DOME PROCESS
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The 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
rebar.
Steel reinforcing rebar is
attached to the foam using a specially
engineered layout of hoop (horizontal) and
vertical steel rebar. Small domes need small
diameter bars with wide spacing. Large domes
require larger bars with closer
spacing.
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 Dome is
finished. The blower fans are shut off after
the concrete is set.
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