Building a Monolithic Dome
The Monolithic Dome starts as a concrete ring foundation, reinforced with steel rebar. Vertical steel bars embedded in the ring later attached to the steel reinforcing of the dome itself. Small domes may use an integrated floor/ring foundation. Otherwise, the floor is poured after completion of the dome.
An Airform - fabricated to the proper shape and size - is placed on the ring base. Using blower fans, it is inflated and the Airform creates the shape of the structure to be completed. The fans run throughout construction of the dome.
Polyurethane foam is applied to the interior surface of the Airform. Entrance into the air-structure is made through a double door airlock which keeps the air-pressure inside at a constant level. Approximately three inches of foam is applied. The foam is also the base for attaching the steel reinforcing bar.
Vertical and horizontal steel rebar is attatched to the hangers embedded in the foam. The size, amount, and spacing of the rebar are determined by the size, shape, and purpose of the dome.
Shotcrete—a special spray mix of concrete—is applied to the interior surface of the dome. The steel rebar is embedded in the concrete and when about three inches of shotcrete is applied, the Monolithic Dome is finished. The blower fans are shut off after the concrete is set.