Effectiveness of Tensile Membrane Structures in Green Building

8/2/2019 Effectiveness of Tensile Membrane Structures in Green Building

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Effectiveness

of TensileMembrane

Structures in

GreenBuilding

Espiritu,Arianne Rose F.


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Effectiveness of Tensile Membrane Structures in Green Building

I. IntroductionA. Background of the Study

The advocacy of Green Building has been around for many years now. Individuals

and organizations from different professions are one in the goal of discovering, reinventing

and re-using green building materials and methods that are in line with this advocacy.

Normally, what comes to mind when one strikes up a discussion regarding Green Building is

the harnessing of the natural forces in order to provide for man's basic power needs. This is

true but it does not fully encompass the essence of the Green Building advocacy. Green

Building is also the use of context and climate in building a place for man that optimizes the

use of the natural forces to create a holistic place of work, play and rest, among others. Green

Building includes not only harnessing the natural forces to create electric power, but also

implementing green building methods that have been used many centuries and have thrived

in the rural areas of most countries since they have been replaced by fleeting new building

styles that do not, in any manner, so to speak, take into consideration context and climate.

Green building also includes the use of green building materials to be incorporated in the

design in order to produce the minimum amount of carbon footprint during and after the

building is constructed. These factors are to be taken into account if one is to follow green

building into ones design.

HARNESSING NATURES FORCES

SOLAR ENERGY

The sun gives the earth a total of 174 petawatts of energy. 30% of this amount is

absorbed by the clouds, oceans and land masses which is 3,850,000 EJ. This is more than

enough to provide for one hour of energy consumption in one years span. If harnessed

properly, either through passive or active technologies, the suns energy would have

efficiently provided for most of the power needs of man.

There are two kinds of solar technology: passive solar and active solar technologies. Passive

solar technologies include methods of building like orienting the building towards the sun

and incorporating thermal materials into thebuildings faade. Active solar technologies on

the other hand, include the use of photovoltaic cells and solar thermal collectors.


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Since the ancient civilizations of the Greeks and Chinese, building orientations were

referenced from the latitude of a place to the Sun in order to receive the optimum needed

daylight to warmth and light the interiors. They oriented their buildings due South in order to

achieve this. However, the captured heat was also released through open windows. The

Romans came to a solution of using glass windows to trap the required amount of heat inside.

This was around 50A.D. These glass windows were essential for the greenhouse effect to take

place. The use of glass was so efficient that the wealthy classes in the Roman society had a

room called the heeliocaminus added to their villas. However proliferate the use of glass was

during the glory days of Rome, it also saw its decline with the fall of the Roman empire

together with the use of solar energy. In the seventeenth century, however, better glass-

making techniques were invented which thus led to the incorporation of solar energy in the

buildings design once more.

In the 1500s , photovoltaic power was discovered in the height of the Industrial Revolution,

by Heinrich Becquerel when he witnessed solar power transformed into electric power. With

this discovery, solar panels were built starting in the 1700s, to harness the suns energy and

utilize it to help in supplying the electrical power needs of a community.

RAINWATER HARVESTING

Another prominent way of harnessing natures forces to produce energy needed by

man is through rainwater collection or Rainwater Harvesting as it is more popularly known.

The idea of rainwater harvesting was first conceived in 3 BC when farming communities of

Baluchistan and Kutch used rain for irrigation. It was also used by the Chola Kings of the

Ancient Tamil Nadu, India and the Indus Valley Civilizations.

The practice of rainwater harvesting still proliferates to this day. Rainwater is used to provide

for the domestic chores where water is needed such as watering plants, water for livestock

and water for small irrigations. The use of this method has apparently been very effective in

lowering the amount of water level dependencies around the world that new building laws in

some places, like Bermuda and the US Virgin islands, require new construction projects to

include rooftop rainwater collection systems to provide for the water needs of residents.

Below is a diagram of the typical installation of a rainwater collection system.


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As seen in the diagram, rainwater is flowed through pipes that lead to an outdoor storage

tank. The level of purification the collected water undergoes depends on the type of use for

which it is collected. Generally, water collected is used for watering plants and thereforerequires no purification at all. But on occasions when this water is collected and used for

drinking purposes, then a high level of purification is needed.

Other than Rainwater Harvesting, other methods for the collective reuse of water are also

available. Some of these methods are the reed bed system and the Playpump system.

The reed bed system is a method of water purification which utilizes either natural or man-

made floodplains. Artificial reed bed systems are useful in removing pollutants from grey

water. The process of purification that takes place in the system is very much similar to the

conventional sewage treatment process without the artificial aeration, of course because the

same organisms are used.

The PlayPump system on the otherhand, is an innovative method of collecting and

distributing water for communities which used to have unclean and unpurified water, or in

worse cases, have no water at all. This system was first introduced in the rural areas of South

Africa where most residents of the communities there have to travel a long way just to collect

clean and safe water and travel back to return to their families.


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The above photo shows a typical section of the Playpump. The concept behind this system is

to incorporate work with play. Children are expected to use the knob (1) as a merry-go-round

of sorts so that it could generate enough hydraulic power and momentum to pump water from

the waterbed (2) until it reaches the storage tank(4). When the tank is full, people can now

utilize the water stored. This Playpump system is usually situated in schools where a crowd

of children could play without realizing that they are helping in collecting water for their

community. However, this Playpump system was not designed to be the sole provider of the

water needs of a community as opposed to what most have expected from it.

GREEN BUILDING METHODS OF CONSTRUCTION

PASSIVE COOLING

According to Norbert Lechners book entitled Heating, Cooling, Lighting, there exists

a three-tier design approach for passive cooling of a building. The first tier consists of heat

Avoidance methods, tier 2: Passive Cooling, tier3: Mechanical Cooling.


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At this level, the designer does everything possible to minimize heat gain in the building.

Strategies at this level include appropriate use of shading, orientation, color, vegetation,

insulation, daylight and control of internal heat sources. (Lechner, 258) But sure enough

heat avoidance is not in itself sufficient to keep temperatures low enough. This is where

passive cooling systems come in. Using these systems, the amount of heat in a structure is not

only minimized but also, temperatures are lowered. When both passive cooling and heat

avoidance strategies are insufficient in maintaining thermal comfort, Mechanical Cooling will

be employed. But as much as possible, the first two tiers should be enough in keeping the

thermal comfort level.

Most of these heat avoidance strategies and methods have been around since the ancient

times and are now thriving in the indigenous communities. Decades of experience in trying to

construct buildings that would embody the culture of a place and society without of course

neglecting the primary purpose of giving shelter to man, has brought us these indigenous and

historical use of passive cooling. In Asia, for example, especially in countries in the

Southeast, houses are on stilts that not only protect people from high tide (since houses were

usually situated along bodies of water), but also allow wind to pass under the dwelling spaces

which helps in lowering the temperature inside. High pitched roofing systems are also used in

most Southeast Asian countries to allow space for the upward movement of hot air so thatcool air can be situated just at the right height inside the dwelling space. Large windows

complement this high ceiling to allow hot air to escape.

Passive cooling strategies for hot and dry climates are very different from those for hot and

humid climate. In hot and dry climates, one usually finds buildings with few and small

windows, light surface colors, and massive construction. Since hot and dry climates have

high diurnal temperature ranges, the nights tend to be cool. Thus, the mass cools at night and

then acts as a heat sink from being overwhelmed, small windows and light colors are used to

minimize heat gain. Closed shutters further reduce the daytime heat gain, while still allowing

good night ventilation when they are open. (Lechner, 258)

There are many kinds of passive cooling systems which include Cooling with Ventilation,

Radiant Cooling, Evaporative Cooling, and Earth Cooling. Under Cooling with Ventilation,

two subcategories exist namely: Comfort ventilation and Night flush. Comfort ventilation is

ventilation during day and night to increase evaporation from the skin and thereby increasing

thermal comfort. (Lechner,267) Night flush cooling on the other hand is a method used to


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precool the building. Radiant cooling consists of Direct radiant cooling and indirect radiant

cooling components. Direct evaporation and Indirect evaporative cooling constitute

Evaporative cooling. Under Earth cooling, there are direct coupling and indirect coupling.

GREEN BUILDING MATERIALS

Together with the green building methods are the sustainable building materials

which are to be incorporated in the overall building design. These building materials not only

somehow dictate the form of the building to some extent due to their deformability and

flexibility but also because of their heat retention or insulation properties. Another

consideration that must not be neglected when building green is that the materials should be

readily available whenever there is a need for more supply and/or for replacement if

damaged. The goal is to achieve the least amount of carbon footprint as mentioned earlier.

Also, another consideration is that these materials should readily be replaceable. In line with

this characteristic requirement of green building, the present generation has witnessed the

onset of materials recovery facilities.

MATERIALS RECOVERY/REUSE FACILITIES

Materials recovery/reuse facilities make use of mostly waste materials which are

oftentimes crushed and/or melted to form building materials such as concrete hollow blocks.

All around the world, these facilities continue to spring out and in fact, there are some

existing facilities such as these in the Philippines. One of the most popular materials recovery

facility is located in Teresa, Rizal. This project consists of a Waste Segregation Center,

Compost and Organic Fertilizer Plant, Plastic Recycling Center, and a Hollow Block

Manufacturing Plant.

Waste Segregation Center

Here, waste is sorted to recover the recyclable components such as plastic, glass

leather and metals.

Compost and Organic Fertilizer Plant

In this facility, the biodegradable fraction of waste is segregated, shredded and then

composted, to produce a soils amendment used by local farmers and gardeners.

Plastic Recycling Center


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In this facility, plastic products are removed from the solid waste stream and sorted by

composition and sent to various markets throughout the Metro Manila area where they are

sold to local vendors. Some of the plastics are shredded for incorporation into hollow blocks

production.

Hollow Block Manufacturing Plant

This facility mixes sand, gravel, cement and shredded plastics to produce construction

grade concrete blocks used in local building industry.

(http://www.llda.gov.ph/liscop_teresa.shtml#)

WHY BUILD GREEN?

All of these efforts aforementioned are all in line with Green Building advocacies. But

why build green? After all, the main purpose of constructing a house or a building is to

provide shelter for man against the natural phenomenon. But does this still apply to the

present generation? Building for man alone is not enough. Nature should be taken into

consideration when building. Harmful effects from chemicals and waste products from

construction are evident and cannot be dismissed in nature. Bodies of water are no longer fit

to host healthy ecosystems. Forests continue to diminish in numbers which thus leaves no

home for the animals because subdivisions and residential and /or commercial buildings are

perpetually being constructed here and there. Pollution from factories and cars continue to fill

the atmosphere with harmful chemicals that cause different diseases and worse, have caused

the world wide climate change. With these effects of modern technology, (including modern

building methods and modern building materials), are we just supposed to build for man

only? Or are we to revert back to those building methods and materials that once proved

effective for our ancestors but have now been replaced by a fleeting fad of new in-style

architecture that dont take into mind context and climate? Now the argument is not

proposing to totally revert back to the vernacular ways, since of course, the reason modern

methods and materials have been invented is so that we can improve on these native ways.

The challenge is incorporating these old and new techniques and/or materials to attain

positive outputs that satisfy the goals of the Green Building advocacy.

TENSILE MEMBRANE STRUCTURES

This form of construction has only become more rigorously analyzed andwidespread in large structures in the latter part of the twentieth century. Tensile structures
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have long been used in tents, where the guy ropes provide pre-tension to the fabric and allow

it to withstand loads.

Russian engineer Vladimir Shukhov was one of the first to develop practical calculations of

stresses and deformations of tensile structures, shells and membranes. Shukhov designed

eight tensile structures and thin-shell structures exhibition pavilions for the Nizhny Novgorod

Fair of 1896, covering the area of 27,000 square meters. A more recent large-scale use of a

membrane-covered tensile structure is the Sidney Myer Music Bowl, constructed in 1958.

Antonio Gaudi used the concept in reverse to create a compression-only structure for

the Colonia Guell Church. He created a hanging tensile model of the church to calculate the

compression forces and to experimentally determine the column and vault geometries.

The concept was later championed by German architect and engineer Frei Otto, whose first

use of the idea was in the construction of the West German pavilion at Expo 67 in Montreal.

Otto next used the idea for the roof of the Olympic Stadium for the 1972 Summer

Olympics in Munich.

Since the 1960s, tensile structures have been promoted by designers and engineers such

as Ove Arup, Buro Happold, Walter Bird ofBirdair, Inc., Frei Otto, Eero Saarinen, Horst

Berger, Matthew Nowicki, Jorg Schlaich, the duo ofNicholas Goldsmith & Todd

Dalland at FTL Design & Engineering Studio and David Geiger.

Steady technological progress has increased the popularity of fabric-roofed structures. The

low weight of the materials makes construction easier and cheaper than standard designs,

especially when vast open spaces have to be covered.

(http://en.wikipedia.org/wiki/Tensile_structure)

Could this modern day method of construction and material be able to supply the solution of

a new green building innovation that could incorporate the needs of man without neglectingNatures needs?

B. Project Setting1. Statement of the Development Project

This paper aims to discover the possibility of Tensile Membrane Structures to

effectively conjoin the needs for shelter of man with the need for protection of the natural

environment. This research paper also aims to learn more of the possibilities this modern day
http://en.wikipedia.org/wiki/Tenthttp://en.wikipedia.org/wiki/Guy_ropehttp://en.wikipedia.org/wiki/Vladimir_Shukhovhttp://en.wikipedia.org/wiki/Thin-shell_structurehttp://en.wikipedia.org/wiki/Nizhny_Novgorod_Fair_of_1896http://en.wikipedia.org/wiki/Nizhny_Novgorod_Fair_of_1896http://en.wikipedia.org/wiki/Sidney_Myer_Music_Bowlhttp://en.wikipedia.org/wiki/Antonio_Gaudihttp://en.wikipedia.org/wiki/Colonia_Guell_Churchhttp://en.wikipedia.org/wiki/Germanyhttp://en.wikipedia.org/wiki/Frei_Ottohttp://en.wikipedia.org/wiki/Expo_67_pavilions#National_pavilionshttp://en.wikipedia.org/wiki/1972_Summer_Olympicshttp://en.wikipedia.org/wiki/1972_Summer_Olympicshttp://en.wikipedia.org/wiki/Munichhttp://en.wikipedia.org/wiki/Tension_(mechanics)http://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Engineerhttp://en.wikipedia.org/wiki/Ove_Aruphttp://en.wikipedia.org/wiki/Buro_Happoldhttp://en.wikipedia.org/w/index.php?title=Walter_Bird&action=edit&redlink=1http://en.wikipedia.org/wiki/Taiyo_Kogyo_Corporation#Birdairhttp://en.wikipedia.org/wiki/Frei_Ottohttp://en.wikipedia.org/wiki/Eero_Saarinenhttp://en.wikipedia.org/wiki/Horst_Bergerhttp://en.wikipedia.org/wiki/Horst_Bergerhttp://en.wikipedia.org/wiki/Matthew_Nowickihttp://en.wikipedia.org/wiki/Jorg_Schlaichhttp://en.wikipedia.org/w/index.php?title=Nicholas_Goldsmith&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Todd_Dalland&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Todd_Dalland&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=FTL_Design_%26_Engineering_Studio&action=edit&redlink=1http://en.wikipedia.org/wiki/David_Geigerhttp://en.wikipedia.org/wiki/Tensile_structurehttp://en.wikipedia.org/wiki/Tensile_structurehttp://en.wikipedia.org/wiki/Tensile_structurehttp://en.wikipedia.org/wiki/Tensile_structurehttp://en.wikipedia.org/wiki/David_Geigerhttp://en.wikipedia.org/w/index.php?title=FTL_Design_%26_Engineering_Studio&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Todd_Dalland&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Todd_Dalland&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Nicholas_Goldsmith&action=edit&redlink=1http://en.wikipedia.org/wiki/Jorg_Schlaichhttp://en.wikipedia.org/wiki/Matthew_Nowickihttp://en.wikipedia.org/wiki/Horst_Bergerhttp://en.wikipedia.org/wiki/Horst_Bergerhttp://en.wikipedia.org/wiki/Eero_Saarinenhttp://en.wikipedia.org/wiki/Frei_Ottohttp://en.wikipedia.org/wiki/Taiyo_Kogyo_Corporation#Birdairhttp://en.wikipedia.org/w/index.php?title=Walter_Bird&action=edit&redlink=1http://en.wikipedia.org/wiki/Buro_Happoldhttp://en.wikipedia.org/wiki/Ove_Aruphttp://en.wikipedia.org/wiki/Engineerhttp://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Tension_(mechanics)http://en.wikipedia.org/wiki/Munichhttp://en.wikipedia.org/wiki/1972_Summer_Olympicshttp://en.wikipedia.org/wiki/1972_Summer_Olympicshttp://en.wikipedia.org/wiki/Expo_67_pavilions#National_pavilionshttp://en.wikipedia.org/wiki/Frei_Ottohttp://en.wikipedia.org/wiki/Germanyhttp://en.wikipedia.org/wiki/Colonia_Guell_Churchhttp://en.wikipedia.org/wiki/Antonio_Gaudihttp://en.wikipedia.org/wiki/Sidney_Myer_Music_Bowlhttp://en.wikipedia.org/wiki/Nizhny_Novgorod_Fair_of_1896http://en.wikipedia.org/wiki/Nizhny_Novgorod_Fair_of_1896http://en.wikipedia.org/wiki/Thin-shell_structurehttp://en.wikipedia.org/wiki/Vladimir_Shukhovhttp://en.wikipedia.org/wiki/Guy_ropehttp://en.wikipedia.org/wiki/Tent


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material and building method can offer in terms of integrating the old and new building

methods of construction and materials.

2. DelimitationsThis paper will not include precise mathematical data with regards to the strength of

the material but however, will provide approximations whenever deemed needed.

Furthermore, these approximations will focus only on the tensile membrane itself and not on

the other components such as steel or aluminum members of the system. This paper does not

also cover the exact cost of construction or delivery and/or other such economic concerns. It

will however, contain approximations on the savings and/or debit one can have when this

building material or method of construction is implemented in the building design.

3. Objectives of the StudyThe goals of these paper are as follows:

A.)To be able to study in depth, Tensile Membrane StructuresB.)To be able to determine possible advantages and disadvantages of incorporating

Tensile Membrane Structures in the building design

C.)To be able to determine its overall effectiveness when it comes to the standards ofGreen Building systems

4. Importance of the StudyIf positive results are yielded from this study, the knowledge and synthesized data

and/or facts could be used in order to determine the proper way of designing and

incorporating tensile membrane structures into building to advocate sustainability. Society

will then have another option for building green if positive outputs are produced. Limits of

this material and/or building method of construction should hopefully be derived from this

study.


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II. Theoretical FrameworkConceptual Framework


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The above diagram shows this authors standards in determining whether Tensile Membrane

structures can contribute to green building. Strength refers to the structures physical

characteristics that determine whether it could withstand the forces of nature against which it

was built to stand. Serviceability refers to the structures property to fulfill its purpose of

providing a shelter for man and at the same time, not being obtrusive to the natural flow of

forces in the environment which can stand the test of time also. Lastly, Economy refers to the

structures integrity in providing the users with the optimum benefits possible in exchange for

the amount payable.

III. Project development MethodologyA. Methodology

ORIGINS OF TENSILE MEMBRANE STRUCTURES

The Ancient Egyptians were probably the first civilization to use pieces of fabric for shade.

They also found sails useful for harnessing the power of the wind to travel in sailing boats

from 3,500 BC. Greeks and Romans also used large pieces of fabric in their buildings. In fact

the Romans used large canvas "sails" to provide shade to spectators at the Coliseum in Rome

pulled into place by sailors. Early sails were only as strong as the fabric and techniques of

stitching used. Over the thousands of years these materials evolved and sails were often

made of flax (linen), hemp or cotton in various forms including canvas.

Structures like tents were used extensively by native Americans, Mongolians, Tibetans and

the Bedouin, typically using animal hides or women thread.

Since the industrial revolution, shade structures have increased substantially in size.

The first large canvas building was the circus tent, invented in the United States in 1825.

In 1896, the All-Russia Exhibition featured a number of major technical achievements in

structures featuring tensile steel frames by Nizhny Novgoroed.

But it wasn't until the 1950s that the potential of tensile architecture for providing shade to

large outdoor areas really took off. Although not using fabric, the Sidney Myer Music Bowl

in Melbourne by Barry Patten was an early example of a lightweight tensile structures in

1959.


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Frei Otto, influenced by Patten popularised membrane structures in the 1970s with designs

including the Tuwaiq Palace in Saudi Arabia and the roof of the Olympic Stadium in Munich.

The advent of synthetic fibres such as PVC have produced the modern shade sail.

Ideal for the hot climate, cloth became popular in Australia and South Africa for garden

greenhouses and it soon became obvious that these new materials could also be used to create

shade sails.

Modern architectural sail technology was developed in Australia. Brisbane's Expo '88

showcased the possibilities of architectural shade to the world in 1988. The symbol, logo and

theme for the exposition was the giant tensile "sun sails" which sheltered the main pavillions.

Following the expo, they were used to shelter cars in car yards from the sun and hail damage.

Australia has since become a leader in the manufacture and design of Shade Sails and exports

to the world.

The Millenium Dome in London, built in 2000 showed just how large tensile shade structures

could become.But despite some large tensile structures, in Europe, Shade Sails haven't really

taken off. However the market for Shade Sails has grown significantly in the United States

and is one of the largest importers of Shade Sails. China now manufactures much of the pre-

made Shade Sails, however they are on the whole offer much lower quality and effectiveness

than custom-made Shade Sails. Favourable exchange rates are making it more attractive forcustom made Australian Sails to export to the US commercial market. In the Philippines,

there is a company well-known for supplying internationally competitive and quality tensile

fabric shades. This company is Rize Innovations. For 25 years now, it has provided new

constructions in the Philippines with roofs, awnings and shades using tensile fabric.

COMPONENTS OF TENSILE MEMBRANE STRUCTURES

Tensile membrane structures are an integration of cables, elements which may be

either steel or aluminum and the tensile membrane itself. However, the structure must be

considered as an entity in itself and not a composition of elements.

Membrane Fabric

The membrane fabric is the main component of this system. It is the skin of the

structure which can be fabricated in many ways. The most widely used materials for fabric

membrane fabrication is PTFE & ETFE. This membrane fabric can be glued, sewn,

electrically joined or welded together. Seam styles and methods of fabrication depend on the


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design that the structure needs to achieve. High-frequency overlap welding is the most

common form of fabrication used.

Channel (with grommets) and lacing. Used with PVC-

coated polyester fabric where the edge has grommets spaced at frequent intervals. Rope is laced through the

grommets and to a tie rod within the channel.

Material properties such as thickness, flexibility, strength and weight are critical factors to be

considered when choosing a membrane fabric. Also, its need to be highly abrasion-resistant,

low maintenance and "vandal proof" must be taken into consideration.

Specialized Hardware

Fabric membrane structures are also used in tautliner trucks, yacht racing, bridge

building and rigging. Therefore, specialized hardware is needed to be fabricated to cater to

each specific use. To name a few of these specialized hardware are belts, wire rope grips and

terminal end swages. Most of the time, hardware comes in 304 and 316 grade stainless steel.

Edge cable with clamps. Used mainly for PTFE-coated

fiberglass fabric but also for PVC-coated polyester fabric when edge spans are longer than 20m.

Posts and Framework


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For a tensile membrane structure to achieve the desired form and strength, there is a

need for the integration of posts and framework. These mainly consist of a considerable

amount of steelwork covered with concrete footing. The membrane and posts and framework

of the structure must be specifically manufacture for the project itself. It is not very advisable

to utilize ready-made materials since they might not be able to perform as well as expected.

Arches are used to help shape the fabric roof surface and

promote double curvature.

COMPOSITION OF FABRIC MEMBRANE

Knowing the properties and composition of a fabric used for this kind of structural

system, and when best to use them is critical in deciding on which option is best used for a

specific project. Most architectural fabric consist mainly of woven polyester cloths

which are later on cover with coating materials that give them added strength and waterproof

property. The most widely used materials are woven polyester cloths coated with polyvinyl

chloride (PVC), and woven fiberglass coated with either polytetrafluoroethylene (PTFE) or

silicone. These are the most frequently specified materials because the base cloth is durable,

strong and relatively low cost. The polyester base cloths are then laminated or more usually

coated with PVC to give the fabric color, strength and waterproof properties. The PVC

coating also allows adjoining panels of fabric to be seamed by high frequency welding. By

this process, plasticizers, found in the PVC, are exited by the application of microwaves

along the seam overlap.

FORM and FORM-FINDING

There are many forms that can be achieved in using tensile membrane structures.

These forms can range from the conventional butterfly roof system to the complex hyperbolic

paraboloid roof system. Whatever the form may be, there is only one primary guideline that


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must be satisfied when designing (aesthetically) for tensile membrane structures. This is that

it must be anticlastic. Being anticlastic means having curvatures in two directions. The

opposite of which is synclastic which is not recommended for use in tensile membrane

structures. The anticlastic characteristic roof systems such as the hyperbolic paraboloid

roofing system gives the tensile membrane structure a rigidness that is ideal to withstand

strong winds up to a given limit. It, together with the outer coating of the fabric, helps in

giving the structure waterproofing properties. The possibilities are infinite when it comes to

the form of tensile membrane structures which gives it a high rating when it comes to

aesthetic value.

When it comes to form-finding, a number of ways have been devised by many

professionals as years pass. One of the most common methods of form-finding is the soap

bubbles and soap films method.

ADVANTAGES OF TENSILE MEMBRANE STRUCTURES

The three main advantages of the utilization of tensile membrane structures are:

lightweight materials, flexible, and low cost.

Compared to the usual building materials, tensile membrane structural components and the

membrane in itself, significantly has less weight. Less weight means being able to transport it

to different sites easier and faster. Since most of the time, components are assembled on site;

smaller vehicles will be needed for their transport. This saves on fuel and capital at the same

time.

Tensile membrane structures make use of components which themselves are flexible

entities. Therefore, when combined with each other, they form a semi-rigid structure that also

utilizes the flexible characteristic of each component. This flexible property of the structure

enables it to be formed into designs which are not common. This feature of tensile membrane

structure makes it in-demand to the public and sells itself successfully. Structures which

make use of fabric membrane are usually sought as public landmarks and features.

Most of the materials used in tensile membrane structures are easily and readily

manufactured and easily accessible which makes this structure low cost. Also, when it comes

to damages like wearing and tearing and/or burns, one need not worry. Tensile membrane

fabric are designed in such a way that when a portion of it is torn, it does not continue to doso and affect other parts of the fabric. The fabric is woven tightly in that it does not spread to


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the other parts and the tear is contained. Same is true with the case of burns. In case of fire,

tensile membrane structures have the property of being fire-retardant. It is this property that

gives them the ability of reducing the flammability of the fuels and delaying their

combustion. Tensile membrane structures will allow burns but will contain them in a specific

area and then let the fire die out by itself. Tensile membrane structures are also easy to clean.

Rain water can clean the structure when it slides off it.

CASE STUDY: Application of Tensile Membrane Structure in the UPIS Basketball

Court

The UPIS is now constructing new buildings to house students of the new K+12

curriculum that is will be implementing by next term. Together with other facilities, the UPIS

has decided to construct a basketball court that will make use of tensile membrane structure

for the roofing system. This case study is done utilizing the site details provided in another

class, however, the specific design of the tensile membrane structure is different and are

mutually disjoint.

Above is a perspective view of the proposed design for the roofing system of the UPIS

basketball court. The court has its longer sides oriented along the North-South axis while its


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shorter sides lie along the East-West axis as seen in the photo below.

The succeeding photo shows the sun and wind paths of the site.

The wind path enters the site directly from the North East and Southwest portions of the site

and gives it enough ventilation for the whole day. The propsed designe of the structure

showcases open ends on both the East and the West to allow unobstructed wind toflow


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throughout the structure that keeps the thermal level at the comfortable zones.

Aside from the open ends in the East and West portions of the structure, small opening are

also situated at the upper portion of the roof to enable air to go inside the structure and to

allow the escape of the warm air that situates itself in the structures higher ortions. The

structures being open should not concern the users when it comes to protection from sun

and rain. The structure provides a 1.2 meter overhang in both sides which is deemed to be

sufficient in protecting the users from rain. This overhang allowance also gives the users

protection from the sun but the fabric membranes semi-translucent characteristic allows

enough the sufficient amount of sunlight to enter the court. This will help save the UPIS interms of energy consumption cost since they will only have to use electrical lighting at night

time which is less likely since activities for children of this age bracket are usually done in

the morning or afternoon.

IV. CONCLUSIONSTensile membrane structures, when designed properly, taking context and climate into

consideration, that is, can be considered as one of the modern day innovations that integrate

vernacular building methods and modern building construction materials. The tensile

membranes characteristic of being able to adapt forms that are adept to the climactic factors

of a certain place makes it one of those inventions that can promote green building with less

questions arising from the public. Aside from being able to adapt to the natural phenomena in

the site, tensile membrane structures are also available in different sizes, materials used and

costs that would best fit the users monetary budget but will not, however, affect the quality

of performance, at least at a considerable worryful manner. Tensile membrane structures are

also the cutting-edge elements in architectural design nowadays since they assume forms that


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were once not possible of hard to accomplish with building materials used before. Truly

tensile mebrane structures advocate green building while integrating form and function as

well.


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V. SOURCEShttp://www.waterforpeople.org/extras/playpumps/update-on-playpumps.html

http://www.llda.gov.ph/liscop_teresa.shtml#

http://en.wikipedia.org/wiki/Reed_bed

http://www.rubbusa.com/quality/pvc-coated-membrane.php

http://www.bestfromchina.com/featured_partners/membrane_structure.html

http://fabricarchitecturemag.com/articles/0110_ce_connection.html

HEATING,COOLING,LIGHTING. Lechner, Robert.John Wiley & Sons,Inc., Hoboken,New Jersey

2009
http://www.waterforpeople.org/extras/playpumps/update-on-playpumps.htmlhttp://www.waterforpeople.org/extras/playpumps/update-on-playpumps.htmlhttp://www.llda.gov.ph/liscop_teresa.shtmlhttp://www.llda.gov.ph/liscop_teresa.shtmlhttp://en.wikipedia.org/wiki/Reed_bedhttp://en.wikipedia.org/wiki/Reed_bedhttp://www.rubbusa.com/quality/pvc-coated-membrane.phphttp://www.rubbusa.com/quality/pvc-coated-membrane.phphttp://www.bestfromchina.com/featured_partners/membrane_structure.htmlhttp://www.bestfromchina.com/featured_partners/membrane_structure.htmlhttp://fabricarchitecturemag.com/articles/0110_ce_connection.htmlhttp://fabricarchitecturemag.com/articles/0110_ce_connection.htmlhttp://fabricarchitecturemag.com/articles/0110_ce_connection.htmlhttp://www.bestfromchina.com/featured_partners/membrane_structure.htmlhttp://www.rubbusa.com/quality/pvc-coated-membrane.phphttp://en.wikipedia.org/wiki/Reed_bedhttp://www.llda.gov.ph/liscop_teresa.shtmlhttp://www.waterforpeople.org/extras/playpumps/update-on-playpumps.html

Documents

Effectiveness of Tensile Membrane Structures in Green Building