Sini project, Jimma

The saucer edge bends two ways at once. It curves around the Sini, and it also rolls over from top to bottom. That is a double curvature.

Sheet and slab materials start flat. They can bend one way, but they cannot follow two curves without being cut into small pieces. The architects needed the edge to read as one smooth saucer, not a ring of flat facets and joints.

We designed a mould that carries both curves. GFRC is cast into the mould as a thin shell and takes the double curvature from it, so nothing has to be bent or forced into shape on site.

A double curvature needs a material that is formed, not bent. GFRC takes whatever shape its mould has, stays light enough to fix to the building, and keeps a clean edge along the whole double curve.

Painted white, with the classic red Sini saucer line.