textile roofs 2014 - tensinet · 10.00 - 16:00 cen/tc250 wg5 core group meeting vub, building d,...

N E W S L E T T E R O F T H E E U R O P E A N B A S E D N E T W O R K F O R T H E D E S I G N A N D R E A L I S A T I O N O F T E N S I L E S T R U C T U R E S

NEWSLETTER NR. 27SEPTEMBER 2014PUBLISHED TWICE A YEARPRICE €15 (POST INCL)www.tensinet.com

PROJECTS

REPORT

TEXTILE ROOFS 2014

STUDENT’S PROJECT WEEK

FROM MEMBRANE FORMTO RIGID SHELL

KKIINNGG FFAAHHAADD NNAATTIIOONNAALL LIBRARY

FFIIFFAA WORLD CUP BBRRAASSIILL

IINNNNOOVVAATTIIVVEE MMEEMMBBRRAANNEE AARRCCHHIITTEECCTTUURREE

FFOORR CARPORT

Tensioned white membrane ceiling for the interior. © Christian Richters - SEFAR▲Textile roof World Cup Stadium Brasil © Michael Bredt, Germany /Ceno Membrane Technology GmbH ►

RESEARCH

19 TEXTILE ROOFS 2014 REPORT

The Nineteenth International Workshop on

the Design and Practical Realisation of

Architectural Membranes, took place on

26–28 May at the Deutsches Technikmuseum

Berlin. It was attended by 90 participants

from 27 countries from four continents.

TENSINEWS NR. 27 – SEPTEMBER 20142

CENO Membrane Technology GmbHwww.ceno-tec.de

Dyneonwww.dyneon.eu

FabricArtMembrane Structureswww.fabricart.com.tr/

Form TLwww.Form-tl.de

Messe FrankfurtTechtextilwww.techtextil.com

Mehler Texnologies www.mehler-texnologies.com

Sefar www.sefar.com

Sioen Industries www.sioen.com

Saint-Gobain www.sheerfill.com

Taiyo Europewww.taiyo-europe.com

technet GmbHwww.technet-gmbh.com

Verseidagwww.vsindutex.de

Naizil S.P.A.www.naizil.com

Heytex Bramsche GmbHwww.heytex.com

Hightex GmbH www.hightexworld.com

form TL

Serge Ferrari sawww.sergeferrari.com

Canobbio S.p.A.www.canobbio.com

partners2014

INFO

Buro Happoldwww.burohappold.com

Editorial BoardJohn Chilton, Evi Corne, Peter Gosling, Marijke Mollaert, Javier Tejera

CoordinationMarijke Mollaert, phone: +32 2 629 28 45, [email protected]

Address Vrije Uni ver siteit Brussel (VUB), Dept. of Architectural Engineering,Pleinlaan 2, 1050 Brus sels, Belgium fax: +32 2 629 28 41

ISSN 1784-5688All copyrights remain by each authorPrice €15postage & packing included

n°27

PROJECTS PA G E

4 Germany LORDS GARDEN OF RELIGIONSA PLACE OF WORSHIP FOR THREE RELIGIONS

4 Greece PASSENGERS TERMINAL COVER

5 India TENSILE ARCHITECTUREFOR RESIDENTIAL APPLICATION

6 Germany CARPORTINNOVATIVE MEMBRANE ARCHITECTURE

9 Brasil FAÇADE CONSTRUCTIONAMAZING TEXTILE ROOF

10 Brasil FIFA WORLD CUP FLEXIBLE COMPOSITE MATERIALS FOR EACH PURPOSE

12 Saudi Arabia KING FAHAD NATIONAL LIBRARYA SECOND SKIN FOR FACADE AND CEILING

17 Thailand SHOPPING MALL OUTDOOR ROOF COVER

REPORT

RESEARCH

contents

PA G E

18 TEXTILE Hybrid Softhouse HAMBURG, GERMANY

24 24 STUDENT'S PROJECT WEEK TEXTLE ROOFS 2014

14 FROM MEMBRANE FORM TO RIGID SHELLAPPLIED RESEARCH ON MATERIAL AND PROCESS TECHNOLOGY TO APPLY AND STIFFEN MEMBRANE STRUCTURES WITH SHOTCRETE

TENSINEWS NR. 27 – SEPTEMBER 2014 3

EditoDear Reader,

Years with important sport events lead to many new or renovated sports facilities. Largespan together with translucency are the main advantages of structural membranes,that’s why many new membrane projects are built for these events. This year for the FIFAworld cup 2014 most of the 12 stadiums have been realised with structural membranes.For one of them you find a project article in this new issue of TensiNews.

Since the last TensiNews many activities were going on within the Eurocode workinggroup and in the COST Action on 'Novel structural skins'.The Eurocode working group is preparing the scientific and policy (SaP) report“Guideline for a European Structural Design of Tensile Membrane Structures made fromFabrics and Foils”. This report is summarizing the actual code of practice in differentEuropean countries, and gives an outlook for a future Eurocode. It will be finished andsubmitted by the end of this year. It is supposed to be published by the joint researchcenter (JRC) as background information to the future technical specification andEurocode. The ETFE working group has contributed to the Eurocode working group achapter on the limit states for ETFE foil, and is supposed to contribute also furthergeneral information based on the ETFE Design Guide.After a first meeting in March, the COST Action on 'Novel structural skins - Improvingsustainability and efficiency through new structural textile materials and designs' ismeeting this September in Brussels. TensiNet members are involved in the differentworking groups.TensiNet was present at Textile Roofs 2014 in Berlin, with many interesting lecturesabout projects, research and student work. Josep Llorens has prepared a report about thisnineteenth international workshop held in Berlin this May.

Actual research on rigid shells, photovoltaic integrated in ETFE cushions and naturalventilation to avoid air-conditioning are beside many interesting projects subjects of thisissue. Please enjoy it. I hope to meet you at our activities and events.

Yours sincerely,Bernd Stimpfle

Forthcoming MeetingsTensiNet Meetings

Espace Vinci, 25 rue des Jeuneurs, 75002 Paris │ 23/09/201410.00 - 16:00 CEN/TC250 WG5 core group meeting

VUB, Building D, Pleinlaan 2, 1050 Brussels, Belgium│ 30/09/201413:30 - 14:00 Annual General TensiNet meeting - welcome14:00 - 15:00 Annual General TensiNet meeting - Presentation and summery of the activities

WGs of both TensiNet and the COST action TU1303 - Novel structural skins15:00 - 16:00 Partner meeting

COST Action TU1303 Meetings

TensiNet members can also attend the COST Action TU1303 meetingsVUB, Brussels, Belgium │ 29-30/09/201429/09 morning plenary session, afternoon parallel Working Group sessions30/09 morning parallel Working Group sessions, afternoon joined COST TU1303

+ TensiNet meeting

Additional information can be found at http://www.novelstructuralskins.eu/events/meetings/

Forthcoming EventsCLADDING and FIXINGS for humanitarian sheltering Luxemburg, Luxemburg │ 3-4/09/[email protected] 2014 symposiumBrasilia, Brazil │ 15-19/09/2014www.iass2014.orgEssener Membranbau Symposium2014 Essen, Germany │ 26/09/2014www.uni-due.de/imlAachen - Dresden International Textil ConferenceDresden, Germany │ 27-28/11/2014http://www.aachen-dresden-itc.de/ TECHTEXTIL 2015Frankfurt, Germany │ 4-7/05/2015www.techtextil.messefrankfurt.com

Invitation and conditions for participation in the

13thTechtextil Competition TEXTILE STRUCTURES

FOR NEW BUILDING 2015

Areas of textile building • Structural engineering – from construction using

textile-reinforced concrete or plastics to constructionusing membranes for permanent and temporary,adaptable and mobile buildings;

• Interior construction – including such developmentsas the use of polymer fibre-optic cables for lighttransmission, textile air-channel systems for draught-free air conditioning in rooms, movable sound-insulation walls in production facilities, etc.;

• Product design for architecture;

• An additional focal theme has also been included:'Suitability for re-use and recycling';

• Civil and industrial engineering.

The subject of the project submitted is a free choice.Work will be accepted, which has been producedeither under a supervisor or without a supervisor.

The deadline for uploading your summary and yourcontact data online at www.techtextil-student.com is27 February 2015.

The award winning projects will be exhibited and win one of the cash prizes from the total pay-out of € 8.000.

ORGANISED BY TECHTEXTIL / SPONSORED BY TENSINET

The project had a lifetime of aboutsix month, from 26 April 2012 to 7 October 2012. The diameter ofthe base plate was about 10m, theusable floor area was 60m² and thetotal height of the structure wasabout 6,10m. A dome of three, inthe same direction curved, printed

surfaces embodies the three mono -theistic religions that revolvearound a common center. The sup -porting structure of the dome isdivided into a main structure andthree shell structures, which sup -ports on the base plate, and thehigh point of the main structure


KIEFER . TEXTILE ARCHITEKTUR

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Lords Garden of Religions

The structure covers a surface of68mx34m. The bearing frameconsists of 4 calendered hotdipped galvanised arches, placed ina longitudinal way, having a widthof 34m supported by 2 hot dippedgalvanised steel pillars. The heightis 6,70m, reaching a height of3,70m at the perimeter (Fig. 1).

Each arch is braced by means ofcables anchored to the top of thepillars and the membrane isstretched on the perimeter on topof 3,70m high stands.The structure has been calculatedaccording to EUROCODE 1 standards. Accidental loads takeninto consideration were thefollowing: snow: qs = 60kg/m2;wind: qw = 80kg/m2

Due to the shape and the involvedloads, the covering membrane wasmanufactured using a

Précontraint 1002 Fluotop T– witha Polyester reinforcement2x1100dtex – surface treatment100% PVDF, with tensile strengthof 420/400daN/5cm; tearingstrength of 55/50daN and weightof 1050gr/m2.The shape of the single layermembrane has a double negativecurvature, which is stabilized bypre-stressing (Fig. 2).

! Antonella Fedeli: [email protected]: www.plastecomilano.com

www.pmtexarch.com

Figure 1. Front view - side view

Figure 2. Passengers terminal cover

PM ENGINEERING Patrasso Port, Greece

Bamberg, Germany

The National Garden Show 2012 in Bamberg allows for the first time,even if only temporarily, to build a place of worship for three religions.During the State Garden Show 2012, the house of prayer of religions,invited Christians, Jews and Muslims "to touch the paradise".

Name of the project: Passengers Terminal cover Location address: Patrasso Port, GreeceClient (investor): Mekaterattiki Diodos SAFunction of building: Passengers Terminal coverYear of construction: 2004Architects: PM Engineering SRLConsulting engineer for the membrane: Eng. Dario Ravasi, Varese ItalyMain contractor: Arka Synthesis LTDSupplier of the membrane material: Ferrari SAManufacture and installation: PM Engineering SRL - Plasteco Milano – Arka Synthesis LTDMaterial: PRECONTRAINT 1002 FLUOTOP TCovered surface (roofed area): 2312m2

PASSENGERS TERMINAL cover

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(Fig. 1). The main structure consistsof three curved, point-sym metri cal -ly arranged steel tubes which meetat the highest point on a cir cularring. The three bowls are biaxialcurved in the same direction, geo -metrically identical latticestruc tures and also arranged point-symmetrically around the center.Two of the dishes are executedmobile and thus provide a settingfor the entrance to the place ofprayer (Fig. 2).To stiffen the shells and as bearingsystem for the membrane lattice

structures were provided with anetwork of bent steel tubes withvery small diameters. This suppor -ting structure is followed by theclamping of a printed translucenttissue consisting of extremely hightensile strength polyester fibers anda PVC coating to protect for UVradiation and other environmentalinfluences. Due to the translucencyof the fabric, the printing can alsobe performed inside the structurewhile also ensuring adequateillumination without additionallight sources (Fig. 3).

! Kathrin Kaltenbrunner: [email protected]: www.k-ta.de


Name of the project: Lords Garden of Religions Location address: National Garden Show 2012, BambergClient (investor): Erzbistum BambergFunction of building: Temporary pavilionType of application of the membrane: Roof and facadeYear of construction: 2012Architects: Michael Kiefer (K.TA)Concept design and print layout: Bernhard KümmelmannStructural engineers: Tobias Lüdeke & Manfred Schieber (K.TA)Engineer for the membrane: Tobias Lüdeke (K.TA)Main contractor: Prebeck Bauunternehmung GmbHContractor for the membrane: Koch Membrane GmbHSupplier of the membrane material: Mehler Texnologies GmbHInstallation of membrane: Membran Service WilflingMaterial: Mehler Valmex Cristal FRCovered surface: 160m²

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Figure 1. Axonometric of the dome structureFigure 2. 3 different positions of the shell structuresFigure 3. Outside and inside views of the printedmembrane

Tensile Gazebo, Sangli, IndiaNOVEL PRODUCTS

The concept of the project was realizedwith the idea of promoting the use oftensile architecture. Presently the tensilearchitecture projects in India are mainlyconfined to metropolis. However, thepresence of tensile structures in the inte-rior parts is relatively low or nonexistent. The gazebo on the terrace of a privateresidence is a tensile membrane canopysupported by two vertical poles & twoinclined needle masts supported bystays. This greatly adds to the beauty ofthe entire ambience. Additional tiltingflaps operated by gas springs are pro-vided on three sides of the tensile canopyto further protect the sitting area fromsun and rain. This is optional and theflaps can be tilted as and when required.The roof also got heavily exposed andsustained to the hailstorm recently expe-rienced by several districts of the stateof Maharashtra. The sole objective ofthis project is to depict how tensile archi-tecture can enhance the beauty of outdoor spaces, retaining its practicalutility with its unique feature of relocatability. This was further developedspecifically keeping in mind the boom in the construction industry in theurban and semi urban parts of India. The project is located at Sangli a smallcity located in the southwestern part of the central Indian state of Maha-rashtra around 300km from Mumbai, the state capital.

! Suhas Kunte: [email protected]: www.novelproducts.co.in: www.pmtexarch.com

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Name of the project: Roof top Tensile GazeboLocation Address 'CHINTAMANI'

145 South Shivajinagar Near Ram Mandir Sangli 416416 (Maharashtra) India. Client: (Invester) Mr. KunteFunction of the building: Outdoor leisureType of Membrane: Pvc coated 502 Precontraint- Ferrari Year of Construction: 2013 Architects: Novel design studioConsulting engineer for the membrane: Novel productsMain Contractor: MechTechSupplier of membrane material: Serge FerrariCovered Area : (Roofed Area) 28m2

TENSILE ARCHITECTURE for residential application


IntroductionIt’s not always easy being green, that’s what we discovered whenattempting to build the AWM (Abfallwirtschaftsbetrieb Mün chen) carportroof in Munich. The project, which involved an ETFE film roof withphotovoltaic cells, came under close and critical scrutiny of city officials,en gi neering specialists and the general public. It was for the team a longand hard way, because every step was controlled. The city and public hadgood reason for its skepticism. The new roof was meant to replace one thathad partially collapsed in 2006 after a heavy snowfall - an event that gavethe city and architect a lot of bad publicity. The same architect, Munich-based Ackermann and Partner, was hired forthe re-construction.

ProcessIn the summer months in 2011, Taiyo Europe GmbH erected the new roofstructure for the carport used for under-cover parking of the trucksbelonging to Munich's waste disposal companies. This structure comprisesa steel construction with a roof cover made of three-layered ETFE filmcushions (3M Dyneon ETFE 6235Z) with integrated flexible photovoltaiccells (Fig. 1). This innovative project, located near to the famous OlympicPark here in Munich, is also used for all-year electricity generation at themain headquarters of the waste disposal companies in Munich (AWM). Thenew carport roof was planned by the architects, in close cooperation withthe city's Building Department and AWM. AWM short-listed two versionsfrom the series of possible solutions presented. The roof variant withintegrated photovoltaic system favoured by AWM was then approved bythe Municipal Committee and thus resolved. For AWM, the reconstructionwork presented the opportunity of designing the large roof area as aninnovative photovoltaic structure. The new roof concept thus makes asignificant contribution to sustainability, particularly to climate andresource protection, which AWM has declared as one of its major maximsalongside efficiency. We are very glad and proud, that we completed thisnew technology project in October 2011. Since then we follow up thisproject and since today we are very sufficient with the result.

Description of the concept One basic pre-condition for thenew roofing was the use of existingpoints of support for the hingedcolumns made of tubular steelwith integrated roof drainage. Thecolumn grid is 10mx12m in size.The primary load-bearing structurecomprises multi-bay framescomprising columns and 3-cordedtie bars which are fanned out at

the edges using tensioned braces. The trussing meant that the curvedtubes could be kept slim. The total steel weight is 480T, or 48 kg/m²covered area. Unlike the earlier design, the primary load-bearing structurehas been designed to be stable irrespective of the roof covering (Fig. 2 - 4).The steel structure is coated with the classic Deutsche Bundesbahn colourDB 703 high-gloss paint.The roof area is made from 220 air-supported cushions. The 220 aircushions covering the roof elements are made of ETFE film. This material isvery translucent and resistant to the influences of the weather. Eachcushion is made of three layers of ETFE film. As is customary in membraneconstructions, the layers are termed upper layer UL, middle layer ML andinner layer IL (Fig. 5). The lower film layer is printed to reduce the light transmitted through thefilm cushions onto the carport deck. There are 12 photovoltaic modulesfixed to the middle layer of each cushion by means of mechanicalconnectors, some of which can be moved, so that the modules are notsubjected to any bending, tensile or shearing forces, even not in the eventof heavy snow loads. As with bridge supports, for example, one of the PVmodule attachments is always without a longitudinal hole, in other wordsit is in a permanently fixed position, preventing the PV module from"floating freely". The middle layer is mechanically pre-stressed to preventcreasing and is without load in the operating state, since the largeventilation openings in it lead to the same inner pressure above and belowthe middle layer. To allow any faulty modules to be able to be replacedeasily even in the long term, the upper film layer was fixed separately fromthe other two heat-sealed film layers in the double-welt clamping profile(Fig. 6). This layer can be opened separately and basically works like aservice cover.The load cases of the pre-tensioned ETFE films, intrinsic weight, snow,wind and change in temperature were considered in the calculation of theroof structure. Whereas the static calculation of the primary load-bearingstructure was carried out using a standard calculation program for spacebar frames, the calculation software using the force-density method,which has been especially developed for architecture membranes, was

used for the final design, staticcalculation and cutting patternlayout specification of the ETFE film. Pneumatic systems becometensioned, pre-stressed structuresdue to the air overpressure at theinside. The pre-stress in the upperand lower membrane is the result ofthe difference in pressure betweenthe inside of the cushions andatmospheric pressure. It alsodepends on the radius of the

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ROOF COVER MADE OF THREE-LAYERED ETFE FILM CUSHIONSWITH INTEGRATED FLEXIBLEPHOTOVOLTAIC CELLS

Innovative membrane architecture for carport

München, Germany

TAIYO EUROPE

corresponding membrane layer. The overpressure in the cushion ismaintained using blowers. The membrane layers are always tensionedunder load and are thus kept stable. Cushions are usually designed withtwo or three layers, depending on the structural-physical requirements.The design of the air supply to the film cushions through blower unitsprimarily depends on the magnitude of the defined inner pressure, thenumber of cushions and the size of the total area. An air dryer is includedupstream of the blower. The supply air is dried to prevent condensationforming in the film cushions.The air supply is connected to the lower cushion chamber. Air is ex -changed between the upper and lower cushion chambers via overflowopenings in the middle film layer (two rows of 12 circular holes with adiameter of 90mm at the edge of the middle layer of the cushion and onerow of 12 holes at the peak of the middle layer). The air escapes via the airoutlet. The flushing rate of the cushion volume (air exchange of thecushion volume was estimated at 3.000m³/24h at planning) was specifiedby the building engineer to 4.500m³/24h, in other words 1,5 times perday. The prescribed flushing rate is set using the cross-section area of theair outlet. In the nominal case, the support air pressure inside the cushionis 300 Pascal compared with the atmosphere. In the event of snowfall,this pressure can be increased to 600 Pascal. If the snow load exceeds 0.6 kN/m², the cushion is compressed in a controlled way. In this case, theupper and lower film layers bear the load together. The geometric form ofthe film cushions chosen means that no water pockets will occur even ifthe blower fails during a period of rainfall. Pockets of snow can formtowards the lower edge in the event of drifting snow. However, the local additional loads do not endanger the structuralsafety and do not lead to any significant deformation.

The stability of the cushion roof structure is not dependent on support airsupply. Nevertheless, it was decided to make this supply particularlyreliable (Fig. 7). Three blower units supply one third of the roof area each.Each station has two redundantly wired blower motors which alternate ona weekly basis and automatically replace each other if one of the blowersshould fail. The air supply is connected to an emergency power supply anda remote warning system. Each cushion assembly with correspondingblower is integrated in a separate ring air pipe. All three ring air systems areseparated from each another by valves which enable the area affected byblower station failure to be supplied by a neighbouring station. In addition,an air pipe system with high density class and non-return valves waschosen for the blower stations, making the whole system extremelyairtight.

Assembly procedureThe static system chosen by the structural planner required assembly tobe carried out in several stages. Following erection of the statically stableprimary load-bearing structure, the film cushions could be fitted. The filmcushions were clamped in all-round aluminium profiles which were thenscrewed to the sub-structure. The photovoltaic thin-layer modulesfastened mechanically to the middle film layer 100μ thick were fixed inplace on site on a special pre-assembly table before installation of thecushions. So-called welts were heat-sealed at the edge for the linear edgeattachment of the film layers. These welts were clamped into theattachment profiles.


TABEL 1 - Technical dataDimensions:Length x Width 120,00m x 70,00mColumn grid 10,00m x 12,00mEaves height +8,45mRidge height +10,03mCovered area 8.400m²Steel structure S355J2H/ E355+AR/St.52.0 S Total coating 280μ: (base pre-treat ment, primer coat,intermediate coat in the factory and finishing coat onsite) with Icosit EG Phosphat Rapid and Icosit Eg 5 and2K-PUR, DB 703 high-gloss paintETFE film cushions 10 x 22 cushions, 220 in totalDimensions 3,33mx10,40mThickness of upper and lower layer: 250μ Thickness of middle layer: 100μEdge clamping profiles made of anodised aluminiumSolar system 12 photovoltaic modules per cushion

2.640 modules in totalPower: 145,73kWpSpecific power yield: 889 kWh/kWpAverage power yield: 129 kWh/a

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Figure 1. Roof cover madeof three-layered ETFE filmcushionsFigure 2. Top view Figure 3. Longitudinalcross section Figure 4. Steel bearingstructure – 3D visualisationFigure 5. Cushion designFigure 7. Diagram showingthe air supply in thecushions

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Properties of ETFE filmsThe cushion membranes are made of ETFE film (Ethylene TetraFluoro -Ethylene) – a fluorine-based plastic with outstanding physical properties.The load-bearing films were dimensioned and selected with a thickness of250μ due to the loads to be expected. The main reasons why the clientand architect decided in favour of the version with ETFE cushion roof wereas follows:> High transparency from UV to IR range and a translucency of 90%.> Flame-resistant and without burning droplets, construction material

class B1, additive-free> Very good separating properties or self-cleaning on the basis of the

non-stick surface> Long service life of at least 30 yearsIn addition to the standard acceptance test certificates for the materialdesignated to be used, a comprehensive range of tests were carried out ontypical details to meet the requirements set in this individual case by theSupreme Building Authorities. There is no generally valid building approvalavailable for Germany for the membrane material ETFE film. For thisreason, a new application must be made for every project. In this individualcase, approval was granted 4 months after the complete technicaldocumentation had been submitted. The physical properties of ETFE filmsare comparatively complex compared to other materials such as steel orconcrete. The load-bearing behaviour is non-linear and non-elastic, and thematerial is anisotropic. The stress-deformation behaviour of the filmsdiffers in machine and cross direction, and can vary from one productionbatch to the next. This means the usual procedure is to determine thespecific material properties by means of tests before specifying the cuttinglayout. In the biaxial test, the load-bearing and deformation behaviour andthe compensation values for the pre-stress are determined on the basis ofthe load to be expected. In the case of the carport project, a meancompensation value of 5% was determined for the cross direction. Themachine direction was not compensated.The ETFE films are manufactured using the slit die extrusion method. Therolls of film used are 1,55m wide and 250μ thick in the case of the upperand inner layer, and 100μ in the case of the middle layer. The density ofETFE is approx. 1,75g/cm³. Due to the limited film width, individual lengthsof film are cut and then heat-sealed together to form a film cushion layer(part-surface connection). At the edge of the cushion the middle layer andthe inner cushion layer were heat-sealed to form so-called edge weltpockets using the same method. The upper film layer was also given anedge welt pocket. All three layers or the two edge welts were then fixed inthe double-welt clamping profile (Fig. 6).ETFE film sealing seams are homogeneous i.e. the sealing seam is made ofthe same thermoplastic (repeatedly meltable) material ETFE as the part-surfaces it connects. The load transmission thus takes place from filmpart-surface to film part-surface without an intermediate layer as sealingaid. Quality assurance for the construction products and their productionis carried out from film production through to installation through thefollowing measures:> Acceptance test certificates from the film manufacturer according to

DIN 10204-3.1 > Incoming goods checks at the manufacturing company > Internal quality control accompanying production by the

manufacturing company > External quality control of production by the membrane expert > Compliance certificate from the inspection, monitoring and

certification office

Description of pneumatically supported film cushionsFilm cushions become load-transferring, pre-stressed membranestructures due to overpressure at the inside. During normal operation, thefilms are tensioned under load and stable even under outer loads such aswind and snow. Depending on the structural-physical requirements, air-supported film cushions are designed as two- or three-layer cushions.

ETFE fluoropolymer film is mainly used as the cushion material. In thisproject, a solution with three-layer film cushions was chosen for theroofing, which is open at the side, whereby in this case the purpose of themiddle layer was not to improve heat insulation but rather to serve as acarrier for the flexible photovoltaic modules integrated in the cushion. Themiddle layer can contribute to load transfer in the case of a snow load, butit is not necessary here since the upper film layer and the inner film layerare sufficiently dimensioned. The film cushions (secondary system) areclamped between the steel arch supports (primary system). The primarysystem is stable without the secondary system. The secondary system isnot required for stabilisation, deformation limitation or load transfer. Thefilm cushions are connected to the primary system all the way round bymeans of aluminium clamping profiles. The film cushions are interlockedinto the clamping profiles and connected by pressure transfer throughcontact pressure between the welt and welt profile as well as between thewelt profile and the basic profile. The interlocking connection betweenbasic profile and steel structure is made using a screw connection. The airsupply to the film cushions was designed and dimensioned by theapplicant in cooperation with the blower manufacturer.

The advantages of ETFE air cushions as space-enclosing components lie intheir transparency and low weight, which also affects the efficient andaesthetic quality of the primary structure, for example. The successfulresult of this unique project finally depends on the cooperation of all whoare involved in that project. For this reason Taiyo likes to thank hissubcontractors for the excellent team work and the power of enduranceduring the hard times. Without them it would have been never such agood result since now. This project is a milestone in the development forfurther applications of photovoltaic in combination with architecturalmembranes for roof and facade structures. Taiyo Europe GmbH and theTaiyo Kogyo Group will continue further developments to combine thistechnology with other membrane materials offering owners the possibilityof combining the superior esthetic properties of architectural membrane

structures and unique energy earnings.

! Dipl.-Ing. (FH) Hubert Reiter: [email protected] : www.taiyo-europe.com

Location address: Munich, GermanyClient: City of Munich-Building Division and Abfallwirtschaftsbetrieb® AWM MünchenFunction of the building: Carport RoofYear of construction: 2011Architects: Ackermann und Partner Architekten BDA, MunichStructural planner: Ackermann Ingenieure, Prof. Dipl.-Ing. Christoph AckermannSteel structure production and assembly: Steel Concept, ChemnitzContractor for the complete structure: Taiyo Europe GmbH, Sauerlach, in cooperation

with Konstruct AG, Rosenheim and the assembly service LB, HallbergmoosMaterial (ETFE foil): ETFE NOWOFLON ET 6235, 250μ, clearRaw material supplier: 3M Dyneon ETFE 6235ZSupplier (ETFE foil): Nowofol Kunststoffprodukte GmbH & Co. KGCovered surface area: 8.000m2

TABLE 2 - Properties of ETFE filmsProperties ETFE NOWOFLON ET 6235, 250μ, clearPrinting on the lower layer Negative dot, silver standard,

décor no. 920201, Reisewitz printingResistance to Permanently frommax. +150°C to a temperature high temperatures range of up to 230°C for short periods (6-8h)Melting point approx. 270°CTear-growth resistance N/mm 470Mass per unit area (g/m²) 350Fire behaviour DIN 4102 B1, flame-resistantTransparency 90%Anti-soiling properties excellentFungal development Not possibleService life 30 years


6 Figure 6. Diagram of the clamping profile

The final stage of the FIFA WorldCup™ has never before been held asclose to the equator as it was in2014. The latitude of the venue inManaus is a mere 3 degrees south.Making use of lightweight textilearchitecture, the newly constructedArena da Amazônia provides thebest possible protection from thesun and optimum ventilation.The 240m x 200m arena is locateddirectly on the central corridorconnecting the airport with the citycentre. Integrated into a sport park,which also contains a Sambadrome,a track-and-field-sport complex,multi-purpose halls and a swimmingcentre, the arena is ideally suited tohold professional and local sportsmeetings and events.

Ceno Tec took only four months toerect the textile roof-façadeconstruction covering a total areaof 32.000m². The spectacularsupporting structure for the 35mhigh textile roof took the jungle forits inspiration, while also evokingthe veins on leaves. Hugecantilever beams made of steelhollow-box girders, whichmutually brace each other, servesimultaneously as large roof drains,to absorb the enormous deluge ofwater generated by the tropicalrainfall. In view of the hot andmoist climate on the Amazon, theroof merges into a facade, whichprovided shade for the spectatorpassages and vertical develop -ments. The natural ventilationresulting from the interaction withthe façade openings should providea pleasant micro-climate forroughly 45.000 spectators.

The membranes, manufacturedand coated by Verseidag IndutexGmbH, are made from glass clothwith a tensile strength of up to10kN/5cm. Coating themembranes with the high techplastics 3M Dyneon PTFE achievesan elongation at break of up to600% and protects the cloth

against UV rays, humidity andother environmental effects. Thishigh-performance material hasbeen used in textile architecturefor several decades and has provento be extremely durable. One keyadvantage of the coating,particularly relevant in a tropicalclimate, is its almost universalresistance to environmental effectsand to chemicals of all types. PTFEbelongs to the fluoropolymerfamily and needs no plasticisers orstabilisers, which can evaporateover time leading to brittleness ofthe coating. This means that, evenafter decades of use in a tropicalenvironment, there are no cracks inwhich bacteria and fungi can lodge.At the same time, the surface is sosmooth that it virtually cleansitself during a rainstorm.

The overall roof-façade supportingstructure consists of 252 mem -brane elements. The translucentmembranes protect the spectatorsagainst direct solar radiation, whilealso pleasantly spreading out thelight. Because of the complexnature of the details involved,approximately 52.000m² ofmaterial were used. A hugechallenge faced by this project was

the low dimensional tolerances forthe 252 membrane fields. Thesehad to be prefabricated withextremely high dimensionalaccuracy at the plant, because theconstruction site itself was nolonger able to accommodate anymajor adjustment operations. Ontop of all this, the huge haulingdistances into the region posed anenormous challenge in terms oflogistics, while the tropical rainyseason greatly hampered theassembly process.

! Anne Bosse: [email protected]: www.ceno-tec.de

! Helmut Frisch! Michael Dadalas : [email protected]: www.dyneon.eu

Figures Interior and exterior views

© Michael Bredt, Germany /

Ceno Membrane Technology GmbH

The Arena da Amazônia is one of the first stadiums to have been certifiedunder the criteria of the US Green Building Council’s LEED programme(Leadership in Energy and Environmental Design). This holistic ecologicalapproach takes into account the entire life cycle of buildings, including thestructural materials. 3M Dyneon PTFE fits well into this philosophy as thecoating is fully recyclable, therefore making a contribution to sustainability.

CENO-TEC

DYNEON

Manaus, BrasilJungle as inspiration

AMAZING TEXTILE ROOF Arena da AmazôniaFAÇADE CONSTRUCTION FOR THE WORLD CUP STADIUM

Name of the project: Arena da AmazoniaClient: Companhia de Desenvolvimento do Estado do Amazonas, ManausLocation address: Manaus, Brasil Year of construction: 2014General contractor: Andrade Gutierrez, BrazilArchitect: gmp - Archtitekten Gerkan, Marg & Partner, GermanyEngineering: Schlaich, Bergermann & Partner, GermanySteel structure: Martifer Steel Construction, PortugalMembrane structure: Ceno Membrane Technology GmbH, GermanyMembrane: Verseidag premium-quality glass-fibre fabric Coating membrane: 3M Dyneon PTFE Dispersion coatingCovered surface (roof and façade): 52.000m²



Choosing FLEXIBLE COMPOSITE MATERIALS for each purpose

SERGE FERRARI

! Francoise Fournier: [email protected] : www.sergeferrari.com

www.texyloop.com ! Christine Marchand, Ad'hoc Presse : [email protected]

Composite material recyclability through the Texyloop® process was oneof the determining factors since LEED (Leadership in Energy and

Environmental Design) certification of this stadium is now underway.

Total material area: 11.400m2

Maximum size of the 72 panels: 47,90x8,2m

FIFA WORLD CUP, BRAZIL

Zooming in on Serge Ferrari's architecturally inspirational flexible composite membranes,ensuring sports facility aesthetics and guaranteeing spectator visual and thermal comfort forthe Arena Pantanal (Cuiabá), Arena das Dunas (Natal) and Arena Corinthians (São Paulo).

ARENA PANTANAL CUIABÁIntroduction Cuiabá, with its 570.000 inhabitants, is situated in the Brazilian State ofMato Grosso and is known as the "capital of Southern Amazonia". It isconsidered the hottest city in Brazil with a climate that is humid in thesummer and dry in the winter. Football fans therefore anticipated astadium that takes into account the climatic criterion. Right from designstage, the project evolved around three main guidelines established bySerge Coelho, the GCP Arquitetos associate architect: "Sustainabledevelopment to ensure a stadium with the lightest possible environmentalfootprint, secondly, the "legacy" aspect with its stands composed of fourindependent modular units, of which two could be dismantled for re-use inan identical configuration or for shows, exhibitions, etc., and thirdly, urbanredevelopment of an initially disadvantaged neighbourhood andconversion into a leisure and cultural area". Nicknamed "Verdão", as muchfor the environmental commitments embodied by it as for its cactus greenshell by Serge Ferrari, this stadium projects a strong architectural identityand will play host to both Mixto and Operario football clubs. The stadiumhas a capacity of 39.900 spectators.

A microclimatic facade made of Soltis FT 381 composite material This highly graphic, cactus green façade integrates totally into itsenvironment. Installed on a steel structure, the microclimatic façadeprovides visual and thermal protection for spectators. The North standsare exposed all day, the West stand late in the afternoon, while offeringpleasant outward visibility and ensuring the structure's natural ventilation.To counter the stifling heat that afflicts this region, the microclimaticfaçade allows water from basins located right next to the stands to passthrough it and evaporate. The system's ingenuity contributed to spectatorrefreshment and comfort.

Portals framing the terraces made of Précontraint 902 S2 composite material Specified requirements for these shells to be illuminated at night by LEDswere of three orders: to offer an aesthetic aspect through membranedimensional stability and a lightweight aspect to the huge steel structuresand to guarantee ease and speed of installation.

Figure 1. View of the microclimatic façades of the Pantanal stadium

Total material area: 15.000m2

Maximum size of the 28 panels: 40,6mx17,2m

Figure 2. Detail of the envelope with metal louvers and a microclimatic façade made of of Soltis FT381 composite material © GCP Arquitetos


Total material area: 28.000m²Maximum panel size: 7,5mx60m

Total material area: 20.000m²Panel sizes: 400m² to 1.500m²

ARENA DAS DUNAS NATALIntroduction Built in 1972, this stadium was demolished and rebuilt within the scope ofa global urban redevelopment project. It was officially inaugurated inJanuary 2014. The spectacular sand dunes in the Rio Grande Do Norteregion - one of Brazil's 27 states - inspired the design and construction ofthis new undulating sports infrastructure. Its architectural shell made upof 20 petal-shaped modules allows perfect thermal and acousticinsulation, while offering better ventilation and facilitating the naturallight contribution. The stadium has a capacity of 42.600 spectators. Dueto the resizable structure 10.600 seats will be removed after the WorldCup. Architects Ben Vickery and François Clément have banked on theinstallation versatility through implementation of a custom, flexible,lightweight structure. More than a stadium hosting an internationalcompetition, the Arena das Dunas is a real endowment for the Rio GrandeDo Norte region. The multi-functional nature of the stadium ensures itshosting of many socio-cultural, sports, leisure or business events.

Tensioned ceilings made of Précontraint 1002 T2 composite material installed under 20 asymmetrical petals forming the stadium roof. A veritable engineering challenge since none of the 20 modules is of thesame size or has the same curvature. In addition to its thermal andacoustic insulation performance, the visual comfort offered to thespectators, the design "in movement", hugging the steelwork outlines, thestructural strength and dimensional stability of the Serge Ferraricomposite membrane makes all the difference here!

ARENA CORINTHIANS SÃO PAULOIntroductionLargest football club in the State of São Paulo in terms of the number ofsupporters - 30 million - and second largest on a national level (afterRegatas do Flamengo in Rio de Janeiro), the Corinthians club, whichcelebrated its centenary in 2010, didn't have its own sports facility andplayed its matches at the Pacaembu municipal stadium. Located in theworking class neighbourhood of Itaquera, this newly built emblem is aforerunner of sporting facilities of the future: it incorporates anauditorium, a museum, multiple boxes for club sponsors, restaurants and...the largest video screen in the world! The Arena is an embodiment of theregion's economic dynamics which, in the long term, should ensuredevelopment of transport infrastructures, educational facilities and settingup of private companies. The stadium has a capacity of 61.600 spectators.Due to the modular system on long term, the stadium will offer 48.000seats. Together with Coutinho Diegues Cordeiro Arquitetos , PopulousArchitects (preliminary design) and Grupo Stadia (detailed design) WernerSobek Engineering & Design was involved with the design of the roofconstruction with a span of 200m x 245m and covered with an opaquemembrane.

Tensioned ceilings made of Précontraint 1002 S2 opaque composite material A special production of 30.000m2 of material for screening event imageswas fabricated. The membrane was installed beneath the four standssheltering the spectator terraces. The panels - whose flatness anddimensional stability are essential since they are used as video screens,conceal the structural steelwork and effectively black out all light sources.Aesthetic, lightweight, durable and 100% recyclable through theTexyloop® process, these composite membranes also ensure optimumvisual, thermal and acoustic comfort for spectators.

Figure 4. Interior view of the shell made up of petal-shaped modules © Canindé Soares

Figure 5. Membrane panels used as video screen © Marcus Bredt

IntroductionThe way in which tried and testedbuilding materials and newelements clearly complement oneanother symbiotically can be seenat the King Fahad National Libraryin Riyadh, Saudi Arabia. Here in thenational capital, already rich incontemporary architecture, theapplication of modern materialshas turned a building dating backto the 1970s into an urbanlandmark which skillfully blendsinto the Arabic city skyline.Tradition and progress in equalmeasure characterize modern lifein Saudi Arabia. Architects fromGerber International Berlin realizedthe existing building complex wasworth preserving and so retainedits monumental precision whilstproviding the exhibits with a lotmore space and light. A new squarebuilding now encases the library ina seemingly floating, but at thesame time geometrical form. Justas the graceful building appears tobe embroidered into the spaciousOlaya City Park, so after nearlythree years of construction it nowappears open and transparent. Insearching for the most suitablefabric for the ceiling solution, afinal decision was made to useSefar. By employing SEFAR®Architecture IL-80-OP Fabrictogether with a Sefar LightceilingSystem specially developed for thisproject, the entire area is nowilluminated by a translucent,seemingly floating light ceiling.

Reading the traces of the pastThe new solution supplements theold with a cubic ring, meetinghistorical conservation criteria andresulting in an optically successfulentity in which the existing flatroof of the original structure hasbeen transformed into a readingroom. Here in the interior – like atreasure trove – the books can befound. The main entrance hall,exhibition area, restaurant, and abook store can be found on theground floor, arranged around theexisting building. Visitors from thereading room reach the open-access section on the third floor ofthe new building via bridges. Thelibrary for women, separated fromother functions and independentlyaccessible, is on the first floor ofthe new south-west wing. Anexisting dome was converted to asteel-glass construction whichtowers above the entire innercourtyards and reading room withan integrated roof.

Restful under the translucentlight ceilingThe recommendation of projectdirector and leading on-sitearchitect, Thomas Lücking, was fora spatial interior effect whichreflected typical urban life. Belowthe roof is a tensioned whitemembrane of Sefar fabric totalingaround 16.000m2 which filterspowerful sunlight shining throughthe long, narrow skylights,providing all areas with an even

and non-blinding light source.Acousticians involved in theproject recognized an ideal noiseinsulator in a material chosenprincipally for its optical properties.The fabric forms a closed skincomparable to an eardrum; verylittle reverberation is directeddownwards – and the echo abovethe membrane is absorbed by themineral wool and perforatedtrapezoidal metal sheets of theinsulated ceiling. Installing themembrane presented a particularchallenge since working in a dust-free environment, as is customary,was simply impossible in a citysuch as Riyadh, surrounded by thedesert. For this reason, themembrane construction had to beinstalled before the building wasairtight and cleaned only at thevery end.

Architecture lightceiling systemThe SEFAR® ArchitectureLightceiling System was developedas part of the King Fahad NationalLibrary (KFNL) project in Riyadh,Saudi Arabia. The obvious taskfacing Sefar and ArtEngineeringwas to invent a system capable ofsupporting the 16.000m² fabricceiling within the library building.

Performance / area of application:The SEFAR® ArchitectureLightceiling System is ideal forcovering surfaces with unitmembranes up to 10m×25m.

Ideally, the geometry of themembrane boundaries should bepolygonal. The system ischaracterized in particular byhaving very short assembly timesfor the individual mem branepanels. As was seen in the case ofthe KFNL project, the systemtechnology is also straightforwardenough for contractors notimmediately familiar with fabric orceiling assembly to use withoutdifficulty.

System description and system components:The essential parts of the systemconsist of light-technical fabric,attachment components andassembly tools, as well as planningand maintenance documentation.The light-technical fabric forms thevisible surface and with the help ofattachment components it isfirmly fixed to the main structure(steel or concrete supports etc.),tensioned and crease-free. Theattachment component consists ofa three-part extrusion profile – thesupporting rail, the tensioning rail,and covering rail.

Basic functioning principlesFast and safe assembly is madepossible by the use of acontinuous, pivoted tensioning railwhich is threaded into the fabric. Aspecial tool permits the rolled-upmembrane panels to be insertedinto the tensioning rail directlyfrom the ground.


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ARCHITECTURAL SHROUDING: A SECOND SKIN FOR FACADE AND CEILING

King Fahad National LibraryRiyadh, Saudi Arabia

SEFAR


Planning, production and assembly

Planning: The fabric tailor receivescutting plans and detail plans forthe stitching design and for themanufacture of handling aids. Theassembly company receives thelayout for the attachment com po- nents as well as detailed solutionsfor corners, open edges, ceilingbreaches, etc.

Membrane panels: Membranepanel manufacture is carried outby a tailor and these are sewn to-gether from individual sections offabric. At the factory, the fabric iscut into exact parallel widths.These preset widths, together withspecially developed stitching details and a predefined sewing pro-cedure, make it possible to aligntwo neighboring membrane panelsexactly at a later date if required.Despite the stitching having a verydiscreet width of only 10mm, thereis still a visible outline within amembrane panel. Once the indi-vidual fabric sections have beensewn together to form a mem-brane panel, the edges are seamedwith piping. Following a final qual-ity control check, the membranepanel is rolled onto a cardboardtube and prepared for shipping tothe construction site.

Fixing elements: Just like themembrane panels, the fixing ele-ments are precisely defined duringthe planning phase, cut to rightlength, and if used for connections

predrilled or prepunched. In theKFNL project, the supporting railswere attached to the main struc-ture by means of M10 weldingstuds. With the help of a template,the position of the bolts on themain structure is marked in ad-vance and afterwards the bolts areset. Although the work took placeoverhead, the technology provedto be consistently robust with auniform and visually verifiable re-sult. As soon as the bolts arewelded, the supporting rail is in-serted, positioned, and then fixedusing slotted holes and spacers.Guide bolts at the points wherethe two supporting rails meet en-sure an exact alignment. In thenext stage of construction, ten-sioning rails are mounted along themembrane panel. Here too, guideplates ensure a precise and fric-tion-locked connection at the junc-tion points. Special retentionclamps prevent the tensioning railfrom accidentally falling out of thesupporting profile groove duringthe threading of the fabric. Oncethese preparations are complete,the fabric is fed into the groove ofthe tensioning rail and final adjust-ments made. As soon as the de-sired position is reached, both openedges are overlaid with tensioningrails, tensioning always takingplace in both directions (warp andweft). In one final stage, a delicatecovering rail similar to a zipper is“unrolled.” The rail ensures thatnot only the gap between the twomembrane panels is covered, butalso the preload force on the two

neighboring panels is short-cir-cuited and the bending load on thearms of the tensioning rail is mini-mized.

! Sarah Dupont: [email protected]: www.sefar.com

Name of the project: King Fahad National LibraryLocation address: Riyadh, Saudi ArabiaClient (investor): Saud Bin Ladin Group, Saudi ArabiaFunction of building: LibraryYear of construction: 2013Architects: Gerber Architekten International GmbH, GermanyLightceiling

Engineering and system development: ArtEngineering GmbH & Pollux GmbH, GermanyTailoring: ALI TAMIMI SONS CO.Supplier of the membrane material: SefarMaterial: SEFAR® Architecture IL-80-OPCovered surface (ceiling): 16.000m²

Light-technical fabric / Fabric-technical specifications:Fabric material PVDF (polyvinylidene fluoride)Material coating 100% fluoropolymerFabric width (cm) 160 Weave Plain weave 1/1Surface weight (g/m²) 250 Highest tensile strength warp/weft (N/5cm) 1,050/1,050 according to EN ISO 13934-1Highest tensile elongation warp/weft (%) 40/25 according to EN ISO 13934-1Tear propagation force warp/weft (N) 35/50 according to DIN 53859-5Water column (mm) > 500Fire performance B1 according to DIN 4102; B-s1, d0 according to DIN EN 13501-1Light-technical specifications Grade of transmission (%) > 80 according to ASTM D1003Degree of reflection (%) 19Absorption (%) 1

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Figure 1. Tensioned white membrane ceiling for the interior. © Christian RichtersFigure 2. Membrane panels assembly detailsFigure 3. The erection of the membrane panels

Information on the façade concept see http:// www.archdaily.com/469088/king-fahad-national-library-gerber-architekten/


Institute for Membrane and Shell Technology - IMSThe comprehensive interest for membrane andshell structure was the reason that Prof. RobertOff, Director of the IMS e.V. Dessau, initiated aresearch project with the research objective to„develop a method to harden mechanicallypre-stressed membrane structures by sprayingthem with concrete – fabric used as reinforce-ment and as dead formwork”. Our overall goalwas to use mechanically pre-stressed fabricstructures, on behalf of formal approach andstructural behaviour and spray them with con-crete. Beside the research of the material tech-nology, an important structural question washow to activate the pretension within themembrane to optimize the load bearing behav-iour of the overall composite structure.

The IMS, which is an associated Institute of theAnhalt University of Applied Sciences inDessau, has been teaching and researching inthe field of membrane structures since 1999.Among others innovative approaches withfoam/hardened composite fabric structureswere elaborated.

Together with a partner for the membrane fab-rication tasks (Stegmaier Zelte) and a partnerfor concrete restoration respectively expertisefor shotcrete (Lenz&Mundt), an interdiscipli-nary team was formed and a foresightful re-search was conducted. The funding came fromthe Federal Ministry for Economic Affairs andEnergy respectively from the AiF (German Fed-eration of Industrial Research Associations).“As an industry-driven organization, the AiFaims at initiating applied research and devel-

opment for small and medium-sized enter-prises, as well as qualifying the new generationof academics in innovative fields and organiz-ing the distribution of scientific knowledge.Furthermore it is intended to turn ideas intosuccessful products, processes or services inthe market.”

Figure 1. Ice structure by Heinz IslerFigure 2. Philips Pavilion in Brussels by Le Corbusier © wikimedia

commons / Wouter HagensFigure 3. Inside view of the IL-Pavilion by Frei Otto © ILEK/Uni

StuttgartFigure 4. Hanging model for the Multihalle Mannheim

RESEARCH

FROM MEMBRANEFORM TO RIGID SHELL

APPLIED RESEARCH ON MATERIAL ANDPROCESS TECHNOLOGY

TO APPLY AND STIFFEN MEMBRANESTRUCTURES WITH SHOTCRETE.

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The topic of how to stiffen fabric structures respectively converting flexible curved struc -tures into rigid shells is not a new one. As early as the 1950s and 60s, Heinz Isler amongst

others, experimented with new form finding methods to freeze wet, hanging and drapedtextiles (Fig. 1). He developed a unique, detailed and very practical approach to generate

uncommon structures. Likewise his pneumatic experiments and the resulting “Buckel -schalen” show his elaborate technique of utilizing soft forms to build concrete shells.

Another example is the Philips Pavilion for the Brussels Expo in 1958 which was designed byLe Corbusier and Yannis Xenakis (Fig. 2). The geometry was built up from conjoining

hyperbolic paraboloids. The surface which started as sand hills divided into quadrangles bya grid of casing planks and consequently placing reinforcement meshes into the mould,were casted with concrete. The 1.5m² large and 50mm thick prefabricated panels were

numbered, transported to site and re-assembled. The primary loadbearing structure wasmade from a set of beams that defined the borders and ridges of the structure and a

combination of steel rods and a cable net structure upon which the panels were mounted.In contrary to the ephemeral icing approach of Isler, Frei Otto solved the conversion prob-lem from flexible to rigid with his IL-Institute building in a more enduring way (Fig. 3). The

flexible cable net structure initially designed to hang a fabric underneath (for the ExpoMontreal 1967) was converted to carry a rigid multilayer roof construction made up of

wooden slats and slate shingles that followed the initial tensile form. This method was verylabour intensive and required sophisticated and skilled craftsmanship.

Another technique of conversion was used at the Multihalle Mannheim (“Bundesgarten-schau” 1975). The conversion and inversion of a hanging form into a compressive grid-shell

structure was achieved by lifting up a wooden lattice construction to a given position, fix-ing the borderlines and locking the lattice joints. A PES-PVC fabric was cut, connected to

the structure and welded on site (Fig. 4).

RESEARCH

Material testing and composite development Starting point was the evaluation of the mate-rial properties to get an in-depth understand-ing of each material component. Differentcements and strength classes, additives andmaximum grain size categories were evalu-ated. With compression tests on cubical speci-men, splitting tensile strength on cylindricalspecimen and three-point-flexural-tensiontests on prismatic specimen, we surveyed thecompressive stresses and ductility of the con-crete. Second step was the evaluation of thefabric material. Beside the physical parame-ters, the main focus was on the chemical re-sistances (NaOH, H2SO4, Paraffin, NaCl,MgSO4 and K2CO3). The applicability of thedifferent yarn materials, coating material aswell as the size of the mesh openings and theweaving styles had to be assessed. Beside thetechnical values the properties concerning theprocessing and workability of the materialswere of high interest.With the same testing program as for the indi-vidual materials we surveyed the compositebehaviour. In this stage of the research wetook the influence of the level of pre-stress inthe membrane layer (uniaxial as well as biax-ial) into consideration. Special specimens weredeveloped and the testing rigs had to be modi-fied. With the three-point-flexural-tensiontesting we succeeded to record the character-istic material curve which was used to setup amodel in a FEM Software (Fig. 5).

Simultaneously to the investigation of the lab-oratory specimen, we executed spraying trialswithin “real” conditions to adjust the parame-ters (type of spraying, pressure, water-cement-ratio, distance and angle of the gun nozzle tothe membrane) of the spraying process. Fromthese trials we retrieved numerous samplesand identified a big difference in the values be-tween the “handmade” laboratory specimenand the sprayed specimen. Due to the parame-ters of the spraying process and the so called“Rückprall” (the bouncing back of particleswhen they hit a surface) the applied concretemixture differs from the initial mixture that isprovided by the producer and was used for thelab-specimen.

Prototyping and evaluationWith a sail setup we started the evaluation ofthe findings from the material testing. Theelaboration of the spraying process, the con-struction details and the overall structural be-haviour was the focus in this stage of theresearch. For simplification reason our firststructure was a 4 point sail with cable edges(3m x 3m). 3d scans of the upper and lowerside of the sail structure revealed the struc-ture´s property to move and the insufficientlevel of pre-stress in the membrane caused akind of ponding, hence a very uneven thicknessof the sprayed concrete layer could be noticed.In close collaboration with the Institute ofGeoinformation and Surveying a very detaileddeformation analysis was executed. Resultsand the applicability of the photogrammetricversus the 3d scanning survey during staticand dynamic load tests were evaluated (Fig. 6).This first large scale attempt was very fruitfulin detecting the real problems of the sprayingprocess and helped to improve the design ofthe structural details.

With the realization of the final prototype wewanted to gather more detailed knowledgewhile getting as close as possible to a real build-ing situation. Curvature, usability, cost, testingfacilities (also for the long-term behaviour)were taken into account for the design task.The geometry of the prototype is described byan anticlastic surface between 3 high pointsand three low points with rigid edges andridgelines in the surface. It is 4.5m in heightand 6.2m (at the highpoints) in diameter, andconsists of the following building components:

- three steel A-frames (plus foundations) fromHEA beams,

- three stay cables (plus foundations) with ten-sioning fittings,

- three ridge cables meeting in the centralpoint of the surface.

The steel frames were connected to the foun-dations with hinged supports to allow move-ment for mounting and pre-stressing and formeasuring the cable forces. In the axis of eachstay cable we implemented two units for ten-sioning as well as a load cell to control, defineand monitor the cable forces. From the prelim-inary large scale tests and the material surveywe could develop a catalogue of specificationsand hence decided for a steel fibre reinforcedshotcrete and an open mesh fabric (Fig. 7a - b).

For a future application we decided to applythe concrete in more than one step. For largescale projects a first thin layer should give thestructure enough stiffness to allow craftsmenwalking on the structure for the following ap-plication steps. The second layer should guar-antee the end rigidity of the concrete shell.The third and last layer was intended only forthe final surface appearance. A smoothingtreatment by hand was executed to seal thesurface and prevent water and dirt from stick-ing on the surface. For an optimal bonding andadhesion of the shotcrete layers each layerwas sandblasted before the next spraying ap-plication. Loose grain material was removedand cracks were “opened”. During the building process we executed vari-ous 3d scans to evaluate the geometry and

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Figure 5. 3 point flexural tension testingrig with external displacementtransducer

Figure 6. Evaluation of the geometry ofthe 4 point sail structure from a 3dscanning survey

Figure 7a - b. Digital model (MisesStresses) and reaction forces

7b 7a


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RESEARCH

tested how well the digital model and realisedstructure matched. Specimen from the onsitespraying were taken to the lab and comparedto the assumed values. Cable forces were con-stantly monitored and adjusted according tothe specifications. The structural behaviour was observed duringmounting of the fabric structure, spraying andhardening process of the concrete (Fig. 8). Theverification of the various results and themerging of all parameters was challenging butalso very promising. The comparison betweenthe digital model and the real prototype gavevarious surprising findings and a holisticknowledge of the structures properties andbehaviour (Fig. 9 - 10).

One key issue when applying the shotcretewas to guarantee an even distribution of thesprayed concrete. The geometry of the edgebeams helped to define the layer thickness atleast close to the edges. The thickness in theinner surface areas had to be monitored andmanually adjusted by the skilled craftsman.

By matching scans from the upper and thelower surfaces and processing them, we couldevaluate the variation of the layer thickness(Fig. 11). Even though the specifications wereheld, a perspective for future structures couldbe to adapt and optimize the control of thelayer thickness.

IMS e.V. (Institute for Membrane and ShellTechnologies, Building and Real Estate)Institute at Anhalt University of Applied Sciences! Henning Duerr: [email protected]: [email protected]: www.ims-institute.org

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Figure 8. Monitoring of the cableforces during spraying andhardening process

Figure 9. Matching of the digital“form finding” model (red) and the3d scan (grey)

Figure 10. Deflection of the lowershell surface after spraying (green)compared to the plain prestressedmembrane structure (red)

Figure 11. Evaluation and supervisionof shell thickness from 3d scanningsurvey Range of thickness from30mm (green) up to 70mm (red).

Figure 12. Final Prototype

© List of figures / Fig.1. http://safetythird.wordpress.com/2011/04/18/heinz-isler-ice-structures/ Fig. 2. http://www.archdaily.com/157658/ad-classics-expo-58-philips-pavilion-le-corbusier-and-iannis-xenakis/ Fig. 3.http://www.stuttgarter-zeitung.de/gallery.tag-des-offenen-denkmals-in-stuttgart-ist-einiges-geboten-param~8~7~0~23~false.3544c3db-1d5b-417c-a355-75528a4b5f7a.html / Fig. 4. “IL 13 Multihalle Mannheim”, 1978

Conclusion - call to cooperateEven though not all of the intended findings are fully evaluated yet, the outcome of the researchproject is satisfying and gives a perspective towards further research objectives. - From large scale load tests as well as the simple material tests with specimen extracted from

the shell, we expect a comprehensive knowledge of the structural behaviour of the prototype. - The long term behaviour of the composite (durability of bonding and the membrane material)

will be evaluated.- Questions regarding the design, the scale and economic matters of the shell structure are going

to be investigated. Therefore we are very much interested in cooperating with new partners to proceed and extendthis research. Aside from this topic, further research in the field of textile and polymer façadestructures are just about to be launched at the IMS. However we are also open for your researchproposals. For further interest or discussion please do not hesitate to contact us via www.ims-institute.org.

Name of the project:Location address:Client (investor):Function of building:Type of application of the membrane:Year of construction:Architects:Multi disciplinary engineering:Structural engineers:Consulting engineer for the membrane:Main contractor:Contractor for the membraneSupplier of the membrane material:Manufacture and installation:Material:Covered surface (roofed area):


ContextAs the climate change has moreand more impact on our lives, ar-chitects need to develop wellthoughtout solutions for this issue.The outdoor roof cover for theshopping mall Porto Chino wasbased on a "green thinking" design.Architects get rid of air-condi-tioned shopping mall types andwhen constructing in a tropicalarea they want to keep the mostvaluable natural ventilation. Eachblock of the building is placed insuch a way that it does not ob-struct the others from the main di-rection of wind, which is seasonaldepending (Fig. 1). All interestinglandscape and eye-catching mem-branes are placed in the front towelcome the clients at the firstsign while they cross the Rama IIroad.

ProjectAs the shopping mall consists ofseparate stores the overall air-con-

ditioning can be reduced. Thus,having separated energy is easierto manage and it can minimize thebudget. The challenge is how toconnect all small stores to becomeone unique mall without puttingall within four walls, so the intro-duction of a tension fabric coverbecomes the best choice at thetime. The design allows cool windto flow downward and hot air torise so the tensile structure canfunction as a natural air-condition-ing system (Fig. 2).

With a large span of nearly 40mthe membrane structure gives atremendous free space to the pub-lic area. The structure refers to aninverse flower blooming in springwith a transparent layer at the cen-ter to make a lighting effect, whichserves as a landmark for the shop-ping mall. With this lightweightstructure, Fastech tried to create acontrast among the crowded spacebelow and the cover on top. People

have lots of activities to do whilethey are walking and shopping andwhenever they look up, a big sim-ple soft white membrane makethem feel relax and comfortable(Fig. 3). The result of this lightingeffect does not only take advanceduring the day as less artificiallights save more energy but it alsobecomes a beautiful landmark atnight with a diffuse lighting illumi-nating the dark sky.

! Yimm Somrutai: [email protected]: www.fastech.co.th

The project Porto Chino receivedfrom the Lightweight Structures Association Australasia the 2013DESIGN AWARD High Commendation.

Porto Chino Rama II, Samutsakorn province, Thailand

Porto Chino Rama IISamutsakorn province, Thailand

D-Land Property Co., Ltd.Outdoor roof cover

Life Style Shopping Mall2012

CONTOUR CO., LTD.ENPLUS CO., LTD.

EDMA CO., LTD.GEOMETAL LIMITED (New Zealand)

Cho. Runglert Co., Ltd.FASTECH CO., LTD.

FERRARIFASTECH CO., LTD.

Fabric 1202s2 for Roof Membrane2.700m²

FASTECH

SHOPPING MALL OUTDOOR ROOF COVER

Figure 1. CFD Windsimulation to calculatethe pressure coeffi-cient and direction ofwinds (seasonal de-pending)Figure 2. ConvectionFigure 3. Interior viewFigure 4. Connectiondetails

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IntroductionAs part of the international exhibi-tion ‘Bauausstellung’ IBA 2013 inHamburg Germany, architectsfrom KVA MATx team and engi-neers from Knippers Helbig Ad-vanced Engineering havedeveloped an integral energy har-vesting façade shading system fortheir ‘Softhouse’ project. Its over-all energy concept includes an en-ergy harvesting hybrid textile rooffeaturing flexible photo voltaic,which contributes to create amicro-climate for the building aswell as a shading second skin forthe terrace and glass façade. Thisresponsive façade is based on atextile hybrid system, using textilemembranes and glass fibre rein-forced plastics (GFRP) in an intri-

cate form- andbending-active structure.

ConceptThe textile façade of the ‘Soft-house’ undergoes two modes ofshape adaptation. The form-findingand simulation of the initial systemas well as its shape adaptationsand the performance of all posi-tions under wind and combinedsnow loads set a particular chal-lenge to the engineering of theproject (Fig. 1). The adaptive façade shading sys-tem consists of a parallel arrange-ment of 32 individual strips whichare combined in sets of 8 per hous-ing unit. Each strip is a textile hy-brid system with a 4m x 0.6mpre-stress form-active membraneattached to a bending-active 6mpultruded GFRP Board (500mm x10mm). Flexible photovoltaic cellsare attached to the upper third ofthe membrane,

continuing to the apex of theshape-adaptive GFRP board. In ayearly cycle, the GFRP boards onthe roof top change their bendingcurvature and therefore adjust thePV cells to the vertical angle of thesun, while the daily east-west suntracking and daylight harvesting isachieved by a twisting of the verti-cal membrane strips in front of thefaçade in a range of +-90°. Themembrane strips are attached tocantilevering GFRP boards whichwork as compound springs com-pensating the change in length ofthe membrane strip through twist-ing (Fig. 2). The two modes of shape adaptiondescribed above necessitate a sys-tem which is able to compen satethe nonlinear change in length ofthe membrane strip from twisting.An intricate system was devel-

oped, in which a cantilever-ing GFRP board works as acompound spring to theattached membrane strips

and thereby freely compen- sates the nonlinear change in striplength during twisting. On top ofthe roof, the cantilevering board

continu ous ly evolves into a bend-ing-active arch system which offersa change in rise and curvature dueto the kinematics of the underlyingsteel structure. In order to main-tain constant pre-stress in both di-rec tions of the membrane, crossbars are introduced at 60cm dis-tance in the strips. In order to con-trol shear deformation of the fabricduring twisting an open mesh glassfibre membrane was chosen. Some early pictures of this projectshow vertical wrinkles in the mem-brane, this is due to the fact, thatthe expanding ends of the crossbars where not yet tensioned dur-ing the opening of the project. Figure 3 shows the final pre-stressstate without wrinkles.

! Julian Lienhard: [email protected]

Figure 1. FEM analysis of storm and winter position in a coupled system including thesteel kinematicsFigure 2. Testing the various modes of shapeadaptation on the finished structureFigure 3. Finished ‘Softhouse’ at IBA HamburgApril 2013

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Hamburg,Germany TEXTILE Hybrid Softhouse

Name of the project: IBA SofthouseLocation address: Hamburg, GermanyClient (investor): PatriciaFunction of building: ResidentalYear of construction: 2013Architects: KVA MATxStructural engineers: Knippers Helbig Advances EngineeringConsulting engineer for the membrane and GFRP: Dr. Ing. Julian LienhardContractor for the membrane (Tensile membrane contractor): Textilbau GmbHSupplier of the membrane material: VerseidagManufacture and installation: Textilbau GmbHMaterial: Verseidag duraskin B 18656Covered surface (roofed area): 200m² including GFRP Boards2

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TEXTILE ROOFS 2014 REPORT

Introduction to the topic and overviewProf. Dr. Arch. Josep Llorens from the School ofArchitecture of Barcelona introduced the topicof textile roofs and structural membranes,pointing out their main characteristics. Hestarted with tents and awnings for shading, andmentioned the crucial contributions of Frei Ottoand other pioneers who established the funda -mentals. He formulated a typology based onthe pretension mechanisms and shapes (Fig. 1).Deployable, movable, adaptable, and transf or -mable roofs were also included, as well asstructural supports, cables, arches, masts,beams, and frames. Reference was made to thethree basic principles of textile roofs andstructural membranes (only tension, doublecurvature and prestress) and to the characte -ristic values of the most commonly-usedmaterials (PVC- coated polyester, PTFE- coatedfibre glass, and ETFE).The main membrane requirements (other thanstructural) were listed, with special reference tolight, thermal performance, acoustics, fireresistance, environmental impacts, sitelocation, visual expression, geometry, instal -lation considerations, and economy. The needto consider all of these requirements at anearly stage of the design process was shown.The design process was also described, and itwas stressed that this does not only includeform-finding, structural analysis and patter -ning. It also comprises initial information,preliminary design, detailing, specifications,

bills of quantities, cost estimation, andculminates with manufacturing, handling,transportation, installation, and maintenance.Details cannot be transplanted from a standardrepertoire, since they have to be adapted to therequirements of each case. Solutions aresuccessful when they meet the specificrequirements of the entire structure. Any timerequirements are changed, the design mustalso be altered.To conclude, future trends were identified suchas the parametric design, multi-layering,façades as envelopes, energy harvesting, glasssubstitution, refurbishment, large span roofingof existing buildings, archaeological areas,translucent insulation, new materials, or theTensairity system for optimizing inflatedbeams.

The design of tensile architecture Dl. Dr. Techn. Robert Roithmayr from theVienna University of Technology described thephilosophy involved in “Formfinder”, a softwaredeveloped to assist architects in the design,planning, and cost-effective assessment for theimplementation of tensile membranestructures: http://www.formfinder.at. The design process is based on a dialogbetween clients, architects, structuralengineers, manufacturers, and builders, andbegins with a hand-sketched spatial model.Forces, form finding, typology, proportion,components, appearance, and proper detailingare considered.

The design can be compared with the projectsof the database provided in the software inorder to know what has already been built (Fig.2). The result goes to the “Technet” relatedsoftware, in order to proceed with the analysisand patterning.He also called attention to the postgraduateMEng program "Membrane LightweightStructures,” launched for the first time inNovember 2010 at the Vienna University ofTechnology. This program preparespostgraduate students to work in the field ofmembrane construction, providing profoundknowledge for qualified participation inarchitects' and engineers' offices, in imple -menting companies in the private sector, aswell as in the public sector.

Computational modelling of lightweight structuresAfter presenting the company “Technet”, itspartners and academic institutions, Dr.-Ing.Dieter Ströbel went over the main restrictionsof physical models, (namely the lack of post-processing, time, and scale), to emphasize theneed for computational modelling:http://www.technet-gmbh.com.He defined the form finding process as aprocedure for the determination of thegeometry of a balanced structural systemwhere “form follows force.” The material isflexible, and only tensile forces can be borne,leading to anticlastic forms prestressedmechanically, or synclastic forms, whereprestress is introduced pneumatically.Regarding the analytical procedure, Dr. Ströbelsummarized the linear force density methodthat begins with the boundaries and mesh, andprovides the shape, support forces, force andstress distribution (Fig. 3), contour lines, slopearrows, and slope lines for drainage. Automaticgeneration of primary structure is alsoimplemented, and different net types are madepossible in combination with rigid membersand enslaved points.

Textile Roofs 2014, the Nineteenth International Workshop on the Design and Practical Realisation ofArchitectural Membranes, took place on 26–28 May at the Deutsches Technikmuseum Berlin, andwas chaired by Prof. Dr.-Ing .Rosemarie Wagner (Karlsruhe Institute of Technology, KIT) and Dr.-Ing.Bernd Stary (Berlin Academy of Architectural Membrane Structures, AcaMem). It was attended by 90 participants from 27 countries from four continents. Once again, the attendance demonstratedthe success of the event, which has become firmly established since it was first held in 1995.

Figure 2. A.Korren & I.Shani: Palma de Mallorca Aquarium

Figure 1. Typology.

Mechanically pre-stressed,anticlastic.(1) Saddles and (2) conoids inunits or (5-6) compositions. (9) Wave forms (ridges andvalleys and (10) archsupported.

Pressurized, sinclastic. Air supported: (3) single or two layered and (4) reinforced.

Air inflated: (7) arches,(8)cushions and (11) beams(FESTO Airtecture Pavilion,1996).

At the moment, cushions (8)are particularly relevant dueto recent ETFE application.


The subsequent static analysis includes - shearstiffness, prestress, external loads, cables, ben -ding elements, and struts. It connects to RStabfor the stress analysis of the steel membersand provides for cross section optimisation.In pneumatic membranes, the gas law p1 · V1 =p2 · V2 is satisfied so that the volume andinterior pressure are inversely related, and hencethe membrane stresses are relaxed. “Add- ons”to the system are the silo, car shades, andcushion automatic patterning creators.In the description of the cutting patterngeneration, Dr. Ströbel noted the convenienceof following geodesic lines and shortening thedimensions, in order to obtain the prestressedsurface that minimizes the distortion. Hecovered additional aspects, such as checkingthe lengths and marking the seams.He concluded by stating that computer modelsuse information from many different experts,and need to be accurate, fast, and usable formass production.

Figure 3. Easy-Form (Technet). Analytical formfinding: stressdistribution

On shapes, forms and structuresAs usual, Dipl.-Ing. Jürgen Hennicke recountedthe principles of lightweight structures, startingwith the generating processes of objects innature and their ability to bear and transmitforces. Key aspects of his presentation were thesimilarities between form, structure, material,loading, bearing capacity, mass, and energyexpense. These principles can be used for designand optimization processes in architec ture, aswell as a model of thinking, and as a way ofproceeding in design, construction, and in life ingeneral. Sir D’Arcy Wentworth Thompson(1860-1948) developed these approa ches fromthe viewpoint of bio-sciences, and introducedthem into the general scientific discussion.

There are two ways of building: 1) withcolumns and beams (forces follow form) stillcommonly used nowadays (Fig. 4), or 2)funicular shapes (forms follow forces) (Fig. 5). Mr. Hennicke stated that, by taking care of theinfluences of sun, air, water and earth,lightweight structures can provide everydayarchitectural solutions, and can fulfil commonobjectives and demands of people byupgrading the built environment, improvingarchitectural quality by avoiding a conflict withnature, and ensuring our survival throughsustainability.

Integrated analysis and experimental veri-fi cation of kinematic form active struc-tures. “Can fabrics be tensioned in different configu -rations for similar applications?” was the keyissue formulated by Prof. Marijke Mollaertfrom the Vrije Universiteit Brussels, respondingto the growing interest in foldable protections.She presented a typology of adaptablemembrane structures based on the movementof the membrane or supporting structure.Three tests and numerical simulations havebeen conducted with a deployable dome(based on a rotating supporting structure (Fig.6), a full-scale single panel (Fig. 7), and a full-scale single foldable unit (Fig. 8).As a conclusion, Prof. Mollaert indicated thatthe initial question remains unanswered,because the folding of a structure is not anunsurmountable problem. Nevertheless, thetension of the membrane requires adjustmentsand control in each configuration. Thenumerical values of stresses are similar, butreinforcements and wrinkling do not fit theexperimental values. It seems to be a long waybefore experiments and simulations match up

with each other. A supplementary questionarose in this discussion: can a retractablemembrane system be stable in intermediateconfigurations and thus bear snow and windloads without wrinkling? Finally, Prof. Mollaertshowed the “Soft House” designed by Kennedy& Violich Architecture in Hamburg, an exampleof dynamic textile façade that moves and turnstowards the sunlight, similarly to a sunflower,with photovoltaic cells incorporated into themembrane that make the best use of thesunlight for producing energy. Parts of thefaçade also cast shade in summer, while inwinter they minimise energy loss and allowlight to penetrate deeper into the interior. The view can also be adjusted by residents. For more information: http://www.iba-hamburg.de/en/projects/the-building-exhibition-within-the-building-exhibition/smart-material-houses/soft-house/projekt/soft-house.html(see also page 18)

MORE WITH LESS.Multiperformative surfaces in architectural designThe most astonishing contribution to TextileRoofs 2014 was presented by LAVA, the Labo -ratory for Visionary Architecture (T. Wallisser,Ch. Bosse, & A. Rieck). Incredible projects wereparaded under the slogan “Man – Nature -Techno logy.” These projects are based oncomplex surfaces developed by computer fordifferent functions: http://www.l-a-v-a.net.Four milestones by LAVA are: WatercubeStadium, Mercedes Benz Museum, SnowflakeTower and Green Void (Fig. 9). “Learning fromnature and advanced computing enables us toconceive structures of incredible lightness,efficiency, and elegance.”

Figure 6. Full-scale deployable dome / Figure 7. Full-scale single panel / Figure 8. Full-scale single foldable unit / Figure 9. LAVA Mexico Monde d’Eau Hotel Resort

Figure 4. T-shaped hypostyle hall, temple of Chephren’s pyramid complex (2520 BC)Figure 5. A. Gaudi, 1878: “La obrera mataronense” textile cooperative shed, Mataró

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World Cup Membrane Structures. Dipl.-Ing. Arch. Ms. Lena Brögger and Mr. Martin Glass.Lena and Martin have continued to developspectacular textile stadiums, recently for the2014 Brasil World Cup: Mineirao Stadium, BeloHorizonte (Fig. 10), Manaus, and Brasilia:www.gmp-architekten.com/projects.html.

Figure 10. gmp Architekten, 2014: Mineirao Stadium underconstruction, Belo Horizonte

Comparative life cycle assessment: Texlon ETFE and glass claddingDr. Carl Maywald from Vector Foiltec GmbHbegan his presentation mentioning relevantETFE applications.In addition to having transparency,Texlon®ETFE is resistant, aseptic, non-metabolizable, acid-resistant, alkali-resistant,UV stable, self-cleaning, flexible (elongation atbreak > 300%), and lightweight (1 kp/m2 for 3 layers).To compare the characteristics of glass withETFE, a life cycle assessment has been made oftwo existing roofs: DomAquarée Complex,Berlin and Kapuzinergraben, Aachen (Fig. 11).The Texlon cladding system is moreenvironmentally friendly than glass fortransparent roofs because the production ofEFTE cushions is much more ecological, and theamount of steel and aluminium required is less.Improvements could be made by usingrenewable energies and less energy-demandingair supply and drying systems. www.vector-foiltec.com

Light structures with and without air: Bus terminal AarauDipl.-Ing. Gerd Schmid from “form TL” showedin detail the development and construction ofthe bus terminal of Aarau, designed by MatejaVeho var & Stefan Jauslin Architektur, whichwas given a 83,8% approval by the citizens ofthe city.www.archdaily.com/473610/aarau-bus-station-canopy-vehovar-and-jauslin-architektur/The reflective semi-transparent canopy,qualified as a “functional sculpture,” or “blueamoeba cloud,” provides protection from rainand snow. The organically-shaped opening inthe middle of the inflated cushion intensifiesthe impression of lightness (Fig. 12).

Figure 12. M.Vehovar & S.Jauslin Architektur, 2014: Aarau busterminal

Précontraint TX 30 a new generation ofPrécontraint flexible composite materialsMme. Françoise Fournier from Serge FerrariS.A.S. presented the Précontraint TX 30 newrange with a design life of 30+ years -for tensilestructures. This durability is possible thanks toa new top coat technology (CROSSLINK), anda 30 YEAR PVC formulation. Specificaccelerated weathering protocols have beendesigned for this polymer, in order to quantifythe photo oxidation rate and the remainingtensile strength after 30 years. She alsoshowed recent applications of the Serge Ferrariproducts in architecture. The Arena das Dunas(see also page 11) is a football stadiumdesigned by Christopher Lee, Australianarchitect of Populous, and

responsible for the master plan of the LondonOlympic Games, 2012 (Fig. 1 3). The stadiumwas built in 2014 in Natal, the capital of RioGrande do Norte Brazilian state, to hostfootball matches for the 2014 FIFA WorldCup held in Brazil:http://populous.com/project/arena-das-dunas/The Arena Corinthians in Sao Paulo, Brazil, isthe stadium of Sport Club Corinthians Paulista,also built to host the 2014 FIFA World Cup. Itwas designed by Aníbal Coutinho, andengineered by Werner Sobek:http://www.ice.org.uk/topics/structuresandbuildings/Case-Studies---Information/World-Cup-2014-Stadiums/Arena-Corinthians

Figure 13. Christopher Lee, Populous, 2014: Arenas das DunasStadium, Natal.

ETFE in China. An overviewDipl.-Ing. Björn Beckert from “Seele CovertexMembranes Shanghai Co” presented a reporton the development of ETFE for architecturalapplications in China over the last ten years,with attention to commercial and institutionalachievements (Fig. 14).From 2007 until now, the main ETFE appli -cations are distributed as follows: 58.3% sport,18.6% commercial, 10.6% transport, 9.3%exhibition and 3.2% leisure, offices, green -houses, industrial facilities, etc. He finallyconcluded that after 10 years, the ETFE marketin China can be seen as fully developed. Privateinvestors are increasingly taking advantage ofETFE, while government funds still play a majorrole in infrastructure projects. The complexityof ETFE projects is increasing.

Figure 14. ETFE in China: Sun Island membrane structure,Heilongjiang (Seele Covertex Membranes Shanghai Co.)

Figure 11. Texlon®ETFE compared to glass: two case studies

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Theory and design of cable-netstructuresDipl.-Ing. Kai Heinlein revealed the projectMemNet, conducted with Prof. Dr.-Ing.Rosemarie Wagner from Karslruhe Institute ofTechnology, which was developed to simulatethe behaviour of cable nets used for security,design, zoos, and façades.Individual cables were tested in tension todetermine the E modulus, which was notconstant. Bending tests were also performed,and the relationship between loads and sagswere measured. From the comparison of thesevalues based on various simulations, it followedthat the moment of inertia under differentbending moments is not constant.Biaxial testing was performed on a singleelement of mesh (spreading it out), as well ason the whole net (Fig. 15 and 16).Due to bending moments, a lower level ofstress in the centre and a higher level in theborder of the net were observed.On the other hand, a mock-up simulationrevealed the interdependency between thebending moments on the knot points and thespreading out of the cable net. Finally, thecutting pattern of the textile covering of thenet was also explored.The conclusions were formulated as follows:- For correct analysis and simulation of cable

structures, it is necessary to use beamelements to represent correct results.

- Associated to beam analysis with largedeformation, the correct curvature has to beintegrated.

- It is possible to simulate with virtualmoments of inertia.

- For structural load analysis of cable netstructures, it is necessary to know the initialcondition of the net or the inner energy.

Figure 15. Biaxial testing on a single element of the mesh

Figure 16. Biaxial testing on the whole net

Fastening details. Ropes and fittingsDipl.-Ing. Thomas Krieger from Carl StahlGmbH recounted the main features of cablesand fittings, and gave some tips on their use instructural membranes.Because there are more than 9.000 differenttypes of ropes, a selective criteria is needed thatcan be based on function (running or stan ding),the required end fittings, tensile strength,breaking load, or environmental conditions.Typical tensile strength of wires is 1.370 to 2.400N/mm2, with higher values corres pon ding tosmaller diameters. The breaking load of the ropeand its metallic cross section depend on thediameter of the cable and its com position.In saddles, if the radius r1 is not less than thegreater of 30d or 400Ø, the breaking resistanceof the strand and rope is reduced by not morethan 3% (d is the diameter of the cable and Øis the diameter of the wire, according to EN1991-1-11: Eurocode 3. Design of steelstructures. Part 1-11). For running cable pulleys,the diameter of the pulley is related to thediameter of the rope.When assembling cable ends, care should betaken with the weakest point because itdetermines the load capacity. Weakest pointstend to be at welded forks, bolt contacts oreccentric connections. With the specialTENNECT Carl Stahl universal connectingelement, most weak points can be avoided:www.tennect.com.Regarding expansion:- for temperature, the thermal coefficient is

16·10-6, which has to be multiplied by thelength and the difference in temperature

- for construction, no proper values can becalculated

- the increase of length due to tension is (ropelength x force) / (metallic section x E modulus).

Handling, assembly, protection, and mainte -nance were the subject of practical advice thatalso apply to stainless steel. Finally, Dipl.-Ing. Thomas Krieger referred to X-TEND, the stainless steel wire mesh for zoos,façades, railings and falling protections (Fig. 17): http://www.carlstahl-architektur.com/en/products/x-tend.html

Figure 17.

X-TEN mesh as

exterior

scaffolding

Installation of membrane structuresRequirements and accomplishments.The installation was the subject of Architect/Project Manager Claudius Dangel from 3dtex.He exposed some case studies that illustrateddifferent particularities of the process:http://3dtex.net/.The Venezuela Pavilion was first erected inHanover 2000, and was re-built inBarquisimeto in 2007. An auxiliary temporarystructure was used for pre-assembling thepetals. The tensioning of the membrane inHanover was difficult due to the size of thecorners. For this reason, they designed a specialtool for Barquisimeto.The installation concept is influenced by:- Choice of -materials (PTFE-coated glass

fabric, or PVC-coated polyester)- Local conditions on building site regarding the

possibilities of delivering, material storage,points of anchoring, other craftsmen, andinstallation of barriers

- Installation model or simulation- Installation team: skills, experience in

membrane installations, industrial climbers,and number of workers

- Tools: development of special tensioningtools, tool list, cranes, and lifting ramps

- Consultation with the person who will be incharge of the installation

- Wind, rain, snow, and ice make theinstallation more complicated or evenimpossible. Weather forecasts have to bechecked before and during the duration of theentire installation

- Safety concepts, as well as an emergency planhave to be worked out

- After the completion of the installation, thereshould be a debriefing between planners andworkers to optimize future installations.

Other cases mentioned were the ponding onthe Berlin Gasometer, 2011, the accumulationof snow on the PTFE-coated fibreglass“Schoolyard canopy” in Aarau 2012, and thecompensation factor for the membrane“Acupture Sail” in Eckernför, 2014, notconsidered in the cable length (Fig. 18).Mr. Dangel concluded by highlighting the needto consider the installation process during thedesign and detailed planning work.

Figure 18. Sculpturesail, Eckernförde

Wind loads on fabric roofs and corresponding dynamic response.Dipl.-Ing. Michael Buselmeier introducedWacker Ingenieure – Wind Engineering consul -tants. Since 1992, they offer services within thescope of applied building aero dyna mics andindoor airflow. They provide expert opinions,analysis, prognoses, calculations, measure -ments, and worked-out solutions which arebased on literature searches, simulations, andwind tunnel experiments: http://www.wacker-ingenieure.de/.

Wind tunnel experiments are useful in caseswhere simple approaches and numericalmodels cannot be applied. For numerical airflow, pressure and temperature simula -tions, they use different computer models,including finite element approaches, computa -tional fluid dynamics (CFD), as well aszone/node models.They combine traditional with modern rapidprototyping manufacturing methods toinvestigate special structures not coveredunder the standards.For the structural design of a fabric roof,realistic dynamic wind loads are required.These loads, together with the variability andcomplexity of shapes make it often necessaryto do wind tunnel testing. Moreover,membrane structures are often attached tolarger structures, which complicate windfactors, and enhance turbulences and dynamicexcitation, which are situations not addressedby codes or past experience.The main characteristics of wind tunnel testingare the modelling laws (geometric similarity,similarity of the approaching flow, the flowaround the structure), and rigidity. Rigidmodels are usually used, assuming thatdeflections are small enough to not influencethe pressure distribution. When deformationsare significant (Fig. 19), additional tests maydetermine the deflected shape, or theoreticalestimations, and numerical calculations may beperformed, because aerolastic modelling isextremely complex, inexact, and expensive.Two case studies were presented: large scale53m x 53m umbrellas and 180m x 90m flatfabric roof exposed to strongly turbulent wind.In conclusion, Dipl.-Ing. Michael Buselmeiersummarized his presentation concluding that:- Wind may affect membrane roof design in

various ways.- Wind effects on membrane roofs can be

investigated by means of appropriate windtunnel tests in a boundary layer wind tunnel.

- The appropriateness of these tests isespecially evident with regard to theassessment of structural and local designwind loads and the corresponding dynamicwind loading effects.

- The benefit of wind tunnel tests isdemonstrable, especially if the wind engineeris involved in an early stage of planning.

Figure 19. The deflections influence the pressure distribution

Gino Park Besenová membraneDipl. Ing. Arch. Ján Dolejsi showed in detail theinstallation of a double-layer membrane for athermal swimming pool in Slovenia. Particularly outstanding features were, amongothers, the deep foundation made of piles, thecentral tripod supporting the high point (Fig.

20), and allthe ductshangingfrom theuppermembranewhich raninto thecavity.

Figure 20. Thehigh “point” ofthe Gino Parkmembranebefore erection

Textile façade for tower on Velaa private island, MaldivesIng. Arch. Zdenek Hirnsal presented Archtex/Kontis, a joint venture that offers completeturnkey projects from architecture design,manufacturing of textile membranes, ropes andsupporting structures. Projects include theinstallation, and are executed around the world.They designed the textile façade of a tower for arestaurant on Velaa Island, the northern atoll ofMaldives Islands (Fig. 21). The façade was basedon irregular elliptical rings with different incli -nations. Total height: 25m, and diameter: 11m.A special feature of the form finding andcutting patterns of the membrane (assisted byD. Ströbel), was the cable net inside the win -dows to transfer the loads through the surface.All the parts were manufactured in the Czech

Republic and in Germany, and weretransported by ship to the worksite. Materialsfor the textile façade included 800m2 of SergeFerrari Stamisol FT381, 380m2 of Carl Stahlcable mesh and ropes, 5T of stainless steel forthe façade and 4,5T of stainless steel for thehandrails. Installation was done floor by floorwith scaf fol ding, and was completed in 24 daysby 9 workers: www.archtex.cz/en/projekty.html

Figure 21. Textile façade of the Velaa Island restaurant

Students’ Project Week“Cloud of shading” The students’ project week ran parallel toTextile Roofs 2014. The subject was “cloud ofshading”, a flying roof that defies gravity,disregards supports, and hangs from the sky onthe Earth instead of standing on the ground,and is easy to install. The final presentation anddiscussion took place at the closing of theWorkshop.The following six proposals were presented anddiscussed by the students, the audience, andthe teaching team composed by R. Wagner, L. Brügger, M. Glass and S. Bringmann:1 Redesigning the logo as a chain of holes.2 Not only a roof for the entrance of the hall.3 Red flag: a hyperbolic paraboloid for the

entrance of the museum.4 Weather balloons.5 Drops connected by a net or by Velcro.6 An inflated torus surface used as a canopy

(Fig. 22).

Figure 22. Student’s Project Week: an inflated torus surface

! Josep I. de Llorens: ETSAB/UPC : [email protected]

The Twentieth International Workshop on the Design and Practical Realisation of Architectural MembraneStructures will be held on 11-13 May 2015. In celebration of its 20th anniversary,

TR 2015 will invite lecturers of the past 20 years. The format will be similar to that of TR 2014, with seminar-stylelectures and hands-on activities. It will be preceded by the student seminar and sponsored

by AcaMem, gmp, Serge Ferrari, KIT, Carl Stahl, Technet and TensiNet: http://www.textile-roofs.de.

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The location of the textile Roofs Workshop2014 was the Deutsche Technikmuseum Berlinand the student’s project within the TextileRoofs Workshop is designing an extremelightweight cover as a sign for the twoentrances of the museum. The museum wasfounded in 1983, the location is the old freightarea of the Anhalter Bahnhof and theexhibitions are showing old and new technicaldevelopments of mankind within an area ofmore than 25 000m². The entrance building ofthe museum is made of brick in 1908 and wasthe headquarter of the Markt- undKühlhallengesellschaft founded by Carl Linde.The second entrance is into the former freightterminal called Spectrum. The distance is app.300m between the two buildings and bothentrances are unspectacular doors of the twoold buildings. The target of the students’project week is to design and to build a coverdefining the entrances of the museum visiblefrom the Tempelhofer Ufer, the street of thenorth side of the museum area. The 11 studentsof the master course in architecture of the KITare accompanied by the followingprofessionals: Martin Glass and Lena Brögger,both employee of von Gerkan, Marg undPartners Architects and Stev Bringmann,working as freelance designer of lightweightstructures in Berlin.

The project started with a visit of the museumby the director of the museum, ProfessorHoppe organized by Dr. Bernd Stary,coordinator of the Textile Roofs Workshop.Developing a canopy for the two entrances ofthe Museum the target is to design apneumatic structure lighter than air and filledwith helium. The requirements of the designare less material as possible, shapes of inflatedmembranes without any rigid bending orcompression elements and high gas tightnessof the manufactured hulls. During the two hour tour through the museumthe task is increased by possible signs andinstallations within the museum and the innercourtyard of the museum.

The next days the students are guests of theSabine Raible, a Berlin Architect and head ofthe platform Elemente Material Forum Berlin,located close the museum. The showroom ofSabine Raible has space enough to host thestudents and the equipment such as foils,textiles, welding and sewing machines forbuilding physical models. Using modern designtools such as CAD software the developmentof free shaped inflated membrane structures iseasy and the students start with thesetechniques. They tried afterwards to buildsmall scale models of welded PE-foil, filledwith helium and testing their shapes. The

experience of welding and testing the flyingstructures gives an impression of the differencebetween CAD designed models and reality. Thestudents learned in the two following days torespect the material behavior of the foils, theinfluence of the manufacturing gastight seamswith the required strength and the physicalrelation between shape, tension stresses andinternal pressure creating an interestingappearance of the inflated structures. Thestudents developed six different proposals withdifferent locations and use in the museum.One of the designs used the inner courtyard ofthe Museum as a playroom for demonstratinggravity by water and helium filled balloons. Asecond design are hexagonal cubes as symbolof the steam of the old steam engines, comingout of the entrance doors, openings in the roofof the old railway depot and used as signthrough the museum (Fig. 1 and 2). The sigh ofthe museum itself gives two groups of thestudents the idea to their design. One groupdesigned 4 cones with spheres at the end, puttogether to a flying roof in front of theentrance building (Fig. 3). The other design isan inflated ring with different scaled spheres;the ring is rotation around a center mast andshows the sign of the Museum for differentviews. One of the students develops an inflatedfour point sail as entrance canopy in front ofthe Spectrum (Fig. 4) and the last design is ahyperbolic shaped inflated ring as well in frontof the same building.

On the third day of the project week thestudents present their proposals to LenaBrögger and Stev Bringmann and one of theproposals is chosen to be built in the scale of M 1:1 within the next three days. It seems to bepossible to build the hyperbolic ring as inflatedand helium filled structure using a hull made offabric and internal gas chambers of 50μm PE-Foil. The whole students group is divided intothree subgroups, one responsible for thecutting pattern of membranes, the second forwelding the gas chambers (Fig. 5) and the thirdfor sewing the hull (Fig. 6). The proposals withthe small scale models and the final design arepresented on the afternoon of the last day ofthe experts of Textile Roof Workshop (Fig. 7).

! Rosemarie Wagner: [email protected]: http://fgb.ieb.kit.edu

Figure 1 and 2. Hexagonal cubes as symbol and sign through themuseumFigure 3 and 4. cones with spheres as a flying roof in front of theentrance buildingFigure 4. Inflated four point sail as entrance canopyFigure 5. Hyperbolic ring - welding gas chambersFigure 6. Hyperbolic ring - sewing the hullFigure 7. Hyperbolic ring - final design

STUDENT’S PROJECT WEEK TEXTILE ROOFS 2014 BERLIN

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