting for the concrete to properly cure. So this is the materials and method we used.

Materials

• Quick set concrete (1 bag, 20kg)
• Textile (83% Polyester, 12% nylon, 5% spandex)
• Zip ties
• Acrylic tubes (16mm diameter)
• Timber
• Chicken wire (5mm steel mesh grid)(for reinforcement)

Method

1. Reuse the timber frame left over from the previous experiment
2. Roll the polyester fabric on a piece of timber until tension is formed and gun it in place using a brad gun
3. Mix 1 bag of quick set concrete
4. Apply a thin layer of concrete along the center line (highest point to the shortest point) and put a 50mm wide strip of chicken wire
5. Apply another thin layer of concrete on top of the wire mesh and on the whole fabric surface
6. Place a layer of wire mesh that is 30mm shy of the surface’s perimeter
7. Let dry for 3 days (over the weekends)
8. Once dry, release from the mold

Links

B GHAUI

Results from the second experiment.

• Method: Applying the wire mesh as reinforcement significantly held the whole structure together. Letting the concrete to properly cure also help strengthen the structure.
• Materials (polyester latex): The fabric was very stretchy and made deep pillows where the surface was lowest. By rolling the fabric on a piece of timber to create tension was a effective.
• Materials (wire mesh): The grid used was 5mm wide grids. This did not properly let the aggregate from the concrete mix to go through and caused air gaps between the first layer and the second layer.
• Materials (concrete): The second experiment had rough edges instead of clean ones.

Things to do differently:

• Materials (wire mesh): Use a larger grid mesh and structure grade wire mesh instead of chicken wire
• Method (concrete pouring): Make a better form work that would allow concrete to be push against the barrier to create crisp edges.

Things to explore:

1. Wire mesh material
2. Fabric
3. Different form work structure
4. Method of applying concrete (layering?, spray on? etc.)