Guadua Chacoensis in Bolivia -An Investigation of Mechanical Properties of a Bamboo Species

Guadua chacoensis in Bolivia -an investigation of mechanical properties of a bamboo species

Maria Lindholm Sara Palm

December 5, 2007

Examiner: Stig-Inge Gustafsson Supervisor: Kenneth Bringzén

Department of Management and Engineering Centre for Wood Technology & Design

LIU-IEI-TEK-A--07/00256--SE http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-10372 ii Sammanfattning

Detta examensarbetete har gjorts vid CTD- Centrum för Träteknik och De- sign vid Linköpings universitet och har utförts i Santa Cruz de la Sierra i Bolivia.

Syftet med detta examensarbete är att studera de mekaniska egenskaperna och användningsområden för Guadua chacoensis, en boliviansk bambuart. Genom historien har bambu använts i en mängd olika applikationer såsom hus, verktyg, möbler, mat, bränsle, papper och land-rehabilitering. I de esta asiatiska länder är bambu en viktig resurs för små- och medelstora företag vilket skapar arbetstillfällen och motverkar fattigdom. I Sydamerika nns många länder, däribland Bolivia, vilka har stora möjligheter att utnyttja bambu på samma sätt. En av huvudidéerna med detta examensarbete är att kunna gynna den bolivianska välfärden genom att belysa denna, hittills outvecklade naturresurs.

Detta examensarbete är en Minor eld study, delvis nansierad av Sida, styrelsen för internationellt utvecklingssamarbete. Under fältarbetet genom- fördes teoretiska studier då internationell och inhemsk information om bambu, speciellt om Guadua chacoensis, samlades in. Olika områden där arten växer besöktes och hållfasthetstekniska tester genomfördes vid UPSA- Universidad Privada de Santa Cruz de la Sierra.

Genom drag-, böj- och hårdhetsprovning har det påvisats att Guadua chacoensis är ett böjligt och medelhårt material med en draghållfasthet som är jämförbar med den för Europeisk ek. Detta gör att denna bambuart lämpar sig bland annat för konstruktioner, såsom hus och broar, samt mö- beltillverkning.

iii iv Abstract

This Master thesis has been performed at CTD- the Centre for Wood Tech- nology and Design at the University of Linköping and has been carried out in Santa Cruz de la Sierra in Bolivia.

The objective of this thesis is to study the mechanical properties and uses of Guadua chacoensis, a bamboo native to Bolivia. Throughout history, bamboo has been used in many countries for a variety of purposes. In Asia bamboo is an important raw-material for buildings and furniture. It is also used for making paper and for land rehabilitation and fuel. In South America many countries, among them Bolivia, have great potential to use bamboo in the same way. One of the key ideas with this Master thesis is to make a contribution to support the Bolivian economy and welfare by elucidate this, hitherto undeveloped, natural resource.

This thesis is a Minor eld study partly nanced by Sida- the Swedish International Development Cooperation Agency. During the eld study theoretical studies were made, collecting local and international information about bamboo and Guadua chacoensis in particular. Laboratory tests were prepared and conducted at UPSA- the Private University of Santa Cruz de la Sierra and several localities of the plant were visited.

Through tensile-, bending- and hardness test it is found that Guadua chacoensis is a exible, medium soft material and is comparable with Euro- pean oak when it comes to the tensile strength. This leads to the conclusion that this bamboo species, among other elds of applications, can be used for constructions, like houses and bridges, and furniture manufacturing.

v vi Acknowledgements

The idea of doing this Master thesis was established in October 2006 which makes this a slightly more than one year long project. During this time several people have crossed our paths and contributed to our work in dierent ways.

We would like to thank our examiner Stig-Inge Gustafsson and our supervisor Kenneth Bringzén at the University of Linköping. We deeply appreciate their support and great interest in our work throughout the whole project. Furthermore we would like to thank Per Larsson and Stig Algstrand, also at the University of Linköping, for helping us to nd the right contacts in Bolivia and Kerstin Johansen at CTD, who proofread the thesis. Special thanks is directed to Per Larsson that helped us arrange the nancing of our stay in Bolivia.

Our gratefulness also goes to Gabriella A. Pinaya Johannessen at Cadefor, Santa Cruz that at all times was ready to answer questions and supported us during our stay in Bolivia. In addition, our thanks go to Gastón Mejia, Jorge Zeballos and Gustavo Quinteros at UPSA- the Private university of Santa Cruz de la Sierra that helped us with the laboratory tests.

Our deepest gratitude goes to our fellow worker and dear friend Luis Fer- nando Ortiz, who's help in Santa Cruz was inestimable. His broad knowledge of bamboo and his useful contacts were very valuable. Thanks to him our work and stay in Bolivia could not have been better. We will never forget our investigation trips and the hanging-out together!

We would also like to thank Sida, Ansgarius-stiftelsen and Sparbanksstif- telsen Alfa whose scholarships nanced our project. It would not have been possible to carry out the Master thesis in Bolivia without their economic support.

vii Finally, we would like to thank everyone that made our time in Bolivia to an enriching and moving stay. Our time in Bolivia was an adventure and we will treasure the memories from this journey forever.

viii Preface

During autumn 2006 the idea of going to Bolivia to do our Master thesis was arised. The possibility to do a Minor eld study in a developing country - nanced by Sida, the Swedish International Development Cooperation Agency, lead to the decision of realizing this idea. The Minor eld study scholarship nance the expenses during an eight week study in a developing country with the purpose to increase understanding of Swedish development work in countries all around the world. The fact that the University of Linköping during several years has been cooperating with UPSA- the Private Univer- sity of Santa Cruz de la Sierra lead to the choice to place our study in Santa Cruz. Santa Cruz is Bolivia's biggest city located in the east of the country, in the Tropical Amazon region.

We hope that the readers will nd the results of our endeavours, to gain a little bit of knowledge about this remarkable plant, bamboo, interesting and that the qualities of this versatile material will be appreciated.

ix x Contents

1 Introduction 1 1.1 Background ...... 1 1.2 Objective ...... 2 1.3 Thesis Structure ...... 2 1.4 Reading Instructions ...... 3

2 Bamboo -a Woody Grass 5 2.1 Brief Bamboo History ...... 5 2.2 The Plant ...... 6 2.2.1 Rhizomes ...... 6 2.2.2 Groves ...... 7 2.2.3 Roots ...... 7 2.2.4 Culms ...... 7 2.2.5 Nodes ...... 8 2.2.6 Branches ...... 9 2.2.7 Leaves ...... 10 2.2.8 Flowers ...... 11 2.2.9 Seedling ...... 11 2.2.10 Growth ...... 12 2.2.11 Environment ...... 13 2.3 World Distribution ...... 14 2.4 Species ...... 15 2.4.1 Sympodial Bamboos ...... 16 2.4.2 Monopodial Bamboos ...... 17 2.5 Cultivation, Curing and Harvesting ...... 17 2.5.1 Cultivation ...... 17 2.5.2 Curing ...... 18 2.5.3 Harvesting ...... 18 2.5.4 Insects ...... 19 2.6 Anatomy and Mechanical Properties ...... 20 2.6.1 Anatomical Structure ...... 20

xi 2.6.2 Mechanical Properties ...... 21 2.7 Renement Techniques ...... 23 2.7.1 Drying ...... 23 2.7.2 Cutting ...... 24 2.7.3 Splitting ...... 24 2.7.4 Bending ...... 25 2.7.5 Joints ...... 25 2.7.6 Laminating ...... 26 2.7.7 Surface Treatment ...... 27 2.8 World Market ...... 28 2.9 Bamboo Uses ...... 28 2.9.1 Constructions ...... 28 2.9.2 Buildings ...... 30 2.9.3 Plybamboo, Laminate and Furniture ...... 30 2.9.4 Paper ...... 32 2.9.5 Ecomaterial ...... 32 2.9.6 Other Uses ...... 32 2.9.7 Recently Developed Uses ...... 33

3 Method and Performance 35 3.1 Research Approach ...... 35 3.2 Pre-Study Phase ...... 35 3.2.1 Brainstorming ...... 36 3.2.2 Mind Map ...... 36 3.3 Evaluation of Possible Working Areas ...... 38 3.4 Delimitations ...... 38 3.5 The Field Study ...... 39 3.6 Analysis ...... 39 3.7 The Quality of the Study ...... 39 3.7.1 Validity ...... 40 3.7.2 Reliability ...... 40

4 Bamboo in Bolivia 41 4.1 Distribution ...... 41 4.2 Species ...... 42 4.3 Bamboo Industry ...... 43 4.3.1 Forestal Communities ...... 44 4.4 Bamboo Uses in Bolivia ...... 44 4.4.1 Historical Uses ...... 44 4.4.2 Modern Uses ...... 46

xii 5 Guadua Chacoensis 49 5.1 The Spicies ...... 49 5.2 Distribution ...... 49 5.3 Uses ...... 50 5.4 Mechanical Properties ...... 51

6 Laboratory Tests of Guadua Chacoensis 53 6.1 Laboratory Standards ...... 53 6.1.1 Tensile test ...... 54 6.1.2 Bending test ...... 55 6.1.3 Hardness test ...... 55 6.1.4 Specimens Preparation ...... 55 6.2 Results of the Mechanical Properties Tests ...... 56 6.2.1 Tensile Test Parallel to Fibre ...... 56 6.2.2 Bending Test ...... 57 6.2.3 Hardness Test Perpendicular to Fibre ...... 57

7 Analysis 63 7.1 Laboratory Tests ...... 63 7.1.1 Tensile Test Parallel to Fibre ...... 63 7.1.2 Bending Test ...... 65 7.1.3 Hardness Test Perpendicular to Fibres ...... 65 7.2 SWOT-Analysis ...... 66 7.2.1 Strengths ...... 67 7.2.2 Weaknesses ...... 68 7.2.3 Opportunities ...... 68 7.2.4 Threats ...... 68 7.3 Possibilities for Guadua Chacoensis ...... 69

8 Conclusions and Recommendations 71

9 Reections 73 9.1 Planning of the Work ...... 73 9.2 Final Results ...... 73 9.3 Further Work ...... 74

A Glossary 81

B German Abstract 85

C Spanish Abstract 87

xiii D Results Tensile test Parallel to Fiber 89 D.1 Lower Parts of Culms - A ...... 90 D.2 Upper Parts of Culm - B ...... 95

E Results Bending Test 101

F Results Hardness Test Perpendicular to Fiber 107 F.1 Lower Parts of Culm - A ...... 108 F.2 Upper Parts of Culm - B ...... 118

xiv List of Figures

2.1 Rhizomes of a sympodial bamboo ...... 7 2.2 Internode ...... 8 2.3 Node ...... 9 2.4 Branches ...... 10 2.5 Mature culm ...... 13 2.6 World distribution of bamboo ...... 15 2.7 White, blue and black bamboo ...... 16 2.8 Microscope picture of Guadua chacoensis ...... 22 2.9 Drying bamboo ...... 24 2.10 Bamboo joints ...... 26 2.11 Dierent types of laminate ...... 27 2.12 Bamboo fence in Bolivia ...... 29 2.13 Veranda made of bamboo ...... 31 2.14 Ford and chrysler cars ...... 33 2.15 Eco-friendly laptop ...... 33 2.16 Artek bamboo table ...... 34

3.1 Mind map ...... 37

4.1 Bolivia's main bamboo growing regions ...... 42 4.2 Reinforced housewall ...... 45 4.3 Sun protection ...... 46 4.4 Family house ...... 47 4.5 Restaurant complex ...... 48

5.1 Culms of Guadua chacoensis ...... 50 5.2 Transversal cut of Guadua chacoensis ...... 50 5.3 Guadua chacoensis chair ...... 51

6.1 Mechanical properties testing machine ...... 54 6.2 Schematic gure over the tested specimens ...... 55 6.3 Tensile test specimen ...... 56

xv D.1 Diagram of tensile test 1A ...... 90 D.2 Diagram of tensile test 2A ...... 91 D.3 Diagram of tensile test 3A ...... 92 D.4 Diagram of tensile test 4A ...... 93 D.5 Diagram of tensile test 7A ...... 94 D.6 Diagram of tensile test 1B ...... 95 D.7 Diagram of tensile test 2B ...... 96 D.8 Diagram of tensile test 3B ...... 97 D.9 Diagram of tensile test 4B ...... 98 D.10 Diagram of tensile test 7B ...... 99

E.1 Diagram of bending test 1-5 ...... 102 E.2 Diagram of bending test 6-9 ...... 103 E.3 Diagram of bending test 10-13 ...... 104 E.4 Diagram of bending test 14-17 ...... 105 E.5 Diagram of bending test 18-21 ...... 106

F.1 Diagram of hardness test 1A I ...... 108 F.2 Diagram of hardness test 1A II ...... 108 F.3 Diagram of hardness test 2A I ...... 110 F.4 Diagram of hardness test 2A II ...... 110 F.5 Diagram of hardness test 3A I ...... 112 F.6 Diagram of hardness test 3A II ...... 112 F.7 Diagram of hardness test 4A I ...... 114 F.8 Diagram of hardness test 4A II ...... 114 F.9 Diagram of hardness test 7A I ...... 116 F.10 Diagram of hardness test 7A II ...... 116 F.11 Diagram of hardness test 1B I ...... 118 F.12 Diagram of hardness test 1B II ...... 118 F.13 Diagram of hardness test 2B I ...... 120 F.14 Diagram of hardness test 2B II ...... 120 F.15 Diagram of hardness test 3B I ...... 122 F.16 Diagram of hardness test 3B II ...... 122 F.17 Diagram of hardness test 4B I ...... 124 F.18 Diagram of hardness test 4B II ...... 124 F.19 Diagram of hardness test 7B I ...... 126 F.20 Diagram of hardness test 7B II ...... 126

xvi List of Tables

2.1 Mechanical properties ...... 22

6.1 Result of tensile test part A...... 59 6.2 Result of tensile test part B...... 60 6.3 Results of bending test...... 61 6.4 Results of hardness test part A...... 62 6.5 Results of hardness test part B...... 62

7.1 Table for comparison of tensile properties...... 64 7.2 Table for comparison of bending properties...... 65 7.3 Table for comparison of hardness properties...... 66 7.4 SWOT-analysis of Guadua chacoensis in Bolivia...... 67

D.1 Dimensions of specimens 1A tensile test...... 90 D.2 Result of tensile test 1A...... 90 D.3 Dimensions of specimens 2A tensile test...... 91 D.4 Result of tensile test 2A...... 91 D.5 Dimensions of specimens 3A tensile test...... 92 D.6 Result of tensile test 3A...... 92 D.7 Dimensions of specimens 4A tensile test...... 93 D.8 Result of tensile test 4A...... 93 D.9 Dimensions of specimens 7A tensile test...... 94 D.10 Result of tensile test 7A...... 94 D.11 Dimensions of specimens 1B tensile test...... 95 D.12 Result of tensile test 1B...... 95 D.13 Dimensions of specimens 2B tensile test...... 96 D.14 Result of tensile test 2B...... 96 D.15 Dimensions of specimens 3B tensile test...... 97 D.16 Result of tensile test 3B...... 97 D.17 Dimensions of specimens 4B tensile test...... 98 D.18 Result of tensile test 4B...... 98 D.19 Dimensions of specimens 7B tensile test...... 99

xvii D.20 Result of tensile test 7B...... 99

E.1 Dimensions of specimens bending test 1-5...... 102 E.2 Result of bending test 1-5...... 102 E.3 Dimensions of specimens bending test 6-9...... 103 E.4 Result of bending test 6-9...... 103 E.5 Dimensions of specimens bending test 10-13...... 104 E.6 Result of bending test 10-13...... 104 E.7 Dimensions of specimens bending test 14-17...... 105 E.8 Result of bending test 14-17...... 105 E.9 Dimensions of specimens bending test 18-21...... 106 E.10 Result of bending test 18-21...... 106

F.1 Result of hardness test 1A...... 109 F.2 Result of hardness test 2A...... 111 F.3 Result of hardness test 3A...... 113 F.4 Result of hardness test 4A...... 115 F.5 Result of hardness test 7.A ...... 117 F.6 Result of hardness test 1B...... 119 F.7 Result of hardness test 2B...... 121 F.8 Result of hardness test 3B...... 123 F.9 Result of hardness test 4B...... 125 F.10 Result of hardness test 7B...... 127

xviii Chapter 1

Introduction

The following chapter introduces the reader to the Master thesis, its background, objective and structure. Some advice for the reader is also given to facilitate the reading of the thesis.

1.1 Background

Throughout history, bamboo has been used in many countries for a variety of purposes. In Asia bamboo is an important raw-material for buildings and furniture. It is also used for making paper and for land rehabilitation and fuel. In South America bamboo grows in abundance but the bamboo industry in these countries is not as developed as in Asian countries. Hence, Bolivia has great possibilities to develop the country's bamboo industry. One of the key ideas with this Master thesis is to make a contribution to support the Bolivian economy and welfare by elucidate this, hitherto undeveloped, natural resource.

Innovation and research are leading to development of new modern uses with large potential markets for this environmentally friendly material. A number of new technologies have been developed that enable the substitution of bamboo for wood in a large number of applications, one of those the manufacturing of bamboo laminates. The Bolivian wood industry is relatively well developed but the renement of bamboo has been neglected which makes this a potential business opportunity.

During several years the University of Linköping has been cooperating with UPSA and this opened a possibility to do the Master thesis in Bo- livia. During the eld work in Santa Cruz the authors were stationed at

1 Cadefor- Amazonic Center for Sustainable Forest Enterprise, a service-based non-prot organization. Hopefully this Master thesis will make a contribution to the bamboo industry in Bolivia by means of illuminating the potential business opportunity of this versatile material.

1.2 Objective

The objective of this thesis is to study the mechanical properties of Guadua chacoensis, one of the bamboo species that grows in Bolivia. The uses of Guadua chacoensis will briey be studied to analyze the possibility to diver- sify the elds of application of this bamboo in Bolivia. The Master thesis is intended to contribute to the development of the bamboo business area in Bolivia, serving as an aid for the country's bamboo research-work and further expansion of its bamboo industry.

1.3 Thesis Structure

Presented below is the structure of the thesis and a brief description of the contents in each chapter.

• Chapter one, Introduction, is a short description of the thesis and its objective.

• Chapter two, Bamboo -a Woody Grass, contains facts and theories concerning bamboo. The chapter is divided into Brief History, The Plant, Anatomy and Mechanical Properties, Renement Techniques and Uses.

• Chapter three, Method and Performance, describes the Research Ap- proach, the Pre-study Phase and the Field Study. The thesis limitations are set and nally the quality of the thesis is discussed.

• Chapter four, Bamboo in Bolivia, introduces the reader to bamboo in Bolivia today; where it grows, species and uses.

• Chapter ve, Guadua Chacoensis, contains facts about the species, for example its distribution, mechanical properties and uses.

• Chapter six, Laboratory Tests of Guadua Chacoensis, describes the laboratory tests conducted at UPSA. The results of the tests are presented to be further analyzed in Chapter seven.

2 • Chapter seven, Analysis, contains the analysis of the laboratory tests. The results given by the laboratorys are compared with corresponding fugures for some Swedish woods.

• Chapter eight, Conclusions and Recommendations, after the analysis some conclusions and recomendations regarding the mechanical properties of Guadua chacoensis and its uses are given.

• Chapter nine, Reections, presents the authors reections about the results, the eld study and the thesis writing.

The nine chapters are followed by a Bibliography and Appendices.

1.4 Reading Instructions

To facilitate the reading of the thesis report a glossary is attached in Ap- pendix A, which contains words and vocabulary used throughout the thesis report. Mostly this is technical vocabulary concerning bamboo and its characteristics. In Appendices B and C the reader will nd abstracts of the thesis content in German and Spanish.

For the reader who wants a quick overview of the thesis is the Abstract combined with the Introduction and Conclusions and Recommendations sug- gested. The frame of reference in Chapter 2 is written to introduce the reader to the bamboo plant and can be disregarded by those readers already familiar to the plant. The work carried through in the studies of this Master thesis is described from Chapter 3 and forward.

In the bibliography, the references are sorted alphabetically in the following groups: reference number [1]-[6] are books, [7]-[19] academic articles, [20]- [23] master thesises, [24]-[26] technical reports, [27]-[42] electronical sources and [43]-[44] verbal sources. The references in the text are given in brackets; before the punctuation if it has reference to the single sentence and after the punctuation if it concerns the whole section.

All tables and gures without specic references are made by the authors.

3 4 Chapter 2

Bamboo -a Woody Grass

In the following chapter a frame of reference will be presented in order to create theoretical understanding of the bamboo plant and bamboo as a material. First an overview of the bamboo history is made to introduce the reader to the principal subject of the thesis. After that, the chapter will describe the bamboo plant and its physical- and mechanical properties followed by renement techniques and bamboo uses. The theories in this chapter are chosen to cover many aspects of the subject eld of this study. The authors have chosen a rather broad frame of references to be able to properly introduce this multifaceted plant and material to the reader.

2.1 Brief Bamboo History

No bamboo fossils have been found and it is unknown for how long bamboo has been growing on the planet. The bamboo plant is one of the most primitive grasses and there are species that are believed to be more than sixty million years old. Bamboo has played an important role for humanity and will probably continuing doing so in the future. The name bamboo has in dierent countries shows the importance of the plant. Bamboo is named the "the wood of the poor" in India, "the friend of the people" in China and "the brother" in Vietnam.[3]

Bamboo is a plant that plays an important role in the daily life of about 2.2 billion people [41].

Many Asian cultures believe that humanity originate from a bamboo stem. The Philippine creation myth tells that after a great battle between the elementary forces, the rst man and women aroused from a bamboo culm. There is a similar legend in Malaysia, which tells about a man who sleeps

5 under a bamboo grove and has a dream about a beautiful woman. When the man wakes up and splits a bamboo culm he nds the women from the dream inside.[39]

Farelly[3], tells about one of the most amazing stories in the bamboo history; when a grove of bamboo survived in the very epicenter of the rst atomic bomb in the city of Hiroshima. This was the only living thing close to the epicenter that held out the blast. Today a portion of this bamboo grove can be seen in the Memorial Museum for Peace, which is built at the same place where the plants once grew.

2.2 The Plant

Bamboo is the general name for members of a particular group of large woody grasses. There exists approximately 1 250 species of bamboo and those are divided into 75 groups. Most bamboos are fast-growing and reach maturity in ve years but owers very seldom. There are species of dwarf bamboo that can be as small as 10 centimetres high, but tall species can reach up to 15-20 metres. The largest known bamboo species Dendrocalamus giganteus is, fully mature, 40 metres high and has a culm diameter of 30 centimetres.[16]

2.2.1 Rhizomes

Bamboo plants are divided into sympodial (tropical) and monopodial (temperate) species, depending on the type of root-system, also called rhizomes, they possess [3]. The rhizomes are very important in the bamboos since they control when the culms develop and how they spread [17].

The sympodial bamboos have thick and short rhizomes, see Figure 2.1, and their culms grow in groups, which shape is decided from how the rhizomes spread under ground. The rhizomes of the monopodial bamboos are long with symmetrical internodes that are longer then they are broad. The rhizomes produce new culms and new rhizomes for up to ten years.[3] Thanks to the underground growth of the rhizomes, and the system they create in the top layer of the soil, bamboo is a great resource for soil preservation, erosion control and protection against earthquakes [21]. A healthy and still fertile rhizome is yellow-ivory coloured and has nodes from which the culms of the plant rise from. In the nodes of the rhizome nutrients are stored to be distributed to the most active part of new growth in the bamboo grove.[3]

6 Figure 2.1: Rhizomes of a sympodial bamboo [37].

2.2.2 Groves Each individual bamboo culm is often referred to as a single isolated plant. The truth is that each culm is a branch of an underground system of growth. The culms grow up from the rhizomes and all culms in a grove are thereby connected through the rhizomes. Each culm collects nutrient and liquid which is stored mutually in the rhizomes. The form of the bamboo grove depends on how the rhizomes grow below ground. The monopodial species is characterized by free-standing culms while the sympodial bamboos grow in thight clumps.[3]

2.2.3 Roots Bamboo roots are the only part of the plant that do not grow in segments of nodes and internodes. The roots are thin and brous with a cylindrical shape. The diameter of the roots does not change when the bamboo gets older. The roots can be up to one meter long and one centimetre thick.[3]

Many bamboo species wear small roots on the culm, above ground. These roots are fading in the direction of the top of the plant. Those aerial roots are predicting the possibility that the culm will be felled by a storm or other falling plants. If this would happen, the roots will establish new culms and rhizomes at the nodes of the fallen culm.[3]

2.2.4 Culms Depending on the species, soil, age of stand and climate the growth of the bamboo culm varies very much. Larger species can grow between 7 to 40

7 centimetres a day. The documented growth-record is 120 centimetres in one 24-hour period and comes from Japan.[3] A mature culm can be from ten centimetres to 40 metres high [14]. The growth of the culm does not only depend on the climate and the soil where the bamboo grows. The maturity of the bamboo grove also inuences. When a maximum stature and productivity for each species is reached, the culms do not grow taller or thicker. The normal lifetime of a culm is ve to ten years but some species grow culms with an age of twenty years. The bamboo culm is erect and very often the tip is nodding much or slightly.[3]

2.2.5 Nodes The node is the part of the culm from where the branches grow out [21]. The nodes makes possible a greater exibility and strength of the culm [20], and through their solid cross wall they provide the transversal connection, see Figure 2.2, between the internodes of the bamboo [6].

Figure 2.2: A split internode.

The nodes of the bamboo are very important for the growth and function of the culm. The nodes enable the necessary cross-transport of water and nutrients in the plant. The nodal structure also aect the transportation

8 of liquid during drying and conservation and inuence many physical and mechanical properties.[6]

The visible nodal ridge, see Figure 2.3, is created by cell dierentiation by some cells that are compressed when a new shoot of the bamboo is emerging. When a shoot is raising the cortex is compressed by the upper portion of the new shoot and forced outwards. The morphology of the nodes varies greatly between dierent species.[6]

Figure 2.3: A node from a young bamboo culm.

2.2.6 Branches

Most species are branching at all nodes when they are pre-mature. Various species of Guadua, a South American bamboo, have thorns that can shred and cause severe damage to cloth or skin. When the culm is mature it does not wear branches at the lower nodes. Normally, the branches appear just above the nodes at alternate sides of the culm, see Figure 2.4. Like the culm itself, the branches also have nodes and the branch nodes nearest the culm is often covered with small aerial roots.[3]

9 Figure 2.4: Bamboo branches.

2.2.7 Leaves

The size of the leaves of the bamboo plant varies greatly, from tiny to enormous [3]. According to Flores[20], there are two types of bamboo leaves:

Caulinary: These are the leaves that cover the culm from its birth until it reaches maturity. They have a brownish colour and are provided with small u as a defense system. These leaves protect the culm during its growth, embracing it until they fall of when the culm has reached maturity and the branches starts to grow out.

10 Ramifying: The coating of the ramifying leaves is ribbed and has vains that stretches out from the center of the leaf. These leaves are green and the amount of sunlight they absorb decide how much water the plant take up, when it owers, when it matures and dries.

The leaf fall of many bamboo species often equals, in weight, the growth of new culms during the same year. The leaves of a bamboo fall o progressively and are replaced by new fresh leaves.[3]

2.2.8 Flowers Most bamboos almost never ower. The normal is once in a period from 15 to 100 years [5]. The owering cycle of bamboos is much disputed and very mysterious since it is very hard to study [3]. The owering pattern of bamboos is gregarious, that is; all bamboos of the same species growing all over the planet, ower at the same time [20]. Gregarious owering can take place over small or enormous areas. Cases have been documented when the blooming started in one area and spread, taking a few years to cover the entire owering zone. The Gregarious owering can sometimes continue for as long as from ve to fteen years. Most species die after owering.[3]

During owering, the bamboo stops growing and all the energy of the plant is used for making tiny owers [3]. The ower is very small and looks like an orchid. Its colour depends on the soil where the bamboo grows and it has a very short life, approximately 48 hours.[20]

Since the bamboos ower so rarely, the phenomenon has been very poorly researched. In 1912 an investigation was carried out in Tokyo. Some seeds were sown but non of the bamboo plants, that emerged then, has owered yet.[3]

2.2.9 Seedling A bamboo seed is very similar to a wheat grain in size and shape. When germinating, the seedling rst develops a primary root and a primary culm. The root is the rst to emerge and through cell division the culm follows. When cells grow longer in the zones of growth, the culm elongates like a tele- scope that opens up. When several culms have grown up, the rhizomes start to develop. When a seedling has developed a rhizome, it has the complete structure of a mature plant. The shape of the rhizome will transform during the maturation of the bamboo.[3]

11 2.2.10 Growth

The largest reserve of bamboo grows in natural forests, which is the primary habitat of bamboo. Bamboo also rise in plantations and homesteads in many parts of the world.[5] The sympodial bamboos are quite sensitive to frost since they are tropical species. The culms of the sympodial bamboos normally grow from summer to autumn or at the beginning of the rainy season. The increment of the plant is controlled by the levels of moisture in the soil. In warm areas with frequent rainfall during the whole year, the sympodial bamboo can continue to grow all year around. The monopodial species can suer a colder climate than the sympodial ones. A monopodial bamboo can survive in temperatures around minus 20 degrees Celsius [12], and live in areas with mild winters without severe snowfall. The shooting of the monopodial species is controlled by temperature, which makes them sprout in springtime. After a bamboo has completed is growth, wich takes 80 to 120 days for a sympodial bamboo and about 60 days for a monopodial one, the culm hardens and matures but the height and diameter of the culm do not change. Some species grow faster during night, sometimes up to two to three times the growth by day, but other species grow faster during daytime.[3] According to Medrano[23], a Guadua bamboo can be said to have four stages of maturity:

Young culm: This phase is initiated by the growth of both primary and secondary branches. The culm is not yet so hard and has a clean surface. The coloring of the internodes is intense green and the nodes are white.

Premature culm: This stage of maturity is characterized by the fading luster of the culm and the emerging presence of fungus on it. The culm has normally reached an age of two or three years at this stage and has a high level of resistance.

Mature culm: This is the maturity stage, see Figure 2.5, when the whole culm is covered by fungus and the nodes in some places covered by moss. The mature phase normally continues for one year and during this period the culm starts to dry.

Over mature culm: The over mature bamboo has lost all its humidity and there is very little or non physiological activity in the culm, that at this stage has turned yellow. The culm has lost up to 80 percent of its resistance at this stage and starts to loose the protecting sheaths that covers the culm and branches.

12 Figure 2.5: Mature culm.

2.2.11 Environment Janssen[5], writes about studies made 1990 by Billing and Gerger, who clas- sied the impacts of bamboo on the environment. The results of the study were that the bamboo has many positive impacts on the environment, some of them are:

• Erosion. Bamboo grows fast, and in a short time develops an extended root system, supporting the soil and prevent- ing it from being washed away by heavy rains. The dense roof of branches and leaves protects the ground from forceful

13 tropical rains. Bamboo is a lightweight material, without a need for heavy machinery for felling and transportation. • Physical soil structure. The root system loosens up the soil, which was made hard and compact by exposure, machinery and cattle. The leaf roof protects the soil from further exposure. • Ground water level. Bamboo consumes water, but this is more than compensated by the reduced evaporation created by the leaf roof, and by the layer of fallen leaves. Owing to the increased permeability of the soil, water run-o is reduced, allowing more water to penetrate the soil and thereby more water remain in the area. • Soil fertility. This is improved by protecting the soil from exposure and by the falling leaves providing organic material. • Drainage by the root system and the layer of fallen leaves. • Micro and local climate. The bamboo plant is a helping factor for stabilization of humidity and temperature. • Feeding area and habitat for fauna. Bamboo provides a rich environment for insects, birds and some mammals.

In the study one minor negative impact was found:

• Bamboo Guadua is found to have a slight negative eect on the pH-level.

2.3 World Distribution

Bamboo has a broad weather tolerance which leads to a rather extensive distribution of the plant. Bamboo can live in areas with temperature ranges from minus 4 degrees Celsius to plus 47 degrees Celsius, rainfall extremes from 762 millimetres to 6 350 millimetres per year, from sea level to 3 658 metres in altitude and from 46 degrees north and 47 degrees south in lati- tude, see Figure 2.6.[3]

Bamboo grows naturally in North and South America, Africa, Asia, Aus- tralia and has recently been introduced to Europe as well. Asia has an old tradition to use and rene bamboo. The countries with the largest area, where bamboo is growing, are China, India, Bangladesh, Philippines and

14 Thailand. In 2003 the total world bamboo forest area was more than 22 million hectares.[14]

Moisture is a determining factor for the growth of bamboo and the plant is mostly found along waterways, rice paddies or in the tropical forests and jungles and never in dry places.[3]

Figure 2.6: World distribution of bamboo [31].

2.4 Species

The classication of plants in genetic groups and families was made by Lin- naeus (1707-1778). The classication is mainly based on the reproductive structures of the plants, but since many bamboo species bloom so rarely, it is very dicult to give an exact dierentiation of its species. Bamboos have been treated as a separate family of plant by some botanists and as a subfamily of grasses by others. The correct classication of the whole group is therefore uncertain.

Since 1789, when the rst bamboo genus, Bambusa, was described, seventy- ve generic names and more than one thousand specic names have been published. Each species has a need of a various type of soil and climate and has dierent physical properties. This makes dierent species suitable for

15 dierent elds of applications.[3]

The size and colour varies broadly between the species. Most bamboo species have green culms, but they can also be yellow, black, red, blue and white, see Figure 2.7. There are also canes with stripes. The blueness of the blue bamboo culms is often a product of new bloom powder on the new culms. When these culms come to maturity the blue colour may turn into dierent shades of green. An example of a white bamboo is Bambusa chungii. It got its name because the new shoots are covered in a lot of powder so that they appear white. One example of a black coloured bamboo is Bambusa lako. It is a sympodial bamboo with an upright and vertical prole.[40]

Figure 2.7: White, blue and black bamboo [40].

2.4.1 Sympodial Bamboos The bamboo species can, according to Farrelly[3], broadly be divided into sympodial (tropical) and monopodial (temperate) species.

Three well known sympodial bamboos are:

Bambusa vulgaris: The Bambusa vulgaris is the world's most widely distributed bamboo and grows in many dierent type of soil and can stand various types of weather.[3]

Bambusa textiles: The Bambusa textiles has extremely strong bres which makes it convenient for ne splitting and weaving. This makes this species

16 very suitable for baskets, mats, ropes, hats and fences.[3]

Dendrocalamus strictus: Dendrocalamus strictus is the most broadly distributed species of all Indian species and it is being used in a vast volume. Since it is the most distributed species it is also the most studied.[3]

2.4.2 Monopodial Bamboos Some examples of monopodial (temperate) bamboos are:

Arundinaria amabilis: The Arundinaria amabilis is from southern China and was the most traded and used bamboo from 1880 to 1930. The large culms of this species were particularly used for shing rods, for which this species is ideal.[3]

Phyllostachys bambusoides: More than 60 percent of the bamboo harvest in Japan comes from this species. Considering that Japan has 662 species this is remarkable. It is well adapted for constructions and other industrial uses and is also exceptional for erosion control.[3]

Phyllostachys nigra: This species is a native to China. In the end of its rst season it turns into a solid black color. Thereby it got its name. Phyl- lostachys nigra is, thanks to its excellent culm wood, especially appreciated for cabinetwork and furniture.[3]

2.5 Cultivation, Curing and Harvesting

Not many bamboo species are cultivated in a controlled way. The species which are used for industrial purposes are tall growing ones whit large culm diameters. For the use in gardens, a group of small species have been domesticated.[12]

2.5.1 Cultivation Although most of the bamboo stock in the world grow in natural forests, it can also be seen in plantations in some parts of the world [5]. The bamboo plant prefers a fertile, well drained soil that should not be to dry. Thanks to the system of rhizomes that rmly anchors the plant, the bamboo helps to prevent erosion on the slopes were it often grows. A bamboo growing in a cold climate prefers facing south, while a bamboo in a warm or mild climate

17 faces north.[3]

The bamboo should be planted as small plants, cuttings or osets, at the start of the rainy season or in the beginning of spring [3]. The distance between the plants should be approximately seven metres, which equals 225 plants per hectare. For an individual farmer it is hard to grow bamboo as a crop, the cultivation of bamboo is an industrial and commercial activity. The existing plantations in the world today are owned by cooperatives or companies. A positive aspect of growing bamboo is that it can be planted at places that normally are not put to any good use. A strip of land by the side of a road or railway can be an ideal place for growing bamboo.[5] A negative aspect of planting bamboo is the plants tendency to spread out when the rhizomes elongate fairly big distances [3].

2.5.2 Curing When starting up a bamboo plantation the selection of the site and the species that will be planted is crucial. A market survey can identify the future uses of the bamboo and thereby help select the appropriate species. When choosing the species the local climate is also an important factor.[5]

Before planting the unwanted vegetation on the site must be taken away. The small plants, cuttings or osets can be taken from a natural forest or plant nursery. Since the bamboo owers gregariously it is advisable to use planting material from various sources to avoid the possibility to lose the entire plantation at the same time, when the plants die after blooming.[5] According to Janssen[5], it is recommendable to use herbicides during the rst two years. In the third year, the bamboo can struggle with other vegetation on its own.

2.5.3 Harvesting While timber may need more than 100 years rotation, bamboo can normally be harvested after three to seven years [14]. The yield of a bamboo plantation varies depending on the location, grove management, species and the time since the previous cutting. There is no standardisation of how the yield gures should be given. Sometimes the gures are for green weight of entire plants or culms and sometimes for dried bamboo. The weight given sometimes is for mature culms only and sometimes for clear cutting of all bamboo at the site.[3]

18 A bamboo management problem is the over-harvest of groves at forest edges. This is due to the fact that people often chose to harvest the culms at the shortest distance from their village. A consequence of this is that the inner part of the bamboo groves grows so thick that it is impossible to reach mature culms, ready to be harvested. [5] Since sympodial bamboos grow in clumps, it is sometimes dicult to harvest those species. The oldest culms that are ready to be harvested are often surrounded by younger culms that are still growing. The solution is to cut into the grove from the direction were the fewest young culms grow. In this way, a minimum amount of young culms have to be sacriced.[3]

According to Flores[20], there is some important aspects that needs to be considerated while harvesting bamboo:

• Do not fell culm less then three years old.

• If possible, harvest in winter when the insects hibernate.

• Make the cut at a maximum height of 25-35 centimetres from ground level and always above the node. This is to avoid uid gathering in the culm that would aect the rhizomes negatively.

• Do not harm the shots and small plants that surround the chosen culm.

• Before felling the culm, be aware of the age of it and its future use.

• Facilitate the drying of the culm by leaving it in a vertical position, leaning on its branches or towards a support, at the site of felling.

• Just cut the culms that has been chosen for use.

• When felling the culms, make sure to leave enough mature culms to protect the smaller plants against wind and direct sunlight.

• Remove the felled culms in 10-15 days after felling.

• Store the felled culms vertically in a covered and protected place.

2.5.4 Insects If bamboo is not treated with wood preservatives or kept very dry, it is easily attacked by insects [39]. There are various kinds of insects that can attack bamboo. The attacks reduce the vitality of the plant and prevent the increment. The insects that attack the bamboo have natural enemies, which

19 control the populations of these insects in natural stands of bamboo. Be- cause of this natural control of the insects, the attacks are not considered serious in natural stand of bamboo that has a good biodiversity and stable population. In Asia, more than 800 species of insects that attack bamboo has been recognized.[36]

In Asia, there exists more than 50 species of insects that can destroy n- ished bamboo products or felled culms. This should be considered a serious threat to the Asian bamboo industry because the damages can have a big economical impact, for example in big constructions.[36]

Unfortunately, in most cases the insect attacks are prevented with the help of non-environmentally friendly and poisonous products.

2.6 Anatomy and Mechanical Properties

The mechanical properties of a bamboo culm are determined by its anatomical structure [6]. Below, the anatomical structure of bamboo is briey described before its mechanical properties are presented.

2.6.1 Anatomical Structure

According to the anatomic study of bamboo made by Liese[6], the variation between dierent bamboo species can be seen as rather small. These dif- ferences between the species are of taxonomic value and they have inuence on properties and processing. Bamboo has no radial cells, like trees have rays, to transport liquids and nutrients. In the bamboo plant it is the node that provides the transportation of those substances. The outer part of the culm, the cortex, acts as a tissue protector and water blockader. The cells are dierent in dierent part of the culm; they are vertically along the culm length and transversally across the culm wall.[6]

Structure of the Internode

Most species possess hollow internodes where a culm wall is surrounding a large cavity, but few species have solid internodes. A culm consists of approximately 52 percent parenchyma, 40 percent bres and 8 percent conducting tissue. The outer third part of the culm contains about 50 percent of all the bres of the stem.[6]

20 Structure of the Node The nodes of a bamboo culm are the repeated scars in the sheath that covers the whole culm. A young bamboo has white nodes which can clearly be seen in contrast to the green internodes.

The cells in the nodal area dier signicantly in size and form from the cells in the internodes [6]. The essential chemical components of bamboo are cellulose, hemicellulose and lignin [10]. Hemicellulose and cellulose make up more than 50 percent of the total chemical components in bamboo [7]. Lignin is also an important chemical component which acts as a binder for the cellulose bres.[10]

The nodes have an immense inuence on the mechanical strength of the culm. The shorter bres and distorted vascular bundles of the node lead to higher density, lower volume shrinkage and lower tensile strength than the internodes.[6]

2.6.2 Mechanical Properties Bamboo is an anisotropic material; the properties in the longitudinal direction are completely dierent from those in transversal direction. In the longitudinal direction there are the cellulose bers, which are strong and sti. In the transversal direction there is lignin, which is soft and brittle. Therefore, bamboo is a unidirectionally reinforced composite with comparatively little tangential capacity.[5]

The density decide the mechanical properties of a culm [6]. According to the studies of Liese[6], the density of the bamboo depends on the bre content, bre diameter and cell wall thickness. Therefore the mechanical properties vary signicantly within a culm and between species. The density varies approximately between 0,5 and 0,9 g/cm3. The bre distribution varies in the culm; the outer part of the culm has denser distribution of bres than the inner part, see Figure 2.8, which means that the outer part has a far higher density than the inner part.[6]

The base is the hardest and most resistant part of the bamboo culm [13], and the bending strength is two to three times higher on outer parts than inner parts. The density increases upward the culm, thanks to the thinner culm wall with a higher compactness of vascular bundles. Older culms have

21 Figure 2.8: Microscope picture of Guadua chacoensis. higher density than young culms.[6] In Table 2.1 some mechanical properties of bamboo can be seen.

Density [kg/m3] 600-800 Young's modulus [MPa] 15 000-20 000 Tensile strength [MPa] 160-320 Compressive strength [MPa] 60-100 Flexural strength (modulus of rupture) [MPa] 80-160 Elongation [%] 2.88-3.52

Table 2.1: Mechanical properties of bamboo [33].

In spite of the fact that bamboo is a grass, it has many similarities to wood. The cell construction and the properties of bamboo resemble the structure of wood. Like earlier mentioned, the bamboo culm is harder on the outer parts then the inner. The wood has reverse structure with a hard centre and is weaker in the outer parts. This is an advantage for bamboo, which grounds a more stable construction.[42] Another advantage is that bamboo does not have rays liker woods. Rays are channels necessary for transporta-

22 tion of food, mainly sugar, but they weaken the material. This leads to the fact that bamboo often is stronger than wood.[5]

When bamboo is being compared with construction steel, one important aspect is that constructing in steel needs 50 times more energy than bamboo. Bamboo is a good alternative to steel when it comes to tensile loading. This is due to the fact that bamboo has a six times higher quotient between tensile strength and density than steel. When the humidity content increases the physical and mechanical properties also increases.[11]

2.7 Renement Techniques

When it comes to the processes of rening bamboo, very few books and articles are available. This is the result of that the knowledge about how to rene bamboo in traditional ways, has been passed on from father to son for centuries. The knowledge has not been transcribed to be published and spread to others. The following section gives a very brief overview of the most common renement techniques.

2.7.1 Drying Depending on the species, site of growth and felling, a green bamboo culm can have very high moisture content. In comparison to wood, bamboo take longer time to dry and since there is a risk of deformation a quick drying is preferable.[28]

Kiln Drying: Whole culms that are kiln dried often shows cracking and therefore kiln drying is not recommended in these cases. However, kiln drying is usable for split bamboos.[28]

Air Drying: Depending on the initial moisture content in the culm and the wall thickness, air drying takes approximately six to twelve weeks. In some species non-uniform shrinkage and excessively shrinkage causes collapse that makes the culm useless. Those problems are most often seen in drying of young culms, hence it is recommended that only mature culms are used for drying. Fewer problems are seen in drying of split bamboos. Split bamboos can even be dried in open sun-light without any problems. To accelerate the drying of whole bamboos they can be dried in an upright position, see Figure 2.9. Split bamboo can protably also be dried placed in an upright position.[28]

23 Figure 2.9: Bamboo culms drying.

2.7.2 Cutting

The easiest way to cut bamboo in desired lengths is with a saw [3]. It is important that the tools are sharp, since this prevent tearing and splitting [4].

A common belief in many countries where bamboo grows, is that the phase of the moon during which the bamboo is felled, is correlated with the possibility to latter insect attacks. There is no scientic basis to this belief.[4]

2.7.3 Splitting

Dierent splitting techniques have been developed in dierent countries. Those are often very simple and depending on the thickness of the culm wall, dierent tools are used.[4] The most common tool for splitting bamboo is a sharp machete. The blade is forced through the culm to separate the pieces from each other. To be able to fasten the process of splitting bamboo, techniques have been developed for dealing with large amounts of raw material.[3]

24 2.7.4 Bending

According to Farrelly[3], bamboo can be bent by heating it or by soaking it rst. When heating the bamboo, the mortar holding the bers becomes exible and it is possible to bend the material to a desired shape. The shape to which the bamboo is formed is preserved after cooling.

2.7.5 Joints

The best placements for joints are near nodes, since the internodes are hollow and can therefore break relatively easy. Making joints in bamboo is not trivial since the culm is hollow, not perfectly circular and has nodes at vary- ing distances. All these restrictions have to be considered while designing a joint.[5] Typical jointing can be seen in Figure 2.10.

Janssen[5], arranges the dierent joints into eight groups, depending on how the jointed pieces are arranged in relation to each other, and if jointed from the inside or outside of the culm. In the groups, dierent ways of putting the pieces together exists; lashes of dierent types and pins of steel or wood. Four of the groups Janssen mentions are:

• Full cross section. This group is characterized by contact of the full cross-section of the bamboo culm. Mostly lashing is used to keep the bamboo culm in position.

• From inside to an element parallel. In most cases, the hollow of the bamboo is lled with material like cement, mortar or a piece of timber, after which the jointing moves into the better known area of joints between steel bars or wooden pieces.

• From inside to an element perpendicular. • For split bamboo. This too is a modern development. Thin pieces of galvanized steel fastened with nails. Used in prefab- ricated housing. Besides glue, nails or pieces of galvanized steel also can act as jointing material.

Janssen[5], further tells that scaoldings made of jointed bamboo culms, are an extraordinary example of good jointing. The culms are jointed together with lashes of bamboo and it is important to apply the strips wet, so that the shrinkage leads to a perfect bonding.

25 Figure 2.10: Bamboo joints.

2.7.6 Laminating In general, laminated bamboo boards are manufactured from monopodial bamboos. The boards are close to wood when it comes to the qualities and appearance. Laminated bamboo is very suitable for ooring and furniture and can replace wood in doors and window-frames and many other applications.[8]

The process of laminating bamboo begins with the translation of the bamboo culms into strips with a uniform rectangular shape. After drying the strips into the right moisture content an adhesive is applied on the sides of each one. The strips are pressed together to get a good bonding. When laminating, the strips can be placed against each other in two dierent ways.

26 Depending on the position of the strips the laminate is denominated vertical or horizontal.[8] In Figure 2.11 vertical and horizontal laminates can be seen.

Figure 2.11: Vertical and horizontal laminates.

When manufacturing bamboo laminates, the wall thickness and the diameter of the culm have inuence on the manufacturing process and the end result. These two parameters limit the size of the bamboo strips which are glued together when making laminates. According to Bansal et.al [8], the colour of the laminate can be darkened by steaming the bamboo strips before drying them. The temperature of the steam and the time of steaming decide the nuance developed. A higher temperature and a longer steaming time gives a darker colour.[8]

2.7.7 Surface Treatment

The nishing method depends on the end-use of the bamboo and also the specic product. Some possible surface treatments are smoking, lacquering and painting.[4]

27 2.8 World Market

The bamboo world market had in 2003 reached a level of 10 billion US dollars and is growing, thanks to the increasing demand of environmentally friendly green bamboo products. Today the bamboo industry has an important role in providing food, housing and income generation for about 2.2 billion people in the world.[19]

The world population and economy are growing at the same time as the demand for wood and wood products are increasing and the world forests are shrinking. One possible solution to this problem is broader exploitation and use of wood substitutes.[14] Bamboo has an immense potential as wood substitute as it is fast growing. In this area, as wood substitute, bamboo's potential is strengthen by the fact that it is a wide spread, low cost and environmental friendly plant.[19] Suitable areas for further development and penetration are ooring, furniture, buildings, constructions, panels, paper and bamboo for plywood.[12]

2.9 Bamboo Uses

In terms of diversity, distribution and uses, bamboo is the unri- valled leader in the world of plants. There are over 1 500 documented uses for bamboo, and more are being discovered by modern science and technology.[6]

Bamboo can be rened in small craft based companies at village level but also in more modern high technological industries. Bamboo and bamboo bre can be used in a wide range of applications, from simple handicrafts to more advanced bre-based products.[19]

2.9.1 Constructions Bamboo products are hard and durable, which makes the material a suitable substitute for wood in many elds of application. One example is constructions.[12]

Bridges: In China and Asia there are bamboo bridges of many designs. Cables of bamboo bres were the rst material used for suspension bridges. Five centimetres thick bamboo cables can be spanned up to 76 metres and manage to support four tons without central support.[3]

28 Waterstorage: Cement tanks reinforced with bamboo have been used as an alternative to aluminium tanks. The cement tanks proved to be four times cheaper than galvanized steel tanks of equal size. Other uses are wa- terwheels, water pipes and water systems.[3]

Fences: Farrelly[3], gives examples of how bamboo can be used in the garden; functional walls around properties, fences for animals and decoration. In Figure 2.12 a typical fence for animals can be seen.

Figure 2.12: A fence of bamboo in Bolivia.

Scaolding: In many countries in Asia is bamboo used for construction of scaoldings. In comparison to steel scaolding, the scaolding made out of bamboo are well known for its low costs and ability to resists hurricanes.[5]

Cases are known wherein bamboo scaolds survived hurricanes that blew away steel ones as if they were matchsticks.[5]

In spite of these advantages, bamboo scaolding faces strong competition from steel scaolding. If bamboo scaolding is going to be spread to other parts of the world it is very important with a standardized system.[5]

29 2.9.2 Buildings Since hundreds of years, bamboo is used for constructions like houses, buildings and other structures [15].

Housing: The qualities and distribution of bamboo make it an excellent material for easy built and cheap houses. Like earlier mentioned, it is a lightweight material with a strength that is large in relation to its weight.[5] Today approximately one billion people in the world live in bamboo houses [9]. One negative aspect is that the bamboo should not be in contact with wet soil, see Figure 2.13. Therefore the bamboo culms need to be extended at the lower end, for example with concrete, to prevent decomposition.[5]

In many parts of the world bamboo is still considered as the poor mans timber and Janssen[5], writes about examples were people have made their bamboo houses look like concrete houses. These processes, mixing bamboo with concrete, weaken the structure of the houses and expose the lives of the people living there to danger. The problem is the bonding between the bamboo and the concrete. The bamboo wants to absorb water when the concrete is poured around it. When the concrete dries and gets harder, the bamboo also dries and shrinks.

Janssen[5], gives an example of a calculation that has been made. It is calculated that 70 hectare of bamboo plantation is sucient to build 1 000 bamboo houses per year. If these houses were built with timber instead, 600 hectare of natural forest would have been devastated each year.

Storerooms: One also important area that Farrelly[3], writes about is how bamboo is being used for building simple, low-cost, small-scale systems for storage and preservation of crops. These storerooms are important for enlarging the supply of food and make it more available to people.

Temporary Shelter: Bamboo is also a well suited material for building temporary shelter that can be put up in only a few hours.[3]

2.9.3 Plybamboo, Laminate and Furniture Plybamboo: Plybamboo is plywood made of bamboo. A positive aspect is that the process of manufacturing plybamboo can start at village level and end up in a modern factory.[5]

30 Figure 2.13: A bamboo veranda.

Laminate: A future possible large eld of application is laminate. New techniques of lamination can be of importance to modern industrial design.[3] Examples of applications for bamboo laminate are furniture and ooring.

Furniture: Bamboo has since a long time been used for furniture, often it is the straight culm that is used. Furniture is a good example of a product that can be made with simple tools at village level.[5]

31 2.9.4 Paper

Paper made out of bamboo has a nearly two thousand year long tradition in Asian countries. The rst seventeen hundred years the paper was made by hand. The following centuries new methods and processes for paper making were developed, and today India leads the bamboo paper production.[3]

Bamboo matures very fast in comparison with woods. This leads to the fact that bamboo can provide two to six times as much cellulose per area compared to pine. It is predicted that the quantity of bamboo pulp will increase dramatically because of the advantages bamboo has.[3]

2.9.5 Ecomaterial

Bamboo has several important ecological roles such as ood tamer, soil binder, windbreaker and earthquake neutralizer. It can also be used for fuel production and as carbon dioxide converter.

Fuel: Farrelly[3], explains that bamboo is an environmental friendly material and that the harvesting does not disturb the soil, which makes it well suited for fuel production. Another positive aspect is that bamboo is a re- newable energy source with an annual increase of 10 to 30 percent.

Carbon dioxide converter: Bamboo consists of cellulose and lignin that both contain much carbon. This means that bamboo needs a lot of carbon to grow. Bamboo acts as a carbon dioxide converter that absorb carbon from the air and store it in a process called carbon sequestration.[5]

Bamboo generates up to 35 percent more oxygen then the same amount of trees [30]. In a project run by the Environmental Bamboo Foundation, individuals are given a way to balance their personal carbon dioxide output by buying a share of a bamboo forest.[29]

2.9.6 Other Uses

Because of bamboo's rich amount of elds of application all uses can not be mentioned. But some other uses of bamboo worth mentioning are: food, health products, medicines, decoration and utensils.

32 2.9.7 Recently Developed Uses Ford Motor Company has recently presented a concept car, see Figure 2.14, with a futuristic combination of materials: bamboo, aluminium and carbon- bre. On the Tokyo motor show 2005 the car company Chrysler presented an idea of a future car, see Figure 2.14, with interior in recyclable material and bamboo ooring.

Figure 2.14: Ford concept car [32], and Chrysler future car [35].

The computer hardware company Asus has developed an eco-friendly laptop, see Figure 2.15. The laptop case is covered in bamboo and all the plastic in it is labelled and recyclable. There are no paints or sprays used on its components and the upgrading of components has been made easier.

Figure 2.15: Asus eco-friendly laptop with a bamboo case [38].

The Finish furniture company Artek has recently released a collection of bamboo furniture, consisting of tables and chairs, see Figure 2.16.

For spring 2007, the clothing rm Northface added new bamboo clothes to their ecoCloth Collection. The cloths consists of cotton and bamboo bres.

33 Figure 2.16: Artek bamboo table [27].

34 Chapter 3

Method and Performance

The following chapter describes the method and performance of the Master thesis. The delimitations of the thesis are also presented.

3.1 Research Approach

Bamboo is probably the fastest-growing and highest yielding natural resource and construction material available to mankind [18].

In spite of the statement above, bamboo has not yet reached its fully potential in Europe. Just recently, European engineers and designers have discovered this multifunctional highly environmentally friendly material. Both authors of this Master thesis are students of Industrial Engineering, spe- cialised in Wood Technology. Although bamboo is a grass, this material is highly interesting to anyone working with wood and wood-products. During autumn 2006 the authors of this report read several articles about the introduction of bamboo products on the Swedish market, mostly ooring, hence the interest of studying bamboo for the Master thesis. The fact that bamboo does not grow in Sweden and the co-operation beteween the University of Linköping and UPSA led to the choice of going to Bolivia to learn more about bamboo.

3.2 Pre-Study Phase

The Pre-study phase began in Sweden in January 2007 at the University of Linköping. During spring, litterature studies were carried out to obtain more knowledge about bamboo. Both books and a large number of academical articles were reviewed. Preliminary contacts in Bolivia were established to

35 be able to visit forest communities and companies working with bamboo in the Santa Cruz region. In April the same year the authors attended to a course in Gothenburg, which was arranged by Sida, to get information about how it is to live and work in a developing country.

3.2.1 Brainstorming Once in Santa Cruz the research objective of the Master thesis was to be decided. The authors brainstormed about possible areas to work within to be able to determine the course of the study. The brainstorming was carried out together with Mr. Luis Fernando Ortiz, an Industrial Engineering student at UPSA, also doing his Master thesis on the subject of bamboo.

3.2.2 Mind Map The brainstorming process was summarized in a mind map, see Figure 3.1, to give an overview of the conceivable areas of the study. The subhead- ings are listed without any relative order. Some areas discussed during the brainstorming process are not included in the mind map due to their vague relevance for the thesis's outcome.

36 Figure 3.1: Possible working areas summarised in a Mind map.

37 3.3 Evaluation of Possible Working Areas

After summarizing the possible working areas in the mind map, an evaluation of each category was made. This evaluation was conducted verbally by the authors together with Mr. Luis Fernando Ortiz. The possible working areas were discussed and evaluated with consideration for the relevancy and the accessible resources, both monetary ones and those concerning the space of time, for the Master thesis. Furthermore, the authors personal interests were taken into account when choosing the working area of the thesis.

The country's lack of information about the mechanical properties of native bamboos lead to the choice of studying this area. After the discussion and evaluation of possible working areas the objective in Section 1.2 was formulated.

3.4 Delimitations

The thesis's frame of reference, in Chapter 2, is deliberately extensive to get a wide-ranged knowledge about bamboo. This makes it necessary to delimitate the research to a specic objective hence many interesting areas described in the frame of reference are not further investigated. The total amount of time accessible to carry out the Master thesis is 20 weeks, 13 of those consists of the eld study in Santa Cruz. The restricted time-frame and the available equipment constitute themselves in important limitations for the research work.

The authors chose to study the mechanical properties of Guadua chacoensis, a bamboo species native to Bolivia. A brief study of the uses of Guadua chacoensis will be carried out. No market research will be made concerning bamboo. The market of bamboo products will only be briey discussed.

There are no existing standards about how to conduct mechanical properties test of bamboo. Therefore the authors used standards for wood as a guidance. Due to the limited time and resources the number of specimens tested had to be limited. For the same reasons the mechanical tests were limited to; tensile test parallel to bre, bending test and hardness test perpendicular to bre.

38 3.5 The Field Study

Between 4th of July and 19th of September 2007 the authors were stationed in Santa Cruz, Bolivia, to carry through the eld study. Cadefor oered the possibility to a working place at their head quarter oce in Santa Cruz and the knowledge and experience of the employees was available during the whole stay. UPSA made laboratory equipment available to facilitate the mechanical properties tests supervised by Gastón Mejia, Jorge Zeballos and Gustavo Quinteros. The contacts in Santa Cruz, made by the University of Linköping, and intermediated by Stig Algstrand, were used to get useful information about bamboo in Bolivia.

During the eld study theoretical studies were made, collecting local and international information about bamboo and Guadua chacoensis in particular. The laboratory tests were prepared and conducted during a period of nine weeks. To get a deeper understanding of the material and its origin several localities of the plant were visited, among them Buena Vista and Ascención de Guarayos.

3.6 Analysis

The results of the mechanical properties tests were analysed through comparison with corresponding mechanical properties of oak, birch, ash, beech and pine. To give further references to the reader some comparison with steel and aluminium alloys were made. Steel and aluminium are common construction materials and are also used in many other applications that are the same as for bambu. Since there exist many dierent steels and aluminium alloys the comparison was made with the types that have uses similar to those for bamboo.

To be able to analyse the future possibilities of Guadua chacoensis in Bo- livia a SWOT-analysis was made followed by brainstorming, where dierent elds of application were discussed.

3.7 The Quality of the Study

To be able to utilize the results given by this Master thesis in a suitable way, it is important to do an analysis of the quality of the study. The validity and the reliability of the thesis are discussed in the following section.

39 3.7.1 Validity In spite of the fact that bamboo grows in abundance in Bolivia, very few investigations of the material and its possibilities have been made. No investigations about the mechanical properties of Guadua chacoensis has been published. Due to this fact this Master thesis can be valuable as a rst initia- tive to further investigation of the bamboo species native to Bolivia. Through amplied knowledge of bamboo, the potentials of the Bolivian bamboo industry can be illuminated and thereby more sources of income can be created.

3.7.2 Reliability Due to lack of resources, as for example precise carpentry equipment, the specimens could not be given exactly the same dimensions and the moisture content could not be explicitly measured. The ve culms tested, all came from the same location, they are believed to be representative to the species but this can not be conrmed.

40 Chapter 4

Bamboo in Bolivia

Approximately 44 percent of the surface of Bolivia consists of forests. The forested area of Bolivia constitute in seven percent of the total Tropical Ama- zon, which makes Bolivia number six of the worlds countries with tropical forests. Historically Bolivia has, in comparison to the volume of the resource, not taken advantage of its forest resources.[21]

In South America the value of the bamboo plant and its variety of uses have been appreciated since the time of the Incas. Bamboo has been used in the majority of all the prehispanic cultures since more then 5000 years ago. It has been used for trade, housing and fences, alimentation, weapons, music instruments and medicine among many other fundamental functions.[2]

4.1 Distribution

No gures of how much bamboo that grows in Bolivia exist. The majority of the areas where bamboo grows in abundance are indigenous territories, where the native Indians use the resource for a variety of domestic purposes. In some areas the bamboo forests are converted into agricultural land and pastures by large landowners. The area with the biggest stock of bamboo is the department of Santa Cruz.[24]

The main bamboo growing areas in Bolivia can be seen in Figure 4.1. The numbers in the gure relate to areas where dierent species grow. Number three is for Guadua chacoensis.

41 Figure 4.1: Bolivia's main bamboo growing regions are marked [24].

4.2 Species

The rst taxonomy study of bamboo in Bolivia was made in 2004. In spite of this study, the number of bamboo species in the country is still very uncertain. Dierent sources give dierent answers according to the question about the number of bamboo species in Bolivia. Some quantities mentioned are 23-27 species [44], 24 species [25] and 42 species [43].

42 4.3 Bamboo Industry

The bamboo sector in Bolivia is still in its infancy. The rst bamboo investigations in Bolivia were not initialised until the 21th century. The knowledge of the geographic distribution of bamboo and the taxonomy of the species in the country was insignicant until 2004.[20]

There are no existing bamboo plantations in Bolivia, with the exception of some small plantations in central Bolivia, in the province of Florida. In this region, bamboo shoots are produced by locals with Japanese origin and used only for consumption.[24]

To be able to ocially exploit bamboo, and other forest products, a permit from the Bolivian forest department in each provincial capital is needed. Since it is very costly and complicated to obtain this permit, many of the ones who exploit and transport bamboo in Bolivia, does this illegally.[24]

In Bolivia there is a big lack of awareness on the multi-functionality of the bamboo and often the resources is wasted through burning and slash methods. Bamboo is often perceived as a weed that is invading the land and is considered a problem for agricultural production. This view has lead to devastation and waste of bamboo resources that could be valuable to many people.[24]

The existing capacity of the bamboo industry is considered low, compared to the resource available in the country. The Bolivian forest raw material are found in the provinces of Santa Cruz, Beni and Pando and the wood industry, which is a very active sector of the economy, is located in the vicinities of Santa Cruz, La Paz and Cochabamba. The number of companies working with forest products is not clear, but there exists around 1 100 companies that are legally known.[22]

Janssen[5], presents results from studies that shows how the bamboo industry can make a contribution to alleviate poverty through counteracting unemployment:

One ton of bamboo in the craft sector can generate an average of 150 working days. This means that two tons of bamboo is enough to employ one person for one year. One hectare of bamboo plantation can easily yield 20 tons per year, thus providing jobs for 10 people in the community.

43 4.3.1 Forestal Communities Bamboo is an important traditional product for many indigenous communities in Bolivia. For other communities, which are not using bamboo today, it could be an alternative to crop and an alternative income source. Uncon- trolled burning of the land and expansion of big cattle pastures is a great menace to the bamboo forests. Although new applications of the plant are found, this is still a very big threat to the natural resource. Ranchers burn the bamboo before the rain season, to kill insects and parasites and encourage new growth, which serves as food for the cattle.[24]

4.4 Bamboo Uses in Bolivia

Dierent species are suitable for dierent purposes, depending on their technical properties. In Bolivia, bamboo has traditionally been used by the native Indians for manufacturing of musical instruments, like utes and violins, fences and baskets.[24]

It is very hard to nd any statistics or gures about the utilization, com- mercialization and exportation of bamboo in Bolivia. One of the biggest reasons for this fact is that the governmental institutions, national non- governmental organizations and external organizations does not appreciate this natural resource or give it any special attention. As a consequence of this lack of awareness, no policies or plans have been developed for the use, renement or conservation of the natural bamboo forests.[24]

In some areas the bamboo can be seen used in dierent types of construction works, but in most regions the bamboo is rened with old techniques and inadequate methods. However, more industrial manufacturing methods are being used in some areas for the production of furniture and handicrafts which are sold on the market.[24] Figure 4.2 shows an example of how bamboo is used in constructions. The wall in the gure is reinforced with bamboo culms.

4.4.1 Historical Uses Many Indians living in the Andes fabricate music instruments of bamboo. Those instruments are manufactured with the purpose of use in cultural events, like traditional celebrations, or for the tourist industry and export market. The Bolivian musical instruments made of bamboo plays an impor-

44 Figure 4.2: A housewall reinforced with bamboo culms.

tant role for the identity and cultural expression of the native people.[24]

Other not so common uses of the bamboo in Bolivia is the use in constructions, see Figure 4.3, housing, see Figure 4.4, fencing, land rehabilitation, soil conservation, water systems, tools, baskets and in the manufacturing of handicrafts. In areas where bamboo grow in abundance and there is a lack of rewood, the plant is used as fuel for heating houses and cooking.[24]

45 Figure 4.3: Overhanging roof for sun protection.

4.4.2 Modern Uses Several species of bamboo are increasingly used for ornamental purposes, and for the manufacturing of furniture and bigger constructions such as garden sheds or houses, see Figure 4.5.[24]

46 Figure 4.4: Family house constructed with bamboo.

47 Figure 4.5: Restaurant complex and childrens playing area.

48 Chapter 5

Guadua Chacoensis

Guadua chacoensis is together with Guadua angustifolia, believed to be the most frequent bamboo species in Bolivia. The species is native to South America and grows in large quantities.

5.1 The Spicies

Guadua chacoensis, see Figure 5.1, is a sympodial species. Its culms can be up to 20 meters high and have a diameter of 10-12 centimetres. The culm is straight but inclines at the top and has hollow internodes. The leaves have a lenght of 10-13 centimetres and a width of 5-8 millimetres.[26] A transversal cut of Guadua chacoensis can be seen in Figure 5.2.

Family: Gramineae (Poaceae) Subfamily: Bambusoideae Species: Guadua chacoensis Native names: Tacuara, Tacuarembó, Bambú, Guadua

5.2 Distribution

Guadua chacoensis grows in tropical forests, most commonly near rivers. The plant prefers clayed and sandy soil. In Bolivia it is distributed in areas situated in altitudes between 260 and 400 metres above mean sea level, in the provinces of Santa Cruz and Cochabamba. In the province of Santa Cruz it grows in the areas of Ichilo and Guarayos, in Cochabamba in the area of Carrasco.[26]

49 Figure 5.1: Culms of Guadua chacoensis.

Figure 5.2: Transversal cut of Guadua chacoensis. 5.3 Uses

As already mentioned in Chapter 4, no ocial information about the use of bamboo and Guadua chacoensis in Bolivia exists. According to Gorena 50 [21], the species is used for baskets, carpets, constructions, furniture, handicrafts and fences. The authors of this thesis have observed the use of Guadua chacoensis for constructions, furniture, see Figure 5.3, handicrafts and fences.

Figure 5.3: A chair made of Guadua chacoensis.

5.4 Mechanical Properties

Prior to this Master thesis no investigations about the mechanical properties of Guadua chacoensis have been published. See Chapter 6 and Chapter 7 for the results of the mechanical properties tests.

51 52 Chapter 6

Laboratory Tests of Guadua Chacoensis

The objective of this Master thesis is to study the mechanical properties of Guadua chacoensis. This was accomplished by examine the tensile strength, bending strength and the hardness of the species. The authors carried out the tests at UPSA. Below the procedure and reults of the mechanical properties tests are presented.

6.1 Laboratory Standards

There are no existing standards describing how to carry through tests of the mechanical properties of bamboo. An ISO standard is currently being developed but has not yet been approved by ISO, the International Organisa- tion for Standardisation. The lack of a bamboo-testing standard submitted the authors to use a standard for wood. While conducting the mechanical properties tests of bamboo, the authors used the following South-American standards as a guidance:

Tension: Copant 742 Bending: Copant 555 Hardness: Copant 465 Some adjustments of the size of the specimens were made due to the hollow characteristics of the bamboo culm, that limits the dimensions of the specimens. The tests were carried out using a mechanical properties testing machine, see Figure 6.1.

53 Figure 6.1: Mechanical properties testing machine.

6.1.1 Tensile test

Through a tensile test the force required to break a specimen can be measured. The Young's modulus can be determined and the data can be used to analyse the tensile strength of the material. The specimen is placed vertically in the grips of a tensile test machine and a pulling force is applied until the specimen breaks.

54 6.1.2 Bending test In a three point bending test the specimen is placed lying on top of two holders with a predetermined distance between them. A compressive load is applied at half the distance between the holders, in other words in the middle of the specimens length. While the load is applied the modulus of elasticity is measured together with the exural stress and strain.

6.1.3 Hardness test The hardness is tested by forcing a steel ball, with a known diameter, into the material. The diameter of the indentation in the specimen is measured and the Brinell hardness can be calculated when the applied load is known.

6.1.4 Specimens Preparation The specimens were prepared from ve dierent bamboo culms felled in the same grove. The culms were felled between 25th and 30th of June 2007 in San Pablito, 250 kilometers from Santa Cruz. The ve culms were all between three and four years old and were randomly chosen. Each culm, with a length of three meters, was divided in two pieces with equal length, see Figure 6.2.

Figure 6.2: Schematic gure over the tested specimens.

Directly after dividing the culms the end of the pieces were painted, to prevent humidity to disappear through the ends and make the culms dry homogeneously. After painting the ends, the culms were brought to Santa

55 Cruz to be sawed into thin specimens and air-dried during a period of eight to twelve weeks. For each test, specimens from the lower part of the culm and the upper part of the culm was prepared. When the specimens were prepared, no consideration was taken regarding the location of the nodes at each specimen. The specimens from the lower part was marked with an A, and the specimens from the upper part was marked with a B. All specimens were labeled according to the following pattern: XYPrZ, were X is the number of the culm and Y is the part of the culm. Pr stands for Probeta which means specimen in Spanish and consequently Z is the specimen number. For example, the rst tested specimen from part B of culm number 2 was labled 2BPr1.

6.2 Results of the Mechanical Properties Tests

In this section, the results of the mechanical properties tests are presented in a comprehensive format. In the bottom of each table the mean, minimum and maximum value can be seen. The complete results can be seen in Appendices D, E and F.

6.2.1 Tensile Test Parallel to Fibre For the tensile test 40 specimens was tested; 20 from part A of the culm and 20 from part B. The specimen, which had a rectangular shape with a waist, see Figure 6.3, had the following dimensions [mm]:

Width: 9.2-11.9 Thickness: 5.2-7.5 Length: 247-263 The specimens were placed in the machine and load was applied until they broke. The maximum load, the tensile stress at maximum load, the extension at maximum load and the Young's modulus were measured.

The complete results of the tensile test is presented in Appendix D and

Figure 6.3: Tensile test specimen.

56 a summary of those are presented in Table 6.1 and Table 6.2. The average of the Young's modulus for the tensile test is 11 185 MPa and the average of the tensile stress at maximum load is 94 MPa.

6.2.2 Bending Test For the bending test 21 randomly chosen specimens, from both part A and part B and from all culms, were tested. The specimens were of rectangular shape with following dimensions [mm]:

Width: 25 Thickness: 6-8 Length: 360 The specimens were placed in the machine and load was applied until they broke. The maximum compressive load, the extension at maximum compressive load, load at break, compressive extension at break and the modulus of rupture were measured. The complete results of the bending test are presented in Appendix E and a summary of those are presented in Table 6.3. The average of the load at break is 144 N and the average of the modulus of rupture for the bending test is 19 MPa.

6.2.3 Hardness Test Perpendicular to Fibre For the hardness test 40 specimens were tested; 20 from part A of the culm and 20 from part B. Both sides of each specimen were tested, the rst side was labeled I and the second side II. The label of each side is randomly given and has nothing to do with inner and outer part of the culm. The specimens had a rectangular shape with the following dimensions [mm]:

Part A Part B Width: 25 Width: 25 Thickness: 8 Thickness: 5 Length: 100 Length: 100 The specimens were placed in the machine and a load was applied corresponding to an impression of three millimetres for the specimens from part A, and one millimetre for the specimen from part B. The dierence in depth of impression was due to the dierent thicknesses of the specimens, depending on if they were from part A or B, which is a consequence of the hollow

57 characteristics of the bamboo culm and that the wall thickness of the culm decreases with the height of the culm. The maximum possible thickness for the specimens from part B was ve millimetres. The maximum load and the maximum compressive extension were measured. The hardness according to Brinell was calculated using the following formula:

2P HB = √ πD(D − D2 − d2)

HB is the Brinell hardness, P the maximum load, D the diameter of the steel ball and d the diameter of the impression.

P was the output from each test, D was 11.5 millimetres and d was calculated using simple geometrics knowing the maximum compressive extension.

The complete results of the hardness test are presented in Appendix F and a summary of those are presented in Table 6.4 and Table 6.5. In the tables, the mean values of the Brinell hardness of each culm are presented. The average of the hardness is 1.85 HB.

58 Specimen Max load Tensile stess Extension Young's at max at max modulus [N] load [MPa] load [mm] [MPa] 1APr1 8518 132 7.4 16673 1APr2 4919 75 6.6 12368 1APr3 6249 101 4.1 18215 1APr4 2457 38 1.0 11358

2APr1 4579 73 5.9 9580 2APr2 7432 116 8.5 8861 2APr3 7111 111 7.7 8725 2APr4 3972 64 3.8 8379

3APr1 4583 71 2.8 10949 3APr2 5954 92 7.1 8497 3APr3 5733 88 5.3 10566 3APr4 5655 91 4.5 11390

4APr1 4208 68 4.0 10580 4APr2 3232 49 2.0 8016 4APr3 4105 65 6.7 7329 4APr4 5354 84 8.6 7582

7APr1 4181 66 3.1 9868 7APr2 2959 47 1.8 9842 7APr3 4190 66 3.7 9559 7APr4 4287 68 5.5 8955 Statistics Mean 4984 78 5.0 10365 Min 2457 38 1.0 7329 Max 8518 132 7.4 18215

Table 6.1: Result of tensile test part A.

59 Specimen Max load Tensile stess Extension Young's at max at max modulus [N] load [MPa] load [mm] [MPa] 1BPr2 6489 85 10.9 3357 1BPr4 8349 111 12.1 5818

2BPr1 6691 105 8.1 8495 2BPr2 6650 104 8.7 6860 2BPr3 7946 95 13.4 3602

3BPr2 4061 64 8.5 6963 3BPr3 9712 133 4.7 20359 3BPr4 5926 87 9.7 12683

4BPr1 6634 99 4.3 15409 4BPr2 5970 90 10.1 14998 4BPr4 8232 131 6.4 17913

7BPr2 9774 183 10.8 19984 7BPr3 10127 159 8.5 19883 7BPr4 4350 92 1.2 20660 Statistics Mean 7208 110 8.4 12642 Min 4061 64 1.2 3357 Max 10127 183 13.4 20660

Table 6.2: Result of tensile test part B.

60 Specimen Load at Compressive Modulus break extension at of rupture [N] break [mm] [MPa] Pr1 156 92.7 0.40 Pr2 79 53.0 1.07 Pr3 70 62.6 1.07 Pr4 70 57.5 0.60 Pr5 123 71.9 0.46 Pr6 216 31.0 32 Pr7 323 32.1 34 Pr8 71 55.8 20 Pr9 70 55.8 18 Pr10 71 28.5 26 Pr11 254 28.6 25 Pr12 70 35.4 17 Pr13 168 35.2 22 Pr14 116 47.9 32 Pr15 268 28.4 33 Pr16 97 53.4 12 Pr17 70 40.2 18 Pr18 292 37.5 42 Pr19 274 47.2 28 Pr20 71 25.4 25 Pr21 88 45.6 11 Statistics Mean 144 46.0 19 Min 70 25.4 0.40 Max 323 92.7 42

Table 6.3: Results of bending test.

61 Culm Hardness Brinell [HB] 1A 2.4 2A 2.7 3A 2.4 4A 1.6 7A 2.3 Statistics Mean 2.3 Minimum 1.6 Maximum 2.7

Table 6.4: Results of hardness test part A.

Culm Hardness Brinell [HB] 1B 1,0 2B 1,9 3B 1,7 4B 1,1 7B 1,4 Statistics Mean 1,4 Minimum 1,0 Maximum 1,9

Table 6.5: Results of hardness test part B.

62 Chapter 7

Analysis

This chapter contains the analysis of the results from the laboratory tests, a SWOT-analysis of Guadua chacoensis in Bolivia and some suggestions and possibilities concerning the Bolivian bamboo industry.

7.1 Laboratory Tests

Each test is analysed separately and the mean value of the results given by the mechanical properties tests are compared with the corresponding gures, from reference [1] and [33], of European oak (Quercus robur), European birch (Betula), ash (Fraxinus excelsior), beech (Fagus silvatica) and pine (Pinus silvestris) together with aluminium and steel. For the tensile test the gures for the Young's modulus and the tensile strength are analysed. The gures for the modulus of rupture and the Brinell hardness are analysed in the bending respectively hardness test.

7.1.1 Tensile Test Parallel to Fibre The most distinct observation made during the tensile tests is the fact that, with very few exceptions, all specimens broke at the node. This clear observation shows that the node is the weakest part of the bamboo culm. The big range of the test results depends partly of the specimens dierent locations of the nodes.

The range of the Young's modulus is 3 357-20 660 MPa. Of 34 tested specimens 22 (65%) have a modulus that lies between 6 500 and 13 000 MPa. Three specimens have a modulus under 6 500 MPa and nine specimens have a modulus over 13 000 MPa. Four reached a modulus around 20 000 MPa.

63 The specimens from the upper part of the culm, part B, have a slightly higher mean value of the Young's modulus than the specimens from the lower part, part A. This is due to the fact that the bre content and thereby the density is higher in the upper part of the culm.

The modulus for Guadua chacoensis is in the same range as the Young's modulus for all the comparing woods, see Table 7.1. This bamboo species has a modulus a little bit higher than the modulus for pine and ash and is comparable with oak.

The range of the tensile strength is 38-183 MPa. Of 34 tested specimens 26 (76%) have a tensile strength that lies between 60 and 120 MPa. Three specimens have a tensile strength under 60 MPa and ve specimens have a tensile strength over 120 MPa. The highest measured value of the tensile strength is 183 MPa.

The specimens from the upper part of the culm, part B, have in general a higher value of the tensile strength than the specimens from the lower part, part A. This is related to the variation in modulus in the dierent parts of the culm.

The tensile strength of Guadua chacoensis is higher than the tensile strength for oak and pine, but lower than for ash, birch and beech. The species has a tensile strength similar to some aluminium alloys.

Young's modulus Tensile strength [MPa] [MPa] Guadua chacoensis 11 185 94 European oak 10 000 - 13 000 90 European birch 13 000 - 15 000 137 Ash 8 300 - 13 400 165 Beech 10 000 - 16 000 135 Pine 10 000 - 12 000 60 - 73 Aluminium alloys 68 000 - 82 000 58 - 550 Steel 165 000 - 217 000 345 - 1 760

Table 7.1: Table for comparison of modulus and tensile strength.

64 7.1.2 Bending Test The bending test was conducted at two separate occasions. Specimen number one to ve were tested rst, and a few days later the test was completed by testing specimen number six to twentyone. Due to the big dierences in the test results, especially in the modulus of rupture, depending on which day the specimens were tested, it is likely that the gures for specimen number one to ve are not reliable. Hence, new overall mean values have been calculated, excluding specimen number one to ve.

The new overall mean value of the load at break is 157 N and the overall mean value of the modulus of rupture for the bending test is 25 MPa. The old values were 144 N and 19 MPa.

The mean value of the modulus of rupture for Guadua chacoensis is much lower than the one for all the compared woods, see Table 7.2. This means that it is very exible. Some aluminium alloys can reach values close to the one for Guadua chacoensis but steel is much less exible.

Flexural strength (Modulus of rupture) [MPa] Guadua chacoensis 25 European oak 112 - 137 European birch 119 - 145 Ash 78 - 96 Beech 93 - 113 Pine 65 - 79 Aluminium alloys 33 - 326 Steel 330 - 1 900

Table 7.2: Table for comparison of bending properties.

7.1.3 Hardness Test Perpendicular to Fibres The mean value of the hardness of Guadua chacoensis, 1.85 HB, is similar to the one for pine and slightly lower than the hardness of the other compared woods, see Table 7.3. Neither bamboo or any of the compairing woods can beat aluminium alloys and steel when it comes to hardness. Aluminium alloys have a hardness that is more than ve times bigger than the hardness of bamboo and steel is more than twenty times harder. The dierence between

65 the hardness of the lower part of the culm, part A, and the upper part of the culm, part B, is signicant. The lower part of the culm is harder than the upper part. This conrms the earlier mentioned fact, in Chapter 2, that the base of the bamboo culm is the hardest part. The lower part of the culm, with a top value of 2.7 HB, has a hardness similar to birch.

Hardness Brinell [HB] Guadua chacoensis 1.85 European oak 3.4-4.1 European birch 2.2-2.7 Ash 3.0-4.1 Beech 2.7-4.0 Pine 1.9 Aluminium alloys 10-140 Steel 100-200

Table 7.3: Table for comparison of hardness properties.

Due to the hollow characteristics of the bamboo culm the thickness of the specimens for the hardness test was limited. To be able to test the hardness of these thin specimens the Brinell test had to be modied to suit this purpose. Normally, testing the Brinell hardness is made by pressing a steel ball with a xed force into the surface of the material. Since the bamboo specimens were so thin, it was only possible to press the steel ball 1-3 millimetres into the surface. In the test conducted the impression of the steel ball was xed instead of the force. This change should not have had any inuence on the test result but it is important to know that the hardness test did not follow the normal procedure.

7.2 SWOT-Analysis

The following section contains a SWOT-analysis, see Table 7.4, which shows the strengths, weaknesses, opportunities and threats for Guadua chacoensis and its possibilities in Bolivia.

66 Strengths Weaknesses Grows in abundance Non homogeneous culm structure Fast growing Hollow culm Good carrying capacities Lack of scientic knowledge Traditionally used by natives Lack of technical knowledge and Big ratio of strength/density standards Can be used for land rehabilitation

Opportunities Threats Growing demand Forest devastation and burning Exportation Lack of regulations and plans Big range of applications Poor felling and transportation Jobcreation possibilities Existing knowledge in Asia Lack of understanding for the value New renement techniques of the plant Plantations

Table 7.4: SWOT-analysis of Guadua chacoensis in Bolivia.

7.2.1 Strengths One important aspect of Guadua chacoensis in Bolivia is that it grows in abundance in several areas in the country. It is a fast growing plant and it is possible to harvest every fourth to seventh year. Bamboo has traditionally been used in many dierent applications by the native indigenous people, which is a good foundation for an increasing use. The hollow culm of the bamboo plant makes it a good construction material since the shape has good carrying capacities. The hollowness also makes the raw material light and easy to transport and handle. The ratio of strength to density is big which makes the material very competitive to other construction materials, for example steel. An environmental strength of this bamboo is that, as all other bamboos, it is an eco-friendly material as it can be used for land rehabilitation and erosion control.

67 7.2.2 Weaknesses The non homogeneous structure of the culm, with its nodes placed at inter- vals, makes it dicult to rene the material and can sometimes limitate the uses of the plant. One example is the problem concerning joining together culms with each other or with other materials. The nodes are also the limi- tation when it comes to the strength properties of bamboo. The hollowness of the culm makes it dicult to use bamboo in some applications. For example nails can not be used with bamboo. The process of laminating bamboo can generate big amounts of waste material, due to the round shape and hollowness of the culm. The big lack of scientic and technical knowledge of bamboo in Bolivia constitute in the biggest weakness of all. The fact that almost no investigations of bamboo in Boliva have been carried out and published shows the big lack of knowledge and information about how to handle, rene, use and take advantage of this natural resource. Adequate equipment, like machines and tools for felling and renement, is non existent together with standards over how to examine and handle bamboo.

7.2.3 Opportunities The growing local and international demand of bamboo raw material and products is a great opportunity for Bolivia. The exportation possibilities to other South American countries, North America and Europe can be signif- icant for a future bamboo industry. Guadua chacoensis have a big range of dierent possible application elds. In general, today it is only used for some construction work, small-scale furniture manufacturing and handicrafts. Bamboo plantations and new renement techniques are other possibilities to strengthen the bamboo industry in Bolivia and thereby create employment. Bolivia has the possibility to take advantage of the great existing knowledge of bamboo that exists in Asia. If knowledge about cultivation, harvest and renement of bamboo would be brought from Asia, this would make it possible to avoid the most common mistakes, when developing this hitherto undeveloped industry.

7.2.4 Threats Forest devastation and burning for conversion of forest into pastures is a big threat to the bamboo industry. Today farmers burn, according to tradition, the land to create more pasturage. This is done without knowing the long term consequences, like impoverishing the soil. This burning kills all the natural growing vegetation including the bamboo. Like mentioned in Chapter 4,

68 hardly any of the government institutions, national non-governmental organizations or external organizations involved in the use and management of natural resources, have paid special attention to bamboo. This has lead to a big lack of regulations and plans according to the use and cultivation of this plant. The lack of understanding of the value of bamboo is a threat since this prevents the possibilities to take advantage of this natural resource. Today, the transportation possibilities are very poor. Bad roads or no roads at all makes it very dicult to fell and transport raw-material from the jungle.

7.3 Possibilities for Guadua Chacoensis

Below, some thoughts discussed during a brainstorming about the Bolivian bamboo industry are presented.

The prospects for developing the bamboo industry in Bolivia are good. To be able to make business out of Guadua chacoensis in Bolivia there are some important aspects, that are recommeded by the authors. For example the location of the company is very important due to the poor infrastructure and transportation possibilities. Another very important aspect is the choice of products which will be produced. Since there are very little technical knowledge and experiences concerning production of bamboo products it is important to start with rather simple products. This will create a technical knowledge about how to work the material and gradually more advanced products can be manufactured. Suitable products to start with are health- care products and products for educational purposes, since there is always an existing demand of these kinds of products.

The possibility to export bamboo products to other South American countries, North America or Europe is signicant. In the case of exportation it is extremely important that the products have a high quality which is competitive with existing products on the market. In consequence, the quality management and quality control of nished products must be highly pri- oritised. A standardisation of each product should be made to be able to guarantee that all products of the same type are equally good.

A good organisation, with motivated employees and structured production processes, is the foundation of a successfully company and must be a striving. When a new industry is developed it is important to learn from existing knowledge, in this case from Asia. It is also a good idea that companies working with bamboo in Bolivia, share information and knowledge with each

69 other. This is something that in a long run will favour the whole industry and thereby the country. Long-term planning is important to create healthy companies that can survive recessions and be competitive, both nationally and internationally.

Below, the above mentioned suggestions are summarised:

• Suitable location of the company.

• Careful choice of products.

• Start with simple products.

• Export to other countries.

• Structured organisation of the company.

• Learn from existing knowledge.

• Share information within the country.

• Make long-term planning.

70 Chapter 8

Conclusions and Recommendations

Through tensile-, bending- and hardness tests it was found that Guadua chacoensis is a exible, medium soft material and is comparable with Euro- pean oak when it comes to the tensile strength. This leads to the conclusion that the species can be used for some type of constructions, like houses and bridges, and for furniture.

It is recommended that Bolivia invests in developing the bamboo industry in the country. The bamboo business has great potential and can lead to a new income-source for low-income takers. Furthermore, scientic investigations ought to be carried out and know-how, concerning bamboo, should be brought from Asia. If this can be done, the value of the bamboo plant will be illuminated and the country will be able to take advantage of this natural resource in a more suitable way.

71 72 Chapter 9

Reections

The following chapter contains the authors' reections about the planning of the work and the nal results. Suggestions for future work on the subject are presented.

9.1 Planning of the Work

Already in October 2006, the authors started the planning of this Master thesis. To start this early was shown to be valuable since the authors were well prepared arriving in Santa Cruz. Once in Santa Cruz the objective of the thesis could be decided rather fast and the work could start immediately. Although the work was well prepared the laboratory tests were delayed one month. This delay was due to circumstances the authors could not inuence, for example the access to the laboratory equipment and the preparation of the specimens that was made by a local carpentry. Besides this delay of the laboratory tests, the work proceeded very smoothly.

9.2 Final Results

The specimens tested were taken from one single geographic area. It would have been interesting to test culms from other areas and compare the results. The soil, climate and growth circumstances might inuence the mechanical properties. It would have been desirable to carry through other mechanical properties tests as well. For example compression test and bending test with whole culms.

The lack of a laboratory standard for bamboo investigations was a problem when conducting the tests. This also makes it dicult to compare the

73 test results with those from earlier studies of bamboo. An ISO-standard is currently being developed and when this standard is available it will be easier to carry through investigations of bamboo.

9.3 Further Work

There is a big lack of available information and knowledge in Bolivia about bamboo and a lot needs to be done in this area. All work that can be done to increase the knowledge and illuminate the potential of this material is of great value for the country. Today there only exist small scale businesses working with bamboo, mainly based on handicrafts and constructions. The trade and production of bamboo products is likely to be considerable and have export prospects. A developed bamboo industry could make a contribution to the welfare of the country and help to reduce the country's high level of unemployment.

74 Bibliography

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79 80 Appendix A

Glossary

Bending strength The limit state of the stress leading to exion of a physical body.

Cadefor Amazonic Center for Sustainable Forest Enterprise.

Compressive load The load leading to compression of a physical body.

Cortex The bark or barque of a plant or tree.

Culm The trunk or stem of the bamboo plant.

Density Mass per unit volume.

Diaphragm The solid cross-wall between two hollow internodes.

Gregarious owering All bamboo of the same species owers at the same time and the leavs stops growing.

Inbar International Network for Bamboo and Rattan

81 Internode The part of the culm or rhizome that lies between two nodes.

Lacuna The inner space of a hollow internode [6].

Minor eld study A scholarship founded by Sida and aimed for university students. The scholarship nances a eld study in a developing country during eight to ten weeks with the purpose to create knowledge about developing issues.

Modulus of rupture The maximum stress at break.

Monopodial A type of rhizome that is long and has symmetrical internodes more long than broad.

Node The piece of the culm or rhizome from were branches or roots orginates. At the node a cross-section devides the culm.

Parenchyma Cells that store and distribute food materials [6].

Protoxylem The rst-formed primary xylem cells, formed as a part of the vascular bundle [6].

Rhizome The under ground growing system of stems of a bamboo plant. Two types; Monopodial and Sympodial.

Root primordia The rst visible trace of a root.

SD Standard deviation.

Sheat scar The mark on the culm were the sheat is interupted and the node is situated.

82 Sida Swedish International Development Cooperation Agency, .

Specic weight The weight per unit volume, in other words the density multiplied with the gravity constant.

Strain The deformation caused by stress on a physical body.

Sympodial A type of rhizome that is thick and short with asymmetrical internodes more broad than long.

Tensile strength The limit state of the tensile stress.

Tensile stress The stress state leading to elongation.

UPSA Private University of Santa Cruz de la Sierra, Bolivia.

Vascular bundles Consists of vessels, protoxylem and phloem surrounded by bre sheaths and in sympodial bamboos accompanied by bre bundles [6].

Vessels Large cells arranged in axial series for water conduction [6].

Young's modulus The ratio, for small strains, of the rate of change of stress with strain.

83 84 Appendix B

German Abstract

Diese Diplomarbeit wurde durch das CTD- Zentrum für Holztechnik und Design an der Universität Linköping betreut und in Santa Cruz de la Sierra in Bolivien durchgeführt.

Das Ziel dieser Arbeit ist es die mechanische Beanspruchung und die Anwendungen von Guadua chacoensis , einer bolivischen Bambusart, zu un- tersuchen. Bambus wurde in der Vergangenheit in vielen Ländern für die unterschiedlichsten Anwendungen wie zum Beispiel Häuser, Werkzeug, Mö- bel, Lebensmittel, Treibsto und Papier verwendet.

In meisten asiatischen Ländern ist Bambus ein wichtiger Rohsto für kleine und mittlere Unternehmen. Damit werden Arbeitsplätze geschaf- fen, was der Bevölkerung hilft die Armutsgrenze zu überwinden. Auch in Lateinamerika haben viele Länder, wie zum Beispiel Bolivien, die Chance Bambus in der gleichen Weise zu nutzen. Ein zentraler Gedanke dieser Ar- beit ist es daher eine Grundlage für die bolivische Wirtschaft zu schaen damit dieser bislang kaum entwickelte Rohsto genutzt werden kann.

Diese Arbeit wurde von Sida- der Schwedischen Internationalen Entwick- lungsorganisation, teilweise nanziell unterstützt. Im Rahmen der durchge- führten Studie wurden sowohl theoretische Aspekte betrachtet, als auch Ver- suche im Labor der privaten Universität von Santa Cruz de la Sierra durchge- führt. Des Weiteren wurden verschiedene Arten des Bambus in der Natur untersucht.

Biege- Streck- und Festigkeitsversuche haben gezeigt, dass Guadua chacoensis ein exibles und weiches Material ist. Von den Streckeigenschaften ist es mit europäischer Eiche zu vergleichen. Diese Ergebnisse führen zu der

85 Schlussfolgerung, dass Guadua chacoensis für die Konstruktion von Häusern und Brücken, für die Herstellung von Möbeln und andere ähnliche Anwen- dungen eingesetzt werden kann.

86 Appendix C

Spanish Abstract

Esta tesis ha sido realizada en el Centro de Ciencia de Madera y Diseño- CTD de la Universidad de Linköping y ha sido llevada a cabo en la ciudad de Santa Cruz de la Sierra, Bolivia.

El objetivo de la tesis es estudiar los propiedades mecánicas y usos de la Guadua chacoensis, un bambú nativo de Bolivia. A lo largo de la historia, el bambú ha sido utilizado en muchas localidades del mundo en distintas aplicaciones, vale mencionar: viviendas, herramientas, muebles, alimentos, combustible, papel y para rehabilitación de la tierra. En casi todos los países Asiáticos el bambú es un recurso importante para empresas de tamaño pe- queño y mediano, proporcionando empleo y contrarrestando la pobreza.

En América Latina muchos países, incluyendo Bolivia, tienen potencial para aprovechar el bambú del mismo modo. Una de las ideas más impor- tantes de la tesis es hacer una contribución para apoyar a la economía de Bolivia, la cual, hasta ahora, ha desarrollado muy poco este recurso natural.

La tesis es un Minor eld study parcialmente nanciado por Asdi- la Agencia Sueca de Cooperación Internacional para el Desarrollo. Durante el Minor eld study estudios teóricos fueron realizados, acumulando informa- ción nacional e internacional sobre bambú y Guadua chacoensis en particular. Para examinar los propiedades mecánicos de la Guadua chacoensis, pruebas de laboratorio fueron preparadas y efectuadas en la Universidad Privada de Santa Cruz de la Sierra. Asimismo, muchas áreas con bosques naturales donde crece la especie fueron visitadas.

A través de pruebas de laboratorio de tracción, exión y dureza ha sido demostrado que la Guadua chacoensis es un material exible y de dureza

87 media, comparable con el roble europeo cuando se trata de la fuerza de tracción. Eso tiene como resultado que la Guadua chacoensis, entre otros campos de aplicación, puede ser usada para construcciones, como casas y puentes, y para la manufacturación de muebles.

88 Appendix D

Results Tensile test Parallel to Fiber

Date: 24th-29th of August 2007 Name and location of laboratory: UPSA, Santa Cruz, Bolivia Velocity: 1.00 mm/min Relative humidity: 43 percent Temperature: 25 Celcius degrees

Botanical name of species: Guadua chacoensis Air-dried during eight weeks.

89 D.1 Lower Parts of Culms - A

Culm 1

Specimen Width [mm] Thickness [mm] 1APr1 11.3 5.7 1APr2 11.9 5.5 1APr3 11.3 5.5 1APr4 11.6 5.6 Statistics Mean +1SD 11.81223 5.67074 Mean -1SD 11.23777 5.47926 Mean 11.52500 5.57500 Min 11.3 5.5 Range 0.6 0.2 Max 11.9 5.7 Table D.1: Dimensions of specimens 1A tensile test.

Figure D.1: Diagram of tensile test 1A. All specimens broke at node.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 1APr1 8517.70 132.24194 7.38352 0.64410 260 16672.94387 1APr2 4918.50 75.14891 6.64949 0.65450 261 12367.76046 1APr3 6248.65 100.54143 4.05797 0.62150 260 18214.99352 1APr4 2456.95 37.82253 1.01451 0.64960 260 11358.42524 Statistics Mean+1SD 8069.24 126.38790 7.66160 0.65701 260.75 Mean-1SD 3001.66 46.48951 1.89115 0.62784 259.75 Mean 5535.45 86.43870 4.77637 0.64242 260.25 14653.53077 Min 2456.95 37.82253 1.01451 0.62150 260.00 11358.42524 Range 6060.75 94.41941 6.36902 0.03300 1.00 6856.56828 Max 8517.70 132.24194 7.38352 0.65450 261.00 18214.99352 Table D.2: Result of tensile test 1A.

90 Culm 2

Specimen Width [mm] Thickness [mm] 2APr1 11.4 5.5 2APr2 11.6 5.5 2APr3 11.6 5.5 2APr4 11.9 5.2 Statistics Mean +1SD 11.83116 5.57500 Mean -1SD 11.41884 5.27500 Mean 11.62500 5.42500 Min 11.4 5.2 Range 0.5 0.3 Max 11.9 5.5 Table D.3: Dimensions of specimens 2A tensile test.

Figure D.2: Diagram of tensile test 2A. All specimens broke at node.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 2APr1 4579.30 73.03503 5.93638 0.62700 261 9579.79468 2APr2 7432.13 116.49100 8.46763 0.63800 260 8860.51574 2APr3 7110.84 111.45518 7.73192 0.63800 263 8724.88208 2APr4 3971.78 64.18513 3.82701 0.61880 260 8379.05950 Statistics Mean+1SD 7525.83 117.80977 8.56047 0.63979 262.41 9391.02113 Mean-1SD 4021.19 64.77340 4.42100 0.62111 259.59 8381.10487 Mean 5773.51 91.29159 6.49073 0.63045 261 8886.06300 Min 3971.78 64.18513 3.82701 0.61880 260 8379.05950 Range 3460.35 52.30587 4.64062 0.01920 3 1200.73518 Max 7432.13 116.49100 8.46763 0.63800 263 9579.79468 Table D.4: Result of tensile test 2A.

91 Culm 3

Specimen Width [mm] Thickness [mm] 3APr1 11.8 5.5 3APr2 11.8 5.5 3APr3 11.8 5.5 3APr4 11.3 5.5 Statistics Mean +1SD 11.92500 5.50000 Mean -1SD 11.42500 5.50000 Mean 11.67500 5.50000 Min 11.3 5.5 Range 0.5 0 Max 11.8 5.5 Table D.5: Dimensions of specimens 3A tensile test.

Figure D.3: Diagram of tensile test 3A. All specimens broke at node.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 3APr1 4582.91 70.61499 2.80245 0.64900 247 10949.36570 3APr2 5953.65 91.73576 7.07142 0.64900 248 8496.72514 3APr3 5732.63 88.33026 5.26339 0.64900 248 10565.77300 3APr4 5654.89 90.98769 4.47991 0.62150 248 11390.34366 Statistics Mean+1SD 6092.99 95.39291 6.67660 0.65588 248.25 11631.53309 Mean-1SD 4869.05 75.44144 3.13198 0.62837 247.25 9069.57066 Mean 5481.02 85.41718 4.90429 0.64213 247.75 10350.55188 Min 4582.91 70.61499 2.80245 0.62150 247 8496.72514 Range 1370.74 21.12077 4.26897 0.02750 1 2893.61852 Max 5953.65 91.73576 7.07142 0.64900 248 11390.34366 Table D.6: Result of tensile test 3A.

92 Culm 4

Specimen Width [mm] Thickness [mm] 4APr1 11.3 5.5 4APr2 11.9 5.5 4APr3 11.4 5.5 4APr4 11.6 5.5 Statistics Mean +1SD 11.81458 5.50000 Mean -1SD 11.28542 5.50000 Mean 11.55000 5.50000 Min 11.3 5.5 Range 0.6 0 Max 11.9 5.5 Table D.7: Dimensions of specimens 4A tensile test.

Figure D.4: Diagram of tensile test 4A. All specimens broke at node.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 4APr1 4208.09 67.70863 4.02790 0.62150 248 10579.60031 4APr2 3231.78 49.37780 2.01897 0.65450 248 8015.67444 4APr3 4104.83 65.46783 6.73995 0.62700 247 7328.86119 4APr4 5354.22 83.92194 8.64843 0.63800 248 7581.62289 Statistics Mean+1SD 5095.81 80.75132 8.28314 0.64980 248.25 9872.34777 Mean-1SD 3353.65 52.48678 2.43449 0.62070 247.25 6880.53165 Mean 4224.73 66.61905 5.35881 0.63525 247.75 8376.43971 Min 3231.78 49.37780 2.01897 0.62150 247 7328.86119 Range 2122.44 34.54414 6.62946 0.03300 1.00 3250.73913 Max 5354.22 83.92194 8.64843 0.65450 248 10579.60031 Table D.8: Result of tensile test 4A.

93 Culm 7

Specimen Width [mm] Thickness [mm] 7APr1 11.5 5.5 7APr2 11.5 5.5 7APr3 11.3 5.6 7APr4 11.5 5.5 Statistics Mean +1SD 11.55000 5.57500 Mean -1SD 11.35000 5.47500 Mean 11.45000 5.52500 Min 11.3 5.5 Range 0.2 0.1 Max 11.5 5.6 Table D.9: Dimensions of specimens 7A tensile test.

Figure D.5: Diagram of tensile test 7A. All specimens broke at node.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 7APr1 4180.84 66.10021 3.06361 0.63250 250 9868.10710 7APr2 2959.29 46.78724 1.84821 0.63250 248 9841.70472 7APr3 4190.14 66.21579 3.73660 0.63280 248 9559.2700 7APr4 4287.10 67.78021 5.49441 0.63250 248 8955.27084 Statistics Mean+1SD 4536.20 71.70605 5.05749 0.63272 249.5 9980.32247 Mean-1SD 3272.48 51.73568 2.01394 0.63243 257.5 9131.85388 Mean 3904.34 61.72086 3.53571 0.63258 248.5 9556.08817 Min 2959.29 46.78724 1.84821 0.63250 248 8955.27084 Range 1327.81 20.99297 3.64620 0.00030 2 912.83625 Max 4287.10 67.78021 5.49441 0.63280 250 9868.10710 Table D.10: Result of tensile test 7A.

94 D.2 Upper Parts of Culm - B

Culm 1

Specimen Width [mm] Thickness [mm] 1BPr2 10.2 7.5 1BPr4 10.7 7.0 Statistics Mean +1SD 10.66056 7.48426 Mean -1SD 9.93944 6.58241 Mean 10.30000 7.03333 Min 10.0 6.6 Range 0.7 0.9 Max 10.7 7.5 Mean 10.45000 7.25000 Min 10.2 7.0 Range 0.5 0.5 Max 10.7 7.5 Table D.11: Dimensions of specimens 1B tensile test.

Figure D.6: Diagram of tensile test 1B. Specimen two and four broke at node and specimen one and three were discontinued.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 1BPr2 6488.89 84.82208 10.91744 0.76500 247 3356.51287 1BPr4 8349.29 111.47245 12.12698 0.74900 261 5817.51831 Statistics Mean 7419.09 98.14727 11.52221 0.75700 254 4587.01559 Min 6488.89 84.82208 10.91744 0.74900 247 3356.51287 Range 1860.40 26.65037 1.20954 0.01600 14 2461.00544 Max 8349.29 111.47245 12.12698 0.76500 261 5817.51831 Table D.12: Result of tensile test 1B.

95 Culm 2

Specimen Width [mm] Thickness [mm] 2BPr1 9.2 6.9 2BPr2 10.8 5.9 2BPr3 11.1 7.5 Statistics Mean +1SD 11.38810 7.57496 Mean -1SD 9.34523 5.95838 Mean 10.36667 6.76667 Min 9.2 7.5 Range 1.9 1.6 Max 11.1 7.5 Table D.13: Dimensions of specimens 2B tensile test.

Figure D.7: Diagram of tensile test 2B. All specimes broke at node. Specimen four was not tested due to poor sample.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 2BPr1 6691.06 105.40430 8.05239 0.63480 260 8495.33129 2BPr2 6650.45 104.36997 8.74882 0.63720 260 6859.84270 2BPr3 7945.68 95.44366 13.37479 0.83250 256 3601.63308 Statistics Mean+1SD 7832.09 107.21598 12.95155 0.81496 260.98 8810.22167 Mean-1SD 6359.38 96.26264 7.16578 0.58804 256.36 3827.64971 Mean 7095.73 101.73931 10.05866 0.70150 258.67 6318.93569 Min 6650.45 95.44366 8.05239 0.63480 256 3601.63308 Range 1295.23 9.96064 5.32240 0.19770 4 4893.69821 Max 7945.68 105.40430 13.37479 0.83250 260 8495.33129 Table D.14: Result of tensile test 2B.

96 Culm 3

Specimen Width [mm] Thickness [mm] 3BPr2 9.5 6.7 3BPr3 10.9 6.7 3BPr4 9.9 6.9 Statistics Mean +1SD 10.82111 6.88214 Mean -1SD 9.37889 6.65120 Mean 10.10000 6.76667 Min 9.5 6.7 Range 1.4 0.2 Max 10.9 6.9 Table D.15: Dimensions of specimens 3B tensile test.

Figure D.8: Diagram of tensile test 3B. All specimens broke at node. Speci- men one was not tested due to poor sample.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 3BPr2 4060.53 63.79463 8.48772 0.63650 257 6962.57981 3BPr3 9711.61 132.98109 4.71494 0.73030 261 20359.30561 3BPr4 5925.72 86.74753 9.70312 0.68310 261 12683.04792 Statistics Mean+1SD 9445.38 129.74775 10.23631 0.73020 261.98 Mean-1SD 3686.53 59.26775 5.03420 0.63640 257.36 Mean 6565.95 94.50775 7.63526 0.68330 259.67 13334.97778 Min 4060.53 63.79463 4.71494 0.63650 257 6962.57981 Range 5651.08 69.18646 4.98818 0.09380 4 13396.72580 Max 9711.61 132.98109 9.70312 0.73030 261 20359.30561 Table D.16: Result of tensile test 3B.

97 Culm 4

Specimen Width [mm] Thickness [mm] 4BPr1 11.6 5.8 4BPr2 10.0 6.6 4BPr4 11.0 5.7 Statistics Mean +1SD 11.67496 6.52662 Mean -1SD 10.05838 5.54005 Mean 10.86667 6.03333 Min 10.0 5.7 Range 1.6 0.9 Max 11.6 6.6 Table D.17: Dimensions of specimens 4B tensile test.

Figure D.9: Diagram of tensile test 4B. Specimen two and four broke at node. Specimen three was not tested due to poor sample.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 4BPr1 6634.16 98.60520 4.26897 0.67280 261 15409.02030 4BPr2 5969.64 90.44917 10.05641 0.66000 260 14998.25098 4BPr4 8231.92 131.29060 6.42701 0.62700 260 17913.20459 Statistics Mean+1SD 8108.02 128.39523 9.84219 0.67690 260.91 Mean-1SD 5782.46 85.16808 3.99274 0.62964 259.76 Mean 6945.24 106.78166 6.91746 0.65327 260.33 16106.82529 Min 5969.64 90.44917 4.26897 0.62700 260 14998.25098 Range 2262.28 40.84144 5.78744 0.04580 1 2914.95361 Max 8231.92 131.29060 10.05641 0.67280 261 17913.20459 Table D.18: Result of tensile test 4B.

98 Culm 7

Specimen Width [mm] Thickness [mm] 7BPr2 10.7 5.0 7BPr3 11.6 5.5 7BPr4 9.5 5.0 Statistics Mean +1SD 11.65357 5.45534 Mean -1SD 9.54643 4.87799 Mean 10.60000 5.16667 Min 9.5 5.0 Range 2.1 0.5 Max 11.6 5.5 Table D.19: Dimensions of specimens 7B tensile test.

Figure D.10: Diagram of tensile test 7B. Specimen three and four broke at node. Specimen one was not tested due to poor sample.

Specimen Max load Tensile stess Extension Area Length Young's at max load at max load modulus [N] [MPa] [mm] [cm2] [mm] [MPa] 7BPr2 9774.46 182.71881 10.78507 0.53500 248 19984.22070 7BPr3 10126.65 158.72493 8.49854 0.63800 247 19883.45728 7BPr4 4349.83 91.57534 1.19531 0.47500 248 20660.27855 Statistics Mean+1SD 11323.61 191.58358 11.83511 0.63177 248.24 Mean-1SD 4845.35 97.09581 1.81750 0.46689 247.09 Mean 8083.98 144.33969 6.82631 0.54933 247.67 20175.98551 Min 4349.83 91.57534 1.19531 0.47500 247 19883.45728 Range 5776.82 91.14347 9.58976 0.16300 1 776.82127 Max 10126.65 182.71881 10.78507 0.63800 248 20660.27855 Table D.20: Result of tensile test 7B.

99 100 Appendix E

Results Bending Test

Date: 13th and 18th of September 2007 Name and location of laboratory: UPSA, Santa Cruz, Bolivia Velocity: 5.0 mm/min Relative humidity: 47 percent and 40 percent Temperature: 22 Celcius degrees and 23 Celcius degrees

Botanical name of species: Guadua chacoensis Moisture quotient: 17 percent, air-dried during a period of twelve weeks.

101 Specimen Width [mm] Thickness [mm] Length [mm] Pr1 25 8 360 Pr2 25 8 360 Pr3 25 8 360 Pr4 25 6 360 Pr5 25 6 360 Table E.1: Dimensions of specimens bending test 1-5.

Figure E.1: Diagram of bending test 1-5.

Specimen Max compres- Extension at Load at Compressive Modulus sive load max compres- break extension at of rupture [N] sive load [mm] [N] break [mm] [MPa] Pr1 216.32 56.37 156.15153 92.68 0.40 Pr2 425.73 21.75 79.39923 52.98 1.07 Pr3 381.78 22.77 69.96184 62.61 1.07 Pr4 248.41 24.65 69.97135 57.54 0.60 Pr5 209.19 28.53 122.70779 71.85 0.46 Statistics Mean 296.29 30.81 99.63835 67.53 0.72 SD 100.41986 14.51672 38.39397 15.70800 0.32785 Min 216.32 21.75 69.96184 52.98 0.40 Range 216.54 34.62 86.18968 39.70 0.67 Max 425.73 56.73 156.15153 92.68 1.07 Table E.2: Result of bending test 1-5.

102 Specimen Width [mm] Thickness [mm] Length [mm] Pr6 25 8 360 Pr7 25 8 360 Pr8 25 6 360 Pr9 25 6 360 Table E.3: Dimensions of specimens bending test 6-9.

Figure E.2: Diagram of bending test 6-9.

Specimen Max compres- Extension at Load at Compressive Modulus sive load max compres- break extension at of rupture [N] sive load [mm] [N] break [mm] [MPa] Pr6 248.79 25.87 216.16959 30.95 32.25 Pr7 418.62 29.73 323.10907 32.13 33.62 Pr8 256.01 28.40 70.71493 55.83 19.86 Pr9 268.06 40.02 70.33463 55.83 18.02 Statistics Mean 297.87 31.00 170.08206 37.24 25.94 SD 80.88987 6.21864 122.96978 12.42379 8.13542 Min 248.79 25.87 70.33463 30.05 18.02 Range 169.83 6.21864 252.77444 25.78 15.60 Max 418.62 40.02 323.10907 55.83 33.62 Table E.4: Result of bending test 6-9.

103 Specimen Width [mm] Thickness [mm] Length [mm] Pr10 25 8 360 Pr11 25 8 360 Pr12 25 6 360 Pr13 25 6 360 Table E.5: Dimensions of specimens bending test 10-13.

Figure E.3: Diagram of bending test 10-13.

Specimen Max compres- Extension at Load at Compressive Modulus sive load max compres- break extension at of rupture [N] sive load [mm] [N] break [mm] [MPa] Pr10 293.35 26.07 71.15418 28.52 25.61 Pr11 291.51 26.17 254.18093 28.60 25.36 Pr12 228.69 35.13 69.92128 35.41 16.76 Pr13 279.42 30.15 167.58405 35.23 21.85 Statistics Mean 273.24 29.38 140.71011 31.94 22.39 SD 30.33637 4.28167 88.40611 3.90969 4.13034 Min 228.69 26.07 69.92128 28.52 16.76 Range 64.66 9.07 184.25966 6.90 8.85 Max 293.35 35.13 254.18093 35.41 25.61 Table E.6: Result of bending test 10-13.

104 Specimen Width [mm] Thickness [mm] Length [mm] Pr14 25 8 360 Pr15 25 8 360 Pr16 25 6 360 Pr17 25 6 360 Table E.7: Dimensions of specimens bending test 14-17.

Figure E.4: Diagram of bending test 14-17.

Specimen Max compres- Extension at Load at Compressive Modulus sive load max compres- break extension at of rupture [N] sive load [mm] [N] break [mm] [MPa] Pr14 253.91 15.73 115.52852 47.93 32.26 Pr15 354.64 25.50 268.42335 28.40 33.47 Pr16 220.45 51.47 96.66248 53.43 11.84 Pr17 178.33 21.78 69.95977 40.16 18.25 Statistics Mean 251.83 28.62 137.64353 42.48 23.95 SD 75.19349 15.75345 89.16833 10.84990 10.62664 Min 178.33 15.73 69.95977 28.40 11.84 Range 176.32 35.73 198.46358 25.03 21.62 Max 354.64 51.47 268.42335 53.43 33.47 Table E.8: Result of bending test 14-17.

105 Specimen Width [mm] Thickness [mm] Length [mm] Pr18 25 8 360 Pr19 25 8 360 Pr20 25 6 360 Pr21 25 6 360 Table E.9: Dimensions of specimens bending test 18-21.

Figure E.5: Diagram of bending test 18-21.

Specimen Max compres- Extension at Load at Compressive Modulus sive load max compres- break extension at of rupture [N] sive load [mm] [N] break [mm] [MPa] Pr18 484.40 28.03 291.89677 37.48 42.48 Pr19 386.39 43.35 274.38228 47.22 27.95 Pr20 272.36 24.35 70.82636 25.40 24.84 Pr21 181.41 44.45 88.45882 45.63 11.09 Statistics Mean 331.14 35.05 181.39106 38.93 26.59 SD 132.18432 10.34367 117.92630 9.97913 12.88067 Min 181.41 24.35 70.82636 25.40 11.09 Range 303.00 20.10 221.07041 21.82 31.39 Max 484.40 44.45 291.89677 47.22 42.48 Table E.10: Result of bending test 18-21.

106 Appendix F

Results Hardness Test Perpendicular to Fiber

Date: 3rd and 6th of September 2007 Name and location of laboratory: UPSA, Santa Cruz, Bolivia Velocity: 6.0 mm/min Diameter of steel ball: 11.5 mm Relative humidity: 54 percent and 66 percent Temerature: 22 Celcius degrees

Botanical name of species: Guadua chacoensis Air-dried during nine weeks.

107 F.1 Lower Parts of Culm - A

Culm 1

Figure F.1: Diagram of hardness test 1A I.

Figure F.2: Diagram of hardness test 1A II.

108 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 1APr1 I 1850.98 3.02 10.12119 1.73021 1APr1 II 3459.18 3.01 10.11037 3.24422 1APr2 I 3566.02 3.04 10.14266 3.31142 1APr2 II 3102.35 3.03 10.11037 2.90956 1APr3 I 2149.79 3.03 10.13195 2.00289 1APr3 II 1517.97 3.02 10.12119 1.41893 1APr4 I 2390.89 3.01 10.11037 2.24231 1APr4 II 2536.71 3.03 10.13195 2.36337 Statistics Mean 2571.735 3.025 10.12251 2.40286 Min 1517.97 3.01 10.11037 1.41893 Max 3566.02 3.04 10.14266 3.31142 Table F.1: Result of hardness test 1A.

109 Culm 2

Figure F.3: Diagram of hardness test 2A I.

Figure F.4: Diagram of hardness test 2A II.

110 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 2APr1 I 2751.99 3.02 10.121186 2.57243 2APr1 II 2708.84 3.02 10.121186 2.53209 2APr2 I 3064.21 3.04 10.14266 2.84543 2APr2 II 2945.04 3.01 10.11037 2.76203 2APr3 I 2983.25 3.01 10.11037 2.79786 2APr3 II 2988.36 3.03 10.13195 2.78416 2APr4 I 2933.54 3.01 10.11037 2.75124 2APr4 II 2799.98 3.02 10.12119 2.61729 Statistics Mean 2896.905 3.02 10.12116 2.70782 Min 2708.84 3.01 10.11037 2.53209 Max 3064.21 3.04 10.14266 2.84543 Table F.2: Result of hardness test 2A.

111 Culm 3

Figure F.5: Diagram of hardness test 3A I.

Figure F.6: Diagram of hardness test 3A II.

112 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 3APr1 I 2435.25 3.02 10.12119 2.27636 3APr1 II 2077.06 3.02 10.12119 1.94154 3APr2 I 3059.74 3.02 10.12119 2.86010 3APr2 II 2873.23 3.01 10.11037 2.69468 3APr3 I 2230.41 3.04 10.14266 2.07116 3APr3 II 1945.19 3.02 10.12119 1.81827 3APr4 I 2864.06 3.04 10.14266 2.65957 3APr4 II 3031.18 3.03 10.13195 2.82405 Statistics Mean 2564.515 3.025 10.12655 2.39322 Min 1945.19 3.01 10.11037 1.81827 Max 3059.74 3.04 10.14266 2.86010 Table F.3: Result of hardness test 3A.

113 Culm 4

Figure F.7: Diagram of hardness test 4A I.

Figure F.8: Diagram of hardness test 4A II.

114 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 4APr1 I 2043.31 3.04 10.14266 1.89742 4APr1 II 1345.96 3.04 10.14266 1.24986 4APr2 I 1487.09 3.01 10.11037 1.39468 4APr2 II 1133.69 3.01 10.11037 1.06324 4APr3 I 1684.17 3.04 10.14266 1.56392 4APr3 II 2024.60 3.03 10.13195 1.88625 4APr4 I 2086.34 3.01 10.11037 1.95669 4APr4 II 1885.20 3.04 10.14266 1.75060 Statistics Mean 1711.29 3.025 10.12921 1.59533 Min 1133.69 3.01 10.11037 1.06324 Max 2086.34 3.04 10.14266 1.95669 Table F.4: Result of hardness test 4A.

115 Culm 7

Figure F.9: Diagram of hardness test 7A I.

Figure F.10: Diagram of hardness test 7A II.

116 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 7APr1 I 2107.30 3.04 10.14266 1.95684 7APr1 II 2369.11 3.03 10.13195 2.20722 7APr2 I 1795.27 3.04 10.14266 1.66710 7APr2 II 2764.05 3.03 10.13195 2.57518 7APr3 I 2154.01 3.03 10.13195 2.00682 7APr3 II 3196.13 3.02 10.12119 2.98759 7APr4 I 2792.16 3.01 10.11037 2.61865 7APr4 II 2740.50 3.02 10.12119 2.56169 Statistics Mean 2489.815 3.03 10.12924 2.32264 Min 1795.27 3.01 10.11037 1.66710 Max 3196.13 3.04 10.14266 2.98759 Table F.5: Result of hardness test 7.A

117 F.2 Upper Parts of Culm - B

Culm 1

Figure F.11: Diagram of hardness test 1B I.

Figure F.12: Diagram of hardness test 1B II.

118 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 1BPr1 I 464.21 1.04 6.59648 1.26004 1BPr1 II 299.19 1.03 6.56783 0.82000 1BPr2 I 336.84 1.01 6.50996 0.94147 1BPr2 II 616.31 1.03 6.56783 1.68914 1BPr3 I 425.19 1.03 6.56783 1.16533 1BPr3 II 298.15 1.02 6.53899 0.82516 1BPr4 I 339.99 1.02 6.53899 0.94096 1BPr4 II 237.44 1.02 6.53899 0.65714 Statistics Mean 377.165 1.025 6.55336 1.03740 Min 237.44 1.01 6.50996 0.65714 Max 616.31 1.04 6.59648 1.68914 Table F.6: Result of hardness test 1B.

119 Culm 2

Figure F.13: Diagram of hardness test 2B I.

Figure F.14: Diagram of hardness test 2B II.

120 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 2BPr1 I 703.72 1.04 6.59648 1.91016 2BPr1 II 315.42 1.04 6.59648 0.85617 2BPr2 I 1017.08 1.02 6.53899 2.81487 2BPr2 II 907.74 1.04 6.59648 2.46395 2BPr3 I 990.11 1.02 6.53899 2.74023 2BPr3 II 473.33 1.03 6.56783 1.29727 2BPr4 I 719.52 1.02 6.53899 1.99134 2BPr4 II 536.79 1.04 6.59648 1.45705 Statistics Mean 707.965 1.03 6.57134 1.94138 Min 315.42 1.02 6.53899 0.85617 Max 1017.08 1.04 6.59648 2.81487 Table F.7: Result of hardness test 2B.

121 Culm 3

Figure F.15: Diagram of hardness test 3B I. Specimen four was not tested due to poor sample.

Figure F.16: Diagram of hardness test 3B II. Specimen four was not tested due to poor sample.

122 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 3BPr1 I 591.00 1.04 6.59648 1.60420 3BPr1 II 836.32 1.04 6.59648 2.27009 3BPr2 I 570.63 1.01 6.50996 1.59491 3BPr2 II 520.75 1.02 6.53899 1.44123 3BPr3 I 675.40 1.03 6.56783 1.85109 3BPr3 II 612.14 1.04 6.59648 1.66158 Statistics Mean 634.37 1.025 6.56771 1.73718 Min 520.75 1.01 6.50996 1.44123 Max 836.32 1.04 6.59648 2.27009 Table F.8: Result of hardness test 3B.

123 Culm 4

Figure F.17: Diagram of hardness test 4B I.

Figure F.18: Diagram of hardness test 4B II.

124 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 4BPr1 I 552.29 1.02 6.53899 1.52852 4BPr1 II 324.19 1.01 6.50996 0.90611 4BPr2 I 393.93 1.01 6.50996 1.10104 4BPr2 II 183.65 1.02 6.53899 0.50827 4BPr3 I 434.62 1.04 6.59648 1.17972 4BPr3 II 435.43 1.03 6.56783 1.19340 4BPr4 I 564.26 1.02 6.53899 1.56165 4BPr4 II 229.75 1.03 6.56783 0.62968 Statistics Mean 389.765 1.02 6.54613 1.07605 Min 183.65 1.01 6.50996 0.50827 Max 564.26 1.04 6.59648 1.56165 Table F.9: Result of hardness test 4B.

125 Culm 7

Figure F.19: Diagram of hardness test 7B I.

Figure F.20: Diagram of hardness test 7B II.

126 Specimen Max load Max compressive Diameter of Hardness Brinell extension impression [N] [mm] [mm] [HB] 7BPr1 I 676.70 1.04 6.59648 1.83682 7BPr1 II 290.71 1.04 6.59648 0.78910 7BPr2 I 530.28 1.02 6.53899 1.46760 7BPr2 II 476.25 1.04 6.59648 1.29272 7BPr3 I 781.50 1.04 6.59648 2.12129 7BPr3 II 505.69 1.01 6.50996 1.41340 7BPr4 I 621.08 1.01 6.50996 1.73592 7BPr4 II 196.04 1.03 6.56783 0.53729 Statistics Mean 509.780 1.03 6.56409 1.39927 Min 196.04 1.01 6.50996 0.53729 Max 781.50 1.04 6.59648 2.12129 Table F.10: Result of hardness test 7B.

127