International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
173
Study of Dome structures with specific Focus on Monolithic
and Geodesic Domes for Housing
Riya Anna Abraham
1, G. Kesava Chandran
2 13rd Year B.Tech, Civil Engineering, Manipal Institute of Technology, Manipal -576104 2Chief Engineer, DMRC, Karshaka Road, Kochi- 682016
Abstract— Domes have been a prominent part of construction dating back from ancient times due to its uniqueness in providing maximum space with minimum surface area. Their popularity lost ground during the medieval period on account of tedious construction methods and skilled work requirements for large sized domes. Through this paper we take a short tour on the history of domes through a general analysis of domes and a comparison of dome roofs with flat roofs is carried out. The paper also takes a look into the possible future aspects of domes by evaluating popular types - two prominent ones being monolithic and geodesic domes. The paper brings out the various advantages and key aspects of these types of domes as the modern world looks out for energy efficient, eco-friendly and durable housing options. We evaluate housing with geodesic and monolithic domes with this intent. Our paper concludes that both geodesic and monolithic domes are sustainable structures for housing and points out that further research and investigation needs to be undertaken on the same.
Keywords—Geodesic domes, Geodesic spheres, Monolithic domes, Flat Roofs, Airforming, Shell, Geotangent, Surface Area.
I. INTRODUCTION
Domes are hemispherical structures that takes its evolution from the arch and has found popularity for roofs and ceilings. Their use during ancient times have been documented as round huts and ancient tombs in the shape of solid mounds that have been found in the Middle East, Mediterranean region and India. It was the Romans who introduced the large-scale masonry hemisphere of yester years. Because the dome exerts forces all around its perimeter, the early structures such as the Roman Pantheon employed the use of heavy supporting walls. Domes provide unimpeded wide spaces; in other words from minimum surface the maximum amount of area.
This advantage of domes provides unprecedented structures for covering areas where we have minimal interference of internal supports. Their geometrical form, self-supporting condition with stiffness has enabled their use in both ancient and modern architectural works. Today, domes have provided structural economic solutions for exhibition halls, concert halls and swimming pools that require large covered spaces. Many an elegant structures also utilize domes for their splendid and aesthetic appearance. It will be appropriate to trace the evolution of domes over the years which this paper deals in its initial parts.
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
174 Domes in general are lighter structures compared to other conventional forms of structures. For example we find transparent domes have been built over a group of houses in Canada to provide shelter from high winds, safeguarding homes from extreme temperatures, storing solar radiation in the external walls of the house and in the ground. This architecture has demonstrated that it drastically reduces the heating load of the houses during winter. Such transparent or translucent domes also provide pleasant view without the sense of enclosure [1].
With the rising costs for energy, energy demands becomes a vital and important economic characteristic for suitable housing constructions. Further, thermal insulation ensures energy conservation for buildings. Hence, influenced by climatic conditions, the building elements such as roofs play a crucial role in the heat transfer rate [1]. Through this paper we highlight the importance of Geodesic and Monolithic domes as energy efficient and disaster resistant structures that can be suitably employed for housing.
II. EARLY HISTORY OF DOMES
Earliest domes were most likely human huts constructed from saplings, reeds, or timbers and covered with thatch, turf, or animal skins. Over the ages, the materials transformed depending on the local conditions and availability to rammed earth, mud-brick, and stone. Mammoth tusks and bones were discovered to have been used for some of the earliest dome shaped small dwellings.
While one was discovered in 1965 at Mezhirich, Ukraine, archaeologists have unearthed others dating approximately 19,280 - 11,700 BC [2]. The wigwam was the creation of Native Americans by using arched branches or poles that were covered with grass or animal hide. Another ancient usage of domes is seen in the igloo, a shelter built by the Eskimos from blocks of compact snow. Through Fig 1 we have shown three well known ancient domes.
There is almost no authentic literature on the historical development from early dome structures to the more sophisticated ones of the middle ages. Hence it's speculated that dome architecture was known to early Mesopotamian cultures as that in turn explains the existence of domes during the first millennium BC in China and the West. Another hypothesis is that the use of the dome shape in constructions does not have any single point of origin but was common in all ancient cultures long before they were being constructed with better and stronger enduring material.
III. RECENT HISTORY OF DOMES
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
175 Developments in the field of mathematics and statistics during the sixth and seventh century AD helped in formulating more precise formalization of the ideas of the traditional constructive practices of arches and vaults. It was during the eighth century that radical changes commenced in dome structures particularly by considering them as a composition of smaller elements, each subject to mathematical and mechanical laws paving the way to analyse individually, rather than considering the dome as a whole unit.
Developing countries started adopting domes; more often as a less expensive alternative to the sloped-roofed or flat-roofed construction. This arose because dome structure uses less material to enclose a given volume and also a lower rate of heat transfer occurs on account of the reduced surface area. We find domes made with loam in Europe, mud-bricks or adobes in Africa and Asia. The Persian dome technique - a way of building without centring was prevalent in Afghanistan. The Beehive domes at Harran, Turkey, date back to the 19th century. Extraordinarily thin parabolic in-shape domes of sun baked clay were known in Cameroon and had diameters of 20 and 30 feet [3].
While the 19th century saw domes being re-translations of the domes of the past, rotating dome construction for housing large telescopes commenced during this period. The Industrial revolution helped in the new production techniques of cast iron and wrought iron to be produced at cheaper rates and in large quantities. Due to large supplies of iron, Russia had some of the early use of iron architectural domes in use. The Metal framed domes like the elliptical dome of Royal Albert Hall in London, the circular dome of the Halle au Blé in Paris represent the 19th century development of the simple domed form.
Very large spanned Domes were possible with steel and concrete during the late 19th and early 20th centuries. More recently, large reinforced concrete domes have been used as innovative forms in the development of silos because of their great height in relation to the span that they cover. Their structural and architectural advantages have been witnessed in the construction of residential buildings, schools and stadiums. Three of the dome marvels during the recent past few centuries is shown in Fig. 2.
IV. ANALYSIS AND FUTURE OF DOMES
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
176 The line which defines the equilibrium point between the resultant of the compression forces within the structure against the external actions is called the line of thrust, and it is required to stay at the middle of the arch to ensure stability.
However, we may note that a circular force depicting a third force is induced. The induced force is generated as a result of the rotation of the arch around a vertical axis. Horizontal rings are generated from domes constructed in this manner. The circle force acts within the plan of a ring and can be assimilated to the thrust by the force of gravity which acts downwards in the vertical plan [4].
For carrying out the analysis of a shell we have to consider two stresses; the stress acting in the meridional direction and the stress that acts in the parallel direction. The concept behind the assumption can be explained using the idea of chains. The line of thrust always follows a certain shape of an inverted catenary curve. We can assume that the suspended chain is under the influence of gravitational force. The inverted chain represents the line of compressive stresses (thrust line) centred in the arch for the catenary chain. This central position helps in optimizing the arch behaviour which ensures the high stability. Although tensile forces will be induced if the thrust line moves away from the centre, the structure will remain stable as long the thrust line remains at the middle third of the structure. The forces in the shell are considered to be compressive and tensile only based on the assumption that the surface has no stiffness against bending. Even though a reasonably thin shell structure can accommodate safely a range of loads, there is a minimum thickness necessary to prevent compressive buckling.
The thickness of the dome is not dependent on the compressive stress required to support the dome. Hence, by increasing the thickness we are increasing the weight and also the area involved for support, resulting in the cancellation of the effects. It is to be noted that for a dome of sufficient thickness, the imposed loads will be much lesser than those arising due to the self-weight. However, if the structure is stable in supporting its own self weight, then any increase of the imposed loads can be seen as negligible. As a result of modern day advanced technology, today domes can be constructed with reasonably thin shells reducing the difference between the imposed loads and the self-weight. It is necessary to apply further analysis to make sure that the stability of the dome applies with additional imposed loads. It may be also noted that local buckling can be considered as no real threat for masonry domes [4].
A. Disaster proof
To know how domes effectively distribute forces laterally the following three reasons are considered key. The first and most important reason being that movements that are strong enough to get a dome to sway will not produce areas of the structure that have no support against gravity, the reason being that the base is much wider than the top. The second reason is that domes are capable of naturally distributing forces in all directions and hence the design itself is best in dissipating energy. For the third reason, mostly the mass of the dome lies low and helps in lowering the centre of gravity. The lowering of the centre of gravity drastically reduces the chance of the collapse of the dome. For these reasons, domes are found to be suitable for the Polar Regions as they can withstand extremely low temperatures and high winds.
Domes are superior to traditionally constructed buildings by their strength, superior building materials, its ergonomic shape, virtually unaffected by time, withstanding seismic activity or man-made assault and assaults of weather changes. Dome constructions of today are meeting standards that are near-absolute survivability. Community hit by earthquakes, tornadoes or hurricanes, however infrequent they may be, should construct large dome structures near their town or villages where they can gather and seek shelter when natural calamities occur. A good example is the city of Tupelo, Mississippi where they have constructed dome shelters. Hence, domes are the most disaster-resistant structures that can be built having price-to-value ratio more favourable than traditional construction.
B. Energy efficiency
A sphere is the most efficient shape that covers maximum living area with the least amount of surface area. If one was to compare a similar sized dome home and a rectangular house, the dome home will have a surface area that will be 30 percent lesser. Thus dome structures can help save the environment from wasted energy. From the energy perspective domes are relevant in several ways. • The decreased surface area results in use of lesser
building materials.
• On account of the lesser surface area the exposure of domes to the cold during winter and heat during summer is decreased.
• Flow of air is even with return air ducts, be it hot or cold air due to the concave interior.
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
177 • As a result of the shape, the inside of the dome prevents
radiant heat flow as it acts as a giant down-pointing headlight reflector and helps concentrate the interior heat.
Apart from the aesthetical characteristics, the presence of domed roof covered by glazed tiles and ventilation possibility through exterior skylight provide the monuments with more efficient thermal performance [8]. For day energy saving and lighting purposes, translucent and transparent domes are being used. Models have been developed to predict and experiment the thermal and optical properties of skylight inside domes. These models are being replaced by single-glazed hemispherical domes. The mathematical model developed predicted that the thermal exchange of a pyranometer, simulated very much like a small glass dome exposed to natural convection. Electrochromic glazing can be used to prevent the overheating inside for such structures in the summer.
C. Endless Design possibilities
Domes have a wide range of design possibilities. The open floor plan allows you to insert or remove walls almost anywhere. The dome home is structurally independent of interior framing. The natural openings that occur within the construction of the dome allow for windows and large openings to the outside, letting light in.
Various designs in geodesic dome housing are being offered by several dome manufacturers. While some geodesic homes can be assembled within a day some others may take up to six months’ time. Many manufacturers provide dome kits that can be assembled and built by no more than one or two persons. The very many options are dependent on the complexity of the design.
It may be noted that even though dome homes can be built from manufactured kits, the designs can also be flexible. It is possible to remove up to half of the triangles in the dome's lowest row without weakening the structure enabling one the choice of having several windows and doors. The built dome can sit directly on ground-level footings (building’s weight is taken by short walls recessed into the ground), or it can be erected at the top of a riser wall up to 8 ft (2.5 m) tall.
D. Comparison of domes with flat roofs
A Dome can add dramatic visual interest and aesthetics to a home by adding it on to a flat roof. The large dome roofs constructed by the ancient Romans gained much fame and popularity during the Baroque and the Renaissance periods in Europe.
Whereas, flat roof gained much importance in the American Southwest and the Middle East during ancient times. This was so particularly because these regions were arid and the drainage of water from the roof was not that important. Flat roofs came into widespread use in the 19th century in the Americas and Europe, as a result of better understanding of the practical use of structural steel and concrete combined with the invention of waterproof roofing materials.
TABLE1
Comparison between Flat and Dome Roofs
Feature Flat Roofs Dome Roofs
Seismic stability
Vulnerable to Transverse loads.
More effective against transverse loads [5]
Deformation
To obtain the same deformation, the column section of a flat roof structure had to be raised by 40mm to obtain the same value as that of a G+4 storied frame dome roof structure [5]
30%, 34.5% and 35%, respectively were the average percentage reduction in the average percentage reduction in deformation, maximum bending moment and maximum shear force [5]
Resistance to Explosion
This type of roof is the most compatible against explosion [6]
The roof because of it being aerodynamic will operate well
against explosion, also with regard to its higher area of vertical plane obtains a remarkable force[6]
Materials usually used
PVC Membrane , TPO Membrane, EPDM, Rubber Membrane, Modified Bitumen, Rolled roofing [7]
Shingles, metal and even glass. However, for a dome roof that will require less maintenance, metal is suggested
Future Expansion
Future expansion of the living space an easy option, since patios, gardens or even penthouse rooms can be added [7]
The unique structure and area consumption makes further expansion a difficult option
Expenses
Less expensive than other popular roof styles
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
178 By definition a roof that has a slope not more than 5 degrees can be called as a flat roof. Such a roof can also be constructed as the ceiling floor of top story in a large-area building such as a hotel, apartment, shopping mall and office. Flat roofs soon became the most commonly used type to cover office buildings, warehouses and other commercial buildings, as well as many residential structures. However, flat-roofs are not popular in geographical areas pertaining to heavy rainfall or snow. Today it is widely used in housing buildings in many regions of Turkey. These roofs helps them avoid the huge costs of installing solar energy systems, a detailed roof construction and construction of additional stories in the future. We have summarised the comparison of Flat and Dome roofs in Table 1.
V. FAILURE MODES OF DOME STRUCTURES
Discussed below are the various key failure modes that might occur and needs to be addressed before the construction of a dome structure.
A. Insufficient thickness
A minimum thickness of 4.2% of the radius is required to ensure the thrust line remains inside the masonry [9]. This thickness ensures that equilibrium is maintained and that there is no distortion. If the dome does not embrace the full 180 degrees, the required minimum thickness falls sharply.
B. Buckling.
Buckling needs to be considered in areas of largest compression (normally at the crown of a shell) and minimum curvature, taking into consideration the non-linear behaviour of concrete, creep strains of concrete and the initial imperfections [10].
C. Slope
An angle of <20 degrees is not viable in design [10]. A slope of this inclination would induce high stresses resulting in buckling. It may also prevent the even curing of concrete.
D. The inner forces
In case of domes the membrane in plane tensile forces are low and can be supported by minimal reinforcement, however post tensioning might be required at the equator to support the presence of large tensile forces. Additionally, cracks may occur as a result of shrinkage due to insufficient reinforcement at the dome base junctions.
E. Edge forces
The edge forces (bending and shear) appear at the boundaries of a shell, they are dependent on the support conditions. Thickness of the shell locally can be increased in order to control these edge conditions. For aesthetic and cost factors this solution may not be valid and therefore an alternative solution can be used by employing suitable amounts of reinforcement. The amount of reinforcement is related to the shape and corresponds to the ultimate limit states and serviceability of the chosen shape. Analysis of shear forces and bending moments are used to determine appropriate amounts.
F. Cracking of domes
Although cracking indicates signs of failure, not all cracks will lead to collapse as seen in case of St Peters, Rome. Further analysis is required to determine the stability of the structure in case yielding occurs due to compressive forces in the dome.
VI. UPCOMING INNOVATIONS FOR DOMES
New age dome construction has applied a patented process known as airforming. The advantage of such constructions are described below.
Firstly, since the shape of the dome has the least surface area and encloses the maximum amount of space, for the given surface area, only a much lesser quantity of expensive building materials is required. Hence the efficiencies and cost savings are substantial. Regardless of weather conditions, the construction of steel reinforced concrete domes is fast because it takes place within an air-inflated form that covers stockpiled materials and equipment, allowing construction to continue regardless of the outside weather conditions. Domes are ideally suited for structures where open spaces are required. They are open span and therefore no columns intrude on or interrupt valuable space. Steel Reinforced concrete domes provide unprecedented flexibility, especially in buildings requiring a large amount of open space. The designer has the total flexibility in the layout of rooms. Virtually any size and number of rooms are possible.
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
179
VII. MONOLITHIC AND GEODESIC DOMES FOR HOUSING
Due to the wide variety of dome structures in terms of varying angles to shapes to support the structure, this paper picks up two of the major types of dome structures namely Geodesic and Monolithic domes since they have been gaining prominence in the building of housing units. Please refer Fig 3 for some illustrations of Monolithic and Geodesic domes employed for housing.
A. Geodesic domes
A Geodesic dome can be regarded to be a portion of a geodesic sphere. Many Building or roof constructions have utilized the geodesic dome that ranges from 5 to 100 percent of a sphere. The domes that are used for houses are mostly arrays of triangles forming geodesic spheres somewhere from three-or five-eighths of a sphere.
The American architect and engineer R. Buckminster Fuller following World War II was involved in designing affordable and efficient housing from mass-produced components and could be executed fast. Fuller began to work with spherical shapes and framed spheres with a network of strips approximating great circles (circles on a sphere with centres that coincide with the sphere's centre), the strips formed triangles as they crossed one another [11]. Geodesic domes are one of the most efficient structures due to several reasons. The triangle is a very stable configuration. Take the case of a rectangle, when a force is applied to a corner it has the possibility of deforming into a parallelogram, which is not the case for a triangle. Therefore, geodesic domes are resistant to tornadoes, forces due to wind and even earthquakes. Another reason for efficiency is that the surface area of a geodesic dome is only 38% of the surface area of a box-shaped building including the same floor area – the surface exposed to temperature variations is much lesser, thus reducing the heating and cooling rates when compared with a rectilinear structure. Also, the construction of a geodesic dome can be done without heavy machinery by employing prefabricated components. It requires only few persons to erect the dome for a 2,000-sq ft (185-sq m) home in a few hours [12]. A geodesic dome does not require internal columns or interior load bearing walls to support itself. This property is the key reason why they are appealing for use as sports arenas, churches and exhibition halls. Lofty ceilings, being aesthetically appealing makes them attractive as homes, and full or partial second-story floors are easily suspended halfway up the enclosure without any support other than attachment to the dome itself.
The main reason behind the popularity of geodesic domes is its inexpensive rates and high efficiency. These factors are of great importance in today’s context with the rising environmental and economic issues. Hence proving the fact that that domes are enjoying the kind of popularity not seen since their heyday in the late 1960s and early 1970s. Some of the largest geodesic-dome structures, listed in descending order of diameters, have been presented in Table 2. The first geodesic dome to attract wide scale public attention was the dome over the Ford Rotunda building, which Fuller designed in 1953 [13].
TABLE2
Popular large Geodesic Domes
No. Name Location Diameter (m)
1.
Fantasy entertainment complex
Kyosho Isle, Japan 216
2 Multi-purpose
arena Nagoya, Japan 187 3 Tacoma dome Tacoma, WA, USA 161
4 Superior dome
Northern Michigan Univ Marquette, MI, USA
160
5 Walkup skydome
Northern Arizona Univ. Flagstaff, AZ, USA
153
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
180 All the vertices must have a pin connection, which allows force transmission through to the foundation. The loads applied include wind load, live load, dead load, seismic load and gravitational load. All these are to be withheld by the foundation. Even though a geodesic dome is typically a self-supporting structure its foundation (Typically, a circular concrete slab poured onto the earth) must be capable of carrying the applied loads and anchoring it into the earth. [14].
The structural Analysis of a geodesic dome might seem challenging and complex initially but when we look at the construction and design they are incredibly efficient and simple structures. The Structural analysis is actually greatly simplified by the spherical shape and geodesic layout of the structure. Loads are distributed in a three dimensional direction, in case of domes, round or circular homes whereas only one or two load directions are utilised in case of traditional structures. Air and energy are allowed to circulate without obstruction in case of a spherical structure or dome, hence they are the most efficient interior atmospheres for human dwellings. This property also enables natural cooling and heating. All over the world geodesic shelters have been built in varying temperatures and climates and still are regarded to be one of the most efficient human shelters.
Geodesic domes provide lightest, strongest and the most efficient means of enclosing spaces. The triangular spherical configuration of geodesic domes give it unique structural capabilities unmatched by other structural systems. Steel geodesic domes have been wind tunnel tested to withstand up to 200 mph winds [14]. As long as the height and span correspond, a geodesic dome can be of any size. One of the design concerns is the weight of the struts compared to their spans. It is similar to an egg with a very thin skin that can resist relatively high uniform load. With a very small amount of materials, they can resist a relatively large load. This is why circular homes and domes are very economical and efficient structures [15].
However, considering the limitations, the geodesic dome possess somewhat an odd shape. The height and diameter of the sphere are fully dependent upon each other. Therefore to reach an attainable height, the diameter must be sufficient. Interior heights near the edges of the dome are rather short and awkward. This can be taken care of by adding riser walls to the dome and also by increasing the volume and height of the dome [14]. Future advancements in geodesic dome construction may arise from improved building materials.
In the year 1997, a concrete cube manufacturer developed a bevelled, hollow, triangular block having scored edges that was capable of interlocking with the adjacent blocks. If properly shaped, these blocks could be employed for construction of dome structures. Another innovative idea involves design of domes based on a different mathematical premise. The edges of the triangular elements, in case of a geodesic dome align to form great circles. Although not exactly a geodesic, a new design patented in the year 1989 uses pentagons and hexagons to form domes having elliptical cross section. Because of its mathematical derivation, this design is called Geotangent [12].
B. Monolithic domes
Another modern dome technology that is gaining importance in both large and small scale is the monolithic dome. The basic difference between a geodesic dome and a monolithic dome is that monolithic domes are much heavier and are cast in one piece. The construction of a monolithic dome begins with a circular concrete foundation, where a canvas ―airform‖ is attached to the slab. The monolithic dome is made of one solid piece of material. The canvas once erected is then inflated using special fans resulting in the formation of a dome shape. Once the interior is covered with a layer of polyurethane foam insulation, a steel bar is enclosed in the foam to give support to the dome. Followed, by a special mix of concrete spread over the interior of the building. The largest monolithic dome in the world is the home of Faith Chapel Christian Center in Birmingham, AL, which is 280 feet (85 m) in diameter ,72 feet (22 m) tall and having a floor area of 74,500 square feet (6,920 m2) in two levels [16].
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
181 Monolithic domes are also fire resistant due to their largely concrete construction and are capable of lasting for hundreds or even thousands of years if maintained in good condition.
In today’s world with the rise in technological innovations their rates are comparable with conventional structures and much cheaper than earthquake resistant conventional structures. In a nutshell they could play an important role in the making of disaster resistant, sustainable cities.
Monolithic domes are energy efficient housing options for example a monolithic dome for a living space, having ceiling and walls with earth-friendly, efficient, extremely durable and easily maintained, the thermal resistances and low emissive windows has reduced the energy cost by over $2000 per year compared to a conventional masonry house of the same size[17]. Most importantly, a monolithic dome consumes 50% less energy for cooling and heating than a same-size, conventionally constructed building. Beginning in the year1970, Monolithic Domes are being widely build and are in use in virtually every American state and in Canada, Africa, South America, Asia, Africa Mexico, Europe, Asia, and Australia. These domes are not restricted by site location or by the climate of the area. In terms of disaster resistance, energy consumption, maintenance, and durability, monolithic domes perform well in any climate, even under extremely cold or hot conditions. They can be constructed anywhere including beaches, mountains and even underground [17].
The spherical sections of the dome offer minimum surface area for the contained volume, because of this there is less surface for transfer of heat with the outside air. The one piece casting of the monolithic dome also helps in eliminating many of the gaps through which air can leak, although this is taken care of to some degree in residential domes by the addition of multiple windows and doors. Placing the insulating foam on the exterior of the concrete shell will make the concrete acts as a thermal mass inside the building, thus reducing the fluctuations in the interior temperature far more when compared to traditional home's insulation of a brick or stone veneer.
The various techniques used in monolithic dome construction are far different from normal methods of construction, so only specially trained construction crews are suited for building a dome employing the modern techniques. The curved surfaces typical to monolithic dome construction often result in oddly shaped rooms when divided, resulting in wasted space at narrow corners. There are issues of wasted floor space due to wall curvature and problems fitting furniture. This effect can be minimized by using an airform of such shape as to allow for straight, vertical walls at ground level or by constructing the dome on a stem wall. Also, the monolithic dome's lack of seams may result in it being too well sealed, this can be taken care of by using dehumidifiers in all but the driest climates.
VIII. CONCLUSIONS
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com
(ISSN 2250-2459, ISO 9001:2008 Certified Journal
, Volume 6, Issue 8, August 2016)
182 REFERENCES
[1] Mohammadjavad Mahdavinejad, Negar Badri, Maryam Fakhari, and Mahya Haqshenas, 2013. The Role of Domed Shape Roofs in Energy Loss at Night in Hot and Dry Climate (Case Study: Isfahan Historical Mosques` Domes in Iran).
[2] Palmer, Douglas; Pettitt, Paul; Bahn and Paul G, 2005. Unearthing the past: the great archaeological discoveries that have changed history.
[3] Creswell, K. A., C. 1915. "Persian Domes before 1400 A.D.". The Burlington Magazine for Connoisseurs. The Burlington Magazine Publications, Ltd. 26 (142): 146–155.
[4] Analysis of domes, Domes of different Geometries, http://concretedomestructures.weebly.com/analysis-of-domes.html [5] Ashim Kanti Dey and Chinmoy Deka, 2012. Effectiveness of Dome
Structures in Reduction of Stresses under Transverse Loadings, Proc. of Int. Conf. on Advances in Civil Engineering.
[6] Ali Akbar Pouri Rahim, Mahdi Bitarafan, and Shahin Lale Arefi, 2013, Evaluation of Types of Shapes of Building Roof against Explosion, Vol. 5, No. 1, IACSIT International Journal of Engineering and Technology.
[7] Ryan Slatton, Sheri Hosale and Aleksandr Biyevetskiy, 2016, Top 15 Roof Types & Their Pros & Cons – Read Before you Build!, http://www.roofcalc.net/top-15-roof-types-and-their-pros-cons/
[8] M.V. Soare and N.Raduica, 1984, A Comparison of the Structural Efficiency of Some Braced Domes, International Journal of Space Structures.
[9] TU Vienna, 2014. The inflatable concrete dome: Better construction method, Vienna University of Technology.
[10] Aurelio Muttoni, Franco Lurati and M. F. Ruiz, 2013. Concrete shells - towards efficient structures: construction of an ellipsoidal concrete shell in Switzerland, Wiley Online Library.
[11] Yaolin Lin and Radu Zmeureanu, 2008, Three-dimensional thermal and airflow (3D-TAF) model of a dome-covered house in Canada, Renewable Energy - Volume 33, Issue 1
[12] Geodesic Domes ,http://www.madehow.com/Volume-6/Geodesic-Dome.html{37}
[13] Ching, Francis D.K., 1995, A Visual Dictionary of Architecture, Wiley Publications
[14] Structural Analysis of Domes 2,
http://www.domerama.com/technical/structural-analysis-of-domes-2/ [15] Building Earthquake Resistant Buildings is Best for the Environment
and the People, 2011,
http://greenbuildingelements.com/2011/02/24/building-earthquake-resistant-buildings-is-best-for-the-environment-and-the-people/ [16] Monolithic Dome Institute ,177 Dome Park Place Italy, Texas,
