143367892 Cardboard in Architecture Research in Architectural Engineering

CARDBOARD IN ARCHITECTURE

ARCHITECTURE IN CARDBOARD

Research in Architectural Engineering Series Volume 7 ISSN 1873-6033 Previously published in this series: Volume 6. M. Veltkamp Free Form Structural Design – Schemes, Systems & Prototypes of Structures for Irregular Shaped Buildings Volume 5. L. Bragança, C. Wetzel, V. Buhagiar and L.G.W. Verhoef (Eds.) COST C16 Improving the Quality of Existing Urban Building Envelopes – Facades and Roof Volume 4. R. di Giulio, Z. Bozinovski and L.G.W. Verhoef (Eds.) COST C16 Improving the Quality of Existing Urban Building Envelopes – Structures Volume 3. E. Melgaard, G. Hadjimichael, M. Almeida and L.G.W. Verhoef (Eds.) COST C16 Improving the Quality of Existing Urban Building Envelopes – Needs Volume 2. M.T. Andeweg, S. Brunoro and L.G.W. Verhoef (Eds.) COST C16 Improving the Quality of Existing Urban Building Envelopes – State of the Art Volume 1. M. Crisinel, M. Eekhout, M. Haldimann and R. Visser (Eds.) EU COST C13 Glass and Interactive Building Envelopes – Final Report

CARDBOARD IN ARCHITECTURE

ARCHITECTURE IN CARDBOARD edited by Mick Eekhout, Fons Verheijen, Ronald Visser

IOS Press

© 2008 IOS Press and the authors. All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, without prior permission from the publisher. Published and distributed by IOS Press under the imprint Delft University Press PRINTED IN THE NETHERLANDS Publisher & Distributor IOS Press Nieuwe Hemweg 6b 1013 BG Amsterdam Netherlands fax: +31-20-687 0019 email: [email protected] www.iospress.nl www.dupress.nl Legal Notice The publisher is not responsible for the use which might be made of the following information ISBN 978-1-58603-820-5 Editors Mick Eekhout, Fons Verheijen, Ronald Visser Layout & Bookcover Design Ronald Visser

Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Preface The paper and cardboard industry, just like the building industry, is a long-established business sector with considerable knowledge and experience. Apart from the honeycomb door and paper-based round column formwork, there are few contacts between the two industries. But architects have made many attempts, further back in the past and also more recently, to use cardboard as a building material. ~ 1930 – paper house, USA ~ 1970 – temporary accommodation, TU Delft ~ 1980 – two temporary theatres, Apeldoorn ~ 1990 – temporary accommodation Japan, Shigeru Ban ~ 2000 – Japanese pavilion, Hanover, Shigeru Ban What is characteristic of these attempts is that experience and knowledge acquired during the work threatens to become lost because there is no framework for systematic collection, processing and development of relevant information. Despite the poor image of cardboard, projects by such architects as Ban, Eekhout and recently the interior of Scherpontwerp in Eindhoven show that cardboard is an architecturally attractive material that also has good structural and acoustic properties. Cardboard, with all the accompanying knowledge already present in the mature cardboard industry, has the potential to become a valuable element of the architectural repertoire. Each (building) material has its own FKDUDFWHULVWLFV ZKLFK JHQHUDWH VSHFL¿F DSSOLFDWLRQV LQ WKH building industry. Cardboard consists of ~ 90% endlessly recycled material and, following use, can be recycled again to a degree of ~ 90%. Moreover it is cheap. These two properties allow the material to be viewed in a different light, in contrast to the traditional approach in the building industry of applying materials HFRQRPLFDOO\ DQG HI¿FLHQWO\ 7KH RSWLRQ RI WKURZLQJ WKH material away once it has reached the end of its life – without harming the environment – creates another perspective on sustainability.

v

The Department of Building Technology at the Faculty of Architecture at TU Delft plans to study and develop cardboard as a potential building material on a broad, systematic and where possible comprehensive basis. The guiding research question here is:

“How can cardboard be used in both architectural and VWUXFWXUDOWHUPVDVDIXOO\ÀHGJHGEXLOGLQJPDWHULDO PDNLQJXVHRIWKHPDWHULDOVSHFL¿FSURSHUWLHV"´ An exploratory phase from 2003 to 2005 – including an outdoor pilot structure (multished), a pilot pavilion accommodating an H[KLELWLRQZRUNVKRSVRQUHVLVWDQFHWR¿UHDQGWRGDPSD ¿UVWSDWHQW.&3. WKHGHVLJQRIDQLQWHULRUZDOO%HVLQ WZR MSc students and the publication of the exploratory booklet Cardboard Architecture – was concluded by an international symposium attended by both the paper industry and the building industry. This publication comprises the report on that symposium. In making this publication possible, special thanks goes out to Prof. Richard Horden (Technische Universität München), Prof. Chris McMahon (University of Bath), Prof.dr. Joop Paul (NL) Delft University of Technology, who reviewed the capters and gave constructive and usefull comments in order to improve the overall quality.

Prof. Fons Verheijen

Contents Cardboard Technical Research and Developments at Delft University of Technology Mick Eekhout

1

Cardboard in Architecture; an Overview Elise van Dooren, Fons Verheijen

21

Paper Leaves Peter Gentenaar

49

The Design and Building Process of a Cardboard Pavilion .HHVYDQ.UDQHQEXUJ(OLVHYDQ'RRUHQDQG)UHG9HHU

59

A House of Cardboard Elise van Dooren & Taco van Iersel

69

Structural Engineering and Design in Paper and Cardboard Helen Gribbon, Florian Foerster

95

Application of Cardboard in Partitioning Taco van Iersel, Elise van Dooren

119

Mechanical Behaviour of Cardboard in Construction Julia Schönwälder, Jan Rots

131

The Cardboard Dome as an Example of an Engineers Approach Mick Eekhout

147

Epilogue

165

Author Details

167

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Cardboard Technical Research and Developments at Delft University of Technology Mick Eekhout

Abstract Cardboard research at the TU Delft is performed by 4 researchers, who divide their interest between, fundamental research, technology development and application designs. However these domains have strong relationships and need one another in order to become effective. The research in cardboard has 8 or 9 different aspects to cover all relevant aspects in architecture. The approach at the TU Delft is methodical; one of these methods is based on the development of new products and could give D SURSHU OHDG WR HI¿FLHQW SURGXFW GHYHORSPHQW HYHQ LQ QHZ territories. At the end a number of 12 different questions are posed on aspects that matter in fundamental research; 14 on development questions and another 14 on design questions. With WKHVHTXHVWLRQVUHVHDUFKFRXOGEHHI¿FLHQWDQGSHUPDQHQW for the coming 5 years. The industry should respond to these questions by selection and support. If not, the TU Delft has its own preferences.

1. Cardboard research on the TU Delft This congress on Cardboard has the character of a spontaneous eruption, releasing many interests both form the academia as well as from the industry. In the last year a number of discussions took place at the university that introduced a global ambition and vision to precede the cardboard industry with new knowledge and insight on cardboard for use in architecture. Naturally, this industrial market has completely other characteristics. Yet the interest from the industry is very positive, the university is geared up and presents its SRVVLELOLWLHV5HVHDUFKLQWKH¿HOGRIµ&DUGERDUGLQ$UFKLWHFWXUH¶ has been set op in the department of Building Technology at the faculty of Architecture by the professors dr. Jan Rots (Chair of Structural mechanics), Fons Verheijen (Chair of Architectural Engineering) and dr. Mick Eekhout (Chair of Product Development) since 2003 and has gradually grown WRWKHFXUUHQWOHYHO7KHUHVHDUFKVXESURJUDPµ&DUGERDUG¶LV SDUWRIWKHµ=DSSL¶UHVHDUFKSURJUDPZKLFKFRQWDLQVUHVHDUFK

1

development and design of new materials, new techniques and their applications in architecture. The current cardboard research group is composed of: •

PhD student Julia Schönwälder µ0HFKDQLFDO3URSHUWLHVRI&DUGERDUG¶ 

•

PhD student Maria den Boom µ&DUGERDUG3DUWLWLRQLQJ:DOOV¶ 

•

PhD student Taco van Iersel µ$SSOLFDWLRQ'HVLJQV&DUGERDUG&DEOH'XFW¶

•

Staff member Elise van Dooren for co-ordination and integration;

•

In 2006 a research fellow from Washington State university, architect Robert Barnstone, has been invited to spend his sabbatical in the cardboard research group.

2. Research, Development & Design In the world of technical sciences, Research & Development and Design & Development are both very related, yet sometimes on extreme polarities. The family relationship between research and design has been illustrated in the Fig. 1. which, as a principle, reveals the six different categories as VFLHQWL¿FDUHQD¶V •

Fundamental Research

•

Fundamental Technical Research

•

Building Technology Development

•

General Systems Development

•

Commercial Systems Design

•

Architectural Application Design Fig. 1. The relationship between Research and Design

2

CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

The two fundamental research domains (on the left) have been attended by Julia Schönwälder. Elise van Dooren and the crew of the Chair of Architectural Engineering are engaged with the right hand domains of Architectural Application Design. Maria den Boom and Taco van Iersel develop General Systems and Commercial Systems. The distinction between the fundamental research and application design becomes apparent when illustrated in the case-study of the IJburg/Utrecht cardboard dome (2003). The project was undertaken in 3 domains simultaneously: x fundamental technical research on the behavior of cardboard tubes, x the cardboard technology of production of elements, connection to components and the assembly to a structure and x the design of a suitable structural system and application of this system in as the project dome.

Fig. 2. The scheme of Fig. 1., showing the relationship between the Chairs at Builting Technology at Delft University of Technology

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The development of the basic structural technology to enable us to produce a 30m span cardboard dome, initially took us 4 months of Research & Development were spent on the statical analysis and material composition research of spirally wounded cardboard tubes as load bearing elements, including the glue spiraling method of cardboard tubes up to their connections. After these four months the gained technology of cardboard tubes was fertilized with the well-known space frame technology of engineering single layered domes including their nodal designs. It was also linked with the project design wishes of the Japanese architect Shigeru Ban, who had proposed at the invitation of the client a 10-frequency Buckminster Fuller iconosahedronal type dome. From these requirements plus the available funding a general system was designed and developed, and worked out as a compromise

3

between the proposals of Ban and Eekhout. The engineering took 2 weeks and the production and assembly took a further some 4 weeks. For future possibilities the developed project system ought to be developed to become a commercial (marketable) system with more general applications.

3. Research embedded in the department of Building Technology The department of Building Technology has 6 major researcj programs (Fig. 3): x Blobs x Zappi x Industrial Building x Informatics x 5HWUR¿WWLQJ x Climate Design The Cardboard research is one of the subprograms of Zappi Research, that is directed towards Material Design: Designing with Materials. Originally targeted to obtain unbreakable glass strong and stiff enough for structural purposes, the name µ=DSSL¶ LQWURGXFHG E\ WKH DXWKRU LQ  ZDV ZLGHQHG WR embrace also other material research approaches. In the section of building technology design, consisting of the three Chairs of Architectural Engineering (prof. Fons 9HUKHLMHQ 'HVLJQRI&RQVWUXFWLRQVSURIGU8OULFK.QDDFN  and Product Development (prof.dr. Mick Eekhout), one of the 3 sections of the department of Building Technology, a survey of the research topics is illustrated in Fig. 4 (the research of the Chair of Statics has not been enclosed as this Chair belongs to another section, but is strongly related, as is the (vacant) Chair of Material Science and the Chair of Building Physics). Also the Chair of Sustainability of prof. Cees Duivesteijn has to be involved. The most important clusters of research in this overview of BTD are: x Zappi/Cardboard, x Blobs x Industrial Buildings/Concept House It is imperative that the relationship between these subprograms ZLOOEHLQWHQVL¿HGDIWHUWKLVLQDXJXUDOFRQJUHVVDQGRQFHWKH cardboard research group is growing towards maturity.

4

CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

Fig. 3. Overview of research programs in Building Technology

From Research Overview of Building Technology dated November 2005 (internal publication) the following pages of the subprogram “Cardboard Structures and Constructions“ have been selected. They have been worked out by the researchers involved and display the aim [quote]: “to establish cardboard DVDUHDOEXLOGLQJPDWHULDO´,QWKHVXESURJUDPWKH¿HOGVDQG possibilities are investigated on how and where cardboard can be integrated in the building sector. Cardboard, traditionally used for packaging, has potential for DSSOLFDWLRQLQPDQ\VWUXFWXUDO¿HOGVEHFDXVHLWLVUHF\FODEOH

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Material Platform

OZ School Bouw

DDi DSD

Speerpunt Bouw

Delft Scientific Design

Tillman Klein

Thimo Ebbert post-doc Karel Vollers

Walter Lockefeer

Daan Rietbergen

BLOBs

Shore Shahnoori

GRP Structures vacancy

Martijn Veltkamp

2006

Façades

Complex Processes vacancy

Reinhardt Hasselbach

Hein Doeksen

Complex Design & Engineering

Stefanos Anestasiou (Bath)

Wim Poelman 2006 Joris Molenaar

Jordan Brandt

Constructions

ZAPPI Zappi design vacancy

Kunça Saher

Jeroen Geurts

Product Development

Pablo vd Lugt

Martin Smit

Chair Research

Dave van Eijnsbergen

Architectural Engineering 2006 Sannie Verwey

Elise van Dooren

And Andreas dr Vögler

Huib Plomp

KNAW

Ties Rijcken Rijck

Elise van Dooren

Wind

MKB

vacancy 1

vacancy 2

Robert Barnstone

Concept House

Ype Cuperus Erik Vreedenburg

Cardboard

Robert Barnstone

marketing 2006 vacancy

Cardboard Domotica vacancy 2006

Taco van Iersel

Maria den Boon

Taco van Iersel

Maria den Boon

Julia Schönwälder

Julia Schönwälder

Glass industry Composites industry

Façades industry

NWO

vacancy

STW

Ring of PhD students

Satelite Orbit Research Arenas

Research overview BTO December2005

biodegradable and made from renewable resources. It is an inexpensive material which is remarkably strong considering its low weight.

Fig. 4. Relationships of research clusters of Building Technical Design Section

Several examples and case studies (e.g. by Shigeru Ban) GHPRQVWUDWHWKDWFDUGERDUGLVDQHI¿FLHQWEXLOGLQJPDWHULDO for temporary structures“ [end of quote]. The opportunities of FDUGERDUGIRUWKHEXLOGLQJLQGXVWU\DUHVWURQJO\LQÀXHQFHGE\ its low unit price, and inferior quality yet numerous technical potential improvements. The main question is how to upgrade quality-wise an inferior material for serious building purposes. Marketing studies and technological opportunity studies should go hand in hand. 7KHFHQWUDOVFKHPHRI:LP3RHOPDQ¶VGLVVHUWDWLRQ1 shows that for a trustworthy and long lasting match between demand and supply side both the opportunities from the design side (demand) and the functionalities from the production and

6

CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

Fig. 5.3RHOPDQ¶VPDWFKRIVXSSO\ and demand

supply side have to be developed simultaneously. It should be understood that, while the Dutch cardboard industry is focused on packaging, the interest of the research group Cardboard is only directed towards building products, whether as parts of permanent buildings, temporary buildings, or interior parts. It is good to recognize a sliding scale for the VDNHRIDYRLGLQJFRQIXVLRQLQRXUUHVHDUFKLQGLIIHUHQW¿HOGV of interest: x Cardboard for Structural Purposes, that is load bearing structures, which generally speaking could lead to a progressive collapse of the entire structure after failure of one single structural element or component; (Example: the 30m dome of Ijburg/ Utrecht) x Fundamental Research on Structural Behaviour of Cardboard, to support the new structural applications of cardboard, including the PDMRULQÀXHQFHVRIKXPLGLW\RQWKHUHPDLQLQJ strength of structural elements and components

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x Cardboard for Constructional purposes, where the element or component has a stand alone function of minor structural nature (wind loading as a outside wall) and major cladding nature of separating spaces x Cardboard for Temporary Buildings, where cardboard has both a structural and a constructional use (example the Apeldoorn theatre designed by architect Hans Ruijssenaars) x Cardboard for Emergency Housing Purposes in combinations of structural and constructional use, with assistance of other materials like plastic foil; (Many examples in the work of Shigeru Ban) x Cardboard for Interior Purposes, to be applied in cupboards, kitchens furniture (examples Ikea products) x Cardboard for Furniture Purposes, to be worked out on the Faculty of Industrial Design Engineering of TU Delft, rather than Architecture x Cardboard for Installation Purposes, where the packaging practically could be deformed to become GXFWVH[DPSOHV7DFRYDQ,HUVHODQG7KH;;RI¿FH by Jouke Post) x Cardboard for secondary purposes in structures like honeycomb sandwich cores, tubular FRUHVRIUHLQIRUFHGFRQFUHWHÀRRUDQGFDUGERDUG castings for concrete columns next pages: Fig. 6. Project 4.6. Cardboard Structures and Constructions Fig. 7. Project 4.6.1. The Mechanical Properties of Cardboard Fig. 8. Project 4.6.2. Product Cardboard Wall for 2I¿FHVDQG+RXVLQJ Fig. 9. Project 4.6.3. Product Cardboard Cableduct for Unit Building Industry

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

4. Working methods of engineers & architects The general approach in research in engineering is to state a certain research challenge, to analyze the problem in sub-problems, brainstorm on these sub-problems, come to synthesis of the different sub-problems and combine them in overall product solutions which are examined in overall technical and (later) economic feasibility. (This approach is described in books on the methodology of product development and2). In general in the development of new building products 5 main phases are distinguished: x Concept Design Phase x Preliminary Marketing Phase x Prototype Phase x 'H¿QLWLYH0DUNHWLQJ3KDVH x Production phase ,Q)LJWKHOD\RXWRIWKH¿UVWSKDVHµ&RQFHSW'HVLJQ¶LV given as an illustration of the above given description. In my opinion it is unavoidable in order to attain ambitious targets to work systematically as an engineer. This route unavoidably leads to a planned and time consuming enterprise. This approach is called a deductive approach. Reference is made to the dissertation of Mieke Oostra „Componentontwerpen, de rol van de architect in productinnovatie“3. I would rather call this approach the engineers approach. In the world of architects and designers another approach is often followed: to make a design and to see whether there is a market for it and how to optimize the design. This could lead to a short route with surprising results. This is more or less the approach which was followed by professor Fons Verheijen and has lead to the pavilion in the Blokkenhal on Bouwkunde, currently on exposition. This approach is characterized as an inductive approach. I would even call it for the sake of the debate the architect’s approach. The cardboard pavilion that was on exposition at the Faculty was the result of a spontaneous eruption of activities by the group of researchers around the super-enthousiastic prof. Fons Verheijen, supported by the fundamental researchers of prof. Jan Rots and dr. Fred Veer in order to try to tie together architectural design and fundamental research. His typical architects approach and the short time schedule

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involved show an absence of cautious product development. The pavilion is also the result of the massive support by the cardboard industry to sponsor the cardboard necessary for the building of the pavilion.

Fig. 10. Concept Phase of Mick (HNKRXW¶V2UJDQRJUDP of Product Development

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

5. Transition of knowledge and technology in Cardboard During the development of the cardboard dome in Amsterdam in 2002/2003 no practical material data was available from the side of the architect Shigeru Ban. No data was obtained form the city of Hannover concerning the Japanese pavilion. Hence the research had to start all over. One year later a beautiful book was published in which many data were available4. I heard structural designer Jörgen Schlaich once say on a conference in Stuttgart, 1988: “Es ist nichts Neues GDVV:LVVHQYHUJHKW´RU³1RWKLQJQHZWKDWNQRZOHGJHIDLQWV´ %XWGRHVLWKDYHWRJRWKDWIDVW"$UHZHDVGHVLJQHUVLQWKLV LQIRUPDWLRQDJHKRQHVWRUVHO¿VKWRRQHDQRWKHU":K\GRQ¶W ZH VKDUH PRUH NQRZOHGJH" ,Q WKLV FDVH 2FWDWXEH KDG WR regain the knowledge that has been already available on other places, by other designers and engineers. Octatube is willing to share a major part of its knowledge via the Delft University of Technology to the Dutch industry and to other cardboard researchers at other universities in order to increase the body of knowledge. It is the task of the universities to generate and distribute knowledge and insight. Therefore the cardboard research group sees it as one of its immediate tasks to make an extensive overview on all cardboard research in Europe directed towards architecture and structural use, most likely in the form of a book. Hopefully this avoids that new researchers have to start from the bottom upwards.

6. Ambitions on the short run in cardboard research The best cardboard research on the TU Delft has an equilibrium between: 1. Fundamental technical research (to develop the packaging material to a structural/ constructional material), 2. Technology development (mixing appropriate cardboard elements with suitable structural and constructional systems) and 3. Design of commercial systems and project applications (for a match between society needs and the supplied cardboard technology in the building industry). It is imperative that the industry, waiting for the TU Delft to develop a new cardboard market in the building industry for

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them, will be involved in all three major phases, of the earlier mentioned 6 main stages of Fig. 1. The industry shall not expect to consume easily prefabricated cardboard knowledge: LWWDNHVPXFKHIIRUWWRGHYHORSDQHZ¿HOGRIH[SHUWLVHDQG the support and time of many. The university cannot develop new technology without the practical remarks of the current industry, but never in absence of creative future-directed marketing. I would like to give you a number of around 40 interesting topics for research, development & design with which the research group at TU Delft has to occupy itself, coming from a one-person brainstorm while writing this lecture/article. A further strategic brainstorm and analysis seems inevitable, as well as a logical chain of related activities through research, development and design in preference and feasibility as well as in view of positive market opportunities. The production may be done by the Dutch cardboard industry, but the application market is worldwide.

6.1. Research topics 1.

Research on improved glue for better strength, humidity indifference 2. Improved strength of the basic cardboard material 3. Appropriate statical systems for cardboard in separate bending, compression and tension systems 4. Appropriate element connection methods for structural and constructional loadings 5. Improved winding methods with larger overlaps increasing strength of CHS tubes  ,QÀXHQFHRIKXPLGLW\DQGPRLVWXUHRQ cardboard in constructions and structures 7. Creep behavior and structural safety, especially for cardboard structures  ,PSURYHG¿UHUHVLVWDQFHRIFDUGERDUGHOHPHQWV and components 9. Extrusion possibilities of (improved) solid cardboard material with complex cross sections for multiple connections 10. Casting of nodular connection elements based on (improved) cardboard material

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

11. Research in load carrying walls for housing with LPSURYHGFUHHSDQG¿UHSURWHFWLRQ  5HVHDUFKLQORDGFDUU\LQJUHLQIRUFHGÀRRU components for smaller spans (houses)

6.2. Development topics 13. Make marketing studies of opportunities for cardboard in the building industry seen its current and potentially improved properties 14. Development of glued connections between elements 15. Development of (de)mountable connections between components 16. Development of protection of cardboard against humidity, moisture and rai 17. Development of a vocabulary of structural forms most suited for the use of cardboard 18. Development of suitable production methods for improved cardboard for use in building structures and constructions 19. Develop a kit of tools for do-it-yourself use of cardboard sandwich panels for non-load carrying partitioning walls 20. Develop self supporting book storing shelf systems of cardboard 21. Develop 2,5 D paneling system (curved in 1 direction) for outside cladding carriers 22. Develop e production methodology for cast improved cardboard nodes 23. Use temperature and moisture as deformation techniques in production of elements  GHYHORSRSSRUWXQLWLHVRIµQDQR¶VWUHQJWKHQLQJRI skins for cardboard sandwiches 25. Develop improved skins of cardboard sandwich constructions with improved resistance against PRLVWXUH¿UHDQGVWUXFWXUDOORDGLQJLQERWK stressed skins 26. Develop demountable printing techniques for the sandwich surfaces  'HYHORSZDOODQGUHLQIRUFHGÀRRUFRPSRQHQWV for semi-permanent housing

6.3. Design topics 28. Design folding systems with constructional sandwich cardboard for large spaces

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29. Design large scale pre-fabricated emergency housing with minimal transport volume 30. Design structural skeleton systems with tubular elements and cast cardboard nodes 31. Design interior partitioning systems with cardboard for do-it-yourself use 32. Design one-off structural systems with honeycomb core for 3D blob surfaces 33. Design cardboard chalets for use in private gardens 34. Design self-build partitioning walls for spontaneous accommodation of home guests 35. Design cardboard outdoor storage spaces, to be VXVSHQGHGIURPEDOFRQLHVRIÀDWV 36. Design summer house units for temporary use;  'HVLJQHDVLO\GHPRXQWDEOHRI¿FHSDUWLWLRQLQJ with printing surfaces and acoustic absorbing qualities 38. Design structurally independent indoor partitioning system for museum purposes 39. Design Student housing for fast expanding needs  'HVLJQURRIWRSH[WHQVLRQRIÀDWURRIVXVLQJ cardboard constructions and structures 41. Design Concept Houses with load carrying walls DQGÀRRUV

7. Conclusion for Cardboard Research Research with potential possibilities for cardboard in the building industry is impossible without a serious and strategic approach and research set-up. This approach has to be consciously designed and developed both analytically as well as with creativity and originality. It should be looking over the borders of the current Dutch cardboard industry, translating possibilities from the current building industry as well as transmitting knowledge from other disciplines. This approach has yet to involve both marketing, sustainability DQGRWKHUUHVHDUFKSURJUDPVOLNHµ=DSSL¶µ%OREV¶DQGµ&RQFHSW +RXVH¶ DURXQG WKH FHQWUDO FRUH RI &DUGERDUG UHVHDUFK LQ fundamentals, development in technology and design of architectural applications. For a long term and successful research, development & design program appealing to the Dutch industry a strong, structurally interwoven cardboard research set-up has to be made. Funding from both sides (university and industry) has to be pursued at a later

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CARDBOARD TECHNICAL RESEARCH AND DEVELOPMENTS AT TU DELFT

stage when the cardboard research program has become convincing and appealing. The proposal given in this article is the result of short notice FRQVLGHUDWLRQV ¿WWLQJ LQ H[LVWLQJ UHVHDUFK SURJUDPV DQG needs continuous response from my colleague researchers and from the industry. At the moment the researchers are paid by the university or on temporary hold, waiting for PRUH HQWKXVLDVP DQG ¿QDQFLDO VXSSRUW 7KH 78 'HOIW ZLOO SURYLGH¿QDQFLDOVXSSRUWIURPLWVLQWHUQDOUHVHDUFKSURPRWLRQ tendering system. The industry is also asked to read this article carefully as a proposal and consider participation, SK\VLFDOO\DQGRU¿QDQFLDOO\,QRWKHUUHVHDUFKSURMHFWVZH have successfully introduced a consortium-form of sponsoring around individual researchers. This is a method suited for the VPDOOHUDQGPHGLXPLQGXVWULHVµ0.%¶LQ'XWFK ZKHUHWKH amounts per industry are modest and the consortium effort leads to larger research impulses.

References

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1

Wim Poelman, Technology diffusion in product design: towards an integration of technology diffusion in the design process, S.l: S.n, Delft, 2005, ISBN 9051550235

2

Mick Eekhout, POPO, Delft University Press, Delft 1996, ISBN 9040716315

3

Mieke Oostra “Componentontwerpen, de rol van de architect in SURGXFWLQQRYDWLH´(GLWRU(EXURQ'HOIW,6%1

4

Matilda McQuaid, Shigeru Ban, Phaidon, London, 2003, ISBN 0714841943

5

Mick Eekhout, Ontwerpmethodologie 28 en 29 mei 1998, TU Delft Faculteit der Bouwkunde, Delft, 1998, ISBN 9052692556

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Cardboard in Architecture; an Overview Elise van Dooren, Fons Verheijen

Abstract The image of cardboard still remains that of a packaging material, but in the last few years, at home and abroad, different projects have been built using cardboard. This article gives a broad spectrum of projects and products using cardboard. Cardboard tubes are being used by Shigeru Ban as a means RI FRQVWUXFWLRQ LQ D VKRZ RI OLJKW DQG RSHQ VSDFH $G YDQ .LO DSSOLHV WKH VSHFL¿F WH[WXUH RI KRQH\FHOO ERDUG 7KH OLJKWQHVV DQGWKHDELOLW\WRUHF\FOHDUHSURSHUWLHV¿WWLQJDVKRUWOLIHVSDQ and temporary applications. As a result of these properties, two temporary theatres and one party tent have been built. Cardboard is a lightweight, cheap and environmentally positive material. The packaging industry has a lot of knowledge on cardboard as a packaging material, in the building industry it is VWLOODODUJHO\XQNQRZQPDWHULDO7RDFTXLUHDVLJQL¿FDQWUROHLQ architecture, the mechanical and physical properties will have to EHUHVHDUFKHGDQGGHWHUPLQHG,QSULQFLSDOWKH¿UHDQGGDPS resistance problems could be overcome. Research also will have to be done into the possible areas of appliance, considering its characteristic properties. The lightness of the material and the possibility to fold and slide it, already led to a number of designs for temporary housing in disaster and war stricken areas.

1. Introduction Materials – we want to know everything about them. Where they come from, how you work with them, how far you can push them, what else you can make from them.1 Paper and cardboard have earnt their success in history2 mainly as writing paper and packaging. Especially with the exchange of stone and hides by the relatively light and more easily writable paper and the development of book printing, two quantum leaps were made in the world of communication and science. The wooden box (a few thin plates reinforced at the corners and connected using small laths) has been replaced by

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a cardboard box; foldable, lighter, easy to discard of and recyclable after use. Especially Japan has a rich paper tradition2. Well known types of paper are Washi (hand scooped paper, which stands out because of its strength, shine, natural colour, life span and low weight) and Nagashizuki (extremely thin paper, multi OD\HUHGFURVVHGZLWKDVWURQJ¿EUHEXLOGXS .QRZQIURP architecture are the semi-transparent sliding doors (Shoji and Fusuma). The measurements vary from 33,3 x 24,2 cm up to (in extreme custom cases) 620 x 210 cm The material is also being used in interiors and furniture. A very well known and traditional application of paper in the building industry is wall paper. Paper is, regarding the enormous success of typography, probably the best material for printing. The Wiggle chair3 by architect Frank Gehry is probably the best known piece of cardboard furniture. Tables, cupboards and even beds have been designed using cardboard. With the furniture of Stange Design4 in Germany there is a cheap way of decorating your house. Moreover, the lifespan of this furniture coincides with the average time we own our furniture. ,Q$G.LOHQ5R.RVWHUGHVLJQHGDFRPSOHWHRI¿FHLQWHULRU using cardboard5. The explicit demand was an interior which would give a soul to the somewhat boring space. By gluing cardboard in several layers on top of each other, walls with an exceptional texture were created, which moreover had a positive affect on the sound inside the room. The walls of honeycell board serve a double function; as separation as well as being spacious because of the many

Fig. 1.,QWHULRURIWKHRI¿FHRI Scherpontwerp, a graphic design company in Eindhoven.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

recesses, wherein niches, workplaces, shelves, a canteen, a library and presentation area have been placed. Honeycell plates of 1.2 by 3.0 metres (thickness varying from 1.2, 2, 3 and 8 centimetres) were cut to pieces and glued together. A computer drew in the design layer by layer. The worktops have been covered with a transparent acrylic plate in order to keep out moist and protect the vulnerable HGJHV RI WKH WDEOHV 7KH ¿UH GHSDUWPHQW DQG LQVXUDQFH companies issued the demand that each building element KDG WR EH LPSUHJQDWHG ZLWK D ¿UHUHWDUGDQW 7KH VHDOLQJ boards were also made from honeycell cardboard. The neon tube lighting above the desks was placed inside semi-circle cardboard tubes Historically Japan has a rich tradition in the use of paper, even to the present day the Japanese architect Shigeru Ban is the best known architect when it comes to cardboard as a building material. Paper and wood for him form a direct line, one evolves from the other6. Therefore he sometimes uses the WHUPµHYROYHGZRRG¶IRUFDUGERDUG6KLJHUX%DQLVFRQVWDQWO\ VHDUFKLQJ IRU PDWHULDOV ¿WWLQJ WKH DVVLJQPHQW RU VLWXDWLRQ (QYLURQPHQWDO FRQVLGHUDWLRQV VLPSOLFLW\ DQG HI¿FLHQF\ DUH key words to him. Cardboard tubes, originally used for the transportation of tapestry, are being used as constructive and architectonic elements. For a theatre production of a dance/ mime company in the Netherlands, Shigeru Ban was asked to design a temporary space using cardboard. In cooperation with building architect and construction engineer Mick Eekhout, a dome from cardboard tubes was built in 2004.7 Covering the cardboard

Fig. 2. Close-up of the Paper Dome.after application of the membrane

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construction a coated polyester fabric was used. The cardboard tubes were interconnected by use of steel nodes. 7KHVHQRGHVDOVRJXDUDQWHHGDQHI¿FLHQWGH DVVHPEO\7KH dome has already been taken down and rebuilt on another site functioning as an expo-centre as well as skating-ring. The latter turned out to be not such a good idea, because of the humid condititions. The projects of Shigeru Ban are beautiful examples of using cardboard in architecture. Still the image of cardboard remains WKDWRIDSDFNDJLQJPDWHULDORUWKDWRIDKRPHOHVVSHUVRQV¶ sleeping place. That invokes a few questions. Why use FDUGERDUGDVDEXLOGLQJPDWHULDO":KDWDUHWKHDGYDQWDJHV DQGZKDWWKHGLVDGYDQWDJHV",VLWDSDVVLQJRQHWLPHHYHQW" The last couple of decades, here as well as abroad, different projects from cardboard or using cardboard have been designed and built. This article gives an overview of most of WKHSURMHFWVµEXLOGLQJZLWKFDUGERDUG¶WKHPDWLFDOO\RUGHUHG

2. Projects 2.1. Shigeru Ban Shigeru Ban placed cardboard tubes in circular shapes behind a (semi) transparent façade in his Paper House and Paper Church (1995), thus creating beautiful spaces, each with their own character, in a show of light. His designs intertwine two WUDGLWLRQV -DSDQHVH VLPSOLFLW\ DQG WKH RSHQ ÀXLG VSDFH RI modern architecture. These and other projects, were he used cardboard tubes in construction, like Library of a poet (1991) and the Japan Pavillion at the Expo in Hannover (2000) are YHU\ZHOOGRFXPHQWHGLQWKHERRNµ6KLJHUX%DQ¶6 Shigeru Ban also used cardboard tubes for temporary housing shaped like tents and small houses for the shelter of victims after natural disasters and refugees from war stricken areas, for it is a cheap material, abundant, recyclable and easy build with. Moreover, cardboard tubes can be produced onsite and will not be sold on for some quick money as has happened with aluminium. It also does not require any extra tree-logging. After research using prototypes and testing, Ban placed cardboard tent frames in Rwanda (1995) spanned E\D7HÀRQWHQW3UHFHGHGE\DVKRUWLQVWUXFWLRQWKHORFDO inhabitants were soon able to build them themselves.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

Fig. 3. Temporary emergency KRXVLQJLQ.REH-DSDQ after the earthquake that hit the area in 1995.

In Japan (1995) and later in Turkey and India (2000/2001) small houses have been built, small square spaces with a few windows and a door. The tubes were standing next to each other thus forming the walls; the roof was a tent canvas. Depending on the site where the dwellings will have to be built, a solution for the foundation will be devised. This has to be as simple as possible using local materials. In Japan sand ¿OOHGEHHUFUDWHVZHUHXVHGLQ,QGLDGHEULVIURPWKHGLVDVWHU

2.2. Emergency housing Between 1970 and 1980, Paul Rohlfs8 designed emergency housing from cardboard during his graduation project for buldingproducttechnology and thereafter as researcher for the University of Technology in Eindhoven, the Netherlands. The structure has been built from load bearing wall panels with rubber strips for glazing. He developed a few prototypes. The wall panels in prototype 1 consist of a core of honeycell board ZLWKWZRRXWHUOD\HUVRI³7ULZDOO´DWULSOHOD\HUHGFRUUXJDWHG cardboard with an extra thick top layer (liner). It proved to be very strong and stabile, but laborious prototype. For the development of types 2 and 3, a different building method was chosen: Honeycell cardboard with an exterior breather foil and DQ LQWHULRU YDSRXU UHWDUGDQW OD\HU 7KH HYHUPRUH VLPSOL¿HG form provided for easy detailing, less manual production, less waste and quicker assembly in prototype 4. This prototype was actually inhabited for a while and survived a harsh winter, while the entire site in the province of Groningen was cut off by a thick layer of snow from the rest of the Netherlands.

2.3. Temporary housing prototype In the Netherlands, Rene Snel9 developed a temporary housing prototype. Using a machine, he developed himself, KHZLQGVHOHPHQWVÀRRUZDOODQGURRIIRUPRQHFRQWLQXRXV

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element. Connecting several elements comprises a small dwelling. When covered in a protective layer they can be erected on site en a relatively short amount of time. ,Q 6\GQH\  WKH H[KLELWLRQ µ+RXVHV RI WKH )XWXUH¶10 was being held. Prefabrication and durability are the central themes in these buildings which were projected at the future. Six houses were built, each from a different material: concrete, wood, steel, glass, masonry and cardboard. The cardboard house could be delivered to the building site as a relatively lightweight package with cardboard frames and panels. It takes only two people to assemble one house in approximately 6 hours. The construction consists of a few roof frames, stabilized by cardboard lateral baulks. The construction-elements can be slid together like the partitions of a wine-box. The construction is covered by a synthetic FORWKWKLVKHOSVNHHSLQJWKHEXLOGLQJ¿UPWRWKHJURXQGDQG also permits light to pass inside.

2.4. Temporary theaters On the occasion of the 1200-year anniversary of the city of Apeldoorn (1993) both Rudy Uytenhaak11,12 and Hans Ruijsenaars13 were asked to design a temporary theatre. The choice for cardboard as the building material was made EHFDXVHRI$SHOGRRUQV¶VLWXDWLRQQH[WWRWKH9HOXZHKDYLQJD long tradition of paper and cardboard manufacturers. Visitors could buy a foldable cardboard stool as their entrance fee; they could take them home after the show. Hans Ruijsenaars in cooperation with ABT building technology consultants, designed a theatre with a total span of 12 metres and a length of 20,5 metres. The entire building weighed less than a large car! It could seat 100 – 150 visitors. The cylindrical theatre was built using a construction of rods. each 1200 mm in length and 250 mm in height. Each rod consists of 7 layers of corrugated cardboard glued together. At the node, where 6 rods connect, wooden plates have been glued into the rods. With a block of two plates and a steel connection the nodes were kept together. The thus created triangles in the structure were covered with plasticized corrugated cardboard covers. The seams were sealed with tape. The necessary tools were a hammer and screwdriver. Finally the theatre was covered with an exterior tent canvas, allowing ventilation and the entrance of daylight at the nodes. The entire theatre was

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Fig. 4. Theater in Apeldoorn. Designed by Hans Ruijsenaars.

CARDBOARD IN ARCHITECTURE; AN OVERVIEW

placed on prefabricated concrete slabs. 5XG\8\WHQKDDNGHVLJQHGDÀRDWLQJWKHDWUHRQWZRSRQWRRQV in the Apeldoorn canal. The load bearing structure was to be made from steel, with beams and cables. The roof and some of the side-wings were to be made from cardboard elements. The elements in the roof were coated with polyethylene to ensure water-resistance. Inside the side-wings they are uncoated.

2.5. Barn In the nineteen seventies and eighties research was being done into the development of cheap cattle barns. The aim LV WR PDNH WKH EDUQV¶ WHFKQLFDO OLIHVSDQ HTXDO WR WKH VKRUW economical writing off term. Different materials were tested amongst which corrugated cardboard. With triangular cardboard beams large spans are achieved and the demanded insulation values are met. The cattle barn remained standing for a couple of years.

2.6. Cardboardschool Cottrell and Vermeulen in cooperation with bureau Happold designed an after school child care connected to a school in England14,15 :HVWERURXJK SULPDU\ 6FKRRO 8.  2002). The central idea for the design of the extension was the folding of paper. Furthermore the aim was to use as much recyclable and recycled material as possible. At the end of its 20 year lifespan all the materials used (cardboard, wood, natural rubber tiles) are to be recycled. Before actually building the extension, a scale model of 6 x 2.4 metres was EXLOW7KHNQRZOHGJHDFTXLUHGIURPWKLVPRGHOVLPSOL¿HGWKH design. One of the major changes was the application of wooden edges on the entirely cardboard panels. To protect the cardboard from water during the actual build, a temporary scaffolding structure covered in plastic was erected. The cardboard was made water resistant in of couple of ZD\V$W¿UVWDVXEVWDQFHZDVDGGHGWRWKHSXOSPDNLQJWKH material itself more vapour-retardant, but without interfering with the process of recycling the product. The second step was the addition of an interior coating to stop vapour and water resistant building paper on the outside. The third and ¿QDOVWHSZDVPDNLQJWKHSDQHOVPRUHGDPDJHUHVLVWDQWD 1 mm cardboard layer on the inside and a product on the outside which can be seen as close to cardboard: wood-

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¿EUHFHPHQWSDQHOV7KHFDUGERDUGDQGDLUEHWZHHQWKHVH materials provides enough insulation and acoustically the material meets the standards. The façades were covered in prints with patterns drawn by the children themselves. Next to the panels, cardboard tubes were used, supporting the ZRRGHQ EHDPV 7KH %%& SURJUDP µ7RPRUURZV :RUOG¶ KDV WHVWHGWKHH[WHQVLRQLQWHQVLYHO\E\OHWWLQJWKH¿UHGHSDUWPHQW WU\WRPDNHWKHIDoDGHOHDNDQGGRLQJ¿UHWHVWVDVZHOODVD test with the weight of a car.

2.7. Multished On the occasion of the opening of a paper recycling company in Duiven (2002), a temporary extension was designed and EXLOWDFDUGERDUGSDUW\WHQWWKH³0XOWLVKHG´HUHFWHGIURP cardboard tubes, honeycell and solid cardboard.14 7KH ¿UH UHVLVWDQFH SURYHG WR EH VXI¿FLHQW LQ FDVH RI D WHPSRUDU\ structure, because the solid cardboard plates meet the demands of fire-class 4 (non-housing structures). The extension is built up from a skeleton of cardboard tubes with honeycell plates laminated with solid cardboard between the tubes. With a minimal addition of cellophane and a small amount of PE foil, water resistance of the tubes and the plates was achieved. In order to also waterproof the end grain, black tape was used in all connections.

3. Products 3.1. Ventilation duct 7KH;;DUFKLWHFWVRI¿FHLQ'HOIWE\-RXNH3RVW16, was based on the thought, that when the economical lifespan of a building does not coincide with the technical lifespan, the latter should DGDSWLWVHOIWRWKH¿UVW7KLVOLIHVSDQZDVVHWRQ\HDUV7KH materials were chosen in such a way, that they could be reused or returned to nature. Part of this concept is the use of cardboard tubes as ventilation ducts.

3.2. Floor-heating system &DUGERDUGZDVDOVRXVHGLQDÀRRUKHDWLQJV\VWHPZKLFKFRXOG be de-assembled17. Aluminium heat conducting plates were placed on pre-shaped corrugated cardboard plates, sandwiching DPP3(WXEH7KHÀRRU¿QLVKLQJERDUGVZHUHVXEVHTXHQWO\ ODLGRQDORDGGLYLGLQJOD\HURIJ\SVXP¿EUH7KHFRUUXJDWHG FDUGERDUG KDV DQ LQVXODWLQJ IXQFWLRQ EHWZHHQ WKH ÀRRU DQG the ground itself. The materials used have little to no negative environmental effects and are easy to move or recycle.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

Fig. 5. Multished

Fig. 6. Close-up of the Multished

3.3. Cable-duct The cardboard cable-duct by Taco van Iersel18 is an example RIDSUHIRUPHGÀDWSODWHZKLFKFDQEHIROGHGDWWKHZRUNVLWH and placed into brackets. The predecessor of this cable-duct in the design process was the semi-round tube. However, the IROGDEOHSODWHLVPXFKPRUHHI¿FLHQWEHFDXVHLWUHTXLUHVOHVV space during transport.

3.4. Cardboard duct in a sound barrier $ORQJVLGH WKH $ KLJKZD\ )RQV 9HUKHLMHQ GHVLJQHG µ7KH :DOO¶19 (2005) which at the same time functions as a sound barrier for the residential area behind it. The building is being EXLOW LQ GLIIHUHQW SKDVHV ¿UVW D VROLWDU\ IDoDGH DV D QRLVH controlling screen, then the rest of the building. Directly behind the screen will be a delivery street for the shops inside WKHEXLOGLQJ7KHIDoDGHZLOOKDYHWREHFORVHGIRUWKH¿UVW years in order to block the noise of the highway, where after

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the façade will have to be partly open to ventilate the exhaust fumes of the cars on the delivery street. The lower part of the façade is built from concrete slats of which the grooves will EH¿OOHGZLWKFDUGERDUGWXEHVDVORQJDVWKHIDoDGHIXO¿OVWKH function of sound barrier. This is a simple and cheap solution ZKLFKVXI¿FHVDVDVRXQGEDUULHU7KHDGYDQWDJHKHUHLVWKDW the 5 km of tube can be recycled after having been through the shredder.

Fig. 7. The cardboard cableduct. Designed by Taco van Iersel.

3.5. Cellulose insulation In principle, paper is suitable to be used as an insulation material. Using cellulose, different kinds of insulation plates KDYHEHHQPDGHHFRORJLFDOO\VSHDNLQJ¿WWLQJLQWKHFDWHJRU\ µEHVWPDWHULDO¶7KHSODWHVDUHFRQWLQXRXVO\EHLQJGHYHORSHG making them just as usable as their less ecological competition. For example, Homatherm20 has developed a plate with an LQVXODWLRQFDOFXODWLRQ YDOXHRIP.:ZKLFKLVEHQGDEOH and can be processed, dust free, using standard equipment. Moreover, the plate breaths, thereby temporarily buffering moist and has a higher warmth accumulating value than comparable isolation materials. Isovloc20 are loose cellulose ÀDNHVZKLFKFDQEHVSUD\HGEORZQRUPDQXDOO\GLVSHUVHGLQ VHDOHGFRQVWUXFWLRQVOLNHZDOOVÀRRUVDQGFHLOLQJVLQVXODWLQJ warmth.

3.6. Dividing wall Out of the building community the idea was born to develop a dividing wall from cardboard. The evermore strict building legislation (maximum weight to be lifted by man: 25 kg) and the demand for increasingly shorter building trajectories, led to new solutions. Because of companies moving, merging and JRLQJEDQNUXSWPDQ\GLYLGLQJZDOOVLQRI¿FHEXLOGLQJVKDYH a very short lifespan. The building industry is therefore the industry with the greatest amount of waste. Cardboard has as one of its main advantages its re-usability; when the wall has worn out or has become obsolete, it can easily be dumped as used paper.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

Fig. 8.'HWDLORI³7KH:DOO´ alongside the A2 highway near Utrecht.

Fig. 9.³7KH:DOO´DORQJVLGHWKH A2 highway near Utrecht.

The cardboard interior wall uses the lightweight and high strength properties of honeycell board. The panels consist of honeycell plates with a solid cardboard liner. Both sides of the panel contain grooves, wherein a connecting element can be placed. This way, different panels can be assembled into a smooth wall. Inside the wall, hollow channels have been incorporated, offering space for electricity cables. The walls will be built from panels 90 x 280 cm each, but still lighter than 25 kg. By using these large panels the building speed can be guaranteed and because of its ability to be covered in any kind

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RI¿QLVKIURPZDOOSDSHUWRWLOHV WKHGLIIHUHQFHZLWKWUDGLWLRQDO interior walls is invisible. 7KHZDOOKDVEHHQVXEPLWWHGWRPDQ\WHVWV¿UHFRPSUHVVLRQ tension) and experiments (Sandbag swinging test). On some points the wall reached a surprisingly high score, but sometimes improvement of the wall is necessary. Some of the growing pains can be deduced from the way of production. 7KHSDQHOVZHUHDVVHPEOHGE\KDQG7KLVKDVJUHDWLQÀXHQFH on the total quality of the wall. For many applications the wall in its current shape is satisfying, but optimisation will improve the chances for cardboard as a partition.

3.7. Paper composite In Australia Adriano Pupilli20 and others developed a prototype shelter for those forced to live in marginal, insecure or LQDSSURSULDWHKRXVLQJ,PSRUWDQWSDUWRIµ7KH3DSHU+RXVH¶ is the Armacel composite technology. Recycled and renewable materials, like paper, cardboard, straw and rice, are cocooned in a impermeable membrane of recycled Polyethylene Terephthalate (PET). So the often delicate and porous material is protected and strengthened by a process of vacuum forging a thin layer of part recycled, part virgin polymer.

4. Study projects It is clear that cardboard is a relatively new material in the building industry and not a lot of data is known yet. We need research on a broad basis, as well as in depth research, meaning: research in a designing, synthesizing way and research in a specialized way (e.g. research into the mechanical properties and moisture-resistance of cardboard) The broad-range research combines many different aspects. Especially this kind of research results in associations and leaps of thought as well as relations which are less obvious in specialized research. Broad-range research asks questions and makes mutual and unexpected ties. At the Faculty of Architecture of Delft University of Technology an increasing amount of research is being done into cardboard, broad-range as well as specialized. Part of it is done by researchers, part of it as student (graduation) projects.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

4.1. Graduation project Chiel van der Stelt, Hans Mesman and Wim Kahmann ,Q&KLHOYDQGHU6WHOW+DQV0HVPDQDQG:LP.DKPDQQ designed temporary housing for their graduation project20. When folded, one house could be transported inside a container. The transport packages are about 3.00 x 1.80 x 0.30 metre and weigh about 200 kg. The aluminium foundation, protecting the houses from drawn up moisture functions also as impact protection of the package. The elements are connectable at both sides.

Fig. 11. Temporary housing as a graduation project by Chiel van Stelt, Hans Mesman and Wim .DKPDQQ

Cardboard panels gain in strength by folding them into piers. The roof needs to be converted, folded out and covered with aluminium as well. Between the piers closed, semi-open and rotating parts are placed. Normally these are cardboard, but local materials could be used as well. The outside is covered in a white coating, the inside in a transparent one. The connections are made from glue and synthetic materials. The uplift by wind is counteracted by a rope from the edge of the roof to the foundation.

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4.2. Graduation project Taco van Iersel During his graduation project (2002), Taco van Iersel developed a wall built from cardboard boxes21. With this system he designed a dwelling for temporary use on wasteland (building locations). The principle idea is based on converting DSDFNDJLQJER[WRDµFDUGERDUGEULFN¶7KHER[HVDUHEHLQJ stacked in a stretching bond. The boxes also slide together XVLQJ ÀDSV DQG WKHUHDIWHU JHW JOXHG WRJHWKHU 2Q WKH WKXV created wall of boxes a liner of cardboard gets glued, assisting in the force transmission in the wall like in a sandwich panel. 7KLVFRQVWUXFWLRQFRXOGEHXVHGIRUZDOOVÀRRUVDQGEHDPV In order to stack the boxes, there are two different sizes: a small box (150 x 300 x 300 mm) and a large box (150 x 300 x 600 mm). In the fall of 2005 student Arne Arends developed a corner-box, which will improve the stability of the walls. 6SHFL¿FWHFKQLTXHVXVHGLQWKHSDSHUDQGFDUGERDUGLQGXVWU\ are: folding, creasing, scribing, bruise and blanking out. The boxes used were made with a computer operated blanking knife. A blanking knife is a wooden pate with knives, steel strips, and rubbers mounted on it. The plate is placed in a blanking machine, which gets fed a cardboard plate where the NQLIHJHWVSXVKHGLQWR7KHUHVXOWLVDSODWHVKDSHGOLNHDÀDW 7$.2ER[7KLVVXEVHTXHQWO\QHHGVWREHIROGHGDQGJOXHG

Fig. 12. Wall made of stacked boxes by Taco van Iersel.

The type of cardboard determines largely the accuracy of WKHZDOO:KHQFDUGERDUGPDGHIURPDORWRIYLUJLQ¿EUHLV used, the result will be a dimensionally stable box. When FDUGERDUGZLWKDORWRIUHXVHG¿EUHVLVEHLQJXVHGWKHER[ will be weaker and less dimensionally stable. Also the accuracy during the folding and gluing of the boxes is of importance.

Fig. 13. Corner box in order to improve stability by Arne Arends.

Fig. 14. Dwelling for temporary use on wastelend.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

4.3. Paper building, Monique Verhoef

Fig. 15. Strength test of triangular folded packaging material

Fig. 16. Section of a cardboard construction using

During her Building-technology graduation project (2002), Monique Verhoef designed and researched a cardboard structure22. The objective of the project was “to research the ways in which cardboard can be applied in the building industry responsibly, whereby it clearly retains DQ LPDJH RI LWV RZQ´ 7KH UHVHDUFK ZDV FRQFHQWUDWHG RQ the different shaping-possibilities of cardboard. Eventually WKH GHYHORSPHQW RI D VSHFL¿F EXLOGLQJV\VWHP D IROGLQJ structure, was chosen. Cardboard has a relatively low stiffness in comparison with other materials (i.e. steel). With a folding construction relatively large spans can be made because of the form stiffness achieved by the shape of the structure. Also the type of connection used – a glued connection – is positive: cardboard has problems handling concentrated loads. And this construction expressively uses one of the characteristics of the material: cardboard can be folded easily.

triangular folds by Monique Verhoef

The structure simultaneously performs a structural and a parting function. Laminated layers of corrugated cardboard form the inside of the structure. Corrugated cardboard is relatively lightweight with a great stiffness and it isolates. The LQVLGHDQGRXWVLGHRIWKHFDUGERDUGLV¿QLVKHGZLWKDOD\HURI solid cardboard. The solid cardboard can well be protected from moisture and forms a good water end damp resistant layer. Furthermore, it handles impact loads better, thereby protecting the corrugated cardboard from damages. The folding structure was built from similar triangles. Using the ability to easily fold the material, the building elements can be made from several triangles, thereby reducing the number of connections and the associated risk of moisture getting through. The outer layer of solid cardboard is one strip covering many triangles. The laminated corrugated cardboard and the inner layer of solid cardboard are divided in triangular elements glued to the outer layer of solid cardboard.

Fig. 17. Elevation of a cardboard buidling using triangular folds by Monique Verhoef

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4.4. Blobboard Blobboard was entered in a design competition for the new Stylos bookshop (2003) by Pim Marsman and Jop van Buchem19. The design originated from a cooperation EHWZHHQ WKH ODERUDWRULHV ³%OREDUFKLWHFWXUH´ DQG ³%XLOGLQJ ZLWK FDUGERDUG´ DW WKH IDFXOW\ RI $UFKLWHFWXUH RI WKH 'HOIW University of Technology. Blobboard consists of double curved surfaces. In the design a new way of building with cardboard instead of using the traditional building techniques has been researched. The motive and inspiration for the design were found in honeycell cardboard and egg-boxes; it turned out to be very easy to make double curved surfaces from egg-boxes by making them moist and letting them dry in the desired shape. The load bearing structure consists of honeycell strips, connected by glue or bolts. This structure is then covered in a skin, formed into the desired shape while wet.

Fig. 18-20. Blobboard Pavilion

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

4.5. Umbrella shaped roof, Henk van Dijke The graduation project of Henk van Dijke at the Design Academy, Eindhoven19 (2003) was inspired by examples IURPWKHZRUOGRIÀRUDQHUYHVWUXFWXUHVRIOHDYHVDQGEUDQFK formations on trees) and by the work of Antoni Gaudi and Frei Otto. He designed an umbrella shaped roof construction, PHDQWDVDWHPSRUDU\VSDFHZLWKDVSHFL¿FDWPRVSKHUHIRXQG underneath the vaults of classical buildings.

Fig. 21. An umbrella shaped roof construction made of cardboard. Designed by Henk van Dijke.

Fascinated by the abundance of cardboard as well as by the recyclable properties, Henk van Dijke searched for shapes on the boundaries of the possibilities of the material. This project XVHV µIRUPLQJ FDUGERDUG¶ RU  GLPHQVLRQDO FDUGERDUG WKH SDSHU¿EUHVDUHEHLQJPL[HGZLWKDORWRIZDWHUFUHDWLQJD pulp which subsequently gets sucked through a porous mould. 7KHZDWHUSDVVHVWKURXJKWKHSRUHVDQGWKH¿EUHVIRUPDOD\HU on the surface of the mould. The umbrella shaped construction has been fabricated in such a way that the entire structure can be placed on columns or hung. During the graduation process, experiments have been conducted and a model was built. Through the interest taken into the production process, all kinds of problems have been discovered, solved and used DVDSRVLWLYHFRQWULEXWLRQWRWKH¿QDOGHVLJQ

4.6. Paper parasite, Jop van Buchem 7KHLPDJHRIFDUGERDUGLVVHHQDVZHDND¿UHKD]DUGQRW capable of handling humid conditions, material for packaging and the homeless. In his graduation project23 (2004), Jop van Buchem assumes that it is possible to improve the image of cardboard by designing a temporary house following current trends and developments; he wants to design a trendy house which belongs to the consumptive society. His concept is that cardboard is a suitable material to design a house according to the wishes of the users, where after the structure, once out of grace, can be discarded of without shame. The house is seen as a fashion article, an expression of individuality. The designer was inspired by the car-industry, with its marketing and anticipation of trends. He assumes that new GHYHORSPHQWVVXFKDVZLUHOHVVQHWZRUNVZLOO¿QGWKHLUSODFH in the housing market, decreasing the amount of cables in buildings. The dwelling is meant for two well earning partners, who wish to live in the city temporarily and covers about 80 ±P7KHGZHOOLQJZLOOEHXVHGIRUDPD[LPXPRI¿YH years. It has been designed as an autonomous object in the

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city and can be built on locations which are temporarily out of use (e.g. during planning) or on rooftops; locations that otherwise would remain unused. The design consists of a cocoon-like shape with double curved surfaces. This shape combines two wishes: a clear identity and a stable form. The mechanical properties of this shape are very favourable and, moreover, with the choice of a fabric as the outer layer a certain degree of expansion by moist and creep by loads is possible. The characteristic of the house is mainly determined by the choice of material: cardboard, with its plastic and architectonical aspects en building technological possibilities. 7KHHQWUDQFHVFRQVLVWRIDRXWIROGLQJÀRRUFRPSDUDEOHWRWKH integration of the steps in the door of small aeroplanes. The dwelling is prefabricated at the factory and can be assembled on site in a relatively short time. The interior blocks can be placed prefabricated, the exterior is foldable. The boundaries consist of the load bearing structure and an outer skin. From outside to inside the skin is built up from a transparent membrane (cloth) against the rain, a foil with chosen print and isolating air cushions. The choice for a fabric came from the degree of form freedom of this material and the transparency. The variation in colouring and print and the amount of transparency ensures different views, chosen by the owner. The fabric forms a tight outer skin, because as the DLUFXVKLRQVJHWLQÀDWHGWKHWHQVLRQRQWKHVNLQLQFUHDVHV Through a strip the skin gets connected to the structural frame and tightened. The structural frame consists of three shells, each with parallel placed trusses with beams in between them. The trusses are made from solid cardboard, glued together with a lighter corrugated cardboard core. Trusses and beams are connected in the factory; the beams are folded in and folded out on site. 7KHVKHOOVDUHNHSWWRJHWKHUE\µEDFNERQHV¶ULEV IRUPLQJWKH spinal chord from the design. They are kept under tension with bracing wires, just like the beams. The wires connect at WKHHQGVDWFDSV7KHZLUHVOLHLQSODVWLFGXFWVIRUPLQJD¿UVW waterproof barrier for the cardboard of the backbones and the beams. Because of the wiring, point shaped connections, in order to keep the structure together, such as bolts, are

38

CARDBOARD IN ARCHITECTURE; AN OVERVIEW

avoided. Cardboard is vulnerable for concentrated loads, EHFDXVHRILWV¿EUHVWUXFWXUH ,Q WKH FRFRRQ VKDSHG IRUP D KRQH\FHOO ÀRRU KDV EHHQ placed covered with solid cardboard in order to distribute DQ\ FRQFHQWUDWHG ORDGV %HQHDWK WKH ÀRRU LV WKH SRVVLELOLW\ of storage. The kitchen, bathing room and toilet are inside the interior blocks. These blocks are supplied with water DQGHOHFWULFLW\WKURXJKÀH[LEOHSLSHVIURPDQLQVWDOODWLRQER[ EHQHDWKWKHÀRRU The interior blocks consist of layers of corrugated cardboard, putting the monolith character of the block in perspective through the slenderness of the corrugated cardboard. Inside the blocks the space for the bathing room, kitchen, toilet and pipes has been cut out in voluptuous shapes and covered in a synthetic waterproof foil.

Fig. 22. Model of the paper parasite by Jop van Buchem

Fig. 23. Model of the main structural element

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4.7. Pavilion Delft University of Technology (2006) During the second half of 2005, researchers and students designed and built a temporary cardboard pavilion in the hall of the Faculty of Architecture. Around the pavilion an exhibition and a conference about cardboard was organized. With the idea of showing the different aspects and stages RIWKHF\FOHµWUHH±SDSHU±FDUGERDUG±EXLOGLQJSURMHFWV± UHF\FOLQJ¶7KHSDYLOLRQZDVEXLOWIURPDIHZSDUDOOHOZDOOVZLWK DÀRRUEHWZHHQWKHP The walls were built from a few layers of honeycell glued together, creating a beautiful texture. The wall actually consists of two slabs, with a honeycell stair between them. This wall also provides a large part of the stability. The Block wall is a follow-up from the graduation project of Taco van Iersel. Cardboard boxes are stacked and glued, like the bricks in a masonry wall are being stacked and connected with glue or mortar. The cardboard boxes are somewhat special compared to standard cardboard boxes; they have been provided with ÀDSVZKLFKVOLGHLQWRWKHRWKHUER[HV%HFDXVHRIWKLVDQGDOVR because of a layer of solid cardboard glued on the “cardboard PDVRQU\´WKHZDOOVJDLQWKHLUVWUHQJWK7RVKRZSDUWRIWKH

Fig. 24-26. Cardboard Pavilion

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

Fig. 27-28. Structural tests on cardboard

paper recycling process, a few paper bales were shown. The idea of using these bales to create a wall failed because of the large weight of the bales (500 – 600 kg each). Finally, one wall was built from panels which are meant as an interior wall. This wall has been developed as a result of cooperation between 'HOIW8QLYHUVLW\RI7HFKQRORJ\WKH.QRZOHGJH&HQWUH3DSHU DQG&DUGERDUG.&3. WKHFDUGERDUGLQGXVWU\DQGDEXLOGHU of units. The purpose of the wall is using the low weight of cardboard, light relatively large elements, making them easy to place and not too heavy for the participants. Researching the mechanical properties of cardboard, the TU Delft uses cardboard beams. Building the pavilion, these beams turned out to be inadequate and because of WKHVKRUWDJHRIWLPHWKHVZLWFKZDVPDGHWRDµVROLG¶SODWH of honeycell. Further research will have to prove this, but it seems that rectangular beams are not the ideal solution when XVLQJ FDUGERDUG ÀRRULQJ $ ÀRRU XVLQJ IROGHG DQG VOLGLQJ solid cardboard plates appears to be more promising. History often shows that when searching for the possibilities of a new material, the solutions coming from the materials properties, DUHRQO\GLVFRYHUHGDIWHU¿UVW WU\LQJDQGH[SORULQJH[LVWLQJ and well-known directions. For example, the caves in Petra (Jordan) were created as square spaces, which, from a FDUYLQJSRLQWRIYLHZLVDQLOORJLFDOZD\$OVRDW¿UVWVWHHO plates were not connected using welding; these solutions surfaced later on. During the building of the pavilion a few preliminary conclusions were drawn regarding the mechanical and physical properties. The type of cardboard, the type of glue and the

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ZD\WKHFDUGERDUGHOHPHQWVDUHPDGHKDYHJUHDWLQÀXHQFH on the end result. The handling, often manual because of test situations, produces a number of problems which could be solved when factory conditions are simulated. Cardboard is also a very vulnerable material to work with, for example: WKHHGJHVIROGHDVLO\7KH¿UHUHVLVWDQFHLVDFFHSWDEOHVROLG FDUGERDUG KDV VXI¿FLHQW ¿UH UHVLVWDQFH WKH KRQH\FHOO ZDOO when impregnated, as well. Creep is a problem; cardboard EHQGVIDUWRRHDV\XQGHUWKHLQÀXHQFHRIODVWLQJORDGV7KLV seems to point in the direction of small spans, instead of large spans.

Fig. 29. Model of a cardboard ÀRRU

5. Conclusion 5.1. Fascination There is a lot of enthusiasm. Architects, researchers and students feel challenged by an unknown material (in their area of expertise). People will always be fascinated by the texture or the structure of a material. And experiments follow. Tom Dixon1, who we quoted before, has become fascinated by the possibilities of recycled glass. Without drawings he creates objects in an evermore evolving series. The core of honeycell cardboard provides a beautiful texture DQGLQVSLUHVGHVLJQHUV$G.LODQG5R.RVWHU5WRFUHDWHDQRI¿FH interior with a soul. The cardboard tubes lying around on a building site which were used to transport carpet, inspired Shigeru Ban6 into designing a few beautiful dwellings with a cardboard structure.

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

The choice of cardboard for the theatres in Apeldoorn by Rudy Uytenhaak11 and Hans Ruijsenaars12 followed from the wish to show the rich paper related past of the Veluwe during a centennial party. The temporary housing projects in cardboard are based on the relatively low price of the material, the possibility of local production sites and the relatively low weight during transport. For the dwelling in Sydney10 the possibility to recycle the material played an important role. The cardboard ventilation tubes in the building of Jouke Post16¿WWHGLQWKHVHDUFKIRU a new environmental concept, whereby the lifespan of the chosen materials is being adapted to the user life of the building.

5.2. Temporality/Lifespan Looking at all the realised projects up till now, the amount of temporary projects stand out. This must be inherent to the material. Packages have a relatively short lifespan. After having been used for a few times, boxes will have been torn or become wet and should be discarded. Formulated differently: FDUGERDUGLVD¿UPPDWHULDOEXWHVSHFLDOO\FRQVLGHULQJVKRUW periods of time. When used for longer periods it becomes a vulnerable material. Some consideration is needed, because especially the temporary projects which are most suitable for experiments with new (and relatively cheap) materials. For the Multished13 WKHUHTXLUHG¿UHUHVLVWDQFHZDVPHWEHFDXVHWKHGHPDQGIRU temporary spaces is relatively low.

5.3. Recycling Environmentally, cardboard seems to get high scores. Further research will have to acknowledge this. One of the aspects in such research are the additives which can be added during the production process. During this process this additive could be many natural materials, such as clay, chalk and starch. After the production process many different kinds of paint, coating DQGIRLOPDNHFDUGERDUGZDWHUUHVLVWDQWDQG¿UHUHWDUGDQW Also the types of glue used to glue the different layers of paper together, could play an important role. In a number of cases the quality of the cardboard improves, like the moisture resistance, but at the same time the ability to recycle the

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material decreases.

5.4. Economy Cardboard is a relatively cheap material. This means that there is a reasonable margin for experimenting and working the material, so that products and applications can be marketed reasonably positively considering its price. The material also seems to be suitable for temporary housing after natural disasters.

5.5. Humidity Next to some clearly positive properties, there are also a few properties, which are without a doubt, a nuisance when cardboard is being used as building material. The behaviour when in contact with moist is a perfect example. A successful application of cardboard is mainly achieved inside a building (structural tubing by Shigeru Ban6, texture KRQH\FHOOLQDQRI¿FHLQWHULRUE\$G.LODQG5R.RVWHU5 and a structural rib-structure in the cardboard House of the Future in Sydney10. As soon as cardboard comes into direct contact with water, measures must be taken. The easiest one is cladding it with PE foil (Multished13) The cardboard school14,15 might have a cardboard outer layer, but one can wonder whether this material still has any relation with the original cardboard material. The paper and cardboard industry experiments with increasing the water resistance of paper and cardboard, yet the question remains whether the current developments can be of immediate use for building with cardboard.

5.6. Knowledge Up till now different projects have been designed or built using cardboard and cardboard has been applied inside buildings. However, most of the knowledge is bound to the VSHFL¿FSURMHFWDQGQRWDORWRIH[FKDQJHWDNHVSODFH0RUH general information is only accessible through the book by Mathilda McQuaid about Shigeru Ban6 and on the website of the cardboard school.15 With a rich variation of production techniques and raw materials OLNHIUHVKDQGUHXVHG¿EUHVDEURDGVSHFWUXPRIW\SHVRI paper and cardboard are created. The paper and cardboard

44

CARDBOARD IN ARCHITECTURE; AN OVERVIEW

industry has a lot of knowledge about these products, but in DQHQWLUHO\GLIIHUHQW¿HOGRIDSSOLFDWLRQDQGRQDFRPSOHWHO\ different scale than in the building industry, where materials are described with mechanical and physical characteristics and accepted design rules (like tensile strength, bending strength DQG FODVVL¿FDWLRQ RI TXDOLW\  /RQJ WHUP JXDUDQWHHV DUH demanded from the quality of building materials. Cardboard is an unknown material in the building industry. In further research, the demanded mechanical and building physical characteristics, standards, design rules and guarantees will KDYHWREHGHWHUPLQHG(DFKLQGXVWU\KDVLWVRZQµODQJXDJH¶ ZLWK VSHFL¿F GH¿QLWLRQV DQG YDOXHV &DUGERDUG DV LW LV currently produced, is meant for packaging etc. The machines and mindset are aimed at just that. The use of cardboard in WKHEXLOGLQJLQGXVWU\GHPDQGVWKHGHYHORSPHQWRIµEXLOGLQJ FDUGERDUG¶ZLWKLWVRZQPDFKLQHVDQGPLQGVHW

5.7. Development Cardboard has been used as a building material a few times, and some cardboard products have been designed and produced. Most of the time, it is not really clear why a product did not make it on to the market. It seems that most of the committed parties abandon the project when the product is EHLQJGHYHORSHGWHFKQLFDOO\DQGWKHSURFHVVRIFHUWL¿FDWLRQ KDVWRVWDUW,WPLJKWEHZRUWKZKLOHWU\LQJWR¿QGRXWZK\WKH process stagnated. Does it happen because the viability of the product is limited or because there is a lack of perseverance and the right type of people.

5.8. Future Experiments with cardboard as a building-material are being conducted worldwide. The many practical examples seem to support the search for a broader application of the material. Cardboard is not expected to replace current building materials. When there is a place for paper and cardboard in architecture and as a building material, then it will be for its own content, LQUHODWLRQWRWKHVSHFL¿FSURSHUWLHVRIWKHPDWHULDO The future will have to determine what will be the role of cardboard in architecture and the building industry. Thereby, the properties of cardboard and its context are of importance. An example of external developments is the change in legislation. The environmental demands in the national building decree are hardly extensive. It can be imagined that in the near future building elements or products will come with

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a removal fee. The moment something costs money, cheaper re-usable alternatives like cardboard are likely to be accepted easier. The properties determine the uniqueness of a material. The characteristic structure of honeycell cardboard gives it a special texture. An unexpected advantage appeared to be the damping quality of honeycell: the typical sound nuisance LQVLGHDQRSHQSODQRI¿FHFDQEHUHGXFHG 6FLHQWL¿FFXULRVLW\DQGWKHQHZQHVVRIDPDWHULDOVWLPXODWH researchers, students and architects to think further than traditional materials and solutions. The different appearances (tubes, honeycell, solid and 3D) and the characteristic properties of cardboard, like folding, sliding together, printing, lightness and temporality are an inspiration and starting point in the research into the possibilities.

References 1

Brower, Mallory, Ohlman, Experimental eco design, architecture/ fashion/product. Rotovision, 2005, ISBN 2-88046-817-5

2

Therese Weber, die Sprache des Papiers, eine 2000-jahrige Geschichte, Verlag Haupt, ISBN 3-258-06793-7

3

http://www.powerhousemuseum.com/collection

4

http://www.stange-design.com

5

BN/DeStem van 9 juli 2005 op: www.besin.nl

6

Mathilda Mc Quaid, Shigeru Ban, Phaidon, 2003, ISBN 0-71484194-3

7

Prof.dr.ir.Mick Eekhout, Het ontwikkelen van de kartonnen IJburgkoepel, in: kartonnage, Rumoer 30, sept 2003, jaargang 9, Periodiek voor de bouwtechnoloog, uitgave van Bout, praktijkvereniging Bouwtechnologie faculteit Bouwkunde, TU Delft. ISSN 1567-7699

8

Taco van Iersel, report interview Paul Rohlfs

9

http://www.rsdevelopments.nl

10 http://www.housesofthefuture.com.au 11 T.Verstegen, Rudy Uytenhaak, 010 Publishers, 1996, ISBN 906450-241-2 $.RRLVWUD'RRVMHGRRVJURWHGRRVIHHVWWKHDWHU%RXZZHUHOG nr. 13 (25 juni 1993) 13 Taco van Iersel, Feesten in kartondoos, detail in architectuur, maart 2003 14 Andrew Cripps, Cardboard as a construction material: a case study, Building Research & Information (may-june 2004) 15 Buro Happold en Cotrell & Vermeulen, Constructing a prototype cardboard building, on www.cardboardschool.co.uk .ORPSHQ3RVWOHYHQVGXXUJHEUXLNVGXXU;;HHQJHERXZ als prototype van een nieuw mileiuconcept, Stuurgroep

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CARDBOARD IN ARCHITECTURE; AN OVERVIEW

Experimenten Volkshuisvesting, Rotterdam, 1999, ISBN 90 5239 153 X &KULVWRSK0DULD5DYHVORRW,QGXVWULHHOÀH[LEHOHQGHPRQWDEHO vloerverwarmen, Gezond Bouwen & wonen, 2001-2 18 Henk Wind, Leidinggoot eerste bouwproduct van karton, Bouwwereld nr.9, 10 mei 2004 19 Fons Verheijen, The wall, highway architecture, Fons Verheijen, 2005, ISBN 10 9081015710 20 http://www.warmteplan.nl 21 Adriano Pupilli, The paperhouse report, op: www.thepaperhouse.net 22 Hans Mesman en Chiel van der Stelt, Nooddorp ontwerp van een noodwoning voor rampgebieden, 2004, ISBN 90-6450-001-0 23 Graduation project Taco van Iersel 24 Graduation report Monique Verhoef 25 Jop van Buchem en Pim Marsman, Blobboard, in: kartonnage, Rumoer 30, sept 2003, jaargang 9, Periodiek voor de bouwtechnoloog, uitgave van Bout, praktijkvereniging Bouwtechnologie faculteit Bouwkunde, TU Delft. ISSN 15677699  +HQNYDQ'LMNH)RUP¿QGLQJPHWNDUWRQLQNDUWRQQDJH Rumoer 30, sept 2003, jaargang 9, Periodiek voor de bouwtechnoloog, uitgave van Bout, praktijkvereniging Bouwtechnologie faculteit Bouwkunde, TU Delft. ISSN 15677699 27 Graduation report Jop van Buchem

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Paper Leaves Peter Gentenaar

$SDSHUVKHHWLVWKLQVWURQJDQGÀDWWKDWLVZKDWZHDUHXVHG WR,WLVIRUFHGWREHÀDWDQGWKHSDSHULQGXVWU\XVHVORWVRI HQHUJ\GU\LQJLWVSDSHUVÀDW However, if you would make a sheet of paper, scooping pulp on a mould and onto a felt and leave it there to dry, you would see that the paper dries up like a deep fried potato chip. Paper can be compared to a leaf on a tree or plant. If we reinforced the sheet of paper with very thin ribs of bamboo that look like the ribs of a leaf, the analogy between the sheet of paper and the leaf form is emphasized even more. $WULDQJOHPDGHZLWKEDPERRULEVDQGEOHDFKHGÀD[SXOSZDV DFRPSOHWHO\ÀDWVKDSHZKHQLWZDVOD\LQJZHWRQP\VFUHHQ After drying you see that a triangle keeps its shape, because as architects know, triangles are stiff and are great to build railroad bridges with. A square made in the same way, on the other hand completely changes shape and, looking for the smallest and shortest way, the shrinking pulp turns it into something like a leaf fallen off a tree in the autumn. The evaporation of the water shrinks the leaf and also the sheet of paper. In the process of drying the cellulose molecules fall back on their internal form memory and that is the spiral. A leaf in autumn curls up just like a sheet of paper that is not been pressed after it is formed. This discovery became the most important reason for me to stay in papermaking To make a sheet of paper is like making a wild weaving with SDQW¿EHUV7KH¿EHUVDUHFOHDQHGEHDWHQLQD+ROODQGHUWRD pulp and than poured onto a screen where this wild weaving RI¿EHUVUHPDLQZKLOHWKHZDWHUGUDLQVRXW This is a rough sketch of papermaking. It was developed over the last 2000 years in different places of the world in more or

49

OHVVWKHVDPHZD\EXWZLWKGLIIHUHQWSODQW¿EHUV The industry has taken these techniques and urged by the paper consumers, speeded up the production in an amazing way. Eventually all the research in paper factories is mainly directed to higher and cheaper production. In this way very good paper is being made but there is little time to play around. ,¶PDQDUWLVWVRPHRQHZKRSOD\VDURXQGSURIHVVLRQDOO\ZLWK a background in sculpture, painting and printmaking, etchings and lithography. I recently spent a year at the California College for Arts & Crafts in Oakland where I was getting my Master of Fine Arts (MFA). I made engravings on thick sheets of Plexiglass (polymethyl methacrylate). The plexiglass had air bubbles in them and the factory had dumped them on the campus. In order to use the 2 cm thickness of the plexiglass, I took a drill and made deep grooves, in which the paper was too be pressed. This worked if I did not make the grooves too deep, WRPPPD[LPXP7KHGHHSHUJURRYHVZHUHQRW¿OOHGE\ the printing paper, which was made by Arches.

Fig. 1. Blauwe Wolken

Blue Clouds

Back in the Netherlands I started my own studio where I worked on metal sculptures, color lithography and etchings. Somehow sculpture and printmaking came together and the old idea of the high relief print made on the thick plexiglass was taken up again. I hoped to obtain a higher relief by making my own paper. Experiments with old newspaper pulp beaten up in even older washing machines were not very satisfying. I decided to go to the source and learn about papermaking. A letter to the Royal Dutch Paperfactory in Maastricht resulted in an invitation and I ended up staying 3 days playing in the ¿EUHODEZLWKWKHKHDGRIWKHODE-R3HUVRRQ My introduction to paper was a very industrial and mechanical, one of sheet formers that suck water out of pulp with vacuum, pulp which is made in Hollanders and a dazzling white laboratory with scales and glasses. The factory itself was like a visit to outer space. I had never seen machinery like that and I was convinced that I needed at least a small paper factory in my own studio.

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I built mixers, sheet formers and presses and with those I made huge relief prints. Paper was still a serving material for me then. You used it HLWKHUWRZULWHRUGUDZRQRU\RXFRXOG¿OODPRXOGZLWKLWDQG press it into a 3-dimensional print. This changed when I could buy a laboratorium Hollander IURPWKH.13SDSHUIDFWRU\LQ0DDVWULFKWDQGP\SDSHUPXVK became real paper pulp. What I mean is, until that time I had been using industrial cellulose halfstuff which I mixed with water in a 200l mixer. ,WVHSDUDWHGWKH¿EHUVIURPHDFKRWKHUEXWQRWKLQJPRUH Great amounts of wood glue were added to give the paper some coherence. The paper I made was felty and thick. I put big coloured sheets of this paper on top of each other and built great coloured layered multi sheets, which took ages to press dry. Once it was dry I sawed the sheets into shapes with DEDQGVDZ,QWKHHQGLWZDVRQO\DJORUL¿HGVRUWRISDSLHU mâché, nothing more. 7KH +ROODQGHU IURP WKH .13 ODE ZDV DQ 8PSKHUVWRQ W\SH built by Voight in Germany 1954. Working with it I found RXW DERXW ¿EUH OHQJWK ¿EULOODWLRQ RYHU EHDWLQJ DQG DOO WKH different paper types that come from these pulps. In short I learned what all papermakers know, that paper is really made in the Hollander. The machine was impressive, high speed water cooled and a motor of 7 brake horsepower, and all I did was beat cotton linters. After some years I became more GDULQJZLWKWKHEHDWHUDQGERXJKWP\VHOIDIHZEDOHVRIÀD[ ZDVWHLQ=HHODQG,EHDWWKLVYHU\WRXJKDQGZRRG\¿EUHVR PXFKWKDWLWWXUQHGJROG$W¿UVW,ZDVDPD]HGODWHU,UHDOL]HG that it was the bronze of the knives and bedplate wearing of RQWKH¿EUHV7KHSDSHUEHFDPHFULVS\MXPS\DQGLPSRVVLEOH WRGU\ÀDW7KHZRRGWKDW,ODLGRQWRSRILWWRNHHSLWÀDWVWXFN to it sometimes and on other places the paper pulled away from under it and in those places the paper curled up wildly. 7KRVHZHUHWKH¿UVWWLPHV,QRWLFHGDZD\WRSOD\ZLWKGU\LQJ paper. At the time the paper product I was making probably was a failure because of this curling. Make something of your failures was the motto and it still is. Putting sticks in paper pulp and letting them dry up together became a great way to work. The paper in itself became my tool of expression, it was

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not only a carrier for other media but it became the subject RIWKHVWRU\3OD\LQJZLWKORQJEHDWHQ¿EUHVQH[WWRYHU\VKRUW beaten ones and seeing how both dried up and effected HDFKRWKHU%XLOGLQJWKHWKLQIUDPHV¿QGLQJWKHULJKWNLQGRI bamboo. Finding the relation between beating times, beater adjustments and the shrinkage of the pulp gives you a control over part of your matter, While in other later stages of your work, during the drying, nature really takes its own course and leaves you standing in the side line. The tension between the two materials transforms them into forms reminiscent of a slowly curling autumn leaf. All the forms in my work are caused by pulp drying and shrinking in unison. All my sculptures start as totally 2-dimensional, coloured sheets of pulp.

Fig. 2. Trapezium coated with epoxy 180 x Ø 120 cm

The simplicity of this material, which is carrier, colour, texture and form, all together, make working with it wonderful and direct. Control over the shapes almost completely lays in the preparation of the bamboo frame work. Because there is no turning back on things when you have put the wet paper on the frames and the drying shapes the sculpture. The only way to make a change is in repeating the whole exercise. I see it as my form of sport, I have to do it every day in order to get to grips with forms which slowly evolve, one shape triggers the next. During the drying processes of a paper sculpture the paper will shrink considerably, up to 30%, and the forces associated with that, put the non shrinking bamboo framework under stress. This process goes on through the whole sculpture at WKHVDPHWLPH,XVHIRUFHGDLUDQGGHKXPLGL¿HUVWRVSHHGXS the drying process, because the faster something dries the more dramatic the movement of the paper will be.

Fig. 3. Witte wolk

White Cloud 120 x 60 x 110 cm

But all this comes at great risk, if the paper is too wet it will fall of the bamboo frames. You want to take this risk because the shrinking will be all the more baroque and unexpected when you dare to take the paper of the screen as wet as possible. The more water there is to evaporate the more movement the shrinking will make. The process gives every form its own tension. To enlarge the forms to three or four meters raises the drama caused by the drying process. Last year I was asked to make two 4 meters high sculptures,

52

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to be placed outside on both sides of a bridge in Capelle aan den IJssel. $IWHU FRPSOHWLQJ WKH VFXOSWXUHV , KDG WR ¿QG D EURQ]H caster who would take on the job of casting these two paper sculptures. This was not too hard. Since paper burns very well, you can cast it with the lost wax technique. Following the casters instructions, I covered the inside of the sculpture with a thin layer of wax, about 4 mm thick. At the bronze caster the sculpture was going to be covered in D ¿UHSURRI SODVWHU PL[WXUH RQ WKH LQ DQG WKH RXWVLGH 7KH plaster mould with the sculpture inside it was than placed in a furnace for 3 days. All the wax, paper and bamboo were burned away, leaving a negative form of the sculpture in the plaster mould. This is the principle, in reality the sculptures ZHUHFXWLQSLHFHVWR¿WLQWRWKHIXUQDFHDQGWRHQVXUHQR ash would stay behind in the mould. After casting the plaster is taken off the bronze and the three pieces are welded back together to one big sculpture. I spend a month bringing up the patina and polishing the bronze so that a result of gold skin with blue ribs through it was reached. On January 14 I could place the sculptures at the head of the bridge. It was a weird experience to see the sculptures which I had carried in by hand had to leave the foundry with the help of cranes and trucks.

Fig. 4. Tabakswolken

Tobacco Clouds 1230 x 120 x 45 cm

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Fig. 5. Two paper sculptures cast in bronze on a bridge near the Fascinatio district, Capelle a/d IJssel, 2005

This was an exceptional case, usually my work is commissioned E\SHRSOHOLNH-RRSYDQGHQ(QGH*UHDWKDOOVRURI¿FHDWULXPV asking for a organic forms in a natural material. Because of the lightness of the material it can be hung anywhere ZLWKRXWKDYLQJWRPDNHGLI¿FXOWKDQJLQJSUHSDUDWLRQV7KH SDSHUVFXOSWXUHVDUH¿UHSURRIHGZLWKDÀDPHUHWDUGHUZKLFK I tested out. For the occasion of the 100st birthday of Frits Philips, last year I made electric paper sculptures, lit up by a VHULHVRI/('¶VDQGSDSHUVKDSHGE\WKHSOD\RIHOHFWULFFRUGV I have covered paper sculptures with epoxy which turns the paper more translucent and makes it look like porcelain. This whole paper road I have taken has given me opportunities to satisfy my curiosity and to make new forms using forces stronger and older than my own. When I went to the Royal Dutch Paper factory in 1974 I was the only papermaking artist I knew of, but it must have been in the air because now there are hundreds of them all over the world. Which is a good thing too, because as you know ³WKH'XWFKIDUPHUZLOORQO\HDWZKDWKHNQRZV´DQGLWZDV quite hard to sell my paper art works in the beginning years. 7RKDYHVRPHLQFRPH,NHSWPDNLQJHWFKLQJVDQGOLWKR¶VDQG taught painting and drawing classes at the academy in The +DJXH $IWHU D ¿JKW ZLWK WKH GLUHFWRU WKHUH , ORVW WKDW MRE DQGZLWKPRQH\,JRWZKHQ,ZDV¿UHG,GHYHORSHGP\RZQ Hollander. The old Lab Hollander from Maastricht was not UHDOO\EXLOWWRSURFHVVORQJ¿EUHVOLNHKHPSDQGÀD[ZKLFKKDG EHFRPHP\PDLQ¿EHUPDWHULDO 7KH ORQJ ¿EUHV VSXQ DURXQG WKH D[OH DQG RQFH WKH\ GULHG

54

PAPER LEAVES

up prevented the machine from starting. It was very hard to reach the axle and clean it, because it was an Umpherston type machine, with a completely enclosed water/pulp canal. So time after time I had to take the machine apart what made me very familiar with the way it was built.

Fig. 6. Venus Ø 110 x 200 cm

7KH¿UVW+ROODQGHU,GHVLJQHGZDVEXLOWLQDPDFKLQHIDFWRU\ in The Hague. In the design I had mounted the knives roll on a moving arm so it could bounce over lumps and knots in the ORQJ¿EUHDOVR,JDYHLWDFRXQWHUEDODQFHZLWKZHLJKWVRQ LWWRUHJXODWHWKHZHLJKWLPSDFWRIWKHUROORQWKH¿EHUVDQG combined it with a more traditional open arena shaped tub. In the new machine all the parts, like bedplate and axle are easy to reach and clean. I took the new machine home and placed it next to the old one and found out that my new creation was very unpractical and had a too weak electro motor. So I kept using the old Hollander. One day a stainless steel nut from the QHZ+ROODQGHUIHOOLQWRDEXFNHWIXOORIVRDNLQJ¿EUHV:KHQ I threw this bucket full into the old machine all the bronze knives of the ground plate broke loose and I was forced to continue pulp making with my own new and very unpractical beater. I improved it, gave it a stronger electro motor but it still GLGQRWZDQWWREHDWÀD[RUKHPS,GHVLJQHGDQHZLPSURYHG machine and found a better machine and tool factory who built a beautiful good working Hollander. When I could sell this Hollander I quickly did, improved the design further and had 3 machines built which all sold within a year. This brought on a whole new development. Clients who bought a Hollander also wanted a paper press and a drying box, which I designed and had made also. Over a 100 paper making machines, mostly the Hollanders are sold to places like a university in South .RUHDDQGWKH6&$IDFWRULHVLQ6ZHGHQ My wife Pat Torley who works as a painter uses paper pulp too. Her paintings are not made with paint but with very watery coloured paper pulps made of a great variety of different plants. The images she makes are painted with the IURQWVLGHGRZQ6KHDSSOLHVKHUFRORXUHG¿EUHVGLUHFWO\RQWKH screen starting with what would be the last brush stroke in a UHJXODUSDLQWLQJ6RZKHQRQHRIKHUSDLQWLQJVLV¿QLVKHGVKH looks at the back side of it.

Fig. 7. Blauwe Sigaar µ%OXH&LJDU¶ Ø 90 x 320 cm

PETER GENTENAAR

The coloured pulp is the colour and the carrier or the substrate in one. Her pulp palette gives her much more choice in colour and texture than normal paint would. A red pigmented hemp

55

¿EUHZKLFKKDVEHHQSLJPHQWHGLQWKH+ROODQGHUZLOOEHGHHS red, through and through, comparable with dyed textiles. 7KHGLIIHUHQW¿EUHVDOOWDNHWKHSLJPHQWVLQDGLIIHUHQWZD\ also depending on how long they have been in the Hollander. 'LIIHUHQWSODQW¿EUHVDOVRUHÀHFWWKHOLJKWGLIIHUHQWO\KDYHD different surface and a different texture. It is the richest and most natural material to paint with I know. A great deal off the VXEMHFWPDWWHURI3DW¶VSDLQWLQJVFRPHVIURPKHUSKRWRJUDSKV which she makes in our garden. To share my excitement about all these new possibilities of this old medium I started the Holland Paper Biennial in 1996 in the Museum of my home town Rijswijk. Together with this 2 yearly group exhibition I publish a book and catalogue with the help of my wife, Pat Torley and our friend Loes Schepens a book designer. In 2000 the publishing of the biennale books was taken over by Compres Publishers in Leiden but I still make the contents of the book and Loes still does the book design, which won us several prices including two best book of the year awards. In 2002 I asked the new Museum in Apeldoorn CODA to join the Holland Paper Biennial which they gladly did, and the biennial got twice as big, which was a good thing because the paper art works which are sent in, get bigger every year and more paper artists seem to come from all over the world. In the series of biennial books, 6 books have been published. The formula of these books is always a combination of a story part and a catalogue in which the 27 artists who took part in the Biennial exhibitions in the summer of 2006. My hope is that builders and architects are inspired by my talk and will do some playful experiments with paper pulp yourselves.

PETER GENTENAAR

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

The Design and Building Process of a Cardboard Pavilion Kees van Kranenburg, Elise van Dooren and Fred Veer

Abstract The Faculty of Architecture, University of Technology Delft, has been looking at the possibilities that cardboard offers architectural engineers since 2000. Different disciplines are involved in this research group. One step in this research program was the design, building and exhibition of a pavilion, made of cardboard. The pavilion is designed by master students of the Architecture department and build by master students of the Building Technology department. All work is done in strong corporation with the Dutch cardboard and paper industry. The pavilion has been presented at a 2-day international symposium in January 2006. This paper focuses on the design, engineering and building process.

1. Background In 2000, the Faculty of Architecture started a research project around the material cardboard. Main goal is to establish cardboard as real building material. Cardboard is almost 90% renewable, relatively cheap and can, just because of these aspects, be used shameless. In the past, some temporary constructions were built, using cardboard. Well known examples in The Netherlands are two temporarily theatres in Apeldoorn, built because of the celebration event of “1200 \HDUV$SHOGRRUQ´8\WHQKDDN1,2 and Ruijssenaars3, 1992) and more recently the Paper Dome in Utrecht4 (Octatube, 2003). One step in the ongoing cardboard research project is the GHVLJQDQGEXLOGLQJRIDFDUGERDUGSDYLOLRQVHH¿JXUH%RWK GHVLJQDQGEXLOGLQJSURFHVVRIWKLVSDYLOLRQFDQEHGH¿QHGDV ³DQHGXFDWLRQDOH[SHULPHQWDOH[HUFLVH´$KXJHVORJDQRQD billboard claims the setting of the pavilion project: “Starting SRLQW RI UHVHDUFK´ VHH ¿JXUH  7KLV SDSHU GHDOV ZLWK WKH problems encountered during the building of the cardboard pavilion.

59

Fig. 1. The card board pavilion, an overview

Fig. 2. A huge slogan on a bill board claims the setting of the pavilion project: “Starting point of UHVHDUFK´

60

THE DESIGN AND BUILDING PROCESS OF A CARDBOARD PAVILION

Fig. 3. Top and side view of WKH¿QDOGHVLJQ)RU clearness, the roof at the top of the stairs wall is not shown in this scheme. Exact dimensions of the intended construction could not be given and had to be determined during the engineering phase.

2. Architectural design 2.1. Architectural concept The design of the cardboard pavilion is made by students working on their MSc in Architecture. An important goal for the design concept, was that the pavilion could act as an exhibition in itself: what possibilities offers cardboard as D EXLOGLQJ PDWHULDO" 0RUHRYHU WKH SDYLOLRQ KDG WR KDYH D spacious character from an architectural point of view. A number of design and construction alternatives have been examined. Evaluation of design alternatives learned that a GHVLUHG ÀRRU RQ ÄQRUPDO³ KHLJKW RI DERXW  PHWHU ZDV impracticable because of the need of a balustrade. It was simply impossible to construct and test a safe (cardboard) balustrade within the available time. For this reason a FRPSURPLVHZDVPDGH$WRSKHLJKWRIWKHÀRRURIFPZDV selected which provides safety without a balustrade.

2.2. Final design 7KH ¿QDO GHVLJQ RI WKH FDUGERDUG SDYLOLRQ FDQ URXJKO\ EH GHVFULEHGDVFRPSRQHQWVDÀRRUDQGIRXUGLIIHUHQWZDOOV VHH¿JXUH([DFWGLPHQVLRQVRIWKHLQWHQGHGFRQVWUXFWLRQ could not be given in this stage and had to be determined during the engineering phase. Each component is named, and

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61

a brief description is given below: 2.2.1. Stairs wall The stairs wall is built up from layers of honeycomb cardboard. Total height of the stairs wall is about 3.5 meter. The open cell structure of the honeycomb board is visible. The stairs leads to a small terrace of 1 square meter at a height of 2.7 meters. 2.2.2. Taco wall The Taco wall is build up from boxes, made of corrugated board. Dimensions of these boxes are: a height of 30 cm, a width of 60 cm and depth 15 cm. The thickness of the corrugated board is about 2 mm. The boxes can be used as built-up blocks and offer the possibility to construct large walls partition. The boxes are glued together and a top surface layer is applied. Because of the top layer, a rigid construction arises. Further LQIRUPDWLRQFDQEHIRXQGLQ³&DUGERDUG$UFKLWHFWXUH´5.

Fig. 4. Scheme of impact test

Fig. 5. 4-point bending tests on a reinforced card board beam

62

THE DESIGN AND BUILDING PROCESS OF A CARDBOARD PAVILION

2.2.3. The Paper bale wall The third wall is formed using paper bales. The bales have a weight of 600 kg each. Dimensions of the paper bales are approximately: height 1m, depth 0.6m and a width of 1m. Only 4 bales are used to suggest a wall of paper bales; it was QRWSRVVLEOHWREXLOGDVROLGSDSHUEDOHZDOODVWKHÀRRUZRXOG not support the weight.

Fig. 6a. Fire resistance test

2.2.4. The Bee wall The Bee Wall is a cardboard based inner wall system. One panel is been built up from two cardboard blades, which are coupled by styles of honeycomb cardboard. Both blades are ¿QLVKHGZLWKPPVROLGERDUG7KHZHLJKWRIRQHWRWDOO\ recyclable) panel is less than 25 kilograms.

3. Building technology 3.1 Mechanical tests

Fig. 6b. Impregnation of the stairs wall

In general, the mechanical behaviour and the failure behaviour of cardboard in an architectural engineering setting were not well understood yet. For safety reasons, mechanical properties and failure behaviour of the different cardboard elements used, HJZDOOVVWDLUDQGÀRRU KDGWREHGHWHUPLQHG&DUGERDUG beam specimen in different compositions are made and tested to get an indication of the reliability of structural components, VHH¿JXUH5HVXOWVDUHXVHGWRGHWHUPLQHIRUH[DPSOHORDG FDUU\LQJFDSDFLW\DQGSRVVLEOHVSDQRIWKHÀRRUDUHD7KUHH more advanced series of tests were conducted to characterize the mechanical behaviour of the (soon commercial) Bee Wall. 7KH¿UVWVHULHVFRPSUHVVLRQDQGEHQGLQJWHVWVDUHPDGHRQ small sections of the wall. In a second series impact tests DUHSHUIRUPHGVHH¿JXUH,QWKHWKLUGVHULHVDIRXUSRLQW bending test is made on a whole wall element.6

3.2. Flame resistance 7KHULVNRI¿UHKDGWREHPLQLPL]HG'LIIHUHQWWHVWVHULHVDUH PDGHLQRUGHUWRJHWDQLQGLFDWLRQRIWKHÀDPHUHVLVWDQFHRI VROLGERDUGDQGKRQH\FRPEERDUGDVZHOOVHH¿JXUHD A chemical flame retardant was added to specimen of combustible open cell structure of honeycomb board, to give them a better protection to ignition. This protection was working very well: it was even impossible to ignite the specimen for 5 minutes, while an untreated specimen burns LPPHGLDWHO\6ROLGERDUGKDVDQDWXUDOÀDPHUHVLVWDQFHGXH

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63

to the burning process. During burning, a layer of carbon is formed, protecting the underlying material from burning. Flame resistance of both solid board and treated open cell structure of honeycomb board can be marked as moderate7. For this reason only the visible open cell structure is impregnated with DFKHPLFDOÀDPHUHWDUGDQWVHH¿JXUHE

3.3. Technical engineering Mechanical measurement results and observations are used as input for the technical design of the cardboard pavilion. Results are used, for example, to estimate the needed dimensions for thicknesses of the stairs and terrace and WKLFNQHVVDQGVSDQRIWKHÀRRU Measurements on a layered honeycomb construction, i.e. WKH ÀRRU VKRZ WKH SRVVLELOLW\ RI ODUJH EHQGLQJ EHIRUH ¿QDO failure. Because of this large unexpected bending effect, WKHÀRRUFRXOGQRWEHFRQQHFWHGSURSHUO\WRDQ\ZDOOV$VD consequence of this, every wall had to be stable by it self or VWDELOL]HGXVLQJDGGLWLRQDOHOHPHQWV7KHÀRRULVQRWDWWDFKHG (in)to the stairs wall, to allow expected movements of the ÀRRU0RUHRYHUWKHVWDLUVZDOOLVSURYLGHGZLWKDVPDOOFDYH VXI¿FLHQWWRDOORZEHQGLQJRIWKHÀRRUVHH¿JXUH 7KH ¿QDO WKLFNQHVV RI WKH ÀRRU LV  FP ZLWK VSDQV RI  PHWHUV7KHXSSHUSDUWRIWKHÀRRUKDVEHHQ¿QLVKHGZLWK a top layer of solid board in order to protect the underlying honeycomb from intrusion.

Fig. 7. The stairs wall is provided with a small FDYHVXI¿FLHQWWRDOORZ EHQGLQJRIWKHÀRRU

64

THE DESIGN AND BUILDING PROCESS OF A CARDBOARD PAVILION

Fig. 8. A soft push on the balustrade on the terrace on 3 meters height results in movement of the entire construction with considerable amplitude Shown are two principal solutions to make the construction more rigid

3.4. Building process 'LIIHUHQWSDUWVRIWKHSDYLOLRQLHÀRRU7DFRZDOODQG%HH ZDOOKDYHEHHQSUHSDUHGLQGLYLGXDOO\)LUVWWKHÀRRUKDVEHHQ build as a „massive solid“ of layered honeycomb plates. The honeycomb plates are glued with woodworking adhesive. 7KH VWDLU ZDOO LV EXLOW XS WR D KHLJKW RI  FP WKH ÀRRU LV placed and thereafter the stair wall was almost built up to the designed height of 3.5 meter. Afterwards, respectively the Bee Wall and the Taco wall have been placed.

3.5. Use After building, the pavilion in used as part of the exhibition on the 2-days symposium. During „service life“, no considerable problems appeared, except some problems with the weak top layer of the rungs. The rungs were covered with multiplex plates in order to protect them from damage. After a short life cycle of three weeks, the pavilion was demolished and offered for recycling.

4. Conclusions We have faced a number of technical, engineering problems during the design and building process of the cardboard pavilion. In some cases, these problems can be marked as VSHFL¿FWRFDUGERDUGUHODWHG7KHPRVWUHPDUNDEOHSUREOHPV are described below. Moreover, some possible solutions are provided.

4.1. Bending stiffness The density of the used honeycomb board is about 100 kg/ m3. This is low compared to traditional building materials, for example a brick wall of >2000 kg/m3. Another difference between cardboard wall and a brick wall is the bending stiffness of the construction. A wall made of cardboard lacks

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65

EHQGLQJVWLIIQHVV7KLVVSHFL¿FFRPELQDWLRQORZGHQVLW\DQG low bending stiffness, leads to a problem. A soft push on the balustrade on the terrace on 3 meters height resulted in movement of the entire construction with considerable DPSOLWXGH DV LOOXVWUDWHG LQ ¿JXUH D %HFDXVH RI WKLV WKH decision was made not to build higher than 3.40 meter. A logical solution to tackle this problem is to reinforce the ZDOOXVLQJDEXWPHQWVRUJLUGHUVVHH¿JXUHE%\LQWURGXFLQJ these girders, for example every 15th layer, the construction becomes more rigid.

4.2 Deformation A second problem is the permanent deformation introduced during manufacture. The cardboard elements are glued together using adhesive. The adhesive diffuses into the paperboard, as a result of which the paperboard softens and loses its original form. After drying, this deformation becomes permanent. $VLPSOHVROXWLRQFDQEHIRXQGLQ¿[LQJWKHHOHPHQWVXQWLO WKHJOXHKDVGULHG+RZHYHULQVRPHFDVHVLWLVGLI¿FXOWWR¿[ glue and dry large elements at the same time, for example the ¿QLVKLQJWRSOD\HURIWKH7DFRZDOO

4.3. Moisture and temperature Cardboard is very sensitive to environmental effects like PRLVWXUHDQGWHPSHUDWXUHÀXFWXDWLRQV7KHSDYLOLRQZDVEXLOW in an exposition hall of the Faculty of Architecture, just to SUHYHQWWKHFRQVWUXFWLRQIURPODUJHWHPSHUDWXUHÀXFWXDWLRQV and direct contact of water vapour. However, during Christmas time, the temperature in the empty building was lowered, and as a result the relative humidity increased. This change in temperature and relative humidity lead to a deformation of WKHÀRRUDQGVWUHVVHVDSSHDUHGLQWKHDGKHVLYHOD\HUV Any corner, pollution, or hollow areas in the internal area of the material can result in stress concentration and small cracks. Most times, the de-bonding process will begin in one of these areas, simply because of this phenomenon. It is an ongoing process: once a crack exists in a structure, it will tend to grow. Evidently, accumulation of (local) damage zones can OHDGWRIDLOXUHRIWKHZKROHÀRRU+LJKO\LPSRUWDQWLVWKDWLQWKH manufacturing process the introduction of residual stresses is avoided to prevent local high stress concentrations.

66

THE DESIGN AND BUILDING PROCESS OF A CARDBOARD PAVILION

4.4. Plate edges Plate edges seem to be a problem, not only in a mechanical PDQQHU EXW DOVR EHFDXVH RI PRLVWXUH WUDQVSRUW DQG ÀDPH resistance.

4.5. Adhesive Fig. 9.'HODPLDWLRQRIWKHÀRRU

General problem, in a mechanical sense, is the joint between different parts of cardboard. Failure caused by delamination is RIWHQREVHUYHGVHH¿JXUH0XFKUHVHDUFKKDVWREHGRQH LQWKLV¿HOG

5. References 1

T. Verstegen, Rudy Uytenhaak, 010 Publishers, isbn 90-6450241-2, Amsterdam, 1996

2

http://www.uytenhaak.nl

3

http://www.architectengroep.nl/hansruijssenaars

4

http://www.octatube.nl

5

E. Van Dooren and T. Van Iersel, Cardboard architecture, drukkerij Groen, Leiden, The Netherlands, 2006

6

M. Veldhuizen, Mechanical tests on the Bee Wall, (in Dutch), Delft, december 2005

 )$9HHUDQG&YDQ.UDQHQEXUJ9HUJHOLMNLQJYDQGH brandwerendheid van het Bee Wall binnenwandsysteem met verschillende afwerkingen, (in Dutch), Delft, december 2005 Special thanks to the Audiovisuele dienst, Faculty of Architecture, TU 'HOIWIRUWKHXVHRIFRS\ULJKWHGPDWHULDOLH¿JXUHDQG

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

A House of Cardboard Elise van Dooren & Taco van Iersel

Abstract Paper and cardboard are being used on a small scale in the building industry. One of the most common products is wallpaper, less well known are honeycomb door cores and cellulose insulation panels. Some architects use the material for an advanced agenda and more professionally: Shigeru Ban uses cardboard tubes for construction purposes and there are various projects in the realm of temporary housing. This text describes the building of a cardboard house: it describes the current understanding of cardboard as a player in the building industry and the knowledge still missing. ,VDKRXVHPDGHRIFDUGERDUGIHDVLEOH":K\ZRXOG\RXZDQWWR XVHDFDUGERDUGKRXVH",QRUGHUWRJLYHD±WHPSRUDU\±DQVZHU a few thoughts have been written down. Summarized: in the foundation the only application is that of building-aid; constructively, tubes are a proven application. Connections in cardboard are still rather tricky, mainly because of failure at concentrated loads. Thanks to water we have cardboard, and despite water it will have to remain in tact. Building components of cardboard separating the inside from the outside – whereby the material must be water-repellent and the many seams which exist in a building must be sealed – at the moment seem to be far from day-to-day use. Cardboard is recyclable, cheap, lightweight, foldable and printable. Which of these properties is a real addition to the existing WUDGLWLRQDODVVRUWPHQWRIEXLOGLQJPDWHULDOV"$QHZFRPHUPXVW be equal to the existing materials in the existing marketplace and to stand out in order to acquire a place in the building industry. Ecology (recycling, short life-span, light weight) seems to be its greatest advantage. But, considering the thoughts afore mentioned, the application of the materials will often only be feasible in a combined shape, as composites

69

1. Designing a cardboard house? When asked why he climbed Mount Everest (1959) Sir Hillary DQVZHUHG³%HFDXVHLWLVWKHUH´$FRPHGLDQRQFHVSRNHRI a house where, because of sounds, everything was knitted: knitted china, knitted doors, etc. In this text we ask ourselves a few questions: is it possible to EXLOGDFDUGERDUGKRXVH"$QGIRUZKDWUHDVRQVGRZHZLVK WREXLOGDFDUGERDUGKRXVH" ,VWKHIROGRIFDUGERDUGHTXLYDOHQWWRWKHKLQJH",I\RXIROG open a cardboard door, how long will the fold last during QRUPDOXVH"2UFDQWKHGRRUVLPSO\EHDUHPRYDEOHFDUGERDUG SDQHO"%HFDXVHFDUGERDUGLVDOLJKWDQGWHPSRUDOPDWHULDODQG seems therefore to be appropriate to be applied as movable parts in a building. Is this example another way of thinking DERXWWKLQJVZHFRPPRQO\DFFHSW"2UFDQWKHQDWXUHRIWKH material cardboard change the way we think about building DQGDUFKLWHFWXUH" There is always the challenge to play and explore. In our minds we can have the most beautiful and crazy thoughts and we are capable of building entire alternative (utopian and/ RUYLUWXDO ZRUOGV%XWZKDWKDSSHQVZKHQZHKLWUHDOLW\",V it possible to build a house from cardboard, or use as much FDUGERDUGDVZHFDQLQEXLOGLQJDKRXVH"

Fig. 1.&DUGERDUGER[DVµD KRPH¶

70

A HOUSE OF CARDBOARD

Paper and cardboard are being used in the building industry on very small scale. Cardboard (side) products are the ventilation ducts in the XX building by Jouke Post (1995, Delft)1 and the formwork tubes for concrete columns. Cardboard is the bearer RIGXFWVLQDÀRRUKHDWLQJV\VWHP2. Wooden doors often have D¿OOLQJRIKRQH\FHOOFDUGERDUGDQGLQVXODWLRQFDQEHDFKLHYHG with cellulose plates3,4. Building paper (paper with asphalt) is used in constructions as a protective layer for resisting water.

Fig. 2. Projects by Shigeru Ban

%HIRUHEHLQJLQÀXHQFHGE\:HVWHUQDUFKLWHFWXUHDQGFXOWXUH the Japanese build in wood and paper. Or maybe better: the Japanese built in wood. Because in fact paper is a derivative of wood. Shigeru Ban, nowadays a well known architect, VRPHWLPHVXVHVWKHWHUPµHYROYHGZRRG¶IRUFDUGERDUG5. Japan has a particularly rich tradition in the use of paper. Well known Japanese paper varieties are Washi (hand scooped paper, which distinguishes itself through its strength, gloss, natural colouring, long duration, and low weight) and Nagashizuki (very thin paper, multi-layered, crossed, VWURQJ¿EUHEXLGXS 3DSHUZDVXVHGDVFORWKLQJIRUPRQNV (Zen-masters of paper-clothing) and bags (treated against insects).6 Sliding doors (fusuma and shoji) are playing an important role in creating that special Japanese sense of space. In all varieties of transparency, the paper softens the rays of light HQWHULQJ WKH URRP $W ¿UVW ZLWK WKLFN SDSHU ODWHU RQ ZLWK thinner paper the Japanese discovered “the beauty of shade and shading. And then they discovered how to use shade and VKDGLQJWRFUHDWHEHDXW\´7 In the tradition of the Japanese the house is not a castle built for eternity and protection of domestic happiness, but an article of use, which can be discarded of after its lifespan has expired8. There are a few motives at the basis of this mindVHW5HOLJLRQVD\VWKDWWKHµKLJKHVWVWDWHRIEHLQJ¶LQVRFLHW\LV the disconnection of earthly goods. The Japanese culture has a strong respect for nature; people live in and with nature. The Western control of nature and the denial of the temporality of live are alien to the Eastern traditions. In combination of an ever increasing demand for building materials, this leads to reusable materials and products. The choice of material also coincides with the ability to build

ELISE VAN DOOREN AND TACO VAN IERSEL

71

fast, so that the fast changing demands can be met. Moreover; a country like Japan will increasingly have to watch out for earthquakes; this means less rigid constructions in vulnerable places. Rice-paper walls are appropriate to this tradition. Shigeru Ban5 continued this tradition in is own way, when using cardboard tubes for construction purposes. Partly because of environmental considerations, he continuously VHDUFKHV IRU PDWHULDOV ZKLFK KDYH SURSHUWLHV ¿WWLQJ WKH assignment and situation (recyclability, little transport). He VHDUFKHVIRUVLPSOLFLW\DQGHI¿FLHQF\ Basing his initial ideas on cardboard tubes used for transporting tapestry, he continued the Japanese paper tradition in modern architecture. In a dwelling (Paper house, 1995) and a church 3DSHU &KXUFK .REH   KH SODFHG FDUGERDUG WXEHV LQ a circular pattern behind a (semi-)transparent façade, thus creating beautiful areas, in a dance with light. So, he uses, in the Western perspective, an unusual material LQ DQ XQH[SHFWHG ZD\ IRU VKDSLQJ VSDFH LQ D µPRGHUQ DUFKLWHFWXUDO¶ PDQQHU +LV HPSDWK\ ZLWK WKH YLFWLPV RI WKH .REH HDUWKTXDNH PRWLYDWHG KLP WR GHVLJQ FDUGERDUG WXEH HPHUJHQF\KRXVLQJ3DSHU/RJ+RXVHV.REH  Looking around us, we nowadays see a lot more interest in new or existing materials. There are a number of reasons for that. The ecological one is an important reason. There are the aspects of rapidly changing society, which uses more and more short-term products, materials and buildings. The environmentally friendly aspects of paper/cardboard can respond to this demand. Using paper and board instead of traditional materials, could lower the ecological pressure on global material extraction. Another reason is the texture of materials, and therefore the VSKHUH WKH\ FUHDWH ZKHQ XVHG LQ DUFKLWHFWXUH $G YDQ .LO DQG5R.RVWHUXVHGWKHEHDXWLIXOWH[WXUHRIFXWKRQH\FRPE FDUGERDUGLQWKHLULQWHULRUGHVLJQIRUDQRI¿FHLQ(LQGKRYHQ9. So, probably we have four main reasons for making a cardboard house or using cardboard in buildings in general. First, paper and cardboard are an interesting alternate material, that could provide new spheres and textures in

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designing space. New techniques in digital image printing, printable electronic circuits and 3D-cutting computer programs (Papercura) could lead to interesting options beyond the possitbilities of traditional wallpaper. Second, the low weight, recyclability and endless source of wood, provides, an ecological material. The low-ecological impact outstands all traditional materials. Third, by experimenting with cardboard for houses, we can learn about new possibilities for existing materials and the way that we perceive them. For example, new techniques are developed in aluminium by looking to commonly used techniques in corrugated cardboard. And fourth, we hope, we can develop new interesting products and techniques, using the unique material aspects, as folding, printing and lightweight. For playing a role in building tradition, a new material will have WRKDYHVXI¿FLHQWO\HTXDOSURSHUWLHVDVWKHFXUUHQWH[LVWLQJ building materials; it will have to meet some functional demands. And it should have one or more special qualities, validating the material and distinguishing itself. Like transparency being the unique property of glass. Thanks to recent developments the material can be used for load bearing properties as well. The synergy between transparency and construction creates intrigue and unknown possibilities for architecture and the building industry. There is another possibility. The new material should have special qualities. So that it can provide these qualities in combinations with other materials. For cardboard the speciality could be valuable in an ecological ZD\ WKH OLJKW ZHLJKW RU WKH ÀH[LELOLW\ LQ XVH $OVR WKH ORZ production price and the possibilities of machine production seem to be an advantage. At the moment, also at the faculty of architecture at the TU Delft, cardboard is undergoing enthusiastic design and research. The purpose of the research-group, is researching, designing

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and development of new applications of cardboard/cardboard FRPSRVLWHVLQWKHEXLOGLQJLQGXVWU\7KHQHZGHYHORSPHQWV¶ ability to stand out, when compared to traditional (building) materials will manifest itself mainly in maintaining a low ecological impact. Through an analysis of building parts/function we will describe what the customary materials are at the moment, which demands should be met by that building part and especially what was experienced when using cardboard. This will bring to light unknown knowledge and give us the possibility to estimate whether cardboard could be successful for this building part or function.

2. Mechanics and structure A paper sheet is weak; cardboard – actually thick paper – is a lot stronger. The tensile and compression strength YDU\ DFFRUGLQJ WR WKH GLUHFWLRQ RI WKH ¿EUH SDUDOOHO WR WKH machine the strength is much greater than perpendicular to it (anisotropic properties, comparable to that of wood). A well distributed load can be transferred well, yet, with a point-load cardboard is much more vulnerable. A considerable part of building means connecting materials. Concerning cardboard, forces concentrated on one point (peak-stresses) have proven to be the weak link. Glued connections are much stronger. The creep – elongation of a material under a constant pressure during a long time – depends on the type of cardboard, the pressure exerted, the relative humidity and other factors. It might prove to be a factor we will have to watch closely. The mechanical behaviour of a material must be known in order to use it as a building material in constructions. At the moment only incidentally, materials and projects can be subjected to thorough calculations, but common material properties usable YDOXHVIRUWHQVLOHDQGFRPSUHVVLRQVWUHQJWK\RXQJ¶VPRGXOXV values for creep, etc. are still unknown. The long-term behaviour DQGSUHGLFWDEOHEHKDYLRXUDUHWZRYHU\GLI¿FXOWUHVHDUFKDUHDV to grasp, both being at the beginning of their development. 6RPHYHU\¿UVWDQGSURYLVLRQDOGDWDLVDYDLODEOHLQSXEOLFDWLRQV about the research of Julia Schönwälder (TU Delft)10 and in the publications of Buro Happold, Cotrell & Vermeulen and Andrew Cripps about the Cardboard School.11,12 The book about Shigeru Ban also mentions some (test) data.5

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Fig. 3. Structural test of a honeycomb cardboard panel

From a building perspective there are two important divisions: construction and separation. From a construction perspective, GLIIHUHQWSDUWVZLOOEHGLVFXVVHGIRXQGDWLRQÀRRUVDQGURRIV columns and plate constructions. Special shapes are those where vertical and horizontal constructions meet. Connections will also be discussed. 2.1. Foundation Depending on the type of ground we build on and the degree of temporality of the building, we will have to choose a type of foundation. Principally there are two possibilities: a heavy IRXQGDWLRQRUDIRXQGDWLRQZKLFKOHDYHVQRWUDFHDWDOOµOLNH DWUDYHOOHU¶:KHUHFDUDYDQVOHDYHYLUWXDOO\QRWUDFHZHRIWHQ do need a sturdy foundation. The most common material for foundations is concrete. Even when using a wooden skeleton as a construction, the foundation is often made from concrete. Cardboard perishes in the humid ground and thus is principally unsuitable as a foundation material. Only the similarity in temporality of cardboard and mould materials might offer some possibilities. Cardboard tubes used for casting concrete

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columns have already been accepted on the market. One of WKH¿UVWWHVWVZLWKDFDUGERDUGORVW PRXOGDVDUHSODFHPHQW for traditional wooden moulds went less successfully than hoped. A second round has not yet been undertaken. )RUPZRUNFDQEHXVHGDVDQHQYHORSHEXWDOVRDVDQµLQVHUW¶ The formwork thereby keeps the material from reaching that point. In a case-study in Amsterdam13 (not executed) cardboard was the answer to a very tricky formwork problem. 7KHIDFWWKDWQRFHUWL¿FDWHVDQGJXDUDQWHHVIRUFDUGERDUGDVD formwork material were available stopped it from being used. In the past formwork tubes have been used as inserts in cast ÀRRUVPRQRWXEH9DQ$QWZHUSHQ 7KHURXQGWXELQJUHGXFHG the amount of concrete used and thereby the weight of the ÀRRU$WWKHPRPHQWWKHGHPDQGIRUWKHVHW\SHVRIIRUPZRUN is low, most probably because the reduction in weight is also DFKLHYHGE\SUHIDEKROORZFRUHÀRRUV

2.2. Floors and roofs Floors span spaces. They must have enough load bearing capability and be able to sustain concentrated loads. The building industry basically knows a few (traditional) materials suitable to meet these demands: steel, concrete and wood. In the Netherlands (only very recently) concrete became the most commonly used material. Historically seen, until the ¶VZRRGZDVWKHIDYRXULWHPDWHULDO,QWKH6FDQGLQDYLDQ countries, Canada and North-America, where wooden frames DUHDFRPPRQZD\RIEXLOGLQJZRRGHQÀRRUVDUHDIUHTXHQW and accepted phenomenon. Next to being very usable, the actual large scale use of a material is also determined by cultural aspects and habits: the building traditions. A new material in the building industry will have to prove itself; in a technical way, meeting the different functional demands and beyond that, in order to acquire a place between the existing materials (e.g. light weight for building legislation) and be competitive. 7RJHWD¿UVWLPSUHVVLRQRIWKHGLPHQVLRQVRIDÀRRUSDFNDJH and beams we use rules of thumb. For traditional building PDWHULDOVWKHUDWLRKHLJKWVSDQRIDÀRRUHOHPHQWRUEHDP vary from 1/10 to 1/30, depending on the material used and WKHSUR¿OHXVHGVHFWLRQ 0RVWFRPPRQLVWKHUDWLR7KH

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rule of thumb of 1/10 is only used for relatively transparent steel trusses. 5RRIVGLVWLQJXLVKWKHPVHOYHVVWUXFWXUDO\IURPÀRRUVEHFDXVH their dimensions are much more favourable following the lighter load. Shigeru Ban used a cardboard roof construction LQ KLV FKLOGUHQ¶V PXVHXP LQ -DSDQ5 Beams of honeycell cardboard (60 cm x 1 m and 60 cm x 3 m) from a triangular VWUXFWXUH(YHU\WKUHHPHWHUVZH¿QGDFROXPQ7KHMRLQWVDUH made of aluminium. 8QWLOOUHFHQWO\FDUGERDUGKDVEHHQXVHGYHU\OLWWOHLQÀRRUV,Q the pavilion built in January 2006 at the faculty of Architecture, TU Delft, honeycell panels were glued together making a ODUJHGLPHQVLRQHGÀRRU7REHDEOHWRVXVWDLQFRQFHQWUDWHG ORDGVWKHÀRRUZDVVXSSOLHGZLWKDIHZOD\HUVOLQHUV RIVROLG cardboard. Creep (elongation progressing with time) and the type of glue as well as the manual production process presented a reasonable problem. Experiments with cardboard beams have also been undertaken at the TU Delft, Faculty of Architecture (mechanical research, Julia Schönwälder)10. The tested materials were mainly SUR¿OHV ZLWK KRQH\FRPE FDUGERDUG VRPH FRPELQHG ZLWK cardboard tubing. Experiences with the ratio height / span for now point in the direction of 1/10. A relatively large amount of material for the span. /DUJH PDWHULDO VL]HV SURYLGH XV ZLWK D VSHFL¿F LPDJH LQ architecture. Architects usually strive for a minimal use of materials: slender columns, thin window frames and slender cantilevers. Besides that, excess use of material is ecologically unsound. This can however be compensated by the cheap price and the ability to recycle cardboard. In conclusion we can ask whether it is possible to go from a 1/10 ratio to a 1/20 ratio, or to take a different approach. ([SHULHQFHKDVWDXJKWXVWKDWEHDPV¿WZHOOZLWKPDWHULDOV capable of withstanding large spans. When using cardboard LWPLJKWEHPRUHSUDFWLFDOWRFKRRVHDÀRRUSDFNDJHZKLFKLV load bearing by itself, whereby it is easier to spread the loads QRFRQFHQWUDWHGORDGV 6WXGLHVLQWRIROGLQJ ÀRRUV\VWHPV are still in an early stage of development.

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2.3. Columns and load bearing plates For load bearing structures there are different options, varying from columns to parallel plates to a spacious (plate) structure, ZKHUHE\WKHÀH[LELOLW\RIWKHVWUXFWXUHGHFUHDVHVUHVSHFWLYHO\ The existing building materials which are most commonly used for construction are: concrete steel and wood. Plates can be divided as: (1) stacking systems, like masonry walls, (2) hollow partition systems, like a wooden skeleton, and (3) panel systems, whereby the panels are being placed as a unit. Besides the structural function, the different systems often KDYHWRIXO¿OGLIIHUHQWSDUWLWLRQLQJIXQFWLRQV Cardboard columns are promising when using cardboard tubes. The tubes are often being used to transport tapestry. However, in buildings the tubes are being stressed in a different way, namely in axial stresses (following the length of the tube). There is not a lot of knowledge about cardboard tubes in technical building situations. We do know that the production method of the tubes (wrapping) reduces the tensile strength of the tubes. As the houses designed by Shigeru Ban prove, they are however usable only in one story buildings. Also the Multished by Taco van Iersel14 uses tubes in its FRQVWUXFWLRQ7KHSUR¿OHVKHUHKDYHEHHQXVHGDVDFROXPQ and as a roof beam. 5RXQGFROXPQVGRQRWDOZD\V¿WWKHEXLOGLQJLQGXVWU\ZLWK its predominantly orthogonal shapes. The joints are especially GLI¿FXOWWRGHVLJQ,Q-DSDQVTXDUHFROXPQVDUHDYDLODEOHEXW the disadvantage is they are vulnerable to buckling. With cardboard, plates in different typologies have been tested. In the category of stacking systems, a load bearing wall was designed. This wall15, developed by Taco van Iersel during his graduation research, consists of a kind of masonry of stacked boxes. The boxes have been equipped with LQJHQLRXVO\SODFHGÀDSVZKLFKVOLGHLQWRHDFKRWKHULQRUGHUWR get a stable wall. With the same purpose, the surface of the wall is being covered with solid cardboard plates. The result is a cardboard sandwich wall. Starting from the conceptual idea a load bearing wall was designed and tested; serious continuation of the product seems hardly feasible, looking

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at aspects like dimensional stability, building order and load GHÀHFWLRQ 2.4. Special shapes Although we hardly immediately think of special structures like domes and arches when thinking about houses, these FRQVWUXFWLRQV DUH KDQGOLQJ ORDGV HYHU VR HI¿FLHQWO\ 7KH thickness in these constructions can therefore be minimal. When we compare the application of steel and cardboard tubes for a dome, the latter are still larger in diameter. Shigeru Ban used tubes in different kinds of dome and arch-shaped structures. Examples are the Expo Pavilion (Hannover 2000)5 and the temporary theatre of a Dutch theatre company (Mimegroup Jeanette van Steen, IJburg, now a municipal multi-purpose pavilion in Utrecht).16 A disadvantage of the cardboard tubes is the low tensile strength; this is being dealt with in most structures of this type by using steel cables. Optimising the tensile strength of tubes would expand its application possibilities. The experiences with these structures also leads to the preliminary conclusion that a relatively thick use of cardboard is appropriate to the application of the material. However, high safety factors due to the unknown structural behaviour over time and the lack of available data are partly to blame.

Fig. 4. Detail of the roof of the Multished

Fig. 5. The Multished

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Roof frames are another example of a structure where horizontal and vertical constructions meet. Jop van Buchem experimented with more or less arch-shaped trusses in his graduation project.17 In a temporary house in Sydney, Australia18 roof frames were used as well.

Fig. 6. The Cardboard Dome during build-up in IJburg

One more example of a special construction method, are the dwellings developed by Renee Snel.19 On a machine designed E\ KLPVHOI KH ZUDSV HOHPHQWV ÀRRU ZDOOV DQG URRI IRUP a continuous section. The connection of several elements produces a small dwelling. If supplied with a coating, they could be used as emergency housing and built on site relatively fast. The provisional conclusion is that constructions in cardboard until now are mainly applications such as tubular columns and a few special structures. With load bearing walls very little experiments have been undertaken. From a structural point of view it would be logical to make load bearing walls; WKHFRQQHFWLRQEHWZHHQWKHZDOOVDQGWKHÀRRUVZRXOGWKHQ be possible as a line bearing joint, whereby the transfer of loads is better than with concentrated loads such as columns. Too little is known to make a good comparison with these

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materials and building systems, but for now the conclusion that structure in cardboard is only applicable in special situations, like emergency housing, or because it is cheap, EHDXWLIXORUHFRORJLFDOVHHPVMXVWL¿HG

2.5. Connections A distinctive characteristic for the building industry is the manner of connecting. Connections are mainly constructive DQGRUIRUZDWHUSURR¿QJLQWKHLUXVH Structural connections are often point or line shaped. Examples are: Steel girders, connected with bolts (point) and SUHIDEFRQFUHWHÀRRUVVXSSRUWHGE\VWRQHOLNHZDOOVOLQH 

Fig. 7-8. Cardboard house designed by Stutchbury

The most important aspect of, especially point connections, are the relatively large tensions it has to transfer. Historically, many wooden connections and joints were used, nowadays the emphasis lies on steel joints and glue.

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Most of the cardboard building projects at this stage still use non cardboard connections. Often these connections are made from steel or wood and are very characteristic from a architectural point of view. For example, Shigeru Ban used wooden square blocks combined with steel rods5, and the nodes of the Paperdome in IJburg are made from steel16. The Multished by Taco van Iersel14 uses a round wooden block as a connection between the tubes. These are standard blocks used as a intermediary between the driveshaft of the machine and the cardboard tube in the cardboard industry. The tubes have been bolted on the blocks. Another type of connections consists of literally tying together tubes with rubber or rope, like in some of the Shigeru Ban projects.5 The most common connection techniques in the cardboard packaging world (e.g. cardboard boxes) are folding and sliding into each other. ,Q D FDUGERDUG KRXVH LQ 6\GQH\  H[KLELWLRQ µ+RXVHV RIWKH)XWXUH¶17 the structural elements can be slid together like the partitions in a wine-box. The cardboard house could be delivered to the building site as a relatively lightweight package with cardboard frames and panels. It takes only two

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people to assemble one house in approximately 6 hours. An important focal point for future research is the concentration of tensions around point shaped joints. As mentioned above, cardboard seems to be more adaptable for line shaped connections, because this means the internal stresses can be divided better than with point shaped joints.

3. Physics and construction The shell of a building can have a load bearing function as part of the construction. But above all, the façade and roof have to separate the inside and the outside. The demands taken into consideration are: water-resistance and warmth regulation, but also aspects like dampness and sound regulation. A few of these aspects are very much intertwined.

3.1. Water resistance Water resistance is one of the most important functions of the shell of a building in general. There are a few principles that bring about the success of this function. With roofs the DQJOH RI VORSH LV RI JUHDW LPSRUWDQFH (YHQ D ÀDW URRI KDV a slope. With roofs as with facades, the water resistance of the materials used is essential. Wood is painted or varnished, the leaf of a cavity wall disconnected; these are examples of layers of material which are more or less water resistant (together). Furthermore there are a few principles to achieve water resistance in the seams: (1) overlapping of roof tiles and foil strips, (2) added waterproof connection materials and elements, like the mortar and glue with which bricks get connected and (3) the interlocking of building parts through a labyrinth of seams or click systems, like with window frames and panel systems. The variety of materials and products which can be applied in DIDoDGHDUHHQGOHVVHDFKKDYLQJLWVRZQVSHFL¿FFKHPLFDO and physical, strong and weak properties. Water is both a friend and an enemy of cardboard. During the production process a large amount of water is added to the ¿EUHZDWHUDQG¿EUH :LWKVLHYHVDQGSUHVVHVWKH water is then extracted so the paper and cardboard can be formed. When paper and cardboard subsequently come into

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contact with water, it loses its strength and disintegrates to pulp. Therefore it is not a very logical choice to use cardboard as a water repelling layer. And if we do decide to do so, we will have to pay a lot of attention to this aspect. Cardboard can be made more water resistant in two ways: on top of and/or inside of the cardboard. On top of the cardboard it is easy to attach a plastic layer (e.g. PE), thus creating a moisture repelling laminate, whereby the cross cut end will remain unprotected. In the Multished by Taco van Iersel14 these sides were covered by tape for protection. In Australia research has been done into composites with paper. Vulnerable materials such as paper and straw are being protected by a cover of recycled Polyethylene Terephthalate (PET) A thin layer of polyethylene is vacuum drawn around a material like paper20. It is also possible to use all kinds of additives during the manufacturing of cardboard. For example, kitchen paper towels which are much stronger when wet compared to toilet paper. 0HDVXUHVWRPDNHFDUGERDUGZDWHUUHVLVWDQWDUHLQFRQÀLFW with the potential of paper recyclabililty. The paper and cardboard industry points out that a small percentage of these types of cardboard in the pulp-phase are not a limitation for the recycling process.

3.2. Damp regulation Next to repelling water from the exterior, the transport of moisture through the facade, in the form of vapour, is an important item. With a surplus of condensation the moisture can, given time, produce funguses and decrease the insulating properties. For a short amount of time, cardboard can absorb a small amount of moist. The relative dampness of an internal space is of no immediate problem in a normal situation, but when the cardboard construction gets exposed to large amounts of water during a long period of time, it becomes a large problem.

3.3. Warmth regulation Insulation of warmth is an important function of the shell.

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Heat can be transported in different ways, mainly by air and radiation. Most of the time stand-alone insulation materials are being used in a partition. Commonly used materials are glass wool and mineral wool panels. The panels have different properties, from, weak and bendable to stiff and very hard and can therefore be used in various situations and types of façades. Heat transfer through radiation can be limited by DGGLQJDOD\HURIUHÀHFWLQJDOXPLQLXPIRLO In principle, paper is suitable as an insulation material. Using cellulose, different kinds of insulation panels have been made, HFRORJLFDOO\VSHDNLQJ¿WWLQJLQWKHFDWHJRU\µEHVWPDWHULDO¶7KH panels are continuously being developed, making them just as usable as their less ecological competition. For example, Homatherm3,4 has developed a panel with an insulation FDOFXODWLRQ YDOXHRIP.:ZKLFKLVEHQGDEOHDQGFDQ be processed, dust free, using standard equipment. Moreover, the panels breaths, thereby temporarily buffering moisture. Isovloc3 DUH ORRVH FHOOXORVH ÀDNHV ZKLFK FDQ EH VSUD\HG blown or manually dispersed in sealed constructions like walls, ÀRRUVDQGFHLOLQJVLQVXODWLQJZDUPWK For air insulation, cardboard is principally well suited. A project by Paul Rohlfs21 came up with positive results. Honeycomb cardboard as well as corrugated cardboard have insulating properties, based on the idea of still air between layers of paper. Concerning the reduction of heat transport through radiation, experience was gained from a project in The Hague. Cardboard here is one of the elements of a partition system. Using wooden posts and cross beams and adding misprints of orange-juice cartons (a laminate of plastic, paper and aluminium foil) as a WRSOD\HUZKLFKUHÀHFWVKHDWZDVFUHDWHG Cellulose isolation panels insulate just as well as other insulation materials. This might point out the ability of cardboard to insulate. Further research will have to determine what the insulation values of the different types of cardboard might be. For now we can only conclude that cardboard is similar to wood and will not form a heat leak. In a building heat can be stored temporarily. In principal a lightweight construction will heat up quickly and lose

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its warmth just as fast, whereas a building with a heavy construction will temporarily store the warmth (accumulation). Wooden constructions are an example of a lightweight construction and stone-like materials are often used for ZDUPWKDFFXPXODWLQJµKHDY\FRQVWUXFWLRQV¶ A cellulose insulation panel (Homatherm3,4) has a higher warmth accumulating value than comparable insulation panels. The question remains where in the spectrum of warmth accumulation, do the different types of cardboard, like honeycell, corrugated cardboard and solid cardboard are found.

3.4. Sound insulation Sound transfer exists in different ways as well: through air and contact sound. Important issues for the reduction of this transfer are respectively mass and separation of materials (mass-spring system) For partitions each area of application forms different demands. For housing these are rather high, IRURI¿FHEXLOGLQJVDORWORZHU A partition of honeycell plates covered with solid cardboard can be categorised as a panel system. This partition was designed as a non-load-bearing partition and stands out because of its light weight. The sounds insulation is low EXWVXI¿FLHQWIRUOLJKWEXLOGLQJXQLWV 7KHH[SHFWDWLRQLVWKDW through disconnection the values will increase. One of the advantages of cardboard is its light weight. This however counters the principle of sound insulations by mass and therefore asks for some attention. The effect of cardboard on sound insulation varies and because of that we will have to determine the value for each kind of cardboard. Weather cardboard partitions will become a successful building product ZLOOGHSHQGODUJHO\RQLWVVRXQGDQG¿UHLQVXODWLQJSURSHUWLHV Besides air and contact sound there is sound absorption. This form of sound reduction is important with regard to the acoustic properties of a room. Cardboard has a few DSSOLFDWLRQV LQ WKLV DUHD 7KHUH LV D FHOOXORVH VSUD\ ¿QLVK on the market (Sprayplan+)3 which reduces the amount of resonance in rooms. This can be used without seams on almost every kind of straight or curved surface. As well as the honeycell partition in the pavilion of the faculty

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RI$UFKLWHFWXUH-DQ DVLQWKHRI¿FHLQWHULRURI$G.LO DQG .R 5RVWHU LQ (LQGKRYHQ9, the stacking of honeycomb cardboard has proven to have a reasonable damping effect on the amount of sound in the area. In an open area where many people have simultaneous conversations, this is a valuable aspect.

3.5. Fire resistance 7KH¿UHUHVLVWDQFHRIPDWHULDOVLVLPSRUWDQWIRUEXLOGLQJV7KH main factor is time. To be more precise, the amount of time OHIWWRÀHHWKHEXLOGLQJZKHQD¿UHVWDUWV$IHZDVSHFWVDUHRI LPSRUWDQFHKHUHYDU\LQJIURPWKHGHJUHHRI¿UHUHVLVWDQFHRI a material to possible exit routes )LUHUHVLVWDQFHDW¿UVWVHHPVWREHDQXQDFKLHYDEOHDVSHFW of paper and cardboard. Paper is an excellent fuel. But some FDVHVKDYHVKRZQWKH¿UHUHVLVWDQFHRIFDUGERDUGWREHEHWWHU WKDQ ¿UVW DVVXPHG $ OD\HU RI VROLG FDUGERDUG UHDFWV LQ D VLPLODUZD\WR¿UHDVZRRGPLJKW7KHPDWHULDOIRUPVDOD\HU of coal and thereby protects itself. Moreover, cardboard contains a certain amount of chalk-like material as a result from the ink traces left in the recycling SURFHVV&KDONLVDQH[FHOOHQW¿UHUHWDUGDQW7HVWVKDYHVKRZQ that a simple piece of solid cardboard already meets NEN standards22. Besides that, cardboard can be made with extra protection. A wide variety of products are on the market, all of them based on (boric) salts. Adding these materials does not affect the ability to recycle the material. The disadvantage is that the gasses which escape when the material burns, are toxic. Fire retardants have the tendency to increase the development RIVPRNHGXULQJD¿UH7KLVLVDQLPSRUWDQWDVSHFWLQUHODWLRQWR safety. The industry / suppliers have a lot of information about ¿UHUHVLVWDQWFDUGERDUGEXWDFOHDURYHUYLHZLVPLVVLQJ

3.6. Burglar protection Burglars seek the weakest place to enter the building. Cardboard sounds like something you can simply walk through, or at most requires a Stanley knife. Is this true or is cardboard being underrated when looking at the scale of a EXLOGLQJ"$FKDLQVDZZLOOSUREDEO\JUDQW\RXDFFHVVWKURXJKD cardboard panel, but this is no different from a wooden house.

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A possible solution might be found in using (some light form of) reinforcement inside the cardboard walls.

3.7. Moving and transparent parts When we think of a cardboard house, we eventually come to moving parts and transparent parts. Doors and windows, traditionally placed in a wooden frame, with steel hinges in a window frame. Also other materials like steel and plastics can be considered as framework. Recent developments in technology have been able to create glass walls without a frame. Transparency and glass are inextricably bound up with each other. The transparency and sun protection properties of JODVVDUHEHLQJLQÀXHQFHGE\WKHXVHRIPLONJODVVIRUPLQJVXQ protection, or by adding another material inside the cavity of GRXEOHJODVVSDQHOVLQÀXHQFLQJWKHWUDQVSDUHQF\RIWKHJODVV

Fig. 9-11. Cardboard Pavilion at the Faculty of Architecture, Delft

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Doors nowadays are usually made from a solid wooden frame with a plate covering (hardboard, mdf or chipboard) and a ¿OOLQJRIURFNZRRORUKRQH\FHOOFDUGERDUG The Austrian company Gap-solar23¿OOVWKHFDYLW\LQGRXEOH glass panels with the core of honeycell cardboard. The warmth resistance of the glass thereby increases and an interesting effect occurs with the transparency of the panel. :KHQPRYLQJDORQJVLGHWKHVHZLQGRZVWKHWUDQVSDUHQF\¿UVW increases than decreases, vice-versa. Japan has a rich building tradition, as said before. Well known in (historical) architecture are the semi transparent sliding doors (Shoji and Fusuma)6,8. The question is whether there is relevant knowledge to be found here for cardboard research

4. Designing a cardboard house The mechanics and physics in relation to the structure and construction play an essential role in the building industry. But WKHUHLVPRUHWRLW$EXLOGLQJ¿QGVLWVHOIDOVRLQDFKDQJLQJ cultural social context, with for example, ecological demands. Clearly, space, composition and aesthetics are essential in architecture. Materials are not only chosen for technically meeting technological demands. Other factors, like the atmosphere a material creates, play an important role. Some architects let themselves get inspired by materials, with its VSHFL¿FFKDUDFWHULVWLFSURSHUWLHV

4.1. Architectural inspiration Many of the realised projects in the last decade show that cardboard might have been used in spite of, instead of because of these properties. When architects are inspired by a material, they experiment and play with it. The advantages of a material are being used, the disadvantages dealt with as well as possible. The texture of KRQH\ FHOO FDUGERDUG LV EHLQJ XVHG LQ WKH RI¿FH LQWHULRU LQ Eindhoven9, the unexpected strength of a cardboard tube is being used for constructive purposes5,14 and the ability to fold solid cardboard led to the design of a smart cable duct24. ,WKDVSUREDEO\DOZD\VEHHQWKLVZD\ORRNLQJDW0DUF/DPSH¶V FRQFOXVLRQLQ³7KHJUHDWHVWSRZHULVWKHSRZHURIDWWUDFWLRQ´

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“Structure was and still is, that much may be assumed proven E\WKLVSXEOLFDWLRQIRUDUFKLWHFWV¿UVWO\DVRXUFHRISRVVLELOLWLHV a way of escaping from everyday reality, and only secondly a given which has to be solved while working out demands such DVVWUHQJWKVWLIIQHVVVWDELOLW\DQGGXUDELOLW\´25.

4.2. Characteristics Cardboard has advantages with regard to traditional building materials: 1. Low weight, lightweight materials have advantages in many aspects of the building industry (transport, reducing the need for human or mechanical energy) 2. Foldable/printable, in the world of packaging folding and printing is essential when applying cardboard. Considering as a building element, these advantages are less obvious 3. Recycling, the ecological advantage is large. The UDZPDWHULDOLVLQ¿QLWHFHOOXORVH¿EUH DQGWKHF\FOH RIROGSDSHUKDVDQHI¿FLHQF\RI+RZHYHUWKH energy intensive recycling process does increase its impact on the environment 4. Mass production, the bulk production has all the (dis-)advantages of the production process. The OLTXLGDQGµUROOLQJ¶SKDVHSXOSDQGUROOSUHVVLQJ  give us excellent opportunities to guide the properties of the material. 5. Low price, the raw material is very cheap. This means that we have a margin, by working the SURGXFWWRDFKLHYHDFRVWHI¿FLHQWSURGXFWRU building part. Cardboard is a material with many appearances (tubes, FRUUXJDWHGKRQH\FHOODQG'µVKDSHG¶FDUGERDUG DQGZLWK different material properties. It inspires artists, furniture designers and architects into making designs which are (most RIWKHWLPH EDVHGRQWKHVSHFL¿FFKDUDFWHULVWLFVRISDSHU foldability, printability, or the ability to shape (papier-mâché) and texture. The cardboard which is currently being produced can be used directly without any problems for interior applications. Applications in the building industry require a much higher complexity. Therefore, direct application with the current types of cardboard are being blocked by its limitations.

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4.3. Contemplating A house is a complex form with the addition of many architectural, technical, functional and social demands, wherein these different demands can lead to opposing solutions. In order to meet (a part of) these different aspects, PDQ\GLIIHUHQWPDWHULDOVDUHEHLQJDSSOLHGZLWKWKHLUVSHFL¿F characteristics. The connection of materials and building parts heighten the complexity. A cardboard house is just as logical as a concrete house or a glass house. They are all extremes, only useful in contemplating the material. Once they are built, at most they deliver a ephemeral statement. Thinking about a cardboard house, we can set a direction, or many, and we can draw conclusions where to apply cardboard in a house. And questions can be formulated, addressing the paper- and cardboard industry and researchers in the area of material, product development, social context, etc.

4.4. Building cardboard The mechanical data, required to use this material in constructions, are hardly known, especially considering longterm behaviour. The lack of material found for calculating rules/ values, forces us into a project based approach. Therefore acquiring knowledge is fragmentised and discontinuous. Connecting a database to fundamental research could slowly ¿OOLQWKHNQRZOHGJHJDS)RUQRZKRZHYHUEHFDXVHRIWKLV JDSFDUGERDUGORDGEHDULQJEXLOGLQJSDUWVÀRRUVURRIVDQG walls) seem to have a limited future.

Fig. 12. Paper waste ready for recycling

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A HOUSE OF CARDBOARD

Also the physical properties are largely unknown. Regarding sound and warmth the different kinds of cardboard seem to behave neutrally, with one or two exceptions like cellulose board, which has excellent warmth-isolating properties and honeycomb plates and work well as sound-deadening devices. We all know the moisture sensitivity of cardboard and it can therefore often only be used with a protective layer. 5HVHDUFKLQWRWKHPDWHULDOSURSHUWLHVLVQHFHVVDU\WR¿QGWKH connection with the building industry. Not only do we need to research the characteristics, but we also need to establish classes and properties within a set spectrum, in order to set QRUPVDQGEHJLQFHUWL¿FDWLRQ7KHH[LVWLQJSDSHUDQGFDUGERDUG assortment has originated from a long tradition of developing packages. In the development and production of cardboard this market has been the basis. Improvements in the product and the production process are pointed at the functional demands of the package relative to its price. To apply cardboard in the building industry means we must improve it, and yet learn from the knowledge gained in the packaging industry. Precisely that is why it is so important to search globally for different NLQGVRISDSHUDQGFDUGERDUGZH¿QGWKDWFDUGERDUGWXEHV from Germany and Japan are better suited for constructive applications, because these tubes are made from cardboard ZLWKDKLJKSHUFHQWDJHRIYLUJLQ¿EUH 7KH UHVHDUFK EHLQJ VNHWFKHG KHUH ZLOO UHVXOW LQ µEXLOGLQJ FDUGERDUG¶ 7KLV LV D PDWHULDO VSHFL¿FDOO\ GHYHORSHG IRU WKH EXLOGLQJ LQGXVWU\ ZLWK LQGLVSXWDEOH WHFKQLFDO VSHFL¿FDWLRQV divided in classes. It will be specially produced as a material with specific constructive and/or partitioning properties. Moreover, the material has one or more unique qualities with which it stands out from traditional building materials. The data which is interesting for architects, data aimed at application, is known: price per square metre, obtainable and maximum measurements, possibilities in colour and structure, product JXDUDQWHHV  \HDU  FHUWL¿FDWHV GHVLJQ UXOHV DQG UXOHV of thumb. Next to this, we need a (basic) broad knowledge considering the material properties, so that during each building phase, application can be reasoned or proven. For example, we know up to which thickness we can fold cardboard, how well we can process it (among others impact sensitivity, wear and tear, and the way it works), what the isolating values are, how much moisture can be absorbed without damage and the way the materials holds itself when assembled (damage)

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4.5. Combinations For now, it seems evidently that paper and cardboard by themselves cannot satisfy the entire list of demands and wishes in the building industry. So we have to explore other possibilities as well. Material properties necessary for EXLOGLQJDSSOLFDWLRQVFDQEHLPSURYHGE\¿QGLQJFRPELQDWLRQV with other materials or by developing products with new characteristics. Cardboard could for example be reinforced with steel. A paper phone26 might be the predecessor of a ZDOO¿QLVK ZLWKLQWHJUDWHGHOHFWULFDOFLUFXLWV&RPELQDWLRQV with textile or rubber might also produce surprising results. An important shortcoming of cardboard is its behaviour when confronted with moisture. Precisely in this area a combination with another material might provide an appropriate solution. An important reason to use cardboard could be the ecology, as said before. Most plastic products are made of oil. When we can use paper and cardboard (in combination with other materials) in stead of these plastic products, probably we can make biodegradable and recycleble products. In practice, there is a very well known cardboard composite: (WHUQLW7KH¿EUHFHPHQWSODWH(WHUQLWLVEHLQJSURGXFHGLQ D VLPLODU ZD\ DV SDSHU EXW LQVWHDG RI WKH µQRUPDO¶ ZDWHU EDVHG FRQQHFWLRQ WKH FHOOXORVH ¿EUHV DUH EHLQJ ERXQG through cement. The end-product is a moist retardant and strong product, but it is not foldable or lightweight. Also the reuse/recycling properties of cardboard have been lost in the composite. The properties of cardboard have therefore become inferior to the properties of the end-product. Can we VWLOOUHJDUGLWDVFDUGERDUG" Two other products based on paper are cardboard in a vacuum PET cover (Armacel)20 and honeycomb cardboard inserted in laminated glass (Gap-Solar)23. In these products cardboard is recognizable as cardboard.Research and developments of cardboard combinations must be catalogued clearly, so that ZHDYRLGGHYHORSLQJDQH[LVWLQJSURGXFW$¿UVWGULYHLQWKH GLUHFWLRQ RI D FOHDU GH¿QLWLRQ RI FDUGERDUG LQ FRPELQDWLRQV (composites):  FDUGERDUGLVDPDWHULDOEDVHGRQFHOOXORVH¿EUHV brought about through the addition of water during the production phase. This secures the cycle of paper and is to be the basis for new developments.

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2. next to recycling, the presence of one or more of the afore mentioned characteristics in the new product is essential: lightweight, foldable and printable, machine produced and low price.

4.6. Context Not just technical properties play a role in the development of new applications for cardboard, also the social and cultural context is of importance. Two examples will illustrate this. Cardboard seems to be a suitable material for application in temporary housing, because of its relatively short technical lifespan27,28 and its advantages (lightweight, cheap, foldable and thereby easy to transport). The last few decades we have seen several initiatives. Shigeru Ban is the best known architect, who has designed cardboard emergency housing on a large scale. Still, these projects seem to remain incidents. This can have different causes, technical as well as economical or political. The research into these aspects is of importance as well in order to progress with the GHYHORSPHQWRIFHOOXORVH¿EUHVLQWKHEXLOGLQJLQGXVWU\ Next to the suitability of the material, the application is also derived from cultural aspects and habits: the (building) tradition. Traditions come to existence because something proved to be useful or practical, thereby assuring a kind of guarantee. What worked in the past, will work in the future. In the building industry, the parties involved, like the architect and contractor, take a risk, in order to minimize this risk as PXFKDVSRVVLEOHSURGXFWVQRZDGD\VXQGHUJRFHUWL¿FDWLRQ so people know what they are using. A new product (for the building industry) will therefore have to prove itself with guarantee, before it will be accepted as an adequate material.

References  .ORPSHQ3RVWOHYHQVGXXUJHEUXLNVGXXU;;HHQJHERXZ als prototype van een nieuw milieuconcept, Stuurgroep Experimenten Volkshuisvesting, Rotterdam, 1999, ISBN 90 5239 153 X  &KULVWRSK0DULD5DYHVORRW,QGXVWULHHOÀH[LEHOHQGHPRQWDEHO vloerverwarmen, Gezond Bouwen & wonen, 2001-2 3

http://www.warmteplan.nl

4

Christoph Maria Ravesloot, Elastische isolatieplaat van gebruikt papier, Gezond Bouwen & wonen, 2001-2

5

Mathilda Mc Quaid, Shigeru Ban, Phaidon, 2003, ISBN 0-7148-

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4194-3 6

Therese Weber, die Sprache des Papiers, eine 2000-jahrige Geschichte, Verlag Haupt, ISBN 3-258-06793-7

 .DVKLZDJL+LURVKL/LYLQJZLWKSDSHUKWWSZHEMDSDQRUJ nipponia  7RPGH9ULHV.DUWRQSDSLHU%DQZDVKLHU$UFKLWHFWXXU  Detail, december 2000 9

BN/DeStem van 9 juli 2005, gepubliceerd op www.besin.nl

10 Schönwälder J., Rots J.G., Veer F.A., Determination and Modelling of Cardboard as a Building Material, Proceedings, 5th International PhD Symposium in Civil Engineering, Delft, The Netherlands, 2004. 11 Buro Happold en Cotrell & Vermeulen, Constructing a prototype cardboard building, op http://www.cardboardschool.co.uk/ 12 Andrew Cripps, Cardboard as a construction material: a case study, Building Research & Information (may-june 2004)  7DFRYDQ,HUVHO.DUWRQRPEHWRQLQ5XPRHUDSULO jaargang 10, Periodiek voor de bouwtechnoloog, uitgave van Bout, praktijkvereniging Bouwtechnologie faculteit Bouwkunde, TU Delft, ISSN 1567-7699 14 Taco van Iersel, Feesten in kartondoos, detail in architectuur, maart 2003 15 Taco van Iersel, design drawings graduation project 16 Prof.dr.ir.Mick Eekhout, Het ontwikkelen van de kartonnen IJburgkoepel, in: kartonnage, Rumoer 30, sept 2003, jaargang 9, Periodiek voor de bouwtechnoloog, uitgave van Bout, praktijkvereniging Bouwtechnologie faculteit Bouwkunde, TU Delft. ISSN 1567-7699 17 Jop van Buchem, graduation report 18 http://www.houses of the future.com.au 19 http://www.rsdevelpoments.nl 20 Adriano Pupilli, The paperhouse report, http:// www.thepaperhouse.net 21 Taco van Iersel, report interview Paul Rohlfs 22 Testresultaat Multished TNO 17 okt. 2002 23 www.gap-solar.at 24 Henk Wind, Leidinggoot eerste bouwproduct van karton, Bouwwereld nr.9, 10 mei 2004 25 Marc Lampe, De grootste kracht is aantrekkingskracht, publicatieburo Bouwkunde, Faculteit der Bouwkunde, Technische Universiteit Delft, 1992.  YDQ,HUVHO7.DUWRQOLFKWJHZLFKWLQGHERXZZHUHOGGHWDLOLQ architectuur, maart 2003, 27 Life Cycle Coordination of materials and their functions at connections, Design for total service life of buildings and its materials, E. Durmisevic and T.M.van Iersel, Conference Deconstruction and Material Reuse, USA 2004 28 Innovative Construction and design in Cardboard, T.M.van Iersel, 2003

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Structural Engineering and Design in Paper and Cardboard - Approaches and Projects Helen Gribbon, Florian Foerster

Abstract The following paper outlines approaches to the use of cardboard in structural design and construction and illustrates its successful use on a number of example projects. The paper summarises and illustrates the experience gained in cardboard design by the multi disciplinary engineering company Buro Happold Ltd. Cardboard and paper products have been used for decades in the ¿HOGVRILQWHULRUDQGSURGXFWGHVLJQDQGWKHSDFNDJLQJLQGXVWU\ But cardboard has not been used widely in architectural design, building technology and structural engineering and construction, GHVSLWHLWVSRWHQWLDODGYDQWDJHVRIÀH[LELOLW\ORZPDWHULDOFRVW ready availability and good environmental credentials. So far only a few cardboard structures have been built, each GHVLJQHG DV D RQHRII E\ GHVLJQHUV VSHFL¿FDOO\ LQWHUHVWHG LQ cardboard as a structural and building material. As the structural design with cardboard and paper products is not \HWFRGL¿HGDQGRQO\OLPLWHGPDWHULDOGDWDLVDYDLODEOHWKHGHVLJQHU UHOLHVQRWRQO\RQHPSLULFDONQRZOHGJHSURMHFWVSHFL¿FWHVWVDQG WKHXQGHUVWDQGLQJRI¿UVWSULQFLSOHVRIHQJLQHHULQJEXWDOVRRQ a willingness and curiosity to take extra design responsibilities. As a result, cardboard allows the designer to pursue structures not primarily based on precedent and go beyond conventional structural ideas. The designer can thus gain new knowledge from the individual one off structures which might feed back into standard construction practice and lead to a wider acceptance of cardboard as a valid and economic structural material. In addition cardboard responds well to current issues of sustainability: it is primarily manufactured from waste paper products and can easily be repeatedly recycled; it has excellent acoustic and thermal properties; and it is very easy safe to work with on site.

95

1. Cardboard product range No cardboard products specifically manufactured and designed for the construction industry are currently available. Structural projects using cardboard products generally use standard cardboard or paper products from the packaging LQGXVWU\KHQFHLWLVXVHIXOWREULHÀ\VXPPDULVHWKHVWUXFWXUDO and construction qualities of these products.

1.1. Tubes Tubes are manufactured by rolling multiple layers of spirally wound paper plies over a spindle. The layers are glued together by starch or PVA. The tube wall thickness depends on the number of plies but can range up to 16mm. Tube diameters up to 600mm are commonly available. The inner and outer layer of the tube walls can be made from different paper than the interior build up, to give a treated, coloured or stronger paper on the surface. The tube length is not limited by the manufacture process, but by transportation. The winding of the paper plies effectively means that the ORQJLWXGLQDO ¿EUHV RI WKH WXEH DUH QRW FRQWLQXRXV 7KLV reduces the structural capacity of tube members in bending and increases the risk of delamination.

1.2. Panels Cardboard panels are manufactured by laminating sheets of paper or cardboard onto an interior honeycomb structure. The honeycomb boards are made by sandwiching a honeycomb structure between sheets of paper. The honeycomb structure itself is manufactured by gluing multiple sheets of paper together and pulling them apart or by gluing two halves of moulded honeycomb panels together, made by pressing paper pulp into a honeycomb mould. Panels are generally between 1.2m and 1.5m wide and 2.4m to 3.6m long. The size of the sheets is determined by the size of the lamination press used in the manufacturing process. The thickness and build up varies from single layer sheets of 1mm thick to 65mm thick sheets of honeycomb board. Sheets can be laminated or mechanically bonded together to achieve thicker sections. Sheets can be curved and easily cut into any shape, either by hand or by state of the art CNC cutting processes. It is possible to laminate different types of paper onto both sides of the sheets to achieve differing interior and exterior surfaces. It is also possible to laminate non paper

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STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

based sheets into the surface of the boards, ie metal or plastic foils to achieve an enhanced moisture resistance. In construction, honeycomb panels are the most commonly used structural cardboard products.

1.3. Sections A number of L and T shaped and rectangular hollow sections are available in cardboard. They are generally single layer elements with wall thicknesses up to 4mm. cardboard sections are manufactured as connection and stiffening elements for furniture products or packaging. While they are not commonly used in any of the example projects described it is possible to use them similarly to small size steel sections to build up larger sections or connect tubes or panels.

2. Structural form and elements Like all other structural materials, cardboard is best and most HI¿FLHQWO\ XVHG LQ IRUPV WKDW XVH LWV LQKHUHQW VWUHQJWK DQG characteristics. Due to the manufacturing process cardboard is an anisotropic material, hence the material strength varies greatly depending on the direction of the stresses. Cardboard LV PRVW HI¿FLHQWO\ XVHG WR WUDQVIHU RQO\ D[LDO DQG LQ SODQH stresses, which should be kept in mind when deciding the structural form and load path. And due to the critical importance of the connection detail it is generally simpler to transfer compressive forces than tensile ones. Hence the majority of the large scale projects using cardboard uses arches or shells as the primary form.

2.1. Columns Axial loaded columns can be designed using tubes or build up hollow sections. Load bearing columns are generally of a large diameter and the ratio between the tube wall thickness and the diameter is high, hence tubes tend to fail in local buckling. Overall buckling of the tubes is less likely due to the low slenderness ratio of the sections. The critical areas when designing column are the load transfer points. The loads should be spread over the entire tube circumference to avoid stress concentrations and local creep.

2.2. Beams Beams can be designed in using sheets of honeycomb cardboard or sections. Due to the low ultimate strength of cardboard elements the beam sections will appear deep and

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slender compared with all other structural materials. This high slenderness especially of the beam webs or sides increases the risk of local buckling. Hence it is important to stiffen the beams to achieve a resistance against lateral buckling. In addition the system and duration of load application onto WKHEHDPHOHPHQWVLVLPSRUWDQWDQGZLOOJUHDWO\LQÀXHQFHLWV ¿QDOVKDSHDQGGHWDLO7KHVXSSRUWFRQGLWLRQVRIEHDPVQHHG to be considered carefully to avoid stress concentrations and PLQLPLVHVKHDUGHÀHFWLRQDQGVKHDUFUHHS

2.3. Walls Flat panels or rows of tubes sandwiched between panels can be used for the design of walls. The walls can either be load bearing or self supporting stability elements. walls can either be designed entirely in cardboard or more commonly as cardboard elements mounted onto a primary timber frame. In both cases the stiffness of the wall and its performance under lateral loads are critical. The stiffness can be enhanced by utilising stiffeners, cross walls or the design of the wall as a folded plate. If the panels are mounted onto timber frames the cardboard becomes primarily a cladding material and the board a stability element.

3. Design parameters As a result of the projects described within this paper a number of tentative design parameters for cardboard have been HVWDEOLVKHG7KHVHSDUDPHWHUVDUHEDVHGRQSURMHFWVSHFL¿F tests and particular products and can be divided into material properties and connection parameters. However as there are no generally agreed structural requirements and standards for the use of cardboard in construction, it is essential that these parameters are reassessed and re-evaluated prior to each project. It should also be noted that the design parameters depend VWURQJO\RQWKHVSHFL¿FFDUGERDUGSURGXFWXVHGLQDSURMHFW as the quality and range of manufacturing processes varies greatly: the use of differing glues or source materials being two major variants. Hence two similar looking products will not necessarily exhibit the same structural properties. Based on data gathered during these projects the following design parameters can be used as a guidance during the

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scheme design. The following parameters are based on cardboard tubes: Tensile/Compressive strength Lomg term design tensile/ compressive strength taking account of creep effects E value (stiffness)

8.1 N/mm2

0.8-2.2 N/mm2

1000-1500 N/mm2

The following values might be used for the design with 20mm thick honeycomb sheets: Bending strength

6.9 N/mm2

Design tensile/compressive strength taking account of creep effects

0.6 N/mm2

E value (stiffness)

1000 N/mm2

4. Connection design The design and detailing of the connections is the Achilles heel of most cardboard structures. It is the area most GLI¿FXOW WR FRQWURO GXULQJ IDEULFDWLRQ DQG FRQVWUXFWLRQ DQG at the same time the point where by necessity stresses are concentrated and changed in direction. It is also often a point where cardboard is connected to different generally stiffer and stronger materials, ( mainly steel or timber ) and the interaction of these materials needs to be carefully investigated. Technically the connections can either be glued or bolted. A well bonded glued connection, using high strength glues is stronger than the surrounding cardboard. Hence the intersection between the standard cardboard and the connection element will be the weakest point in the design. Glues can either be PVA or epoxy based. Any glued connection should aim to transfer the loads either in direct compression or shear along the sides of the connected elements. Bolted connections behave differently and again form a critical point in the design. Failure occurs due to the different strength

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of the bolts and washers and the cardboard elements. This can lead to stress concentration and in the case of failure tearing of the cardboard. It is advisable to use large diameter or sleeved bolts or large diameter washers. If possible loads should be transferred in shear between the washers and the cardboard elements. The detailing of the connections should take into account the edge distance, number of bolts, bolt spacing and especially the direction of the load application. In addition it should be checked if the loads are static or dynamic. Dynamic loads on cardboard connections will soon lead to plastic deformation of the connection and hence potential weakening. The third type of connections can be achieved by folding or sleeving cardboard elements into each other, completely avoiding glue or bolts for the transfer of load. Very little experience for this type of connection has been gained on structural projects, but it is a technique commonly used for interior and furniture design. It would have the advantage to connect elements of similar low strength thus reduce the risk of stress concentration.

5. Analysis and structural model The choice of the structural models used for the analysis of the design depends on the complexity and function of the project. Cardboard can, in principle, be analysed in the same way as DQ\RWKHUVWUXFWXUHDVORQJDVVWUHVVHVDQGGHÀHFWLRQVVWD\ ORZ+RZHYHUWKHGLI¿FXOW\RIDQ\XVHIXODQGUHSUHVHQWDWLYH analysis is twofold. Firstly due to the lack of design parameters and material properties. The empirical data varies greatly depending on WKHSURGXFWXVHGDQGWRREWDLQLWIRUDVSHFL¿FSURMHFWRQH might have to test a full scale mock up of structural elements. hence the detailed analysis is carried out relatively late in the design process and mainly as a back up check of the initial assumptions and design concept. Secondly the design parameters vary greatly with time and the environmental conditions. Hence, any permanent cardboard project requires a far more wide reaching analysis than a temporary one and might rely on assumptions which can not be tested prior to the construction. This partially explains why the majority of the cardboard project carried out so far have

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STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

been for temporary building structures. Any analysis should concentrate on the detailing of the FRQQHFWLRQV DV WKHVH WHQG WR EH GLI¿FXOW WR UHSUHVHQW LQ D model and are the areas where failure is more than likely to RFFXU$QDO\VLVVKRXOGEHEDVHGRQVLPSOL¿HGPRGHOVWKDWFDQ EHFKHFNHGE\KDQGDQGFOHDUO\VKRZWKHIRUFHÀRZ$VDQ H[DPSOHWKHPRVWHI¿FLHQWZD\WRFKHFNWKHIRUFHVIRUWKH complex shapes and volumes of the Hiroshima peace prize project was a simple strut and tie model. 7KH DVVHVVPHQW RI ORQJWHUP GHÀHFWLRQ LV KLJKO\ FRPSOH[ as cardboard is an anisotropic material and the stiffness is governed by factors such as moisture content, magnitude of stress and duration of loading. It is hence advisable to “design RXW´WKHQHHGIRUORQJWHUPGHÀHFWLRQFKHFNV7KLVFDQEH achieved by the use of stiffeners and by avoiding the use of cardboard in bending. 7KHLQLWLDOGHÀHFWLRQLVVWURQJO\LQÀXHQFHGE\WKHPRLVWXUH content of the cardboard at the start of construction. &RPPRQO\FDUGERDUGGHOLYHUHGWRVLWHLVVWLOO³JUHHQ´DQGLW VWLOOVKULQNVVLJQL¿FDQWO\GXULQJWKH¿UVWPRQWKRIFRQVWUXFWLRQ and building usage, especially if the building is relatively dry and heated.

6. Empirical knowledge and test 6.1. Durability Durability issues are important factors in the design and specification of cardboard structures. The strength and VWLIIQHVV RI FDUGERDUG LV VWURQJO\ LQÀXHQFHG E\ WKH HDVH with which moisture can penetrate. Cardboard itself is a hygroscopic material. This means that it will absorb moisture IURPWKHDWPRVSKHUHZKLFKFDQVLJQL¿FDQWO\LPSDFWRQLWV strength. If it is allowed to become wet, cardboard deforms and ultimately degrades to pulp. If used outside water protection can be applied in a number of ways:

6.2. Chemical Treatment Water resistant cardboard is manufactured with additives in the paper pulp. While this achieves water resistance the use of additives means that the boards can not be as easily recycled.

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6.3. Surface Applications The faces of cardboard can be coated with polymeric paint or laminated with building paper or metallic foil. Painting cardboard surfaces tends to deform the sheets if not carried out on both sides. Therefore the cardboard should be painted off site and during manufacture.

6.4. Overcladding and Internal Use: The use of cardboard can be limited to areas where it has no direct contact with the external atmosphere. this can also be achieved by overcladding with water resistant material. In both cases though atmospheric moisture variations can be VLJQL¿FDQWDQGFDQQRWEHLJQRUHG

6.5. Fire It is a known fact that card and paper burn. They can be a key ¿UHORDGLQVRPHEXLOGLQJVLI¿UHPDQDJHPHQWLVQRWWKRURXJKO\ considered and applied. What has been established through ad-hoc tests carried out during the design and material development of the Locla Zone and Westborough School is:•

Thick card chars like timber: the end os a 12mm walled cardboard tube was exposed to a 1000oC ÀDPH7KHEHKDYLRXURIWKHWXEHZDVVLPLODUWRWKDW of timber in that the material charred, protecting LWVHOIIURPIXUWKHUGHWHULRUDWLRQE\WKHÀDPH

•

Untreated 5mm card nearly achieves a rating of &ODVV2VXUIDFHRIÀDPH

•

With treatment using a clear product typically used on timber this rating is achieved. Alternatively overcladding with a protective board is a solution.

6.6. Cost Cardboard as a raw material is relatively inexpensive. However, recycling can only be achieved by a manufacturing process that is highly repetitive and standardised, hence recycled cardboard is only economically available in a number of basic shapes. As long as standard elements are used cardboard presents an economic material, especially for complex structures. The additional cost of cardboard structures lies primarily in the H[WHQGHGGHVLJQWLPHFRVWVIRUVSHFL¿FPDWHULDOUHVHDUFKDQG testing and the use of specialist labour. As the use of cardboard in building develops and the knowledge base increases, the effects of these parameters may be reduced.

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STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

6.7. Recycling Cardboard is a recycled material that itself can be recycled. Consequently it is a material with very low embodied energy and almost no material take. The critical issue is not cardboard itself but other material used for connections, weather protection or additional structural elements. In addition there is a surplus of cardboard material in economic terms hence the transportation of a demolished cardboard structure to a recycling yard might be more expensive that the production of new cardboard from different source material. In developing early stage concepts, it is important to consider these life-cycle cost issues to ensure the loop is closed for the design, construct, use and deconstruct cycle.

7. Case Studies The next pages describe 7 projects in which Buro Happold was involved: 7.1. Westborough School 7.2. Japanese Pavilion, Hanover Expo 7.3. Exhibition Models for the Hiroshima Peace Prize 7.4. Trial and Error Exhibition, Building Centre Trust, London 7.5. Cardboard Arch, MOMA, New York 7.6. Nomad exhibition, New York 7.7. Local zone, Millennium dome

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location client architect contractor engineer cost

104

Westcliffe on Sea Westborough School Cottrell and Vermeulen CG Franklin Ltd Buro Happold n/a

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.1. Westborough School In a project partly funded by the Department of the Environment Transport and Regions (DETR) Buro Happold engineers headed a team to construct a building for Westborough Primary School, Westcliffe on Sea, Essex, which uses cardboard components wherever possible. The projects main objective was to produce a building which was 90% recyclable at the end of its life and which is almost entirely constructed from recycled materials. In addition we had the aspiration of producing a product which could be made available to the construction industry fo ruse in other buildings. The new building, intended for use as an after school club, is actually used by the school pre, post and during school hours. In order to realise the project, we teamed up with an architectural practice, Cottrell and Vermeulen, paper and board manufacturers; Paper Marc Ltd, Essex 7XEH :LQGLQJV /WG 4XLQWRQ DQG .DLQHV /WG and, at the time of construction, a building contractor, CG Franklin Ltd.

A prototype bay was erected to test the ease of manufacture and erection of the panels. The prototype erection proved important in the development of the scheme. In particular, panel junctions FRXOG EH UH¿QHG DQG VLPSOL¿HG DLGLQJ the manufacturing time and the ease of erection. This prototype construction provided us with a building which could be created from a number of panels simply screwed together on site along their edges.

At Westborough School we have used a combination of board, tubes and panels, all made from the same basic board material. The concept of the form of the building ZDV WR OLWHUDOO\ UHSUHVHQW WKH XVH RI ³SDSHU´ through the folded/origami aesthetic of the building, which, whilst proving challenging when detailing the panels and the junctions of the panels, did provide for a distinctive eyecatching form. With the input of manufacturers, the process of design and development for the building was informed by the products and processes currently available in the industry. The team were keen to ensure that the development of any product was realised through the use of current available materials and processes.

HELEN GRIBBON, FLORIAN FOERSTER

105

location client architect contractor engineer cost

106

Hanover Expo 2000 Shigeru Ban n/a Buro Happold n/a

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.2. Japanese Pavilion, Hanover Expo The Japanese Pavilion was built for the Hanover :RUOG¶V)DLULQDQGUHPDLQHGLQSODFHIRU seven month. The theme of the exhibition ³GHVLJQ IRU SODQHWDU\ FRQWLQXDQFH´ UHTXLUHG pavilions to be designed to demonstrate reduced use of resources and CO2 emissions. The architect Shigeru Ban, working with Buro Happold, designed a pavilion hall formed from cardboard tubes and clad in a paper membrane. 7KHEXLOGLQJZDVFRQFHLYHGDVDÀH[LEOHJULG shell structure that would be assembled and laid lat on the ground, and then lifted and formed into place by a protruding scaffolding V\VWHPWKDWZRXOGJLYHLWWKHD¿QDOJHRPHWU\ 7KLV¿QDOVKDSHZDV¿[DWHGE\DVWLIIERUGHU element at its perimeter edge. The overall dimension of the hall is 75m by 35m with a rise of up to 15.5m. The main tubes consisted of 120mm diameter, 22mm thick paper tubes. The tubes were formed of three glued spiral card tapes of an exact moisture content and structural strength. Their design was based on material properties established in tests by the University of Dortmund with a partial factor of safety approach similar to the European codes for timber structures. The tubes were lashed WRJHWKHUDWWKHLUFURVVLQJSRLQWVE\¿UHUHVLVWDQW plastic straps.

it is both low energy and easily reusable. The design and modelling of the of this structure was part of an intense design HIIRUWZKLFKLQFOXGHGIRUP¿QGLQJH[HUFLVH and the construction of physical models, in order to determine the project geometry as well as the possible buckling failure modes. Rigidity is aided by wood arches at regular intervals. Steel struts at the ends were incorporated into the grid at the insistence of the German checking authorities, although analysis indicated that these were not needed. Detailing the structure involved the resolution of some key connections. These are the cross points between the two tubes, the connection of the tubes to the ground plane and the connection of the tubes to the cladding as well as to the wood ladders. The connection solutions are similar to the ones designed for the MoMA Arch, described later in this article. The hall was stabilised laterally by rigid end walls and longitudinally by the shells tubular shape structural supported by metal cable cross bracing. The hall was totally recycled by the end of its seven month life.

The connections had to be rigid enough to transfer the design loads once the shell KDG UHDFKHG LWV ¿QDO JHRPHWU\ DW WKH VDPH time the connections needed to remain ÀH[LEOH WR DFFRPPRGDWH WKH FKDQJH LQ VKHOO geometry during the construction process. The foundations were constructed with sand retained by timber boards to avoid as far as possible the use of concrete. Sand was used as

HELEN GRIBBON, FLORIAN FOERSTER

107

location client architect contractor engineer cost

108

Hiroshima & Tokio Hiroshima Museum of Modern Art Studio Libeskind n/a Buro Happold n/a

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.3. Exhibition Models for the Hiroshima Peace Prize Architect Daniel Libeskind was awarded the Hiroshima peace prize in 2001. Following this, four large scale (1:5) building models of recent projects by studio Libeskind formed the centrepiece of an exhibition that started in the Hiroshima Museum of Contemporary Arts in July 2002and moved to the ICC Museum in Tokyo at the end o 2002. The models where approximately 30m in plan and up to 10m in height. The second exhibition in Tokyo was not part of the original design brief, but it was decided to design the exhibition as a travelling show, such that any interest arising from WKH ¿UVW VKRZ FRXOG EH UHVSRQGHG WR ZLWK remounting the exhibition. The design time was extremely tight, with one month for the entire design from the concept to the detailing stage and one month for manufacture and a week for on site construction. In addition the scale of the proposed models required a light construction material to avoid excessive loads onto the museum floors. Hence it was decided to design all models entirely using cardboard and paper fabricated into a modular box system of 20mm honeycomb cardboard sheets, glued and jointed together. The joint – a cardboard angle glued and screwed to the inside of the cardboard facing boards- carries the forces and the screws are for positioning only. The glued connection form a structurally rigid unit which could be transported into the exhibition areas and bolted to the adjacent units. The maximum size of the units was determined by the largest access door into the exhibition hall. Small access doors in one face of the allowed them to be bolted together and give access into the inside of the large models. The modules itself where all of different shape and size and hence there was an enourmous variety

HELEN GRIBBON, FLORIAN FOERSTER

of cardboard panels needed to form the modules. The fabrication of these panels was achieved by CNC cutting all panels from templates supplied by the architects. The models where analysed using by LPSRVLQJVLPSOL¿HGVWUXWDQGWLHV\VWHPV onto the units and hand calculations. This approach gave a clear understanding of D GH¿QHG ORDG SDWK ZLWKLQ WKH FRPSOH[ layering of units formed from plane panels. The models where analysed for strength and stability only. Creep and ORQJWHUPGHÀHFWLRQZKHUHQRWDQDO\VHG because of the temporary nature of the project, but creep issues where addressed by detailing each model as a highly redundant system. The project showed how cardboard could be used effectively to respond to a number specific site issues, ie access and manhandling restrictions, speed of construction and design, ease of maintenance and local repairs, demountability, minimum weight of the overall structure. In addition the project responded well to the Japanese tradition and knowledge of using paper products in construction. Hence the construction of the complex shapes was easily understood by the fabricators, once the design had been demonstrated with a full scale mock up module. This mock up module was constructed by the design team to test the connection detail and stiffening requirements.

109

location client architect contractor engineer cost

110

London Building Centre Trust Magma Architecture n/a Buro Happold £ 15.000

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.4. Trial and Error Exhibition, Building Centre Trust, London The exhibition investigated the use of working models in the design process. The models DUH KRXVHG LQ D VWUXFWXUH FRPSRVHG RI ¿YH layers of cardboard panels, stacked to form walls which loosely follow the outline of the exhibition space. the panels change height and fold in different directions to the ones above DQGEHORZWKH\DUHDOOÀDWEXWQRWJHQHUDOO\ vertical. The folded arrangement creates steps and shelves on which the designers models are positioned. The overall stability of the structure is achieved by the folding geometry of the walls and by overlapping the panels, so that, for example, folded portion of an upper panel is triangulated with the straight portion of the panel below it and vice versa. Using this stacking system the shelves can easily cantilever into the room or draw back into the space behind. The cardboard used was 30mm thick honeycomb panels, faced both sides with an aluminium foil WRJLYHUHVLVWDQFHDJDLQVWWKHVSUHDGRIÀDPHV WKH\KDYHDWKLQZKLWHSDSHU¿QLVK

The design and construction period for the entire exhibition consisted of only 7 weeks, and again cardboard was chosen to rapidly and easily respond to a complex geometric layout. All cardboard sheets were pre-cut and delivered to site and the entire exhibition constructed in two days. The use of cardboard also allowed HDV\PRGL¿FDWLRQVRQVLWHWRUHVSRQGWKH existing structure, which had, due to time and cost constraints, only been surveyed very basically during the design phase. The budget for the exhibition design and construction was just above £ 10.000 and due to the cheapness of cardboard base material, the majority of the budget could be spent on the labour, design and ¿QLVKHV

The panels support themselves and the exhibition models, some of which weigh up to 50 kg. the vertical load transfer is achieved by the cross over points, where one panel rests on the panel below. These points have been locally strengthened with small timber inserts into the honeycomb structure to spread the point loads onto the facing boards. The folds of the panel junctions are made with 50mm EUDVV KLQJHV VFUHZ ¿[HG WR ZRRGHQ EDWWHQV inserted into the panel edges. Hence each OD\HUEHKDYHGVWUXFXUDOO\XQWLOLWZDV¿[HGLQWR position, as a chain formed from panels. The joint is reinforced with white card angles which ZKHUHJOXH¿[HGRQVLWHJLYLQJULJLGLW\WRHDFK layer of panels.

HELEN GRIBBON, FLORIAN FOERSTER

111

location client architect architect of record contractor engineer cost

112

Courtyard Museum of Modern Art New York City Museum of Modern Art Shigeru Ban Dean Maltz Atlantic-Heydt Buro Happold $400.000

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.5. Cardboard Arch, MOMA, New York This temporary structure was erected as part of a retrospective of art and architecture of the 20th century at the Museum of Modern Art in New York City. It is made up by 200mm diameter cardboard tube sections with a wall WKLFNQHVVRIPP7KHWXEHVGH¿QHWKHWRS and bottom chord of 600mm deep paper tube arches. These arches span approx. 24m and are linked transversally by a paper tube gridshell of 150mm diameter tubes with a 25mm wall thickness. Cable stiffening ties are located under the arch and attached to the bottom chord. The overall size of the structure is 24 x 24 m and it was installed over the summer season for a period of 90 days.

vertical elements were inserted and the grid shell elements added. The diagonal truss cables were inserted into the truss and then the top chord was attached in order to complete the truss. Once assembled and painted with waterproof coating the structure was cut into eight half arch slices in order to be able to transport it to the museum. Adjacent to the museum site the pieces were partially connected together, lifted into place and then attached to the receiving support points.

The structural analysis of this structure was relatively straightforward. The gridshell behaviour was conservatively ignored in the arch span direction with the grid shell contributing only lateral support to the primary arches. Detailing the structure was complex because of the mixture of materials, which created different connection conditions. The top and bottom chords of the trusses are paper tubes but the vertical and diagonal members are steel rods and cables. The attachment of the trusses to the building and base are by means of steel connection plates, supporting the tube ends in direct bearing. Initial construction took place offsite where the roof was laid over a series o scaffolding HOHPHQWV PXFK WKH ZD\ RI D VKLS¶V KXOO LQ D shape forming cradle. The grid shell paper tubes the grid shell paper tubes were modelled three dimensionally in order to determine the precise location and angles of the pre drilled holes for the connections, which would follow the project geometry. After the tubes arrived on site, holes where drilled into them, then the bottom chord laid down on the scaffolding, the

HELEN GRIBBON, FLORIAN FOERSTER

113

location client architect contractor engineer cost

114

New York n/a Shigeru Ban n/a Buro Happold n/a

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.6. Nomad exhibition, New York This 4000m2 temporary exhibition hall is intended for a travelling venue that will highlight the work of a contemporary artist. The hall is approximately 20m wide by 200m long. It is constructed of materials typical used in temporary structures including fabric, scaffolding, cribbing and the containers used to ship them.

the museum departs for other countries (expected to include France, China and the Vatican State), the tubes will be recycled, DVLW¶VOHVVH[SHQVLYHWREX\QHZRQHVWKDQ LW LV WR VKLS WKHP ³,W¶V D WUDQVSRUWDEOH PXVHXPZKHUHZHGRQ¶WKDYHWRWUDQVSRUW WKHEXLOGLQJPDWHULDO´

The museum uses 148 shipping containers as external walls and two internal rows of columns, using coated paper tube, topped with roof trusses. It has a central roof support that is made up of two large diameter paper tube triangle that connects to the roof ridge. The structural loads on the paper tubes can be determined from a straightforward analysis. The difference to some of the previously described projects is that although the structure is temporary it is meant to be assembled and disassembled a multitude of times, with the added condition WKDW DOO SLHFHV PXVW EH DEOH WR ¿W ZLWKLQ D standard 6.1m container. For this reason the paper tube detailing has been designed in such a way as to minimise the wear and tear on the paper tubes. This has been achieved by SHUPDQHQWO\DI¿[LQJVWHHOSODWHVDQGHOHPHQWV to the paper tubes. In this way the connection points could be restricted to more durable connections which are steel on steel. 7KH FRQ¿JXUDWLRQ RI WKH VWUXFWXUH ZLOO DOVR change from time to time, as Ban adapts the GHVLJQ WR ¿W WKH VL]H DQG VKDSH RI GLIIHUHQW sites. As long as the museum remains in the US, the paper tubes will be shipped along with the rest of the building components. However, when

HELEN GRIBBON, FLORIAN FOERSTER

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location client architect contractor engineer cost

116

London Building Centre Trust Magma Architecture n/a Buro Happold £ 15.000

STRUCTURAL ENGINEERING AND DESIGN IN PAPER AND CARDBOARD

7.7. Local zone, Millennium dome This building was one of the exhibition buildings in the Millennium Dome. The architects Spence Associates Limited with Philip Gumuchdjian and Shigeru Ban as consultants developed the concept for the project. In addressing issues of sustainability and environmental concerns the building along with the exhibition are intended to highlight how the individual can make a difference to the world around them. Children nation-wide sent cardboard to be recycled and form part of the structure. The zone was a two-storey elliptical spiral of 100 vertical cardboard tubes (10.5m to 24m high) with smaller tubes for mullions and louvers. The primary column elements consisted of 500mm and 200mm diameter tubes, the former in the location of the braced IUDPHV7KHLQ¿OOSDQHOVEHWZHHQWKHPP diameter tubes are formed using a cardboard honeycomb sandwiched between two flat boards. 100mm diameter cardboard tubes positioned horizontally clad the building. All of the members are coated with an intumescent varnish providing a class 0 equivalent surface spread of flame. The 500mm diameter cardboard tubes have an internal and external membrane to prevent moisture ingress ad protecting the inner structural core. The membrane is an aluminium foil which is sandwiched between layers of paper and when wound around the tubes have lap joints to further minimise moisture ingress. At roof level a deep steel truss provided a diaphragm, transferring lateral loads to the braced columns. The "splayed wing" at the entrance to the building was tied back to the lift towers via the roof truss and ties.

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Application of Cardboard in Partitioning Taco van Iersel, Elise van Dooren

1. Introduction Cardboard in the building industry means the enlargement of the share of renewable raw materials in the building industry. Considering that this industry is one of the most polluting sectors, the use of ecologically sound materials is desirable. With the current technical knowledge, application of cardboard inside a building is technically achievable. Cardboard and paper are already being used as furniture and inside panel doors. Still, there is no broad application in the Dutch building market. Different causes can underlie the limited use of the FHOOXORVH¿EUHPDWHULDOFRPSOH[LW\RILQQRYDWLRQDQGPDUNHW VFHSWLFLVPZLWKUHJDUGWRWKHPDWHULDODQGRULJQRUDQFH" Using three case-studies of cardboard partitions based on existing forms of traditional partitions, surrounding factors and possibilities for the application of cardboard systems will be charted.

2. Surrounding The proper functioning of a partition system depends on the materials properties and how far the design meets the markets demands. The demands are a multitude of conditions asked from a building product: the surrounding factors. An analysis of these factors gives an insight in the conditions, traps and success factors, a partition must meet. 7KHWHFKQLFDOVSHFL¿FDWLRQVDUHLQÀXHQFHGE\WKUHHFDWHJRULHV RIVXUURXQGLQJIDFWRUV¿JXUHD  1. legislation and rules 2. user demands 3. economical factors (market)

119

semipermanent

architect

new development

use transport

hallmark

user

do it yourself

professional

housing commercial building

renovation

event

technical specifications

(de)montage

factories act

safety hallmark

project building retail

legislation & rules

building regulations

environment

market

national environment plan

health

safety

utility energy

2.1. Legislation and rules

Fig. 1. Chain of surrounding

The Dutch legislation and rules for the building industry have largely been set in the Building decree (Bouwbesluit). This has EHHQGLYLGHGLQ¿YHGLUHFWLRQVKHDOWKVDIHW\XVDELOLW\HQHUJ\ HI¿FLHQF\DQGHQYLURQPHQW

factors around the WHFKQLFDOVSHFL¿FDWLRQV of a product/system

:LWKLQ WKHVH GLUHFWLRQV IRU H[DPSOH WKH ¿UH DQG VPRNH development, insulation of warmth and sound are being directed. From these directions, technical specifications and achievement levels are being laid upon (new) building products and materials.

2.2. User demands The user demands come into existence in different stages of the actual use. Four user-stages can be determined: transport, assembly, use, and disassembly. Each stage states LWVVSHFL¿FGHPDQGVIURPWKHPDWHULDODQGWKH¿QDOSURGXFW

120

APPLICATION OF CARDBOARD IN PARTITIONING

(E.g. the ability to manoeuvre the product during transport, the placement and adjustment possibilities during assembly and the adaptability during the user stage).

3. Economical factors Each segment of the market (housing, utility building, amd project building) have their own user characteristics, size and tradition. Different existing building systems have taken their place in a segment of the market. Each of the three surrounding factors is the highest common IDFWRUIRXQGLQDORQJFKDLQRIXQGHUO\LQJIDFWRUVRILQÀXHQFH ¿JXUHE 7KHVHXQGHUO\LQJIDFWRUVDUHVRPHWLPHVFORVHO\ connected or intertwined with another large actor. For example, the labour legislation (use) is a direct input for new building legislation and rules.

4. Current building systems Drawing up the inventory of existing product supply results in many suppliers of partitions in the current market. Each system is characterized by it own price-quality level, technical possibilities and building manner. A division of products based on geometry reduces the multitude of products to three archetype partitions (table 1a). geometry

product/brand

1

hollow wall system

Metalstud

2

stacking systems

Xella, Gibo

3

panelsystems

Faay, Verwol

Table 1a. Division of partition systems by geometry

4.1. Hollow wall system Hollow wall systems consist of posts and cross-beams with plating. The posts are the load-carriers of the system. The WKLFNQHVV RI WKH ¿QLVKLQJ OD\HU LV DOVR GHWHUPLQHG E\ WKH demanded strength during transport and assembly. The system is hollow, allowing for the integration of ducts and PDNLQJ WKH DPRXQW RI VRXQG LQVXODWLRQ DQG ¿UH UHVLVWDQFH

TACO VAN IERSEL, ELISE VAN DOOREN

121

easily adaptable. Characteristic for the system is the multitude RIGLIIHUHQWSDUWVDQG¿QLVKLQJSRVVLELOLWLHV

4.2. Stacking system Stacking systems can be divided in structural and nonstructural end products. Light stacking blocks, like cellular concrete, are especially suitable as non-load bearing partitions. Sand-lime stone can be used for load bearing walls.

geometry

product/ brand

case study with cardboard

1

hollow wall system

Metalstud

Stucloper case study 1

2

stacking systems

Xella, Gibo

Tako-dozen case study 2

3

panel systems

Faay, Verwol

Bee-wand case study 3

Table 1b. Division of partition systems by geometry and brand with cardboard case-studies

Fig. 2. Assembly of the hollow wall system panel system

stacking system

hollow wall system

Fig. 3. Assembly of the stucco ÀRRU

122

APPLICATION OF CARDBOARD IN PARTITIONING

The solid character of the wall offers few possibilities for integration of electrical and mechanical installations. Milling is a good but laborious way of integrating ducts in the wall.

4.3. Panel system Panel systems can be characteristized by a high building speed DQGDPLQLPDODPRXQWRIEXLOGLQJDQG¿QLVKLQJDFWLRQVRQVLWH As many demands and wishes as possible are being integrated LQWKHV\VWHPDGDSWDELOLW\DQGÀH[LELOLW\PXWXDOFRQQHFWLRQ  emanation (top layer), integration (skirts for electric cables), etc. Starting January 2007, all partition systems faced an important weight limitation. For then legislation will come into force limiting the maximum weight to be lifted by man at 25 NJ(VSHFLDOO\SDQHOV\VWHPVFRXOG¿QGWKHPVHOYHVLQWURXEOH by this law. Untill now no partial or complete cardboard partition system has been available on the market. The use of cardboard in wall systems is considered an innovation on material level. The design will have to incorporate the properties of cardboard in a positive way, in order to distinguish itself from the existing assortment.

5. Cardboard in partition systems Research has been done into 3 partition systems, based on the earlier mentioned geometry. Each system uses cardboard DQG XWLOL]HV WKH VSHFL¿F WHFKQLFDO FKDUDFWHULVWLFV LQ LWV RZQ way. Three case-studies can be distinguished.

5.1. Case-study 1 Type of wall Material - core - liner    Connections

hollow wall system whitewood laminate of PE, aluminium foil and paper OLTXLGSDFNDJLQJFDUGERDUGRUVWXFFRÀRRU glue and stitches

The system in case-study 1 makes use of traditional wooden posts and beams. The liners are made from cardboard. These are being stapled on the beams, creating a 20 mm air cavity. The purpose of the system is to realize an insulting partition with a stock cardboard product. The misprints from the liquid FDUWRQV LQGXVWU\ ZHUH FKRVHQ 7KLV µZDVWH¶ LV DOVR EHLQJ XVHGDVÀRRUSURWHFWLRQGXULQJEXLOGLQJVWXFFRÀRRU ,WLV

TACO VAN IERSEL, ELISE VAN DOOREN

123

a laminate of synthetic, paper and aluminium foil. The result of the construction of the wall and the choice of material has two effects; the stationary air inside the cavity insulates DQGWKHDOXPLQLXPOD\HULQVLGHWKHFDUGERDUGUHÀHFWVKHDW from radiation, contributing to the heat balance. Concerning UDGLDWLRQUHÀHFWLRQWKHFDUGERDUGODPLQDWHGRHVQRWUHDFK the level of eminent synthetic foils. To reach the same level many layers were applied. 5.1.1. Sub-conclusion 7KHORZFRVWSULFHRIFDUGERDUGZLWKLWVUHÀHFWLQJSURSHUWLHV shows that it technically might be a replacement for mineral wool. Cardboard can also compete with glass wool concerning cost-price per square metre. The work-intensive assembly of the many cardboard layers makes the system as a whole economically unviable to replace traditional systems (metal stud). Fig. 4. Curve of compression

5.2. Case study 2 Type of wall Type of cardboard Connections

strength according to

stacking wall FRUUXJDWHGFDUGERDUGFÀXWHPP timber glue or starch glue

0F.HH

The stacking system originates from a stackable box shape. However, there are a few essential differences between stacking boxes (hollow) and a stone stacking block (solid). The mechanical properties of the box wall follow a different pattern. Boxes in their current packaging application are stacked on top of each other, without a mutual connection. The mechanics of the box actually lead to this; the corners of the box are the strongest. The compression strength curve RIDER[LVVKRZQLQ¿JXUH7KHV\VWHPRIER[HVLQFDVH study 2 is built as a half bat brick system. The upper box is being carried by the lower box in the centre of the box, at

single box

124

connection in detail

Fig. 5. Assembly of stacking wall

completed wall

APPLICATION OF CARDBOARD IN PARTITIONING

the point with the lowest compression strength. The design of the box overcomes this problem. The boxes are provided ZLWKDIHZÀDSVZKLFKVWUHWFKRXWDQGVOLGHLQWRHDFKRWKHU and get glued at precisely this point. This way the boxes form a stabile wall construction. They in fact create vertical baulks, capable of carrying loads (Figure 5). Extra solidity is created by gluing one or more solid cardboard layers to the wall of stacked boxes. 5.2.1. Sub-conclusion The staking system of glued cardboard boxes shows a direct translation of masonry. However, technically the system is not capable of replacing solid blocks directly. The hollowness of the wall gives it a weight advantage, but the mechanical properties are not parallel to solid blocks. The building speed might be high, but the use of glue requires many handlings and long drying time. A critical remark is the fact that it mimics traditional masonry in detail. A stacking system without adding a third element (glue), would produce a smarter and faster building system.

5.3. Case-study 3 Type of wall Type of cardboard - liner - core Connections

panel system solid cardboard honeycell cardboard tongue and groove system with a strip of honeycell cardboard

This case-study concerns a panel laminated from different types of cardboard. The core consists of plates of honeycell cardboard with a liner of solid cardboard. In the hollow VSDFHVGXFWVFDQEHLQWHJUDWHG7KHSUR¿OHGHGJHVIROORZDQ H-shape. Connections are being made with a few strips of cardboard; dry assembly. The liners can be provided with a print. The main advantage of the use of honeycell cardboard is the light weight. Next to that, by recycling the panels after use the material cycle can be closed. 5.3.1. Sub-conclusion The panel system has a high building speed and remains under 25 kg through the use of honeycell cardboard. The dry assembly offers possibilities for reuse and recycling. When WKHF\FOHLVUHVWRUHGE\WDNLQJEDFNWKHSURGXFWD¿QDQFLDO advantage is created for the user in the demolition phase. This

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125

FRXOGSRVVLEO\EHUHÀHFWHGLQWKHSXUFKDVHSULFH Fig. 6. Assembly and options of panel system



GHWDLORISDQHO 

FRQQHFWLRQWRÀRRU



FRPSOHWHGZDOO

6. Sound Sound insulation takes place in the shape of absorption, UHÀHFWLRQDQGWKURXJKPDVV7KHODWWHULVWKHPRVWLPSRUWDQW but also the missing factor when using cardboard. Corrugated cardboard and honeycell cardboard are lightweight paper constructions. One possibility of overcoming the lack of mass is disconnection. In hollow partition systems this can easily be realised by assembling the posts disconnected. With panel V\VWHPVWKLVLVDPRUHGLI¿FXOWWDVNLWLVDRQHHOHPHQWSDQHO Adding mass is being restricted by government rules. A panel can weigh a maximum of 25 kg. For temporary buildings there are no demands on sound concerning partitions. For utility buildings there are some demands, but the perception of the customer is the standard IRUWKHOHYHORIDFKLHYHPHQW,QDQRI¿FHVXUURXQGLQJVRXQG of conversation should be insulated, no matter what kind of material the walls are constructed from. For the (professional) housing market demands on sound insulation are very strict. The demands can vary per different segment, making one single solution unnecessary or unwanted. It is, however, very easy for the user to determine whether the insulation is VXI¿FLHQWFDQ,KHDUWKHQHLJKERXUVRUQRW" As we write this, the sound aspects of cardboard are being researched broadly.

126

APPLICATION OF CARDBOARD IN PARTITIONING

7. Environment Each mentioned partition system has an environmental advantage because of the use of cardboard. Cardboard can XVH DQ LQ¿QLWH DPRXQW RI UDZ PDWHULDO FHOOXORVH ¿EUH )RU IUHVK ¿EUHV YLUJLQ ¿EUH  ZDVWH SURGXFWV IURP WKH ZRRG industry are being used: bark, branches and sawdust. In The Netherlands for the production of new paper 90% of recycled SDSHULVEHLQJXVHG,QIDFWFDUGERDUGIURPROGRUQHZ¿EUHV is always a re-used product. Table 2 shows the environmental load next to the traditional materials wood and sand-lime stone. The last two materials are known for their low environmental load. The use of renewable raw materials (cardboard) provides a substantial contribution in relieving the environment. When during the further development of cardboard partitions the re-usability of the cardboard is not being lessened by the use of additives or laminated materials, cardboard has a strong ecological position. Within the landscape of surrounding IDFWRUVWKLVIDFWRUZLOOKDYHWRSURYHLWVHOIRIGHFLVLYHLQÀXHQFH concerning the effect of cardboard on the world market.

8. Conclusion To appoint decisive factors in the landscape of surrounding factors which will guarantee a successful product is very hard WRGHWHUPLQH2QVRPHOHYHOVLWLVSRVVLEOHWRGH¿QHVXFFHVV factors and factors that act as a brake. $FWLQJDVDEUDNH¿UVWRIDOOLVWKHIDFWRURILQGXVWULDOSURGXFWLRQ The paper and cardboard industry consists of a long chain of different paper and cardboard producing companies. The basis of this industry is built on large volumes (quantity) The development of a cardboard suitable for the building industry µEXLOGLQJFDUGERDUG¶ ZLOOEHDKDUGWUDMHFWRU\$QDSSOLFDWLRQ with a large sale volume connects to the current nature of the industry. The introduction of a new building material is characterised by a project-basis and small-scale. Secondly, cardboard being well-known by the public acts as a brake. The image as a packaging material and the homeless in KLVFDUGERDUGER[LVGLI¿FXOWWREUHDN7KHJHQHUDOFRQYLFWLRQ RIFDUGERDUGLPPHGLDWHO\FROODSVLQJXQGHUZDWHUDQG¿UHZLOO often have to be proven wrong by many solutions.

TACO VAN IERSEL, ELISE VAN DOOREN

127

subject

material

weight

cardboard

weight

wood

weight

sand-lime stone

exhaustion

cardboard

exhaustion

wood

exhaustion

sand-lime stone

energy content

cardboard

energy content

wood

energy content

sand-lime stone

emissions

cardboard

emissions

wood

emissions

sand-lime stone

use of water

cardboard

use of water

wood

use of water

sand-lime stone

recycling

cardboard

recycling

wood

recycling

sand-lime stone

disassembly

cardboard

disassembly

wood

disassembly

sand-lime stone

waste

cardboard

waste

wood

waste

sand-lime stone

positive

ĺ

negative

Table 2. Positive and negative effect of the partition materials per m2 wall

128

APPLICATION OF CARDBOARD IN PARTITIONING

When a cardboard building system reaches the same level of existing systems, is there still no reason for the customer to choose cardboard. Case-studies have shown that cardboard systems have can distinguish themselves on a few aspects. Especially the ecological factor, the relative low price, the SULQWDELOLW\ DQG WKH OLJKW ZHLJKW DUH GH¿QLWH TXDOLWLHV DQG thereby success factors. As shown above, cardboard can provide a substantial contribution considering the environment. Moreover, paper and cardboard are a bulk material with a subsequent low cost-price. Thirdly, the production process of paper and cardboard has one unique possibility: the printing technique. A visual radiation can be given to cardboard. The existing pressing and printing techniques have reached a level as with no other material than cardboard and paper. Finally, already mentioned, all partition systems will have an important weight limitation starting January 2007. Cardboard will remain under the maximum lifting weight of 25 kg thanks to its relatively light weight.

Literature 1

Rapportage IFD Haalbaarheidsstudie, project nummer 04019, .HQQLVFHQWUXP3DSLHUHQ.DUWRQ$UQKHP

2

Compression Strenght Formula for Corrugated Boxes, 5&0F.HH-:*DQGHU-5:DFKXWD

3

Wijziging Beleidsregels arbeidsomstandighedenwetgeving, nr.02 48717. Convenant Sociale Zaken en Werkgelegenheid. M.Rutte, 5,-0.XLSHUV

4

Indicatieve LCA berekening kartonnen binnenwand, H. van Ewijk ,9$0 .HQQLVFHQWUXPSDSLHUHQ.DUWRQ$UQKHP

 6WXFORSHUDOVZDUPWHUHÀHFWLHIROLH,ULVGH.LHYLHW,Q6LWX Architecten, Den Haag. http://216.154.208.139:8080/recyclicity/ designers/index.jsp 6

Isover Benelux, www.isover.nl, januari 2006

 ((7.LHPUDSSRUW6HQWHU1RYHPSURMQU  (LQGUDSSRUWDJH%RXZHQPHW.DUWRQMXQL

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

Mechanical Behaviour of Cardboard in Construction Julia Schönwälder, Jan Rots

Abstract Recently the interest of architects grows in using cardboard for constructions. For the realization of any structure adequate knowledge of the mechanical properties of the building material is essential. For structural application the mechanical behaviour and the load bearing capacity have to be predictable as well. However, there is not enough information about the mechanical properties of cardboard in terms of a building material. Common numbers and codes are not established yet. In the presented PhD project the mechanical behaviour of cardboard and cardboard structures are investigated concerning structural application. Also DFRPSXWDWLRQDOPRGHOEDVHGRQWKH¿QLWHHOHPHQWPHWKRGZLOO be developed as a prediction tool. The project combines material testing, structural design and computational modelling. In this regard preliminary beams completely made of cardboard were designed and tested. In this paper the outline of the PhD thesis DQGWKH¿UVWRXWFRPHRIWKHSUHOLPLQDU\GHVLJQRIWKHEHDPVDUH presented.

1. Scope of the Research Project Paper and cardboard is indispensable for our daily use, but considering it as a construction material is not a common practice yet. Cardboard is cheap, based on renewable resources, environmentally friendly and recyclable. It is a remarkably strong material considering its light weight. Hence, cardboard has high potential for structural application in temporary constructions. Also from the architectonic point of view cardboard is a very appealing material. Cardboard is variable in form and structure and by bending, folding and gluing many types of structural components can be SURGXFHG+RZHYHULQRUGHUWREHQH¿WIURPWKHDGYDQWDJHV paper and cardboard have and to make this material a real building material, further research in several areas is required. Especially insight pertaining to the mechanical properties of paper and cardboard is essential to make constructions with cardboard possible. A considerable database of knowledge of paper properties is available from the paper industry, but rather concerning production processing, visual quality,

131

packaging and personal hygiene. Most of the mechanical properties required for structural usage are generally not determined for paper or board. Particular little research on long-term behaviour is documented, given that creep is a big issue for cardboard constructions. The topic of this PhD research project is the investigation of the mechanical and structural behaviour of cardboard. The aim is to enable the use of cardboard as a structural building material, that means for load barring components. The focus hereby is on the mechanical behaviour considering structural safety and long-term stability as well as on predictability of cardboard structures. In order to analyse the mechanical and structural behaviour, experiments have to be performed on material level (sheets of paper or board) and component level (e.g. beams, wall-element, tubes). Therefore a cardboard beam will be designed as a structural component. As SUHGLFWLRQWRRODFRPSXWDWLRQDOPRGHOEDVHGRQ¿QLWHHOHPHQW method will be developed for cardboard. Hence, this research combines experimental material testing, structural design and computational modelling.

2. Cardboard in Architecture: Design and Fundamental Research $WWKH78'HOIWUHVHDUFKRQµ&DUGERDUGLQ$UFKLWHFWXUH¶KDV been started in 2000. Since then several examples and case studies have been performed at the Department of Building Technology of the Faculty of Architecture.1,2,3 In 2005, it was decided to build for practical experience a cardboard pavilion in one-to-one scale. Some students got the assignment to come up with a design for the pavilion. Even though the students had interesting ideas, none of the designs was realizable in cardboard. For instance, one of the designs had DELJURRISHUIRUPHGLQDFDQWLOHYHUZLWKD¿[HGVXSSRUW$ cantilever, however, brings big bending stresses at the restrain and requires a very rigid construction material otherwise the deformations would be too large. Generally, cardboard is not very rigid. Hence, as long as there is not a stiffer board developed the stiffness and the deformability of the cardboard always has to be taken into account for the structural design. This example showed again that it is important to know about the construction material and that design and fundamental research have to cooperate. Mick Eekhout illustrates in his

132

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

Fig. 1. The relationship between research and design (by Eekhout4)

paper4 the relationship between research and design (Fig. 1), with the areas of fundamental research, technology development and application design and their relationships. All ¿HOGVDUHLQÀXHQFHGE\HDFKRWKHULQIXQGDPHQWDOO\GLUHFWLRQ (right to left) and application direction (left to right). That means that the fundamentals give indication for technology development and that gives further indication to the design. On the other hand the design also gives application indications to the technology development and the fundamental research. The presented research project deals with the fundamental research in terms of mechanical properties of cardboard. Cardboard is still a very new and unknown building material and many areas have to be explored. The fundamental research on mechanical behaviour is one of them. This research is essential for the possible application of cardboard in construction. It gives indications to the technical development and design of components and connections. The research on the mechanical properties also aims to prove and insure the safety of cardboard constructions. Hereby a computational model facilitates the predictability of the material behaviour. The research project is seen as a start-up project and will give insight in material behaviour of various cardboard structures and components and will provide a basis for further research WRZDUGV µ&DUGERDUG LQ $UFKLWHFWXUH¶ IRU ERWK DUFKLWHFWXUDO design and structural engineering.

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3. Approach The aim of the research project is to enable the use of cardboard as a building material by analysing its mechanical and structural behaviour and developing a prediction tool. In cardboard a structural element is always a composition of many layers of paper or board sheets performed by gluing, bending, folding and cutting. The sheet, the glue and the geometry determine the structural behaviour of the component. In order to understand and eventually predict the mechanical response of a cardboard component it is important to know about the mechanical behaviour of the single sheet of paper or board. For this purpose the material behaviour will be studied by elementary tests on solid board. Based on these results a material model can be developed using a ¿QLWHHOHPHQWSURJUDPVXFKDV',$1$7KHPDWHULDOPRGHO ZLOO EH YHUL¿HG E\ UHSURGXFLQJ WKH PHFKDQLFDO UHVSRQVH RI a structural element. In this case, a beam was chosen to be studied as structural component. Therefore a cardboard beam has to be designed and tested. Hence, this research combines three domains: •

experimental material testing

•

structural design

•

computational modelling

Material Testing

Structural Design

Mechanical Behaviour of Cardboard

Computational Modelling

Fig. 2. Domains of PhD research

3.1. Material testing The material behaviour of paper and board is well documented in the literature, but rather concerning production process, converting and packaging. Many of the mechanical properties required for structural application are usually not determined for paper or board. Hence experiments on single boards are necessary to get the required parameters. Tests are

134

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

performed on three different boards and deliver the inplane material properties such as E-modulus, elastic and plastic strain, Poisson ratio, shear modulus, failure stress and strain, post-peak behaviour, failure energy etc. Also the long-term behaviour of cardboard is studied. All tests are in meso-scale, that means the sheet properties are investigated ZLWKRXWWDNLQJLQWRDFFRXQWWKH¿EUHDQG¿EUHWR¿EUHERQG characteristics. The material testing also comprehends the investigation RI PXOWLOD\HUHG HOHPHQWV WR XQGHUVWDQG WKH LQÀXHQFH RI numbers of sheets and glue on the mechanical properties. Therefore tests on specimen of multiple layers bonded with different adhesives are performed. 3.2. Structural design In architecture, structural elements are columns, bars, beams, slabs or panels. The structural behaviour of these elements depends on their geometry and the type of loading. For this research project a beam was chosen as a structural element to study on. A beam is preferred as it is a well known component in structural engineering. Also all sorts of cardboard (i.e. solid board, honeycomb board, corrugated board or tubes) can be applied in the design of the beam, whereas columns or bars are mostly performed in tubes. Usually beams are made of steel, reinforced concrete or ZRRG )RU WKHVH PDWHULDOV FRPPRQ W\SHV RI EHDP SUR¿OHV H[LVW)RUFDUGERDUGWKHVHSUR¿OHV¿UVWKDYHWREHGHYHORSHG An appropriate cross-section has to be found which can be build in cardboard and meet the structural demands of a beam. However, it has to be mentioned that the design of the beam is not main issue of this research project. In the ¿UVW LQVWDQFH LW VKRXOG DQVZHU WKH SXUSRVH WR GHOLYHU DQ appropriate structural component that can be simulated by the computational model.

3.3. Computational modelling Computational modelling facilitates the structural design as it helps to simulate the structural response of a construction or single component. Therefore a suitable constitutive material model must be developed which describes the mechanical behaviour of cardboard. Cardboard is a quite complex material to model, as it is anisotropic, non-linear, viscoelastic and hygroscopic. The resulting material model will be based RQVKHHWSURSHUWLHVDQGQRWJRLQWRWKHPLFURVFDOHWKXV¿EUH JULIA SCHÖNWÄLDER, JAN ROTS

135

properties and bond characteristics are not considered in the model. Concerning structural behaviour of the components, DOVRJHRPHWULFQRQOLQHDULW\PXVWEHLQWHJUDWHGLQWKH¿QLWH element model. As most of the cardboard structures consist of paper or board layers, buckling and delamination is are the main failure criterion. The computational model can be YHUL¿HG LQ FRPSDULQJ WKH SUHGLFWHG UHVSRQVH DQG IDLOXUH mechanism with the actual response of the beams.

4. Mechanical Properties of Paper and Board 3DSHURUERDUGLVDGLVRUGHUHGQHWZRUNRIFHOOXORVH¿EUHV7KH SURSHUWLHVRIWKH¿EUHVDQGWKHERQGLQJEHWZHHQWKH¿EUHV determine the mechanical behaviour of the sheet. These FKDUDFWHULVWLFVDUHLQÀXHQFHGE\WKHFKRLFHRIWKHUDZPDWHULDO and the papermaking operations. The mechanical behaviour RISDSHUWKXVGHSHQGVRQYDULRXVIDFWRUVDQGLVLQÀXHQFHGE\ ERWKQHWZRUNDQG¿EUHVFDOH$OOSDSHUVDQGFDUGERDUGVGLIIHU from each other unless they consist of the same raw material and were produced in the same way. This makes paper and ERDUG GLI¿FXOW WR VWDQGDUGL]H LQ PHFKDQLFDO SRLQW RI YLHZ However, there are general tendencies and relations of the properties of paper and board, without taking into account ¿EUHRUERQGSDUDPHWHUV In general paper and cardboard is an inhomogeneous, anisotropic, non-linear, viscoelastic and hygroscopic material. The anisotropy is due to the manufacturing process. During WKHIRUPLQJDQGGU\LQJSURFHVVWKH¿EUHVDOLJQPRUHLQWKH production direction (the machine direction [MD]), than in the perpendicular direction (the cross-machine direction [CD]). This has the consequence that in MD the paper or board is stronger than in CD. The MD/CD-ratio, or the anisotropy, GHSHQGVRQWKH¿EUHSURSHUWLHVDQGSURGXFWLRQSURFHVVHVDQG has thus no constant value. Figure 3 shows typical stress-strain curves of paper in tension and compression for MD and CD. The four different curves indicate the anisotropy of paper. In MD the material is stronger than in CD. In CD the board is less stiff, the strength is lower and the deformation higher. Also a sheet of paper has higher tensile strength than compression strength. The curves show, except for tension in CD, a relatively brittle failure, WKDWPHDQVWKHUHLVQRVLJQL¿FDQWSODVWLFGHIRUPDWLRQEHIRUH breaking. In compression the nonlinear region is very short.

136

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

Furthermore in the paper industry the measured stress-strain curves end at the maximum load. There has been hardly any interest in measuring the post-peak and softening properties. Post-peak behaviour, however, is important for an adequate computational modelling as the model provides more precise results when the residual load carrying capacity is included.

Fig. 3. Typical stress-strain curves of a solid board for tension and compression in MD and CD

For the mechanical properties such as tensile and compressive VWUHQJWKıHODVWLFPRGXOXV(PD[LPXPVWUDLQİ3RLVVRQ UDWLRnjDQGVKHDUPRGXOXV*JHQHUDOSURSRUWLRQVH[LVWDQG are collected in Table 1. From the table it can be seen that most of the properties can be derived from one single tensile test, if no more experimental data is available. However, as the relations are still rather vague and depend on the single paper it is always advisable WRGRDFRPSOHWHWHVWVHULHVIRUPRUHVSHFL¿FLQIRUPDWLRQ Time and rate-dependent properties characterize cardboard as a viscoelastic material. Creep is an increase of strain at a FRQVWDQWVWUHVVOHYHOLQWLPH7KHFUHHSUDWHijFUGHSHQGVRQ the type of cardboard, stress level, relative humidity and other factors. Different papers exhibit different creep curves. Stressrelaxation is the decrease of stress at a constant strain level. Most of the stress decay is log linear with time. For both creep and relaxation no reference values are provided. 7KHFHOOXORVH¿EUHVPDNHFDUGERDUGK\JURVFRSLF7KDWPHDQV the moisture content of cardboard is related to the ambient

JULIA SCHÖNWÄLDER, JAN ROTS

137

relative humidity, RH, and temperature. The moisture content is highest in humid and cold conditions. When the moisture OHYHOLQSDSHULQFUHDVHVWKH¿EUHVVRIWHQDQGWKH¿EUHERQGV loosen. As a consequence the stress-strain behaviour of paper changes with moisture content. Increasing moisture contents reduce the elastic modulus and the failure stress. At Û&DQGD5+RIWKHPRLVWXUHFRQWHQWLQFDUGERDUGLV approximately 5%. At a relative humidity of 90% the moisture content is around 14% and the stiffness and strength properties decrease by 50%.

Table 1.

General relations of paper and board mechanical properties

In component level the responses can be different than in sheet level. The behaviour of the component is depending on the paper properties, the adhesive and the geometry. In general, however, for the design of a structural component in cardboard it is important to consider the anisotropy while placing the sheet, so that the MD veers towards the principle stress direction of the component. Also load concentrations VKRXOGEHDYRLGHGLQWKHVWUXFWXUDOFRPSRQHQWDVWKH¿EUH network of paper and board is very sensitive to point loads. 7KH YLVFRXV QDWXUH RI SDSHU DQG ERDUG KDYH DQ LQÀXHQFH on the long-term behaviour of the structure and should be considered in the construction and in the safety factor of the material. Also it is very important that the cardboard components are sufficiently impregnated and have no unsealed areas, to avoid that humidity can penetrate in the cardboard structures and decrease the mechanical behaviour. In Table 2 the mechanical properties of common building materials and cardboard are listed for com-parison. The list shows that cardboard is of course not comparable to steel or concrete, regarding the stiffness and the maximum strength, but that it has similarities to wood. Wood is also anisotropic material whereas wood is stronger in the grain direction but

138

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

has almost negligible properties in perpendicular direction. The comparison shows that cardboard is a reasonable building material in terms of mechanical properties. The table also includes the outcome of the own tests performed on a solid board with the grammage of 1050 g/ m2. The results are not further discussed in this paper but can be found in publications5,6,7. This board was also used for the construction of the preliminary cardboard beams in the following section.

5. Design and Testing of Cardboard Beams A beam is a structural element that carries load primarily in bending due to vertical forces. Internally, a beam experience compressive, tensile and shear stresses as a result of the loads applied to it. Under vertical loads, in the middle of the span the top of the beam is under compression while the bottom of the beam is under tension. Shear stresses become more crucial above the supports. In order to develop an elaborate beam as a structural element LQFDUGERDUG¿UVWSUHOLPLQDU\EHDPVKDYHEHHQEXLOWWRVWXG\ WKHPHFKDQLFDOUHVSRQVHRIHDFKSUR¿OH7KHUHVXOWVRIWKH

Table 2. Mechanical properties of common building materials

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139

preliminary beams give indications for the later design of the actual beam. Here the design and test results of four of the preliminary cardboard beams are be presented. All beams had a span of 2.75 m and were tested in a fourpoint bending test (Picture 1). The requirement for the design was to construct a beam only made of cardboard (solid board, honeycomb, etc) and glue. The aim was to use the qualities of WKHEDVLFPDWHULDOVDQGWR¿QGDSUHIHUDEOHGHVLJQIRUDEHDP with a good strength to weight relation.

5.1. Beam 1 For the construction of beam 1 only solid board was used. The VWUXFWXUHZDVDGRXEOH,SUR¿OHZKLFKZDV¿OOHGZLWKD]LJ]DJ slat to prevent buckling of the web. The solid board was glued WRJHWKHU ZLWK ZRRG JOXH 7KH FRQQHFWLRQ EHWZHHQ ÀDQJH and web was performed by toothing and glue. The overall dimension of the section was 25x30 cm. This beam could bear a maximum force of 6000 N. The top ÀDQJHVKRZHGODUJHORFDOGHIRUPDWLRQDWWKHORDGWUDQVPLVVLRQ SRLQWV 7KLV ZDV EHFDXVH WKH OD\HUV LQ WKH ÀDQJHV ZHUH

140

Fig. 4. Test setup for the four point bending test of the cardboard beams

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

not continuous all over the length of the beam. Hence the stiffening effect of glued layers was missing and the layers in WKHÀDQJHEHKDYHGOLNHVLQJOHVKHHWVFDXVLQJKLJKGHIRUPDWLRQ and local buckling. The load-deformation response (Fig. 4) of the beam was linear until the maximum load and showed a unsteady, but non-brittle post-peak behaviour.

5.2. Beam 2 This construction was also built of solid board. The main VWUXFWXUHZDVDGRXEOH,EHDPZHUHWKHÀDQJHVDQGWKHZHEV consisted of several sheets glued together with wood glue. 7KHWRSÀDQJHFRXQWHGOD\HUVRIERDUGDQGWKHERWWRP one 8 layers. The web was designed with 5 layers. The two webs were stiffened by a triangle construction to prevent HDUO\EXFNOLQJ7KHÀDQJHVDQGWKHZHEZHUHFRQQHFWHGE\ toothing without any additional glue. The overall dimension of this beam was 30x15 cm.

Fig. 5-8. Cross section, local buckling and total buckling of beam

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141

The maximum load of this beam was 10,000 N. The loaddeformation response was linear up to the maximum strength. 7KHIDLOXUHRFFXUUHGLQWKHWRSÀDQJHDQGZDVGXHWRSXUH FRPSUHVVLRQDVWKHWRSÀDQJHEXFNOHGLQWKHPLGGOHRIWKH beam length. With further loading also the web started to buckle in this zone. The load-deformation curve (Fig 5) also VKRZVFOHDUO\WKHVHWZRIDLOXUHV7KH¿UVWSHDNEHORQJVWRWKH EXFNOLQJRIWKHWRSÀDQJHDQGVKRZVDVLJQL¿FDQWGHFUHDVH of load capacity which increased again until the failure of the web (second peak). This beam showed very good results, and the design was clever and easy for manufacturing. Only the overall dimension could be reduced to make the load/ slenderness relation more effective.

5.3. Beam 3 The main material of this beam was honeycomb board. The beam had different cross-sections in side (Picture 11) and middle part (Picture 12). In the compression zone of the beam KRQH\FRPE ERDUGV ZHUH SODFHG YHUWLFDO LQ RUGHU WR EHQH¿W from the high compression strength of honeycomb structures. Around the honeycomb structure solid board was glued in a box shape. The bottom, the tensile zone, of the beam was strengthened by extra layers of solid board. This beam was designed to be smaller than the previous beam and had an overall dimension of 25x15 cm.

Fig. 9-13. Cross-section, top and side view and failure of beam 2.

142

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

The maximum load of the beam was nearly 400 kg. The load-deformation response (Fig 6) was linear until reaching the maximum strength and showed a non-brittle and almost ideal plastic post-peak behaviour. The beam showed buckling on both sides of the beam underneath the load transmission. Later examination of the beam showed that at these areas the solid board delaminated from the honeycomb structure, but also a crashing of the top horizontal placed honeycomb layer in the compression zone (Picture 16).

5.4. Beam 4 As all the previous beams failed in the compression zone, a beam was design with a tube in the upper part of the beam as a compressive reinforcement. The rest of the construction resembled beam 3 to have a clear comparison for the effect of compressive reinforcement.

Fig. 14-19. Cross-section (side PLGGOH¿HOG DQG failure of beam 3.

JULIA SCHÖNWÄLDER, JAN ROTS

The maximum load of this beam was 600 kg. As expected the beam could bear more compressive stress and started to crack in the tension zone. After reaching the maximum strength the crack mouth opened very fast and the beam immediately lost strength. The load deformation response of this beam was

143

hence very brittle (Fig 7). After the crack opening the tube in WKHWRSÀDQJHZDVH[SRVHGWREHQGLQJDQGFRQWULEXWHGWRWKH residual strength of the beam (Picture 19).

5.5. Conclusion of preliminary beams The results of the preliminary beams showed that the glued connections are the weak parts of the structure. Especially WKHFRQQHFWLRQEHWZHHQÀDQJHDQGZHERIWKHEHDPVWXUQHG RXW WR EH GLI¿FXOW $OO EHDPV VKRZHG ORFDO EXFNOLQJ GXH WR elementary slenderness. The structural design should take the buckling into account and minimize the free element length in the compression zones.

Fig. 20-22. Cross-section and failure of beam 4.

Beam 4, with compression reinforcement, was 50% stronger compared to the similar beam 3. Hence the compressive reinforcement improved the load barring capacity of the beam enormously. However, the reinforced beam showed brittle failure, which should be avoided in construction as it gives no warning in terms of cracks before failure. A good balance between strengthening the compression zone and non-brittle failure has to be found. 5HJDUGLQJWKHGHÀHFWLRQRIWKHEHDPVDOOEHDPVZHUHQRW very stiff and showed high deformations. These were due to local buckling and deformation, but also because the basic PDWHULDOGLGQRWKDYHDVLJQL¿FDQWVWLIIQHVVVHHWHVWUHVXOWV own test, Table 2). A stiffer beam can be obtained with a higher modulus of elasticity of the basic material and higher moment of inertia of the cross-section. Nevertheless the prototypes showed, that cardboard is strong

144

MECHANICAL BEHAVIOUR OF CARDBOARD IN CONSTRUCTION

enough to be used as a construction material and through smart design and maybe in combination with other materials it can be a preferable material to use.

6. Conclusion and Outlook This research project deals with the fundamental research of the material properties of cardboard. The mechanical and the structural behaviour of cardboard sheets and components are investigated and a computational model will be developed as prediction tool. This research is essential for the further GHYHORSPHQWRIµ&DUGERDUGLQ$UFKLWHFWXUH¶,WZLOOJLYHLQVLJKW in the material response and hence deliver indications for design and technology development. Concerning the progress of the project, the 3 solid boards are WHVWHG DW WKH PRPHQW :KHQ WKH WHVWLQJ LV ¿QDOL]HG WKUHH

Fig. 23. Load-deformation curve of beam 1.

Fig. 24. Load-deformation curve of beam 2.

Fig. 25. Load-deformation curve of beam 3.

Fig. 26. Load-deformation curve of beam 4.

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design of the actual beam will be build and tested in small scale of 1 meter and the best performing will be rebuilt in large scale. Based on the results of the elementary testing of the solid board the material model can be modulated and YHUL¿HG The outline of the project is presented to give interested people from the building or the paper industry an idea what the research is about and open possibilities to cooperate. As cardboard is still a new and undeveloped construction material, the research area is still very wide. It is obvious that the presented research project can not cover all essential DUHDV (VSHFLDOO\ WKH DUHDV IRU ZDWHU DQG ¿UHUHVLVWDQFH material improvement and development of connections have to be investigated to make cardboard constructions common. This research, thus, should be seen as a start-up project that give indications for the design in mechanical point of view, and PRWLYDWLRQIRUIXUWKHUIXQGDPHQWDOUHVHDUFKRQµ&DUGERDUGLQ $UFKLWHFWXUH¶

References 1

Verhoef, M. Paper Buildings – Onderzoek naar de mogelijkheden van karton als bouwmateriaal. Graduate project, Building Technology, Faculty of Architecture, TU Delft, The Netherlands, 2002

 9DQ,HUVHO7.DUWRQQHQ:RRQKXLV*UDGXDWHSURMHFW%XLOGLQJ Technology, Faculty of Architecture, TU Delft, The Netherlands, 2002. 3

Den Boon, M., Studie naar honingraat panelen van karton. Graduate project, Building Technology, Faculty of Architecture, TU Delft, The Netherlands, 2003.

4

Eekhout M., Cardboard: Technical Research and Developments DW78'HOIW"""

5

Schönwälder J., Rots J.G., Veer F.A., Determination and Modelling of Cardboard as a Building Material, Proceedings, 5th International PhD Symposium in Civil Engineering, Delft, The Netherlands, 2004.

6

Schönwälder J., Veer F.A., Rapid determination of creep properties of paperboard using staircase loading tests, Proceedings, Progress in Paper Physics Seminar, Trondheim, 2004.

 9HHU)$6FK|QZlOGHU-+HLGZHLOHU$.XLSHUV17KHFUHHS fatigue interaction in solid paper, Proceedings, 15th European Confernce of Fracture (ECF15), Stockholm, 2004.

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Cardboard in Architecture. M. Eekhout et al. (Eds.). IOS Press, 2008. © 2008 The authors and IOS Press. All rights reserved.

The Cardboard Dome as an Example of an Engineers Approach Mick Eekhout

Abstract Designing is an incredible experience. Looking for new solutions for posed problems challenges you to keep on improving yourself and others. It is a continuous course of action: you will always UHJDUGLVVXHVDQGVLWXDWLRQVZLWKµGHVLJQHUH\HV¶RIWHQUHVXOWLQJ in passion and enthusiasm. The most energy for the development of the cardboard dome was taken up by technical fundamental research. After 4 months from scratch, a trustworthy cardboard technology with circular tubes was established. This lead to a conventional engineered dome using the state of the art dome technology. Humidity is still one of the major problems of cardboard produced in the current industrial manner. The tubes were partially prestressed to avoid complicated bolted connections in this 3-way single layered dome structure.

1. Designing is composing and inventing Naturally, at Delft University of Technology technical ingenuity scores high. The previous Chairman of the Board dr. Nico de 9RRJG LQWHQGHG WR WUDQVIRUP WKH 78 'HOIW LQWR D µUHVHDUFK GULYHQ XQLYHUVLW\¶ +RZHYHU LQ WKH PHDQWLPH WKH 78 'HOIW DFNQRZOHGJHVGHVLJQDVDUHVSHFWDEOHDFWLYLW\7KHGH¿QLWLRQ of design as a result of designing at the TU Delft is: “The (technical) design is a record of principal and/or eventual working method and/or shape of a technical and realistic VROXWLRQIRUDGHVFULEHGSUREOHP´7KH)DFXOW\RI$UFKLWHFWXUHLV proud of its focus on design. A couple of dozen years ago, the Faculty of Architecture in Delft and the Faculty of Architecture in Eindhoven agreed that Delft would focus on the design process, whereas Eindhoven would focus on the realisation process. Well-known Dutch architects like Jo Coenen, Sjoerd Soeters, Rudy Uytenhaak and Frank Wintermans were all educated as architects in Eindhoven and therefore seem to be lost and an exception to this rule. :KDWVLJQL¿HVGHVLJQDWWKH)DFXOW\RI$UFKLWHFWXUHDQGPRUH

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VSHFL¿FLQWKH0DVWHUV%XLOGLQJ7HFKQRORJ\":KDWH[DFWO\LV GHVLJQ"$SUHFLVHDQGFRPSUHKHQVLYHGH¿QLWLRQLVQRZKHUH to be found. So let us considers design from different points of view: x Functional: The goal of design at the faculty of Architecture is a material solution by inventing an architectural composition for a posed architectural problem. x Composition: Design is composing parts into a larger whole (artefact). Architectural design is composing elements and components into a material artefact. Depending on the three levels this could be: city planning, a building or components of the building. x Artistic: Design is creating an original spatial composition. The material and immaterial means are usually familiar; the position of matter in space transforms a building into a piece of applied art. x Technical: Design is inventing and ingeniously developing new material elements, components, systems and products for city planning/architecture/ building technology and the integration of those parts into an artefact. x Process: Design is the process of analysis, synthesis and development starting with a problem statement and ending in a material solution. x Philosophical: Design is seeking an optimal compromise between ambiguous demands and desires. x Economical: Design is seeking a balance between demand, formulated in many wishes and requirements and supply of a possible technical H[HFXWLRQZLWKWKHUHTXLUHG¿QDQFLDOPHDQV

Fig. 1. The position of the designer is located between the composer and the inventor

Every designer will describe design in a different manner. , ZLOO WU\ LW IURP P\ SRLQW RI YLHZ WKH FKDLU RI µ3URGXFW 'HYHORSPHQW¶ ,Q D FRQYHQWLRQ DERXW GHVLJQ PHWKRGRORJ\ in 19981 I have described design as: “The applied technical design is an original, ingenious and material solution for a WHFKQLFDOSUREOHPDFTXLUHGE\PHDQVRIDQHI¿FLHQWSURFHVV RIPDNLQJGHFLVLRQVIURPLQLWLDWLYHXQWLOH[HFXWLRQ´ (YHUVLQFHP\¿UVWGD\DWWKH)DFXOW\RI$UFKLWHFWXUH,KDYH been interested in design as a collection of activities with a path-breaking result. Novelty is at top of the list. Not only IRU\RXUVHOIZKLFKLVTXLWHFRPPRQZKHQ\RX¶UHDVWXGHQW

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THE CARDBOARD DOME AS AN EXAMPLE OF AN ENGINEERS APPROACH

and still learning) or for the national group of architects and technical designers towards a patented world-novelty. Novelty for yourself, your friends, the Dutch scene and the world are entirely different concepts. These environments could be compared to arenas with different rules of the game and different rewards. Confusing these arenas can cause disillusion. If you, for example, admire your heroes and even identify yourself with them, you skip several arenas and an XQQHFHVVDU\FRQIXVLQJLGHQWL¿FDWLRQDULVHVZLWKXQDYRLGDEO\D big disappointment and a qualitative goal and recognition that will never be attained. Design with a path-breaking result is in many cases just a µIDWDPRUJDQD¶LIWKHGHVLJQHUJHWVWUDSSHGLQGLFKRWRPRXV demands and desires, as a result of which only a meagre compromise can be achieved. Design is often seeking the best compromise. Young and ambitious architects, who primarily strive to attain the maximum amount of novelty in their design and at the same time enhance their own fame (as an archetype: Erick van Egeraat), have their own idea of the concept of compromise. They have to win design competitions. You cannot win those competitions if you blindly obey all dichotomous demands and desires. The design should have something bold, exceptional, and reckless in order to be noticed by the jury of the competition. So a certain balance between character and compromise is necessary. Character to EHQRWLFHGDQGFRPSURPLVHWRIXO¿OPRVWRIWKHGHPDQGVRI the client. I take pleasure in composing as an interpretation of design (which is essential and unavoidable for architects) but from P\ ¿UVW GHVLJQ VNHWFKHV DV D VWXGHQW DW WKH )DFXOW\ RI Architecture I feel more like an inventor. My previous senior OHFWXUHU-DQYDQGHU:RRUGRQHRIP\PHQWRUVLQP\¿UVW\HDU  VWLOOUHPHPEHUVWKDW,QP\¿UVW\HDURIVWXG\ ,DOUHDG\GHVLJQHGJODVV¿EUHUHLQIRUFHGSRO\HVWHUVKHOOOLNH walls and roofs for a gatekeepers building at the Calvé factory, which was an exciting technical adventure. Recently I have designed GRP shells again with a huge span (30 meters) on a core of foam for architect Moshe Safdie from Boston, which is described in another article. I alternate between composing and inventing. But I get the most pleasure from inventing, maybe because so few people can do it. I consider myself more as an inventor-architect than

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Fig. 2.7KH¿YH*53URRIVRIWKH Yitzhak Rabin Center, Tel Aviv, Israel

Fig. 3. Hoisting of one of the roofs for the Yitzhak Rabin Center, Tel Aviv, Israel

as a composer-architect. In that respect I would be called an architect-engineer in Belgium. In the city-hall of the Frisian town of Bolsward (build between 1614-1619) a text on the entrance portal of the council room VD\V³JHLMQYHQWHHUW´ZKLFKLVDth century reference to the entanglement of the notion of invention and design. Nothing new under the sun. Perhaps the Ecole de Beaux Arts stressed composing too much two centuries ago, as a result of which WKHZRUG³LMQYHQWHUHQ´PRYHGWRWKHEDFNJURXQG,QDQ\FDVH the technological designers we educate in the department of Building Technology should be able to become designerinventors. Many inventions can only come to existence by prompt but most of all in-depth and methodical work without the fear RIIDLOXUH7KDWNLQGRIGHVLJQLVPRUHVFLHQWL¿FFRPSDUHGWR the more artistic component that composing possesses. This SURFHVVRIGHVLJQVKRXOGEHWUDQVSDUHQWVRLWFDQEHYHUL¿HG for yourself or your team, so you can discuss it and make the right decisions at crucial moments. Design as a science is hard to achieve, whereas composing primarily requires intuitive GHFLVLRQV 6FLHQWL¿F GHVLJQ FDQ EH DFKLHYHG LQ VRPH FDVHV and in other cases a part of the entire design and engineering SURFHVVFDQEHUHFRJQL]HG,QWKHµ.RQLQNOLMNH1HGHUODQGVH

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THE CARDBOARD DOME AS AN EXAMPLE OF AN ENGINEERS APPROACH

Fig. 4. Plate explaining the word „ “geijventeert inside the City Hall of Bolsward

$NDGHPLHYDQ:HWHQVFKDSSHQ¶5R\DO1HWKHUODQGV$FDGHP\ RI$UWV 6FLHQFHV ,ZLOO¿UVWVXEVWDQWLDWHVFLHQWL¿FGHVLJQWR subsequently gain understanding for design as a process of composing.

Fig. 5. City Hall of Bolsward, The Netherlands

Fig. 6.µ7ULSSHQKXLV¶LQ Amsterdam, where

Many Dutch architects argue that a composer should be FUHDWLYHEXWGRHVQ¶WQHFHVVDULO\KDVWREHDQLQYHQWRUVLQFH DQG LQYHQWRU LV D WHFKQLFLDQ -XVW OLNH D FRPSRVHU GRHVQ¶W have to invent music-notes in order to make a composition, DQDUFKLWHFWGRHVQ¶WKDYHWRLQYHQWPDWHULDOVµPXVLFQRWHV¶  RUFRQVWUXFWLRQVµPXVLFEDU¶ LQRUGHUWRPDNHDJRRGGHVLJQ Composing alone is already enough. The attitude of Dutch architect Jan Benthem is derived of this position: take smart materials and systems that have already proven their quality and reliability and subsequently use them to compose with. That attitude resulted in a respectable portfolio. But there are also architects who see it as their job to design, research and develop the means (elements, components, systems, products) with which they shape their buildings according to their design. The interest of these architects is both focusing on innovation in architecture and in technology. They are focused on both the development of material means to build, as composing a surprising artefact into a building. These designers position themselves both at the producersside as the consumer-side of technology. Think of British high-tech architects, Renzo Piano and Santiago Calatrava for example. In the past decade Piano and Calatrava received an honorary doctorate at the TU Delft and were therefore acknowledged for their professional quality in Delft.

the Royal Netherlands Academy of Arts & Sciences is housed.

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2. Inventing and composing in cardboard This lengthy introduction was necessary in order to comprehend the backgrounds of the designers of the cardboard IJburg dome: Shigeru Ban and Mick Eekhout. Both of them are used to invent and compose: to research and design, research by design and design by research. When I was a student (1968-1973), prof. Dick Dicke proposed WRGHVLJQDVWUXFWXUDOV\VWHPZLWKD¿FWLYHPDWHULDOSRVVHVVLQJ the most diverse properties you could possibly think of. This FRXOGKDYHEHHQµJLQJHUEUHDG¶IRUDOO,FDUHEXW\RXKDGWR ¿JXUHRXWWRPDNHVRPHVRUWRIFRQVWUXFWLRQZLWKLW7KHDLP of the exercise was of course to appreciate the properties of materials without thinking in rigid patters. When Walter 6SDQJHQEHUJ $%7  FDOOHG PH IRU WKH ¿UVW WLPH DERXW WKLV project, I immediately thought of considering cardboard as a sort of gingerbread. I was eager to start working on a material I never would have considered myself. I had absolutely no experience with cardboard construction nor did I posses any prejudice. Shigeru Ban had already realized several projects in cardboard. For the Dutch cardboard industry – thinking primarily of increasing their own market – it was evident that several VWHSVKDGWREHWDNHQLQWKH¿HOGRIIXQGDPHQWDOUHVHDUFK and development in order to establish new applications. The DGYHQWXUHVWDUWHGLQWKH¿HOGRIDUFKLWHFWXUH:H¿UVWKDGWR think of new systems. Therefore it was necessary to expand the cardboard industry. This expansion and foundation occurred by more fundamental research concerning the relation between strength/moisture, elasticity modulus, buckling and bending strength. Only after this process of investigation and research was completed, we could think of new structural systems and experimentally developed them, so new applications could be designed.

Fig. 7-8. Schiphol Airport, designed by Benthem & Crouwel Architects

Fig. 9. Centre Pompidou, Paris. Designed by Richard Rogers and Renzo Piano

3. The cardboard dome design Japanese architect Shigeru Ban was responsible for the design of the Japanese pavilion at the World Exhibition in Hannover 2000. The structure consisted out of long cardboard tubes that were bend over each other. Jeanette van der Steen attended a lecture of Ban at the NAi (Dutch Architecture Institute) and got fascinated by his designs. She asked him to design a temporary dome for her theatre group on the island of IJburg, near Amsterdam. In the fall of 2002 Ban made a design

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Fig. 10. Centre Culturel Tjibaou, New Caledonia. Designed by Renzo Piano

THE CARDBOARD DOME AS AN EXAMPLE OF AN ENGINEERS APPROACH

consisting out of a 16-frequent icosahedron in the tradition of Richard Buckminster Fuller. An icosahedron consists out 20 regular equilateral trianhulated surfaces: a complete sphere is built up out of 20 regular triangles, which were applied 5 times in this spherical roof. Later on I will further address this. Dr. Peter Huybers of Civil Engineering TU Delft has published many studies on this subject. The shape of the dome (span versus height with folded edges) is identical to the 60 meters span Aviodome on Schiphol Airport and the Toyotadome in 5DDPVGRQNYHHU&RPSDUHGWRUHFHQWH[SHULHQFHVZLWKµÀXLG GHVLJQ¶RI2FWDWXEHWKLVGRPHZDVDUHDVRQDEO\HDV\QHDUO\ KLVWRULFGHVLJQ7LPHÀLHVE\%OREGHVLJQDQGHQJLQHHULQJDOVR contaminates ordinary structures. Fig. 11. Aquadrom in Bremen (50m span), Germany

%DQ¶V GHVLJQ ZHQW WKURXJK D YLROHQW SURFHVV WR JDWKHU VXI¿FLHQWVSRQVRULQJIURPWKHVLGHRI*URHS9DQ6WHHQ$W the same time a thorough material research project and material development on part of Octatube, the chair of Product Development TU Delft and also the research & design JURXS µ&DUGERDUG¶ RI SURI )RQV 9HUKHLMHQ ZDV LQYROYHG %DQZDVUHSUHVHQWHGE\:RXWHU.OLQNHQELMO'HVSLWHHDUOLHU experiences of Ban in construction with cardboard, this type of cardboard use seemed to surpass the available amount of knowledge when issues are involved like tensions and weight load. The sporadic available technical data form Japan were GH¿QLWHO\ LQVXI¿FLHQW WR PDNH DQ LQGHSHQGHQW HQJLQHHU¶V judgement about the behaviour of cardboard as a structural material. Despite repeated requests it seemed impossible to acquire structural data from design teams and contractors who participated in the construction of the Japanese pavilion in Hannover (the municipality of Hannover, Buro Happold, cardboard supplier Sonoco and architect Ban). In Stuttgart 1998 I heard my colleague prof.dr. Jörgen Schlaich proclaim:

Fig. 12. Dome of Nationale Nederlanden building (30m span) in The Hague, The Netherlands

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³(VLVWQLFKWV1HXHVGDV:LVVHQYHUJHKW´EXWRQO\DIWHUWZR years this seemed rather fast. Therefore for this design in cardboard all material data had to be determined from our own research. In November 2002 the development was initiated. This included the process of material research based on tests in the Laboratory of Product Development (PO-lab) and Octatube on the Rotterdamseweg 200, Delft and a process of material design: determining the exact geometry, tube lengths, node detailing and so on. In this case research and design could be described as a split: far DSDUW\HWLQÀXHQFLQJHDFKRWKHU

Fig. 13. Japanese Pavillion during the World Exhibition in Hannover. Designed by Shigeru Ban Architects

In November and December 2002 numerous cardboard tubes, supplied by Dutch companies, were tested in the PO-lab. The results of this research were compared with the required load from the construction analysis, which was executed several times and sent in by computer in the mean time. Again and again the results of practical tests proved to be utterly disappointing. The tubes already cracked at the diagonal seams at a minor load. But the horizontally wrapped tubes ZHUHQ¶WWKDWPXFKVWURQJHUHLWKHU7KHXWLOLVHGJOXHSURYHG

Fig. 14. Japanese Pavillion during the World Exhibition in Hannover. Interior.

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THE CARDBOARD DOME AS AN EXAMPLE OF AN ENGINEERS APPROACH

Fig. 15.&ORVHXSVRID¿UVW detail using bolted connections before tensile testing

Fig. 16.&ORVHXSVRID¿UVW detail using bolted connections before tensile testing

to be the decisive factor in construction use of cardboard. On a Boosting meeting in December 2002, colleague designer )ULVR.UDPHUVXJJHVWHGPHWRXWLOL]HDPHODPLQHFRPSRVLWH to reinforce the cardboard, instead of using the inferior glue. A clever idea, yet this would make recycling of the cardboard impossible. After two months of research and a long period of waiting for new tubes from the Dutch cardboard industry, we were still not convinced of the feasibility of the cardboard tubes for this dome design. In the end the German company Sonoco was able to supply us with cardboard tubes that were 40% stronger than all other tubes previously tested. This extra strength was primarily achieved by the use of new instead of recycled paper; a learning stage for the entire cardboard industry. Of course the tested tubes are developed for packaging and not for construction. 7KH¿QDOGHVLJQSURFHVVWKDWIROORZHGWKHGHVLJQRI6KLJHUX Ban, was executed at Octatube under my strict supervision. 7KH LQLWLDO GLYLVLRQV RI %DQ¶V GRPH ZHUH EDVHG RQ D  frequecy subdivision. Because I have designed over 30 domes worldwide – all in steel and aluminium – I know what repetition factors mean. Consequently I proposed to reduce the frequency from 16 to 8, or even 6. The number of tubes could be reduced to a quarter or even less. Ban, however, seemed to be in love with cardboard: the more the better. This was opposed to my minimalist principles including the cost HI¿FLHQF\%XW-HDQHWWHYDQGHU6WHHQKRQRXUHGWKHRULJLQDO design despite the fact that costs would increase if the dome would be realized in its original design. A different issue concerned the edges at the bottom of the dome. The circumference of the dome would have 5 arches with a height of 1.5 meters; too little to walk underneath and use as an entrance. In that phase I proposed to deform the geometry and assign a height of 2,5 meters to the edge arch. 7KLVZD\WKHµIHHW¶FRXOGUHVWRQWKHIRXQGDWLRQSODWHVDQG assure a good accessibility. Subsequently a deformation came to existence with a regular geometry derived of an icosahedron. :HFRXOGPDNHDµUXEEHUEDQGLQJ¶LQWHUYHQWLRQDQGGHVLJQDQ alternative geometry with the help of computers. A slight BLOB edge to it one could say. Nowadays it is quite easy with contemporary computers, but in the days of Buckminster Fuller a similar deformation would be impossible. Ban was relentless; this proposition was no good for him. It was decided to stick to the original geometry and to build 5 corner

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nodes on 5 elevated tetrahedron-shaped supports.

4. Cardboard Engineering By e-mail several discussions arose between cardboard lover Ban and metal-tiger Eekhout about several aspects of the design, including the design of the node. Twenty years ago I developed a useful node for an aluminium dome in Jeddah that was covered with a double membrane and transparent insulation. With the help of this node it was possible to FRQQHFWWKHEDUVDQGWKHWHQWPHPEUDQHWKDWFRXOGEH¿[HG DQGVWUHVVHG%DQNHSWVWUHVVLQJDZRRG¿OOHGQRGHSUREDEO\ due to a Japanese tradition. The next design of the dome was based on a compromise: Ban determined the geometry with a relatively short tube-length (a 10-frequent dome) and Eekhout determined the detailing.

Fig. 17. Cardboard pressure test ZLWKWKHµ6RQRFRWXEHV¶

The detail existed out of a steel head on both ends of the tube ZLWKDÀDWSURWXEHUDQWWDEWR¿[LWWRWKHQRGHV&RQQHFWLRQ tests proved the weakness of cardboard at the transverse screws and bolts. In Hannover Ban did not use screws because the tubes crossed each other. Because the IJburgdome is composed out of different shorter tubes and not continuous WXEHVWKHJHRPHWU\LVGH¿QHGE\WKHQRGHV Just like metal space structures the devilish idea arose: “Why would you shorten a factory-produced tube of 6 meters to OHW¶V VD\  PHWHUV WR HYHQWXDOO\ FRPH EDFN WR  DJDLQ"´ Of course the answer is: utilising continuous tubes eventually results in tubes that have to cross each other. The structural engineers prefer an axial connection. Nonetheless, the design ZRXOGKDYHJDLQHGDEHWWHUFRVWHI¿FLHQF\