Research Collection

Doctoral Thesis

Cardboard in architectural technology and structural engineering a conceptual approach to cardboard buildings in architecture

Author(s): Ayan, Özlem

Publication Date: 2009

Permanent Link: https://doi.org/10.3929/ethz-a-006080626

Rights / License: In Copyright - Non-Commercial Use Permitted

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ETH Library DISS. ETH NO. 18421

CARDBOARD IN ARCHITECTURAL TECHNOLOGY AND STRUCTURAL ENGINEERING : A CONCEPTUAL APPROACH TO CARDBOARD BUILDINGS IN ARCHITECTURE

A dissertation submitted to

ETH ZURICH

for the degree of

Doctor of Sciences

presented by

ÖZLEM AYAN

Dipl. Arch. YTU, MAS-Arch. ETH Zurich

born on 22.07.1978

citizen of Turkey

accepted on the recommendation of

Prof. Dipl. Arch. Andrea Deplazes, ETH Zurich (examiner) Prof. Dr. sc. techn. Mario Fontana, ETH Zurich (co-examiner) Prof. Dipl. Arch. Christian Sumi, USI MENDRISIO (co-examiner)

2009 i Abstract

Corrugated cardboard is increasingly being used in a variety of modern applications, ranging from the printing, packaging and aviation industries to the construction of various indoor elements, including furniture and doors. As a structural building element, corrugated cardboard has many advantages. In addition to being a relatively low cost material, it possesses very strong insulative (thermal and acoustical) properties, is easily recyclable, and can be manufactured using renewable sources. Most importantly though, as a building element, corrugated cardboard possesses a high degree of structural strength and stiffness.

Despite these proven benefits, the growth in popularity of corrugated cardboard as a building material has remained relatively stagnant over the years, due mostly to its perceived limitations. These limitations include its vulnerability to moisture, fire and temperature change, as well as its sensitivity to ultra-violet light and various chemicals. Solutions for many of these issues are currently being addressed and tested by researchers in the field.

In its architectural quest for general acceptance as building material, corrugated cardboard still requires considerable development in order to come into compliance with modern construction paradigms. With this in mind, the fundamental question for this study is therefore:

Is it feasible to build a house out of corrugated cardboard?

Suggesting the implemention of a structurally sound corrugated cardboard construction, this thesis, in marked contrast to prior attempts in cardboard architecture, undertakes the goal of examining potential applications of corrugated cardboard within the existing environmental and social contexts and then exploring its relation to modern design guidelines. In particular, the current demands of wall components in relation to architectural space is thoroughly analyzed.

From the onset, corrugated cardboard was selected as a potential building material based on its low cost, load-bearing capabilities, and strong insulative properties. In addition to these advantageous physical characteristics, corrugated cardboard can also greatly increase certain efficiencies in the construction process. Specifically, cardboard blocks can be prefabricated and mass customized, permitting streamlining on the construction site, and thus improved cost savings.

This thesis is primarily guided by the experimental findings of the CATSE collaborative research platform at ETH Zurich. The engineering team, after testing and modeling various cardboard construction prototypes, was able to demonstrate the sufficiency of the material’s structural strength and stability.

iv The findings of the research team also show that prefabricated cardboard-core sandwich composites are particularly well suited for use as wall components. Promising physical and mechanical behaviors were observed when cardboard was utilized as both an exterior and interior wall component. Further investigations revealed cardboard wall’s thermal control characteristics, implying a strong potential for overall energy and cost reduction. Moreover, the results demonstrated that impregnation of the material with an inorganic substance secures the material against loss of strength and stiffness when exposed to water and moisture. Guided by these experimental findings, the objectives that form the chapters of this thesis can be summarized as follows:

- Chapter I serves as an introduction to the theme and research framework of this thesis. It summarizes the existing research data from the previous attempts to use cardboard as a building material. It further seeks to investigate the background, interrelationships and basic technical comparisons between cardboard and contemporary building demands.

- Chapter II examines the societal aspects of cardboard construction within the framework of Switzerland’s housing construction industry. In particular, it looks at the current perceptions of using cardboard as a building material in modern residences. This chapter also proposes to develop innovative ways to introduce cardboard construction into the housing market. It does so by analyzing user preferences and market trends in both the housing and construction industries. The end result is a workable solution to gradually introduce cardboard constructed houses as a feasible and flexible alternative for the changing needs of renters and buyers in the housing market.

- Chapter III provides an analysis of the environmental aspects underlying the development of corrugated cardboard as a building component. This chapter seeks to make an honest environment assessment using the lifecycle approach (LCA) as a model. The cradle-to-grave cost of corrugated cardboard is calculated by looking at the two main stages of the process: 1) the production stage, and 2) the construction-user stage. For the construction stage, the study evaluates the total environmental impact of manufacturing cardboard wall components. For the environmental cost of the construction phase, the energy costs of various cardboard wall components (constructed with different skin options and thicknesses), in terms of thermal U-value, are compared to the energy costs of other wall materials.

- Chapter IV focuses on the structural aspects of cardboard architecture, drawing on the testing and analyses of corrugated cardboard in a sandwich composite for wall components, conducted by the CATSE engineering team. This chapter provides the groundwork for the subsequent

v chapter pertaining to the possibilities in the architectonic realm. It further looks at the structural and technical elements of cardboard housing in relation to user sector demands. In doing so, this section draws from and elaborates on prior chapters on the social and environments to set the framework for the architectonic approach.

- Chapter V examines the architectonic element underlying the use of cardboard as a wall component within its space-defining function. In this study, nine types of walls, each with varying characteristics, were defined for analysis. The geometric pattern of each wall was modified to control sunlight and its degree of acoustical insulation, as well as to adjust the indoor ambience and spatial qualities. The chapter further looks at other architectonic characteristics of cardboard buildings, including the potential use of cardboard in various other structural elements (i.e. floor slabs).

The concluding chapter describes the developmental criteria for the overall architectural contextualization of contemporary cardboard architecture. An understanding of the structural application potential of corrugated cardboard honeycomb composites as wall components is presented in many perspectives, reflecting its structural performance and environmental benefits within the existing societal context. Concurrently, spatial qualities seeking a distinctive architectural language are specifically suggested for further development in collaboration with the construction sector.

Based on these findings, this study holds that it is feasible to employ corrugated cardboard as the main structural component in contemporary housing. The use of cardboard as an alternative builidng material not only satisfies a building’s structural demands, but also fulfills certain environmental and social demands that make it more potentially more attractive than standard building materials.

vi Kurzfassung

Wellkarton gelangt immer öfter in einer Vielzahl von Anwendungen zum Einsatz: Das reicht von Druckerzeugnissen, Verpackungen über die Konstruktion von Türen und Möbeln bis hin zur Luftfahrtindustrie. Als Bauelement hat Wellkarton zahlreiche Vorteile. Karton ist ein sehr günstiges Material mit hervorragender Wärme- und Geräuschdämmung sowie einfacher Wiederverwertbarkeit. Zudem wird das Material aus nachwachsenden Rohstoffen hergestellt. Der entscheidende Grund für den Einsatz von Wellkarton als Baustoff ist jedoch seine hohe statische Belastbarkeit und Verwindungssteifigkeit.

Trotz allen diesen nachgewiesenen Vorteilen stagniert der Einsatz von Wellkarton als Baumaterial seit einigen Jahren, zumeist aufgrund von gewissen unerwünschten Eigenschaften. So ist das Material empfindlich gegenüber Feuchtigkeit, Feuer, Temperaturschwankungen, UV-Strahlen sowie diversen Chemikalien. Zurzeit laufen Untersuchungen mit dem Ziel, Lösungen für diese Probleme zu erarbeiten.

Damit Wellkarton als Baumaterial anerkannt wird, braucht es noch immer erhebliche Entwicklungen, um den Anforderungen des modernen Gebäudebaus zu entsprechen. In diesem Sinne definiert sich die grundlegende Frage dieser Studie wie folgt:

«Ist es möglich, ein Haus aus Wellkarton zu bauen?»

Ganz im Gegensatz zu vorhergehenden Versuchen in der Architektur mit Karton ist es das Ziel dieser Dissertation, das Potential von möglichen Anwendungsgebieten von Wellkarton innerhalb existierender sozio-ökologischer Zusammenhänge sowie dessen Verhältnis zu modernen Designrichtlinien zu untersuchen. Insbesondere werden die vielfältigen Möglichkeiten für Wandelemente im Verhältnis zum architektonischen Raum eingehend analysiert.

Von Beginn an wurde Wellkarton als mögliches Baumaterial in Betracht gezogen, aufgrund seiner tiefen Kosten, hohen Belastbarkeit und seiner hervorragenden Isolationsfähigkeiten. Zudem kann Karton gewisse Bauprozesse massiv effizienter machen. Denn Kartonblöcke lassen sich massgeschneidert vorfertigen und in hohen Stückzahlen produzieren, was eine rationalisierte Arbeitsweise auf der Baustelle zulässt und so Kosten spart.

Die vorliegende Dissertation stützt sich hauptsächlich auf die Ergebnisse des Forschungsprojekts der ETH Zürich «Cardboard in Architectural Technology and Structural Engineering» (CATSE). Nach Tests an verschiedenen Prototypen konnte das Team von Ingenieuren beweisen, dass Wellkarton über hervorragende statische Eigenschaften und Stabilität verfügt.

vii Die Erkenntnisse des Forschungsteams zeigen, dass sich vorgefertigte Sandwich-Elemente mit Kern aus Wellkarton besonders gut für die Verwendung als Wände eignen. Sowohl als Innen- wie auch auch als Aussenwandkomponente zeigt Karton vielversprechendes physikalisches und mechanisches Verhalten. In weiteren Untersuchungen wurde deutlich, dass Kartonwände über Wärme regulierende Eigenschaften verfügen, die ein Einsparungspotential für Energieverbrauch und Kosten darstellen.

Darüber hinaus hat sich erwiesen, dass die Imprägnierung des Materials mit einer anorganischen Lösung die Bauteile unempfindlich gegen Feuchtigkeit macht und somit den Verlust von Tragfähigkeit und Steifigkeit verhindert. Zudem verleiht die Imprägnierung dem Karton feuerfeste Eigenschaften.

Basierend auf die Forschungsergebnisse der CATSE kommt diese Studie zum Schluss, dass der Einsatz von Wellkarton als tragendes Bauelement im modernen Hausbau absolut geeignet ist. Die Verwendung von Karton als alternatives Baumaterial erfüllt nicht nur die bautechnischen Anforderungen, sondern auch die gesellschaftlichen und ökologischen Kriterien, was Karton viel attraktiver als Standard-Baumaterialien macht.

viii