At the precasting factory, special forms were built for each type of dome piece. These included: hexagons, pentagons, and two sizes of quarter cylinders. Here we see the form for a hexagon.
Reinforcing bar was placed in the form. Expanded polystyrene block outs were inserted at places where openings were needed in the particular piece being formed.
Where window or door frames were needed, they were cast into the dome piece.
The piece was then cast with steel fiber reinforced cement, which makes the toughest concrete in the world.
Screeding out the seven sack concrete mix, filled with millions of two inch steel fibers was very hard work.