High Tech Building Materials: ETFE

STUDY OF HIGH TECH BUILDING MATERIALS

ROSE RANJAN10110050

SNEHA NAGARAJAN10110058

The need for new materials TransparentLightweightResponsive

Weightlessness in architecture and design Material innovations, and the discovery of new materials have served to transform the ideas of materiality from monolithic to ever more ethereal and ephemeral constructions.

TRANSPARENCY From the beginnings of the 19th century to today, glass – composed of

silicates and and an alkalai fused at high temperatures – has ben one of the most widely used construction materials.

Crystal Palace, Joseph Paxton, 1851Great icon for lightweight, modular and transparent architecutreMakes use of mass production processes for iron and glass Designed such that it could be dismantled after the exhibition, reflecting an attitude toward mobility that was ahead of it’s time.

Many different kinds of glass have recently entered the construction industry

Photochromic glass : responds to lightThermochromic glass : responds to heatElectrochromic technology changes the transparency of glass partitions or cladding from clear to opaque by passing low voltage electrical charges across microscopically thin coating on surface

IDEO’s recent projects include hi-tech fitting rooms in the New York Prada epicentre, designed with Rem Koolhaas. Each dressing room is a simple booth with Privalite glass walls that switch from transparent to opaque for privacy

ETFE Replacement for glass needed-Environmentally friendly -Energy efficient-Transparent , light weight

When we think of transparency or translucency, concrete is definitely not a material that comes to ming. Concrete connotes solid and durable, opacity and weight.

Bill Price ‘s work on translucent concrete , made of glass and polymerized synthetics. This has been made possible by embedding an array of tiny glass fibers with concrete blocks.

The material, called i.light, was created specifically for the Italian pavilion at the 2010 World Expo in Shanghai. Italcementi’s creation was made with a proprietary mixture of cement and admixtures that bonds with a thermoplastic polymer resin..

The resin is injected into tiny holes that span the width of each cement panel, resulting in approximately 20 percent transparency. The transparency can be changed by modifying the amount of resin in the panels

LIGHTWEIGHTSFree floating structures and lightweight construction materials.While the aesthetic quality of lightness has become an attribute achieved through transparency of glass and the airy look of free floating forms; the physical qualities of lightweight structures tend to concentrate on structural ingenuity and use of lighter material substances.

“How much does your building weigh?”, Buckminister Fuller. He experimented with aluminium at early as the 1930’s.

Hearst Magazine Building, New York, 2003-2006

Hearst Corporation's global headquarters and the first New York City landmark of the 21st century.

British architect Norman Foster has conceived an arresting 46-story glass-and-steel skyscraper that establishes a number of design and environmental milestones.

Hearst Tower is a true pioneer in environmental sustainability, having been declared the first "green" office building in New York City.

Under ConstructionDiagrid bracing being installed

No vertical structural frames. Gives corner view.

This is the first such case in any North American steel-framed skyscraper.

The exterior honeycomb of steel keeps the interior works area uncluttered by pillars and walls, thus creating superb views of the city from most vantages on the work floors. At night, with its radically angled panes of glass, Hearst Tower looks like a faceted jewel.

Diagrid Pattern: More about the Structure

"The triangular frames carry the gravity load and has inherent strength and resistance to the lateral loads, seismic and wind

The triangles are so efficient in terms of bearing both the gravity and lateral loads, the building use 21 percent less steel (9,500 metric tons) than a conventional building of its size.

Lateral load

Gravity load

Hearst Tower: Green BuildingFirst green building completed in New York City

Hearst Tower is among the top 10% of energy-efficient buildings in the nation

Light sensors inside control the amount of artificial light on each floor, based on the amount of natural light available at any time

Since steel was first mass produced in the 1880s it has always been highly recycled because : - Steel has a relatively high economic value - the price paid for scrap structural steel in 2012 was around £200 per tonne- The versatility of steel means that it can be easily recycled or remanufactured into new applications as demand dictates-Steel’s magnetic properties mean that it can be efficiently segregated from mixed waste streams.

90% of the Tower's structural steel contains recycled materials. The triangulated steel frame uses 21% less steel than a traditionally framed building.

The environmental impact of the first or primary production process is 10 units and the impact of the secondary or subsequent process, i.e. the recycling process, is 3 units.

The Hearst Tower seems to have perfect thermal comfort all year round due to its complex (and incidental) heating systems. 

THERMAL COMFORT 

An innovative type of glass wraps around the exterior of the building. The glass has a special “low-E” coating that allows for internal spaces to be flooded with natural light while keeping out the invisible solar radiation that causes heat.

Millienium Tower, Glasgow by Richard Horden

The entire structure is mounted on a turntable and a bearing ring that tapers to fit a single 300mm stainless steel bearing which allows it to turn towards the wind like a sailboat to minimize the wind forces.

Aerodynamic design contributes to slenderness.

A steel tube clad with aluminium located behind the tower balances it aerodynamically.

Viewing cabin is built out of glass fier reinforced polymer. 25m tall mast located behind the viewing cabin is built out of a carbon fiber composite that improves the natural frequencies of a steel tower.

ETFEEthyleneTetraFluoroEthylene

• ETFE, a fluorine based plastic, was designed to have high corrosion resistance and strength over a wide temperature range.

• ETFE has a very high melting temperature, excellent chemical, and high energy radiation resistance properties.

• ETFE film is self-cleaning (due to its non-stick surface) • It is recyclable. • In sheet form as commonly employed for architecture, it is able to stretch to three

times its length without loss of elasticity. • Employing heat welding, tears can be repaired with a patch or multiple sheets

assembled into larger panels.• ETFE has an approximate tensile strength of 42 N/mm² (6100 psi), with a working

temperature range of 89 K to 423 K (-185 °C to 150 °C or -300 °F to 300 °F).• ETFE resins are resistant to ultraviolet light. An accelerated weathering test

(comparable to 30 years’ exposure) produced almost no signs of film deterioration.

• It is prone to punctures by sharp edges and therefore mostly used for roofs.

The "miracle polymer" for public architecture

ETFE has a wide range of applications from wiring insulation, thermoplastic lining, corrosion protection to wire covers, mold release films.One of the primary uses of ETFE though, is in the building industry.Top manufacturer: DuPontAn example of its use is as pneumatic panels to cover the outside of the football stadium Allianz Arena

ETFE provides excellent heat and chemical resistance and mechanical strength.

Beijing National Aquatics Center a.k.a. The Water Cube

90% of the solar energy falling on the ETFE cushions is trapped within the structural zone and used to heat the pools and interior.

A pump connection and manifold connects each individual bubble to maintain inflation.

The building encloses an area in excess of 100,000 square metres within an ETFE dome, with dramatic views over the city and the Steppes beyond.

Khan Shatyr Entertainment Center, Astana Kazakhstan

What is common among all these buildings is the steel structure. The ETFE pillows are laid out on a steel structure.

The Eden Project, Cornwall, England

1994J. Baldwin invented a permanent, transparent, insulated geodesic dome — using a framework of aluminum tubing, covered with argon-filled laminated vinyl sheet "pillows" — which he dubbed the "Pillow Dome," said to have withstood 135-mph winds and thirty inches of snow. The structure weighed just one-half pound per square foot of floor space. For a variety of reasons including durability and toxicity concerns from vinyl chloride vapor emitted by vinyl sheeting, Baldwin later recommended the use of ETFE film; ETFE had further advantages including transparency and ease of keeping the surface clean, but its ultraviolet transparency reduces its suitability for occupied structures. Baldwin intentionally did not patent his invention. The basic approach has since been applied in large-scale applications such as the Eden Project in Cornwall, England.

Pillow Dome,J. Baldwin

Located in Cornwall, the Eden Project was conceived by Tim Smit and designed by famed

architect Nicholas Grimshaw.

Sir Nicholas Grimshaw is a prominent English architect particularly noted for several modernist buildings.

National Space Center, LiecesterAlthough the structure can be considered ephemeral, various finishes are guaranteed for over 60 years.

The covered biomes were inspired by the moon and are constructed from a tubular steel space-frame clad with (mostly) hexagonal panels made from a thermoplastic called ETFE.What better material to use than ETFE for a fantastical project like this- cheaper, lighter and safer than glass!

Conception and Erection of the Eden Project

'An architect would fall over backwards wanting to build something in it,' said David Kirkland of Nicholas Grimshaw & Partners.

The Eden Project has three main biomes: the Tropical Biome, the Mediterranean Biome and the Outdoor Biome (which is uncovered). The Tropical Biome houses plants such as fruiting banana trees, coffee, rubber and giant bamboo, while the Mediterranean Biome is home to European plants such as olives and grape vines. The Outdoor Biome is filled with plants that can be grown outside in the UK climate like tea, lavender, hops, hemp and sunflowers.

The outdoor biome

The panels vary in size up to 9 metres (29.5 ft) across, with the largest at the top of the structure.

Although the ETFE is susceptible to punctures, these can be easily fixed with ETFE tape.

The ETFE technology was supplied and installed by the firm Vector Foiltec, which is also responsible for on-going maintenance of the cladding.

The steel space-frame and cladding package (with Vector Foiltec as ETFE subcontractor) was designed, supplied and installed by MERO(UK) PLC, who also jointly developed the overall scheme geometry with the architect, Nicholas Grimshaw & Partners

The computer-controlled environmental control system that regulates the temperature and humidity in each dome was designed and installed by HortiMaX Ltd. (formally named Van Vliet Automation Ltd.) who are also responsible for ongoing maintenance of the environmental control and monitoring systems on both the Biomes and Glasshouses at their production site.

The structure is completely self-supporting, with no internal supports, and takes the form of a geodesic structure. At the lines of intersection between the domes are complex, three-chord, triangular steel trusses.

Structural spans of up to 124 metres

The basic form of the construction is a series of intersecting geodesic domes

This geometry offers a number of advantages: it facilitates a lightweight yet rigid structure; and it

is easily prefabricated with a plug-in jointing system that offers a high degree of precision and

can be delivered to the construction site as a series of small components

The dome construction is divided into two layers: The outer skin is based on a hexagonal framework, the inner layer on a triangular and hexagonal grid

A challenging point was the design of the support system. Because the 800 m long foundation varies, each of the 187 support points is geometrically different. The supporting construction also consists of tubes with diameters of 193 mm which are welded together . The connecting top chord beams and diagonals are bolted together. The base plates are fixed to the foundation by anchor bolts M27 and M36 and the horizontal forces are transferred by shear blocks.

The more than 800 hexagon elements are covered by air filled cushions

The basic material is between 50 µm and 200 µm thick with a width of 1.5 m.

The foil material was cut and welded.

The normal cushions are made up of three layers. The top and bottom layer form the cushion and carry the loads. An additional layer between them has the function of enhancing the temperature insulation and also dividing up the airspace in case of leakage.

In areas of high local wind suction the outer surface of the cushions was strengthened by using two layers of foil.

The cushions are attached on an aluminium frame to the top chord beams

Each cushion is also attached to an air supply system

The pressure inside the cushion is about 300 Pa.

The maximum height of the inflated cushion is about 10 to 15 % of the maximum span

Material EFTE has been used for more than 20 years

Cushions in this project size had never been built.

During the design stage, extensive studies and tests were performed by MERO, the consultant Ove Arup (London) and the foil subcontractor Foiltec in Bremen (Germany). Some of the tests were performed on a real 1 to 1 scaled model. The results of this studies lead to the important parameters for the design of the cushions with spans up to 11 m.

After the design phase, the size of each of the 800 elements was calculated, cut, an manufactured.

In areas of high show load, like the arches, some additional cables were needed to support the cushions.

The gutter construction between the single domes is made out of insulated aluminium parts

and is covered on the outside by foil...

The entire roof surface can be maintained by abseilers using ropes attached to steel pins which are attached to each bowl node of the structure.

There are so many materials to explore!

The most interesting aspect… use your imagination!

Thank You!