Monolithic domes are energy efficient, spherical structures constructed using inflatable airforms, reinforced concrete, and polyurethane foam insulation. They offer minimal surface area exposed to outside temperatures and can withstand bomb blasts, earthquakes, fires, and other disasters better than conventional buildings. Many schools, gyms, and other facilities now use monolithic domes, some as tornado shelters. They were invented in 1975 and are built worldwide, ranging in size from small to very large 80-meter diameter domes.

1. SHOLA O. ARIBIDO-HEP12/P/2720
CIVIL ENGINEERING DEPARTMENT

2.  Monolithic Domes are constructed following a
method that requires a tough,
inflatable Airform, steel-reinforced concrete
and a polyurethane foam insulation. Each of
these ingredients is used in a technologically
specific way.

3.  The monolithic dome, for a number of reasons, is
very energy efficient. The spherical sections of
the dome offer minimal surface area for the
volume they contain, so there is less surface for
heat transfer with the outside air. The
construction of monolithic dome with proper
earth sheltering will withstand bomb blasts more
effectively than conventional structures. The
strength and stability of domes make them
virtually immune to climatic catastrophe, or
earthquakes, as well as to fire, or corrosion
hazards. Monolithic Domes are the most energy
efficient and safest buildings that can be built
and that can be designed for many uses.

4. Many schools now conduct their classes in Monolithic
Domes. Some are designated as tornado shelters.
Others have Monolithic Dome gymnasiums,
auditoriums, multipurpose centers, libraries,
cafeterias, etc. Three brothers- David, Barry, and
Randy south- built and patented the first monolithic
dome in 1975. It was 32m in diameter, and 1m high,
and is still used today. Now there are monolithic
domes throughout the world- built north of the Artic
Circle in Murmansk, Russia, to the Equator in
Indonesia. Churches, schools, storage buildings,
homes, and recreational centers all use monolithic
domes. Sizes range from very small 2.5m to very 80m
diameter domes.

5.  To study the design of the dome.
 To study about monolithic concrete domes.
 Discuss about the construction and thermal
performance of the monolithic domes.
 Discuss about the advantages and
disadvantages of monolithic dome.

6.  Generally, a spherical dome may be imagining
consisting of a number of horizontal rings placed
one over the other. The diameters of the
successive rings increase in the downward
direction and the equilibrium is maintained
independently of the rings above it. The circle of
each ring is called latitude while the circle drawn
through two diametrically opposite points on a
horizontal diameter and the crown is known as a
meridian circle. The entire meridian circles
coverage at the crown of the spherical dome.
Two types of stresses acting on the domes are;

7.  Meridional thrust (T) along the direction of
meridian
 Hoop stress along latitudes

8.  The Process for building dome enclosures has
been refined and streamlined over the years.
There are two principle types of dome
enclosures: Monolithic Domes, larger insulated
homes and buildings, and Ecoshells, smaller
domes developed especially for hot weather
climates, disaster relief and redevelopment of
substandard housing. Ecoshells represent the
best option for low cost safe housing in areas
where earthquakes, fires, floods and hurricanes
are a possibility.

9.  Although ecoshells are not insulated, their
design maintains a cool, near constant
temperature. Ecoshells are ideal for areas
with high summer and moderate winter
temperatures. They are constructed using
concrete and rebar and can be built in a short
amount of time. Limited specialized tools are
needed and the skills to build these unique
structures are learnt quickly. Each Ecoshell
airform can be used as many as one hundred
times.

10.  Generally standard materials and methods of
monolithic dome construction were used.
Variations and options chosen are listed below;
◦ Airform kits: The airform kit was obtained from
Monolithic constructors, Italy, Texas. The kit consisted
of a 12 meter diameter form along with reinforcing steel
(rebar) anchors. The form was ordered in the shape of a
half sphere with no custom window, or door
augmentations.
◦ Polyurethane Foam: Sprayed on polyurethane foam
insulation was of a type using a part process in which
Diphenylmethane-4, 4’-diisocynate was mixed with
blended polyolefin.

11. ◦ Reinforcing Steel: Steel in the foundation and slab was
16mm and 13mm grade 40 rebar. In the dome shell,
13mm and 9.5mm grade 60 rebar was used.
◦ Concrete: In the foundation and slab a standard 214 kg
cement per 0.76 cubic meter concrete foundation mix
was used. Concrete used in the dome shell was a 0.7647
cubic meter mix. This was made up of 385 kg Portland
cement, 992 kg sand,179 kg 10mm (3/8”) maximum
diameter gravel, 0.7 kg plastic fibers and 118 ml air
entraining agent delivered at a 50mm slump ready for
the addition of water to pumping consistency. For the
final coat of concrete, the gravel was eliminated and
sand substituted.

12.  Construction Methods
Modern construction differs significantly from
the original concrete-over-dirt method. The
current methods were developed by three
brothers from Idaho: Barry, Randy, and David
South. The first dome built using this method
was constructed in Shelley, Idaho:
A reinforced concrete foundation, or "ring
beam", is constructed, defining the shape of
the base of the structure.

13.  The fabric form, or air form, is attached to
the foundation and inflated with an air
blower. The air form contains an airlock to
allow workers to enter the form while it is
inflated.

14.  A layer of polyurethane foam is sprayed on
the interior of the form. (Its purposes are to
give rigidity to the air form, secure the rebar
in place, provide support for spraying in the
concrete mixture, and insulate the final
structure.)
 Rebar is attached to the outside layer of
foam, using clips that are attached to the
foam. Several inches of concrete are sprayed
over the rebar frame.

16.  After the concrete has set, the blower is turned
off.
 The exposed surface of the air form may be left
as it is, or a surface treatment such as paint, tile,
etc., may be applied. (Proper selection of air form
material will ensure prevention from long-term
degradation due to ultraviolet radiation.)
 In instances where necessity requires economical
construction for multiple small and basic
dwellings, the dome can be built without
insulation and the air form can be removed after
completion and re-used to build additional
domes.

17.  Monolithic is dedicated to improving people’s
lives worldwide by introducing and
constructing Monolithic Domes, for personal
and public use, that are disaster-resistant,
energy-efficient and cost-effective.
Monolithic Domes are the most energy
efficient and safest buildings that can be built
and that can be designed for many uses.
Many schools now conduct their classes in
Monolithic Domes. Some are designated as
tornado shelters.

18.  Others have Monolithic Dome gymnasiums,
auditoriums, multipurpose centers, libraries,
cafeterias, etc. Because Monolithic technology
meets criteria for a structure that can provide
near-absolute disaster protection, And in
most cases, they save money on first cost for
the construction. The monolithic dome has
sufficient durability and which offers
exceptional resistance to earthquake, fire and
extreme wind.