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Development of Simplified Life Cycle Assessment (LCA) Methodology for Construction Materials and Buildings Outside of the European Context Through the use of Geographic Information Systems (GIS)

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The global human population had been growing at an unprecedented rate for the last five decades and it is expected to keep this trend for the coming century. United Nations, estimates that the current world population of 7.6 billion will reach 9.5billion by the year 2050 and estimates a global human population of 10.9 billion by the year 2100. Furthermore, this growth had been mainly concentrated on urban areas, which had increased both the acquisition power and the demand for resources on those on those populations. From the environmental perspective, the magnitude of growth of cities have dramatically changed their material flows and the land use around them mainly through the growth of buildings and infrastructures. The building sector is a multifaceted and decisive actor on this situation, providing benefits on both the global economic and social spheres but at the cost of environmental degradation. The advantages of this situation is that the building sector is financially strong, making it more apt for innovation and development. The challenge for the building sector is to use appropriated construction materials to maximize the economic, environmental and social benefits at a speed that allows it to achieve its main purpose. Consequently, it requires the further development of the existing assessment tools and the generation of data for those assessments for regions where the main urban development is occurring. The main objective of the present research was to develop an approach for the production of life cycle assessment data for conventional and bamboo-based constructive systems and their associated materials. These data were integrated on a geographic information system in order to allow for the characterization of the data to different countries worldwide. The data and characterization methodologies were tested on several case studies focusing on post-disaster reconstruction and social housing projects. The case studies considered the use of alternative construction materials like bamboo and soil stabilized blocks as well as conventional construction materials like bricks and concrete hollow blocks. These case studies focused on the environmental impacts from the production of buildings using these construction materials on different locations. Additional sustainability aspects were also studied, considering the potential job creation; cost; life span; and carbon crediting potential associated to the used of the construction materials. The findings from this research indicated that the appropriated selection and application of construction materials is one of the most important factors to consider on the sustainability of buildings. The results showed under different assessment conditions that sustainable buildings can be produced with a diversity of alternative and conventional construction materials. Moreover, the sustainability of a buildings is not directly correlated to its construction material but to the sustainable use of those materials. However, the use of bamboo as a construction material increases significantly the possibilities of producing sustainable buildings on a wide range of contexts. Furthermore, the results showed that the economic, environmental, and social benefits from the production and use of bamboo in construction can not only support the regenerative development of countries producing it but also it can offset the negative environmental impacts from the production and use of other construction materials.
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DISS. ETH NO. 23193
DEVELOPMENT OF SIMPLIFIED LIFE CYCLE ASSESSMENT METHODOLOGY FOR
CONSTRUCTION MATERIALS AND BUILDINGS OUTSIDE OF THE EUROPEAN CONTEXT
THROUGH THE USE OF GEOGRAPHIC INFORMATION SYSTEMS
A thesis submitted to attain the degree of
DOCTOR OF SCIENCES of ETH ZURICH
(Dr. Sc. ETH Zurich)
Presented by
EDWIN BYRON BENIGNO ZEA ESCAMILLA
MSc. Wageningen University
Born on 29.05.1978
Citizen of Colombia, Switzerland, Hochdorf (LU) / Ettiswil (LU)
Accepted on the recommendation of
Guillaume Habert
Ronald Rovers
Normando Barbosa
2015
In the end he worked out a method which would at
least produce a result. He decided not to mind the
fact that with the extraordinarily jumble of rules of
thumb, wild approximations and arcane guesswork
he was using he would be lucky to hit the right
galaxy; he just went ahead and got a result.
D. Adams
The Ultimate Hitchhiker's Guide to the Galaxy
So long, and thanks for all the fish
To my family
Abstract
The global human population had been growing at an unprecedented rate for the last five decades and it is expected
to keep this trend for the coming century. United Nations, estimates that the current world population of 7.6 billion
will reach 9.5billion by the year 2050 and estimates a global human population of 10.9 billion by the year 2100.
Furthermore, this growth had been mainly concentrated on urban areas, which had increased both the acquisition
power and the demand for resources on those on those populations. From the environmental perspective, the
magnitude of growth of cities have dramatically changed their material flows and the land use around them mainly
thought the growth of buildings and infrastructures. The building sector is a multifaceted and decisive actor on this
situation, providing benefits on both the global economic and social spheres but at the cost of environmental
degradation. The advantages of this situation is that the building sector is financially strong, making it more apt
for innovation and development. The challenge for the building sector is to use appropriated construction materials
to maximize the economic, environmental and social benefits at a speed that allows it to achieve its main purpose.
Consequently, it requires the further development of the existing assessment tools and the generation of data for
those assessments for regions where the main urban development is occurring.
The main objective of the present research was to develop an approach for the production of life cycle assessment
data for conventional and bamboo-based constructive systems and their associated materials. These data were
integrated on a geographic information system in order to allow for the characterization of the data to different
countries worldwide. The data and characterization methodologies were tested on several case studies focusing on
post-disaster reconstruction and social housing projects. The case studies considered the use of alternative
construction materials like bamboo and soil stabilized blocks as well as conventional construction materials like
bricks and concrete hollow blocks. These case studies focused on the environmental impacts from the production
of buildings using these construction materials on different locations. Additional sustainability aspects were also
studied, considering the potential job creation; cost; life span; and carbon crediting potential associated to the used
of the construction materials.
The findings from this research indicated that the appropriated selection and application of construction materials
is one of the most important factors to consider on the sustainability of buildings. The results showed under
different assessment conditions that sustainable buildings can be produced with a diversity of alternative and
conventional construction materials. Moreover, the sustainability of a buildings is not directly correlated to its
construction material but to the sustainable use of those materials. However, the use of bamboo as a construction
material increases significantly the possibilities of producing sustainable buildings on a wide range of contexts.
Furthermore, the results showed that the economic, environmental, and social benefits from the production and
use of bamboo in construction can not only support the regenerative development of countries producing it but
also it can offset the negative environmental impacts from the production and use of other construction materials.
Zusammenfassung
Die globale Bevölkerung ist in den letzten fünf Jahrzehnten mit beispielloser Geschwindigkeit gewachsen und es
wird erwartet, dass sich dieser Trend im kommenden Jahrhundert fortsetzt. Die Vereinten Nationen schätzen, dass
die Weltbevölkerung von aktuell 7,6 Milliarden im Jahr 2050 auf 9.5 Milliarden und bis zum Jahr 2100 auf 10.9
Milliarden ansteigen wird. Das Wachstum konzentriert sich vor allem auf städtische Gebiete, die sowohl gestiegen
konzentriert der Erwerb Kraft und die Nachfrage nach Ressourcen auf die auf diesen Bevölkerungsgruppen. Aus
der Sicht des Umweltschutzes, haben das Ausmaß des Wachstums der Städte dramatisch ihre Stoffströme
verändert, und die Landnutzung um sie herum vor allem gedacht, das Wachstum von Gebäuden und
Infrastrukturen. Der Gebäudesektor ist ein facettenreiches und entscheidende Akteur auf diese Situation und bietet
Vorteile sowohl auf der globalen Wirtschafts- und Sozialbereich, aber auf Kosten der Umweltzerstörung. Die
Vorteile dieser Situation ist, dass der Gebäudesektor ist finanziell stark, so dass es geeignet ist für Innovation und
Entwicklung. Die Herausforderung für den Bausektor ist es, angeeignet Baustoffe verwenden, um die
wirtschaftliche, ökologische und soziale Vorteile mit einer Geschwindigkeit, die es zu seinen wichtigsten Zweck
zu erreichen ermöglicht maximieren. Folglich bedarf es der Weiterentwicklung der vorhandenen
Bewertungsinstrumente und die Generierung von Daten für diese Beurteilungen für Regionen, in denen die
Hauptstadtentwicklung stattfindet.
Das Hauptziel der vorliegenden Arbeit war es, ein Konzept für die Herstellung von Ökobilanzdaten für
traditionelle und Bambus-basierte konstruktive Systeme und die damit verbundenen Materialien zu entwickeln.
Diese Daten wurden auf einem geografischen Informationssystem, um für die Charakterisierung der Daten in
verschiedenen Ländern weltweit ermöglichen integriert. Die Daten und Charakterisierung Methoden wurden
mehrere Fallstudien mit Schwerpunkt auf Wiederaufbau nach Katastrophen und sozialen Wohnprojekten getestet.
Die Fallstudien betrachtet die Nutzung alternativer Baumaterialien wie Bambus und Boden stabilisiert Blöcke
sowie traditionelle Baumaterialien wie Ziegel und Beton Hohlblocksteinen. Diese Fallstudien über die
Umweltauswirkungen bei der Produktion von Gebäuden mit diesen diversen Baumaterialien auf verschiedenen
Standorten konzentriert. Zusätzliche Nachhaltigkeitsaspekte wurden ebenfalls untersucht, wenn man bedenkt das
Potenzial zur Schaffung von Arbeitsplätzen; Kosten; Lebensdauer; und Kohlenstoff Gutsche Potential der
verwendeten der Baumaterialien verbunden.
Die Erkenntnisse aus dieser Forschung zeigte, dass die entsprechende Auswahl und Anwendung von Baustoffen
ist einer der wichtigsten Faktoren, die auf die Nachhaltigkeit von Gebäuden zu berücksichtigen. Die Ergebnisse
zeigten, unter verschiedenen Bedingungen Einschätzung, dass nachhaltige Gebäude können mit einer Vielfalt von
alternativen und traditionellen Baumaterialien hergestellt werden. Darüber hinaus ist die Nachhaltigkeit eines
Gebäudes nicht direkt an ihren Baustoff, sondern auf die nachhaltige Nutzung dieser Materialien korreliert. , Die
Verwendung von Bambus als Baumaterial erhöht jedoch wesentlich die Möglichkeiten der Herstellung
nachhaltiger Gebäude auf einer Vielzahl von Zusammenhängen. Darüber hinaus zeigten die Ergebnisse, dass die
wirtschaftlichen, ökologischen und sozialen Nutzen aus der Produktion und Verwendung von Bambus in der
Konstruktion nicht nur die Unterstützung der regenerativen Entwicklung von Ländern produziert, aber es kann
auch die negativen Auswirkungen auf die Umwelt von der Herstellung und Verwendung von anderen Offset
Baumaterialien.
Table of Contents
1.Introduction ................................................................................................................................... 13
1.1.Global Population growth ............................................................................................................ 13
1.2.The urban growth and environmental degradation................................................................... 15
1.3.The role of the building sector on the environmental crisis ...................................................... 17
1.4.Bamboo .......................................................................................................................................... 18
1.4.1.Bamboo as plant ....................................................................................................................... 18
1.4.2.Bamboo as raw material ........................................................................................................... 21
1.4.3.Bamboo as construction material ............................................................................................. 23
1.4.4.Bamboo in contemporary architecture ..................................................................................... 24
1.5.Life Cycle and its assessment ....................................................................................................... 27
1.5.1.Methodological challenges ....................................................................................................... 29
1.5.2.LCA of buildings ...................................................................................................................... 29
1.5.3.LCA outside of the European context ...................................................................................... 30
1.6.Goal of research project ............................................................................................................... 30
1.7.Dissertation’s outline .................................................................................................................... 30
1.8.References ...................................................................................................................................... 31
2.LCA data for conventional and alternative construction materials ......................................... 37
Summary .............................................................................................................................................. 37
Introduction to the chapter ................................................................................................................ 39
2.1.Environmental impacts from the production of bamboo based construction materials
representing the global production diversity .................................................................................... 40
2.2.Literature review ........................................................................................................................... 40
2.2.1.Bamboo as a construction material ........................................................................................... 40
2.2.2.Life cycle assessment methodological challenges.................................................................... 42
2.2.3.LCA of bamboo-based construction materials ......................................................................... 43
2.3.Data and methods .......................................................................................................................... 43
2.3.1.Functional unit and system boundaries .................................................................................... 43
2.3.2.Inventory data ........................................................................................................................... 44
2.3.3.Impact assessment .................................................................................................................... 50
2.3.4.Uncertainty analysis ................................................................................................................. 50
2.4.Results ............................................................................................................................................ 51
2.4.1.Environmental impacts of the different bamboo products studied ........................................... 51
2.4.2.Process contribution to environmental impact ......................................................................... 51
2.4.3.Uncertainty analysis ................................................................................................................. 53
2
2.4.4.Process contribution to the variability of the results ................................................................ 53
2.5.Discussion ....................................................................................................................................... 55
2.5.1.Choice of impact assessment method ....................................................................................... 55
2.5.2.Process efficiency and energy mix ........................................................................................... 56
2.5.3.Key processes for a simplified bamboo LCA ........................................................................... 56
2.6.Conclusions and recommendations ............................................................................................. 57
2.7.Acknowledgements ........................................................................................................................ 58
2.8.References ...................................................................................................................................... 58
Chapter 2 in a nutshell ........................................................................................................................ 62
3.Methodology and application to characterize LCA data of alternative and conventional
construction materials ......................................................................................................................... 65
Summary .............................................................................................................................................. 65
Introduction to the chapter ................................................................................................................ 69
3.1.Method and application of characterization of life cycle impact data of construction
materials using geographic information systems .............................................................................. 71
3.1.1.Introduction .............................................................................................................................. 71
3.1.2.Methods .................................................................................................................................... 73
3.1.2.1.Developing an LCA geo-database / Characterization of the LCA data ................................. 74
3.1.2.2.Calculation of transport distances per country ...................................................................... 75
3.1.2.3.LCA of the Building .............................................................................................................. 77
3.1.2.4.Identification of seismic and wind risk zones ....................................................................... 77
3.1.2.5.Application ............................................................................................................................ 78
3.1.3.Results ...................................................................................................................................... 79
3.1.4.Discussion ................................................................................................................................ 82
3.1.5.Conclusions .............................................................................................................................. 83
3.1.6.Acknowledgements .................................................................................................................. 83
3.1.7.References ................................................................................................................................ 84
3.2.Case study – Detailed transport distances calculations ............................................................. 87
3.2.1.Abstract .................................................................................................................................... 87
3.2.2.Data and Methods ..................................................................................................................... 87
3.2.3.Results ...................................................................................................................................... 89
3.2.4.Conclusions .............................................................................................................................. 92
3.2.5.Acknowledgements .................................................................................................................. 92
Chapter 3 in a nutshell ........................................................................................................................ 93
4.Additional sustainability aspects from the use of bamboo on buildings .................................. 97
Summary .............................................................................................................................................. 97
3
Chapter’s introduction ........................................................................................................................ 99
4.1.Sustainability of transitional shelters -- Variability on design and transport ....................... 101
4.1.1.Introduction ............................................................................................................................ 101
4.1.2.Methodology .......................................................................................................................... 103
4.1.2.1.Environmental impact ......................................................................................................... 104
4.1.2.2.Cost ...................................................................................................................................... 108
4.1.2.3.Technical performance ........................................................................................................ 109
4.1.3.Results .................................................................................................................................... 111
4.1.3.1.Environmental impact ......................................................................................................... 111
4.1.3.2.Cost assessment ................................................................................................................... 113
4.1.3.3.Technical assessment .......................................................................................................... 114
4.1.3.4.Sustainability assessment .................................................................................................... 115
4.1.4.Discussion .............................................................................................................................. 117
4.1.5.Conclusions ............................................................................................................................ 119
4.1.6.Acknowledgements ................................................................................................................ 119
4.1.7.References .............................................................................................................................. 119
4.2.Sustainability of industrialized bamboo – CO2 Issues ............................................................. 123
4.2.1.Abstract .................................................................................................................................. 123
4.2.2.Results .................................................................................................................................... 123
4.2.2.1.Mass flow model ................................................................................................................. 124
4.2.2.2.Dynamic Model Housing demand ....................................................................................... 124
4.2.2.3.Economic Category ............................................................................................................. 126
4.2.2.4.Social category .................................................................................................................... 127
4.2.2.5.Sustainability assessment .................................................................................................... 127
4.2.3.Discussion .............................................................................................................................. 128
4.2.3.1.Building lifespan ................................................................................................................. 128
4.2.3.2.Electricity mix ..................................................................................................................... 129
4.2.3.3.End-of-life scenarios ........................................................................................................... 130
4.2.3.4.Sustainability Assessment ................................................................................................... 131
4.2.4.Conclusions ............................................................................................................................ 132
4.2.5.Acknowledgments .................................................................................................................. 133
4.3.Environmental Savings Potential from the Use of bamboo in Europe ................................... 135
4.3.2.Abstract .................................................................................................................................. 135
4.3.3.Results .................................................................................................................................... 136
4.3.4.Discussion .............................................................................................................................. 137
4.3.4.1.Uncertainties related to building physics calculations ........................................................ 138
4.3.4.2.Uncertainties related to life span and maintenance needs ................................................... 139
4.3.4.3.Uncertainties related to the selected EMs ........................................................................... 142
4.3.5.Conclusions and recommendations ........................................................................................ 143
4.3.6.Acknowledgments .................................................................................................................. 144
4
Chapter 4 in a nutshell ...................................................................................................................... 145
5.Conclusions .................................................................................................................................. 149
6.Reflections .................................................................................................................................... 153
Acknowledgements ............................................................................................................................ 155
Bibliography ...................................................................................................................................... 157
Annex .................................................................................................................................................. 165
A.Environmental impact of brick production outside Europe ................................................... 167
A.1. Abstract ...................................................................................................................................... 167
A.2. Methods ...................................................................................................................................... 167
A.2.1. Functional unit and systems boundaries ............................................................................... 167
A.2.2. Inventory data ......................................................................................................................... 169
A.2.3. Impact assessment ................................................................................................................... 171
A.2.4. Uncertainty analysis ................................................................................................................ 172
A.3. Results and discussion ............................................................................................................... 172
A.4. Conclusions ................................................................................................................................ 173
B.Bamboo based construction materials ...................................................................................... 175
C.Sustainability assessment of 20 Shelters data in brief ............................................................. 177
C.1. Specifications Table [please fill in right-hand column of the table below] ........................... 177
C.2. Data, Materials and Methods: .................................................................................................. 178
C.2.1. B1 Afghanistan Bamboo ........................................................................................................ 178
C.2.2. B5 Indonesia Bamboo ............................................................................................................. 178
C.2.3. B8 Philippines Bamboo .......................................................................................................... 178
C.2.4. C2 Bangladesh Concrete / Timber ........................................................................................ 179
C.2.5. C6 Pakistan Brick ................................................................................................................... 179
C.2.6. C8 Philippines Concrete ......................................................................................................... 179
C.2.7. C9 Sri Lanka Concrete / Timber ........................................................................................... 180
C.2.8. C11 Nicaragua Ferrocement.................................................................................................. 180
C.2.9. S4 Haiti Steel ........................................................................................................................... 180
C.2.10. S5 Indonesia Steel ................................................................................................................. 180
C.2.11. S10 Vietnam Steel ................................................................................................................. 181
C.2.12. W3 Burkina Faso Timber .................................................................................................... 181
C.2.13. W4(A) Haiti Timber ............................................................................................................. 181
C.2.14. W4(B) Haiti Timber ............................................................................................................. 181
5
C.2.15. W4(C) Haiti Timber ............................................................................................................. 182
C.2.16. W5 Indonesia Timber ........................................................................................................... 182
C.2.17. W6 Pakistan Timber ............................................................................................................ 182
C.2.18. W7(A) Peru Timber ............................................................................................................. 182
C.2.19. W7(B) Peru Timber .............................................................................................................. 183
C.2.10. W8 Philippines Timber ........................................................................................................ 183
C.3. Methods ...................................................................................................................................... 183
C.4. Value of the data ........................................................................................................................ 183
C.5. Acknowledgements .................................................................................................................... 183
C.6. Shelters LCIs .............................................................................................................................. 184
C.7. References .................................................................................................................................. 224
D.Technical performance assessment 20 shelters ........................................................................ 225
6
7
List of Figures
Figure 1.1Global population growth, urban population, life expectancy, and mortality rate at birth[2]14
Figure 1.2 Material intensity: material extraction per unit of GDP[6] .................................................. 15
Figure 1.3 Planetary system boundaries[10] ......................................................................................... 16
Figure 1.4 GDP, CO2 emissions, and construction minerals extraction (Per Capita)[2, 6] ................... 17
Figure 1.5 Global distribution of bamboo ............................................................................................. 19
Figure 1.6 Worldwide distribution of bamboo resources [24] .............................................................. 20
Figure 1.7 Rhizomes structures of bamboo [25] ................................................................................... 20
Figure 1.8 Structure of the bamboo culm [20] ...................................................................................... 21
Figure 1.9 Bamboo fibre distribution [28] ............................................................................................ 22
Figure 1.10 Glue laminated bamboo ..................................................................................................... 23
Figure 1.11 Bahareque house construction Source: Bambusa Project, Lopez / Trujillo, Colombia ..... 23
Figure 1.12 Bamboo dome. Source L.F. Lopez .................................................................................... 24
Figure 1.13 Bamboo Pavilion. Manizales Colombia [19] ..................................................................... 25
Figure 1.14 the Kouk Hhlean youth Centre in Phnom Penh, Cambodia Source: [38] .......................... 26
Figure 1.15 German-Chinese House by Makus Heinsdoff for the World Expo 2010 in Shanghai[39] 26
Figure 1.16 KPMG-CCTH Community centre, PRC [38] .................................................................... 27
Figure 1.17 Product's life cycle ............................................................................................................. 28
Figure 1.18 LCA methodological steps ................................................................................................. 28
Figure 2.1 Example of a spatial structure. Bamboo Bridge in Bogotá, Colombia. Sce: L.F. Lopez ..... 41
Figure 2.2 Example of a load-bearing structure. Bamboo house in Ibague, Colombia ......................... 42
Figure 2.3 Conceptual framework ......................................................................................................... 45
Figure 2.4 Bamboo-based construction materials ................................................................................. 47
Figure 2.5 Relative process contribution to environmental impact for the production of BBCM in (%)
....................................................................................................................................................... 52
Figure 2.6 Environmental impacts of the various bamboo-based construction materials. .................... 53
Figure 2.7 Relative contribution of the different processes to the impact ............................................. 54
Figure 2.8 Variation for glue laminated bamboo induced by a change in the electricity mix ............... 55
Figure 3.1 Conceptual framework of the methodology ......................................................................... 73
Figure 3.2 LCA of buildings, transport distance, and production efficiency ........................................ 80
Figure 3.3 Contribution to the environmental impact ........................................................................... 81
Figure 3.4 LCA and structural performance ......................................................................................... 82
Figure 3.5 Functional Unit -- General Floor Plan. All measurements in cm. ....................................... 88
Figure 3.6 (A) Bamboo frame (bahareque); (B) Concrete hollow block; (C) Ferro-cement panel; (D)
Soil stabilized brick. ...................................................................................................................... 88
Figure 3.7 Environmental impacts at different transport regimes ......................................................... 90
Figure 3.8 Contribution to environmental impact. ................................................................................ 91
Figure 3.9 Environmental and structural performance at different locations ........................................ 92
Figure 4.1 Environmental impact per functional unit ......................................................................... 112
8
Figure 4.2 Cost assessment ................................................................................................................. 114
Figure 4.3 Technical performance. ...................................................................................................... 115
Figure 4.4 Sustainability assessment ................................................................................................... 117
Figure 4.5 Variability analysis. ........................................................................................................... 118
Figure 4.6 Mass flow for one glue laminated bamboo housing unit ................................................... 124
Figure 4.7 CO2 dynamic model .......................................................................................................... 125
Figure 4.8 Economic category............................................................................................................. 126
Figure 4.9 Sustainability assessment ................................................................................................... 128
Figure 4.10 Sensitivity analysis of electricity mix .............................................................................. 130
Figure 4.11 Sensitivity analysis of end-of-life scenarios .................................................................... 131
Figure 4.12 Sustainability assessment with sensitivity analysis ......................................................... 132
Figure 4.13 Wall sections .................................................................................................................... 136
Figure 4.14 LCA results ...................................................................................................................... 136
Figure 4.15 Process contribution to environmental impact ................................................................. 137
Figure 4.16 Effect of XPS thickness on bahareque ESP ..................................................................... 139
Figure 4.17 ESP range – LCI amounts variations ............................................................................... 141
Figure 4.18 Results of accumulated EM ............................................................................................. 143
9
List of Tablets
Table 2-1 Functional units studied ......................................................................................................................... 44
Table 2-2 : LCI of bamboo culm ........................................................................................................................... 46
Table 2-3 LCI of bamboo pole ............................................................................................................................... 48
Table 2-4 LCI of flattened bamboo ........................................................................................................................ 48
Table 2-5 LCI of woven bamboo mat .................................................................................................................... 49
Table 2-6 LCI of glue laminated bamboo .............................................................................................................. 49
Table 2-7 LCI of woven bamboo mat panel .......................................................................................................... 50
Table 2-8 Environmental impacts for the production of bamboo-based construction materials ............................ 51
Table 2-9 Main parameters that need to be addressed to evaluate the environmental impact and uncertainty ...... 57
Table 3-1 Land area and transport distances from literature .................................................................................. 75
Table 3-2 Potential transport distances (sample) ................................................................................................... 76
Table 3-3 life cycle inventories of construction materials used in five house designs ........................................... 79
Table 3-4 LCIs of the five house designs ............................................................................................................... 89
Table 4-1 Shelters' location, structural material and type .................................................................................... 103
Table 4-2 LCIs bamboo based shelters ................................................................................................................ 106
Table 4-3 LCIs mineral based shelters ................................................................................................................. 106
Table 4-4 LCIs steel based shelters ...................................................................................................................... 107
Table 4-5 LCIs wood based shelters (part 1) ....................................................................................................... 107
Table 4-6 LCIs wood based shelters (part 2) ....................................................................................................... 108
Table 4-7 Hazard risk classification ..................................................................................................................... 109
Table 4-8 Shelter's hazard at location and performance ....................................................................................... 110
Table 4-9 Technical performance assessment matrix .......................................................................................... 110
Table 4-10 Contribution from components to environmental impact .................................................................. 113
Table 4-11 LCI construction 1 m2 insulated bahareque wall ............................................................................... 138
Table 4-12 Data input for life span and maintenance calculations – Bahareque wall .......................................... 140
Table 4-13 Data input for life span and maintenance calculations – Clay brick wall .......................................... 140
Table 4-14 Data input for life span and maintenance calculations – Concrete block wall ................................... 140
10
11
Chapter 1: Introduction
12
13
1. Introduction
This chapter presents the context in which the present doctoral dissertation was developed. The first
section describes the current situation in terms of global population growth and the consequent pressure
on resources and the environment. Moreover, it illustrates the concern for the need of housing for the
ever-growing world population and the need for construction materials able to cope with this demand
on a sustainable way. The second section presents bamboo as a plant, its global distribution and its
common uses. Furthermore, this section describe the use of bamboo as construction material and its
application on contemporary architecture. The third section presents an overview of Life Cycle
Assessment (LCA), the methodological challenges its implementation faces and the constrains faced on
its application on buildings, especially those outside the European context. The final section describes
the research project and the contents of this document.
1.1. Global Population growth
The global human population had been growing at an unprecedented rate for the last five decades and it
is expected to keep this trend for the coming century[1]. The department of Economic and Social Affairs
from the United Nations, estimates that the current world population of 7.6 billion will reach 9.5billion
by the year 2050 and estimates a global human population of 10.9 billion by the year 2100[1]. This is
not an isolated process, on the contrary, it is the result of several global trends that started in the middle
of the twentieth century. From the population perspective three main trends can be identified. First, over
the last five decades (1960-2015), the mortality rate after birth had been dropping steadily reaching an
all-time low level of 59 death per 1000 births [1, 2] as seen on figure 1.1. Second, the life expectancy
had been increasing over the same period and reaching a global average of 69 years[2]. And third, the
urban populations had been growing at a stunning rate accounting from more than 50% of the total
human population by 2012[3].
All these factors are intertwined and contribute to the burst of human population, but deeper conclusions
can be drawn from them. The fact that the mortality rate has been so dramatically reduced means that
more women and children are able to receive better medical treatment, which is more accessible to urban
populations. Furthermore, this increase on global population is occurring unevenly and it is concentrated
mainly on Africa and Asia. As a consequence the population of ages under 15 accounts for the 28% of
the populations of those regions [1] while accounting for less than 12% in regions like Europe or North
America. Furthermore, the life expectancy is also increasing which can be also associated not only to a
higher accessibility to medical treatments on urban populations but also with the change of employment
type from rural-agricultural to urban-industrial /services that the human global populations is
experiencing[3, 4]. From figure 1.1 it is also possible to see that the rate of growth of urban populations
is much higher than the one of the global human populations. This has two implication, first humans
14
populations are becoming largely urban in some countries up to 90%. Second, the size and density of
those urban areas must be growing at a similar rate.
Figure 1.1Global population growth, urban population, life expectancy, and mortality rate at birth[2]
This situation has both economic and environmental consequences. From the economic perspective, the
past half a century saw the global economic output (GDP) growing more than twenty times. With a 10%
estimated of the GDP being related with the urbanization process [5]. Furthermore, this growth had been
mainly concentrated on urban areas, which had increased both the acquisition power and the demand
for resources on those on those populations [3, 6]. From the environmental perspective, the magnitude
of growth of cities have dramatically changed their material flows and the land use around them. This
has produce a fundamental change the relation between cities and environment and started a massive
process of degradation of the natural environment [7]. Cities had become consumers of vast amounts of
resources not only to maintain their populations but also to develop their infrastructures and
buildings[4]. On this process the natural environment is being pushed to the boundaries of its carrying
capacity to a level that might be irreversible.
15
Figure 1.2 Material intensity: material extraction per unit of GDP[6]
The work of Krausmann et all[6] has shown that the intensity in which resources are extracted had
almost double over the last century as presented on figure 1.2. Furthermore, the type of resources being
extracted is changing from Biomass towards mineral resources, primordially construction minerals[6]
(fig 1.2.). Moreover, the intensity of extraction of construction mineral is growing at a faster rate than
the GDP over the las century. These patterns clearly show the existence of a link between the
urbanization process, the economic growth and the depletion of natural resources experienced on the
last five decades.
1.2. The urban growth and environmental degradation
The global urban areas had been growing at pair with the human populations. These areas not only
require vast amount of resources for their operation and development but also produces a significant
amounts of emissions and waste[4, 8]. The extraction of these mineral resources can be considered as
one of the main sources of environmental degradation worldwide [9]. It has been estimated that the
environmental degradation is starting to surpass the carrying capacity of the natural environment[10].
The changes on nine quantifiable planetary systems from the beginning of the century to their current
status are presented on figure 1.3.
16
Figure 1.3 Planetary system boundaries[10]
From figure 1.3 it is possible to see that radical changes on the planetary systems had occurred at the
same time as the urbanization process. Moreover, six out of nine planetary systems had already
surpassed their thresholds and the remaining three are about to surpass theirs. Some of these levels are
irreversible like the case of extinction rate but many others like atmospheric CO2 depend on the human
activities and therefore they can be changed and improved[10]. In the case of climate change related
planetary systems there is consensus that these high values come from human activities [11] and that
the focus should be turned now towards the adaptation and mitigation climate change in order to ensure
a sustainable and resilient built environment[12].
As it has been previously presented, global human populations, urbanization levels, extraction of
construction minerals, atmospheric CO2 and GDP are all growing. A striking similarity can be found in
their growth patterns as presented on figure 1.4.
17
Figure 1.4 GDP, CO2 emissions, and construction minerals extraction (Per Capita)[2, 6]
Figure 1.4. Presents the indexed values per capita of CO2 emissions, construction materials extraction,
and GDP. Due to this relation if the values stay stable it means that they are varying at the same rate as
the population. After the turn of the century the values for all three increased, showing that they were
growing much faster than the population over the same period. GDP and extraction of construction
minerals showing a steeper growth pattern than the one from atmospheric CO2 [8]. These rates of growth
are evidence that the global economies are interconnected with the production of construction materials
and buildings. Once all this information is pieced together, it becomes evident that the building sector
is a decisive player on the future of the global economy and the natural environment[8].
1.3. The role of the building sector on the environmental crisis
The building sector is one of the most important sources of economic activity and it is estimated that
contributes to 10% of the global GDP[8, 13]. It providing almost 7% of employment worldwide and it
is considered the largest single employer[8]. Nevertheless, it has been estimated that the building sector
is responsible for the consumption of around half of all the resources extracted from nature[8], and it is
the main consumer of electricity with a global average above 30%[13]. The building sector contributes
more than 7% of all global GHG emission from the production of construction materials and more than
30% from the operation of buildings and infrastructure[8, 13].
18
The building sector also provides infrastructures and housing which are the basis for the economic and
social development of urban areas and their populations. The aforementioned population growth and
urbanization level are creating a rising housing demand worldwide[4, 8]. This demand is more
pronounced in least develop and emerging economies countries but it also occurs in other geographies
[4] . On least develop and emerging economies countries the offer of housing cannot cope with their
rapidly growing populations. This has created a housing gap which size is difficult to assess but it has
been estimated to border the 100.000 units per year[14] and it is expected to continue growing. From
the facts that had been presented on this section it is clear that the provision of urban infrastructures and
housing will be done using non-renewable mineral based construction minerals. Thus, contributing to
further increase the levels of environmental degradation and resource depletion on the global scale. The
building sector is a multifaceted and decisive actor on this crisis, providing benefits on both the global
economic and social spheres but at the cost of environmental degradation. The advantages of this
situation is that the building sector is financially strong, making it more apt for innovation and
development. Moreover, due to its important role in the countries’ economies and societies it counts
with the support from the population and national governments.
A sustainable and resilient built environment requires changes that maximize the economic and social
benefits from the building sector while reducing the associated negative impacts on the natural
environment. On this endeavour it is necessary for the building sector to switch from the mineral based
construction materials towards renewable bio-based solutions, on a purpose specific high performance
basis. The challenge for the building sector is to use appropriated construction materials to maximize
the economic, environmental and social benefits at a speed that allows it to achieve its main purpose.
This is by no means an easy task and few construction materials are able to fulfil all the requirements.
Among them, bamboo had been considered as one with the highest potentials to be sustainably used on
the development of the built environment [15-18].
1.4. Bamboo
1.4.1. Bamboo as plant
Bamboo belongs to the Poeceae – Gramineae family, which mean that it is a giant grass [19, 20]. In fact
bamboos are the only grass adapted to live in a forest. There are about 1250 different bamboo species
and 75 genera worldwide. [21] About 1100 species can be classified as woody bamboo. [22] and they
grow naturally in four continents, Africa, America, Asia and Oceania[19], countries in which bamboo
grows naturally are marked green on figure 1.5.
19
Figure 1.5 Global distribution of bamboo
Bamboo features a wide range of distribution and a great variety of habitats. Bamboo is normally found
in regions where temperature ranges from 8°C to 36 °C with an annual rainfall of 1020 to 6350 mm.
Some bamboo species can develop up to 4000 m above sea level and withstand temperatures as low as
-20 °C [21]. The greatest bamboo diversity can be found in Asia, with about 590 bamboo species and
44 genera. Most of them are endemic to China, where temperate bamboo forests, warm bamboo forests,
hot bamboo forests and plain bamboo forests exhibit the largest number of bamboo species in the
world[21]. The majority of woody bamboo genera and species are endemic to South and Southeast Asia.
This region is gifted with about 150 species with a high economic value [21]. The second richest region
in terms of bamboo diversity is Latin America with a share of 39% of all bamboo species worldwide.
Especially Brazil and Colombia offer a great diversity with more than 100 different species [22].
It is estimated that almost one percent of the world land is covered by bamboo forest [20], 80% of these
bamboo forest are located in Asia and the Pacific regions as it can be seen on figure 1.6. The largest
bamboo resources are found in China, India, Myanmar, Indonesia, Thailand and Vietnam. [21] China
alone has seven million hectares of bamboo forest. More than half of which are managed plantations
and therefore exploited for commercial purposes. The remaining bamboo forests are mainly situated in
mountainous regions and are an important habitats supporting extensive ecosystems[23]. In Latin
America, the bamboo forest area is estimated to be close to eleven million hectares, and a big part of it
belongs to the south-western Amazon basin in Brazil [22].
20
Figure 1.6 Worldwide distribution of bamboo resources [24]
Bamboo plants can be classified based on their rhizome structures: Sympodial, Monopodial and
Amphipodial as shown on figure 1.7. Sympodial rhizomes structures consist only of a culm neck and a
culm base. These rhizomes are quite short and grow vertically into the ground. New shoots emerge on
the culm base and sprout directly into young culms. [25] A monopodial rhizome structure presents long
and thin rhizomes that grow horizontally. Buds develop either into shoots or expand the rhizome
structure. [25] Usually lateral buds become shoots whereas terminal buds form new rhizomes.
Amphipodial rhizomes structures are a case apart as they exhibit features typical for sympodial and
monopodial rhizomes. [25]
Figure 1.7 Rhizomes structures of bamboo [25]
The bamboo culm has a tube shape with walls that consist of different layers. The outer layer of the
bamboo wall is called epidermis and is the oldest part of the plant (fig 1.8). The inner layer is known as
the cortex and has a high content of lignin and silica concentrated in short cells [25]. Under the epidermis
there is the derma section with vascular bundles called parenchyma cells. The innermost part of the
bamboo wall is highly lignified and cells are densely arranged. [25]
21
Figure 1.8 Structure of the bamboo culm [20]
A remarkable process in bamboo is its fast grow stage that takes between six to nine months, depending
on the spices and the environment they grow. During this stage the culm reaches its full height and
diameter. The fast growth is enabled by the simple structure of fibres and the conductive tissue found
on bamboo [20] The parenchyma cells that are arranged axially along the culm allow a rapid flow of
nutrients, thus supporting the grow process. When the bamboo stops growing in height a consolidation
of tissue starts by secondary thickening of the culm’s inner walls [20]. Bamboos are very diverse on
their physiology, the most visible characteristics being the diameters of the canes and their height. The
diameters varies between 0.5cm up to 22cms the height starts from 1m and can reach up to 20m
depending on the species. Roughly classifying, the bamboos can be considered as giant bamboos when
their diameters are beyond 7cms. Another distinctive feature is the way they grow based on the on their
rhizome structures Sympodial and Monopodial structures will produce culms that grow very close to
each other forming clumps while Amphipodial rhizome structures will produce bamboo culms that are
scattered leaving space for new shoots.
1.4.2. Bamboo as raw material
Thanks to its geographical distribution bamboo had been available to many cultures around the world
since immemorial times. None surprisingly an incredible wide range of applications had been developed
for it, this combined with its rapid grow and bio mass production made bamboo a prime resource in
Africa, America, and Asia. The shoots of some species of bamboo are edible and had been used in Asian
cuisine for centuries[26]. The foliage had been used as biofuel and as composting materials[26]. The
bamboo canes be burned directly or processed into charcoal for heating and / or cooking. Thanks to its
mechanical characteristic Bamboo canes had been used to make tools, furniture, and hardware. Bamboo
can also be processes into fibres and /or thin veneers which can be used in the production of textiles or
22
mats. Bamboo canes are on itself very good load bearing elements and can be used to produce furniture.
Moreover thanks to its weight to strength ratio bamboo canes can be used to produce light weight
structures and buildings.
Bamboo is mainly composed of cellulose, lignin, pentosan, soluble extracts. The cellulose content is
responsible for the bamboo’s tensile strength parallel to grain. The components hemicellulose and lignin
serve as backbones to cellulose providing bamboo with elasticity and compressive strength. [25] Lignin
occupies the absorptive space of cell walls and thus contributes to the dimensional stability of bamboo
[25]. Bamboo exhibit many physical properties similar to conventional construction materials like wood.
Bamboo is an anisotropic material like wood, which means that the fibres are orientated parallel to each
other. The fibre density is higher at the outer periphery which is one reason for the high flexibility of
bamboo[27, 28] as it can be seen on figure 1.9.
Figure 1.9 Bamboo fibre distribution [28]
The tensile strength along fibres can be as high as 193 N/mm2, the tensile strength across fibres to 8, 1
N/mm2. The compressive strength along fibres reaches values of about 68 N/mm2. For the Young’s
modulus along fibres a value of about 20600 N/mm2 can be assumed[27]. This characteristics make
bamboo a very interesting material that can be used with little processing or can provide fibres for the
production of composite materials. One of the most know of these bamboo composites is glue laminated
bamboo [29-31]. Glue laminated bamboo consists of flattened bamboo culms that are glued together in
stacks figure 1.10. The flattening process is energy-intensive and produce large amounts of by product
(saw dust)[30] [32] as seen in figure 12. The mechanical properties of this composite can be compared
23
to those of glue laminated wood[31, 33] and it had been proposed that it application could transition
from furniture towards a structural material application [18, 30, 34]
Figure 1.10 Glue laminated bamboo
1.4.3. Bamboo as construction material
As it was mentioned before, bamboo had been available to many different cultures through the centuries.
As a consequence bamboo has been also used to produce edifications and infrastructures. The
constructive systems based on bamboo are very diverse and its application is strongly related to the
culture and environment of the region. Moreover, the morphology of the bamboo affects as well what
kind of structure were developed. Two main types of constructive systems can be identified: Load
bearing walls and spatial structures. The load bearing walls are created using frames of bamboo or mixes
of bamboo and wood[35]. Then these frames can be cladded with different materials, flattened bamboo,
steel sheets, and / or wood. After the cladding a final coat is applied that can be simple paint or a layer
of mortar-plaster. This provides lightweight walls with high load bearing capacity (fig 1.11). This kind
of structures had been utilized for over two centuries in countries like Colombia, Ecuador and Peru. The
positive experiences and good structural behaviour of these structure have created a lot of interest on
the scientific community. The inclusion of bamboo in the Colombian building code started a process of
ratification of this construction technique in the region. This construction technique had been widely
used over the years but recently it had become an interesting option for social housing solutions[36]
Figure 1.11 Bahareque house construction Source: Bambusa Project, Lopez / Trujillo, Colombia
24
The bamboo based spatial structures are based on struts and columns, this type of structures require
special joints to ensure their structural stability. This constructive system can be applied for edification
with either closed or open envelops (fig 1.12). These kind of constructive system had proved to be very
resilient to external environmental constrains like earthquakes or extreme winds. This lead to extensive
research on the field of structural design with bamboo and to the development of building codes for
bamboo based construction first in Colombia[37], and then in Ecuador, Nicaragua, and Peru. These
constructive systems had evolved from vernacular systems into engineered systems capable to perform
at the same level as modern constructive systems. This system allows to produce impressive buildings
and infrastructure and have open doors for the utilization of bamboo as main construction material in
contemporary architecture.
Figure 1.12 Bamboo dome. Source L.F. Lopez
1.4.4. Bamboo in contemporary architecture
Bamboo has a place on modern architecture, its application is not widespread but a good number of
examples can be found around the world. One of the most renowned architects for his work with bamboo
based buildings is Simon Velez. Mr. Velez has worked over decades on the use of bamboo as main
structural material for his designs. In 2009 he was the principal laureate of the Prince Claus Fund for
Culture and Development award for his work on the preservation and further development of this
construction technic and material. The work of Mr Velez ranges from private homes, to social housing
projects, institutional and educational buildings. One of the most renown building was the pavilion for
the Zero Emissions Research and Initiative (ZERI) in the world expo in Hannover(GE) in the year 2000
25
(fig 1.13). This was until recently the largest bamboo building in the world and showed to the world the
potential that bamboo based construction withholds.
Figure 1.13 Bamboo Pavilion. Manizales Colombia [19]
One key element on his work is the type of joints used to connect bamboo canes. This kind of joint is
an evolution of the traditional joint type used in Colombia. The work of Mr Velez had been two folded,
on the one hand he had shown that bamboo has a place in contemporary architecture and on the other
he had inspired students and researchers to better understand how this structures work. Consequently,
this lead to a revival of the use of bamboo as main construction materials and to increase the social
acceptance of the material. Furthermore, the work several research institutions lead to the development
of special chapters on the Colombia building code.
This can also be seen in the work of offices like Komitu Architects with their woke on the Kouk Hhlean
youth Centre in Phnom Penh, Cambodia (Fig 1.14) where a mixture of bamboo, bricks and wood was
used to produce interesting aesthetics and mechanical performance.
26
Figure 1.14 the Kouk Hhlean youth Centre in Phnom Penh, Cambodia Source: [38]
Another interesting example is the German-Chinese House by Makus Heinsdoff for the World Expo
2010 in Shanghai. This structure combines bamboo with steel joiners and a clear façade that allows both
illumination and showcases the building materials used (fig 1.15)
Figure 1.15 German-Chinese House by Makus Heinsdoff for the World Expo 2010 in Shanghai[39]
As it was mentioned glue laminated bamboo can also be used in construction of both buildings and
infrastructure. The examples of the use of this material are more limited due to the lack of regulation
and characterization of the materials. The KPMG-CCTH Community centre (fig 1.16) is one excellent
27
example of the application of glue laminated bamboo in construction. As it can be seen from the picture
the main structural elements are made out of glue laminated bamboo.
Figure 1.16 KPMG-CCTH Community centre, PRC [38]
From this examples it becomes clear that bamboo based construction material can play a significant role
in the build environment and become an alternative to conventional construction materials. To better
understand the potentials these materials withhold it is necessary to assess their production process, their
service life and the impact on the environment that their application will produce.
1.5. Life Cycle and its assessment
The life cycle of a product can be roughly divided in four phases: (i) extraction, (ii) production, (iii) use
and (iv) disposal[40] as it can be seen on figure 1.17. The extraction phase, as the name indicates,
represents the extraction, recycling and/or re-use of raw materials from the environment [41]. This phase
considered activities like mining, harvesting of crops, and/or up cycle of recycled products. The
production phase considers the transformation of raw materials into processed products. This phase
plays an important role because it describes the efficiency of the transformation and the associated
energy and material demand for the studied product or service[42]. The use phase considers the energy
and material demand of the product during its service. This phase also considers the duration of the
service life, also known as the life span of the product[41]. Finally the disposal phase considers how the
products are disposed into the environment and/or recycled into new products. These four phases are
commonly known as the life cycle of a product.
28
Figure 1.17 Product's life cycle
Life cycle assessment (LCA) is the accepted methodology to evaluate the whole life impacts of products
and services[42]. LCA has been standardize and described in the ISO 14040 [43]norm and it consists of
four steps: definition of goal and scope, development of life cycle inventories (LCI), impact assessment
and interpretation. LCA is an iterative process where the definition of goal and scopes is adjusted based
on the results from the subsequent steps[40] (fig 1.18). The term “environmental impact” is used in LCA
to refer to the effects of the studied system on the environment. These impacts depend directly on the
evaluation method used during the impact assessment step.
Figure 1.18 LCA methodological steps
This methodology allow identify hotspots and to propose improvement potential of the studied
product[42]. In order to achieve this goal LCA requires quality data, which is able to represent the
production practices of the studied product[44]. Moreover, LCA requires an evaluation method, for the
impact assessment, able to characterize the results based on the location and time the product is being
29
produced[45]. The availability of these two elements is one of the main barrier for a widespread
application of LCA[44].
1.5.1. Methodological challenges
LCA is a very simple representation of a complex reality[40]. The methodology of LCA is clearly
described on the ISO 14040 norm but its application requires a series of assumptions and
approximations. These assumptions involve for instance how the environmental impacts are allocated
or distributed among products and by products [46, 47], how is going to be the product be disposed or
recycled and under which technical conditions [48, 49], and the extent of the studied systems and why
they are trimmed on that particular location [50]. Furthermore, the quality and availability of data used
along the life cycle phases remains a major challenge[51, 52]. Moreover, the production of LCA data
requires major investments, making it difficult for small companies or alternative solutions to provide
the data related to their products [44]. Besides the financial investment a dedicated LCA practitioner is
needed to produce LCA data following the ISO standards and complying with all the requirements form
databases. In many cases the aim of an LCA is an exploratory work or a support on the decision making
process, thus resources for this kind of investments are usually not viable.
1.5.2. LCA of buildings
LCA has been used to assess buildings for over two decades[53]. Its application at early stages can
highlight the improvement potentials on the different building components[54]. These improvements
can be therefore applied on subsequent buildings. The LCA of buildings is inherently complex due to
the number of components and systems that conform a building[54]. Moreover, the efficiency of
production of construction material can widely vary from country to country [55]. To model the life
cycle of a building it is necessary to know where the construction materials were produced not only to
know the production practices and efficiencies used but also to know the total transport distance from
production centres to the buildings construction site[56]. To calculate these transport distances it is
necessary to have a good estimation on possible routes and means of transport and potential sources of
construction materials[57]. Nevertheless, the use of LCA for the assessment of building has paved the
way to a better understanding on the different embodied and operational energy demands[55].
Furthermore, with the advent of energy efficiency regulations and labels major steps had been taken to
reduce the operational energy demand on buildings[58]. As a consequence the focused has shifted
towards the assessment of embodied energy and consequently on the construction materials used[59].
A similar situation can be found in countries without seasons, where there is no heating demand, thus
making the operational energy negligible.
30
1.5.3. LCA outside of the European context
The quality of the LCA results depend heavily on the quality of the data used to prepare the LCA
models[44]. Therefore, data that is not representative of a certain production practice in terms of it
process or efficiencies will provide vested results. Moreover, data that has very wide scope, either
regional averages or global averages, is not able to represent the different production practices of specific
locations. These data are usually collected on LCA databases, which are managed by research and
private organizations. The largest databases are EcoInvent[60] and ELCD[61] both based in Europe.
Not surprisingly the main core of data corresponds to the European geography. Even though, regional
and global datasets can be encountered on the latest versions of EcoInvent. To work outside the
European context it is necessary to be able to represent the production conditions outside this geography.
This process is described on the ISO standards[43] but it requires a significant financial and time
investments. These two factors hinder further the development of new datasets outside the European
context. Furthermore, this is also an issue for alternative construction materials that do not have the
support from well financed companies. Consequently, the LCA of buildings carried outside the
European context rely on approximations that produce high levels of uncertainty on their results.
1.6. Goal of research project
The main objective of the present research was to develop an approach for the production of life cycle
assessment data for conventional and bamboo-based constructive systems and their associated materials.
These data were integrated on a geographic information system in order to allow for the characterization
of the data to different countries worldwide. The data and characterization methodologies were tested
on several case studies focusing on post-disaster reconstruction and social housing projects. The case
studies considered the use of alternative construction materials like bamboo and soil stabilized blocks
as well as conventional construction materials like bricks and concrete hollow blocks. These case studies
focused on the environmental impacts from the production of buildings using these construction
materials on different locations. Additional sustainability aspects were also studied, considering the
potential job creation; cost; life span; and carbon crediting potential associated to the used of the
construction materials.
1.7. Dissertation’s outline
The present document is divided on five chapters which represent the process in which the proposed
research objective was achieved. Chapter 2 presents the main problem of lack of data and the
complexity to generate it outside of the European context. The first part of this section deals with a
methodological approach to generate LCA of bamboo based construction materials with global
representativeness. The methodology was used to produce the first global LCA data sets on the
EcoInvent database. The second part of this section, presents the application of the methodology for the
31
case of conventional and alternative construction materials like concrete, bricks, soil stabilized blocks
and ferro-cement panels. This is very important not only for the production of this kind of data outside
the European context but also because it validates the methodology’s flexibility. The data generated on
this process is used to carry out comparative LCAs. Chapter 3 deals with the development of a
methodological approach to characterize LCA data. This characterization process allows for the cost-
effective production of LCA data worldwide. The proposed methodology represents the wide range of
production practices encountered worldwide for both conventional and alternative construction
materials and the electricity mix used on their production. Moreover, it allows to estimate potential
transport distances based on the land area of the country of study. Furthermore, it also allows for the
identification of hazard risk zones for earthquake and wind on the studied location. On this section, the
implementation of this methodology on one case study is also presented. Chapter 4 presents three case
studies where additional sustainability aspects from the used of bamboo in construction were studied.
In the first case study, the sustainability of 20 transitional shelters and was assessed. Sustainability was
considered as a three component issue, considering environmental impacts, cost and risk/performance
from natural disasters. The results from this section highlight the important role that appropriate
materials selection and design on the sustainability of the built environment. Moreover it present the
pros and cons from the use of local or global construction materials in reconstruction projects with a
worldwide view. The second case study, deals with the sustainability of different construction materials
used in social housing programs. Here a much larger scale and time frame than previous studies is
presented. Housing programs requiring decades to implement and a significant amount of housing units
to cope with the ever growing global housing demand. Here, sustainability was considered in terms of
CO2 emissions; cost in terms of potential CO2 credits generated; and social as potential job positions
created. Moreover, the analysis from this section show that an alternative to the current building
practices is needed and it should be implemented in the very short term to be able to be effective. But
this implementation is limited by The results from this section shows that bio based construction
materials bamboo and timber have a great potential not only to withhold low environmental impacts and
cost but also to reduce the levels of CO2 and produce additional income in form of CO 2 Credits. The
final part of this section shows the potential that bamboo withholds to reduce environmental impacts
from buildings within the European context. Chapter 5 will present the general conclusions of this
research project reflecting on the overall process.
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35
Chapter 2: LCA data for conventional and alternative
construction materials
36
37
2. LCA data for conventional and alternative construction materials
Summary
LCA is confronted with a number of challenges. One of the most important is the availability of data
able to represent production practices outside the European context. Data is the basic requirement to
carry out an LCA and therefore it was considered as priority. When the research project on this field
was started in 2012, the main LCA database EcoInvent 2.7 included only a few datasets outside the
European context but none of them for the case of construction materials. With the advent of EcoInvent
3 and its subsequent releases a new approach was used. In EcoInvent 3, country specific datasets can be
used to generate regional or global datasets. This is a step forward but it heavily relies on the availability
of country specific datasets. This means that if only the datasets for concrete production for Germany
and Switzerland are available the European regional average will be created based on those two sets and
the same will occur with the global average. This average might be quiet different than the production
efficiencies found on other countries. Thus, a need for a cost-effective approach for LCA data generation
still remained. The ISO 14040 standard clearly describes the procedure for LCA data generation, but
experiences on the field had shown that a major economic and human talent investment are required to
produce country specific dataset. Moreover, this kind of development requires engagement from
different companies that not always able to share their data, due to IP issues or the amount of time that
the data collection requires. This problem is incremented when looking at alternative construction
materials due to its inherent variability of production practices and lack financial capacity for this kind
of endeavours.
This research project was faced with a very complex landscape, where a highly variable production
practices of an industry with not enough capital means to produce LCA data with global and local
validity. Furthermore, this problem needed to be approached with simple solutions that would enable
other practitioners or companies to develop their own LCA datasets in a cost-effective way.
The environmental impacts from the use of bamboo as construction material had been the topic of
several research projects. They were all faced with the same challenges and provided different
approaches to solve it. For this research project Bamboo based construction materials presented a prime
example of high variability, but it was clear that this variability had its limits. It was proposed that the
upper and lower limits for the input values could be used to create a triangular distribution. Thus,
providing with results within a range of variability and known uncertainty.
The case of bamboo based construction materials presented a complex challenge. First, each bamboo
specie has a different yearly yield due to their morphology, this can be further affected by environmental
conditions and production practices. All this factors in return also affect the land required for the
production of the bamboo as raw material. Second, the production practices of bamboo based
construction materials differ significantly from one company to the other and are not completely linked
38
to the geography where they are used, contrary to what would be observed in industries like cement or
brick.
The main objective of this research was to develop a cost-effective methodology to generate LCA data
of bamboo based construction materials. This methodology was based on the principle that the
variability on the inputs can represent the worldwide production practices. The contribution from the
inputs to the variability of the results was studied in order to highlight those process with the highest
contributions to the environmental impact and the variability of the results. The results showed that the
level of industrialization can be directly linked to the level of environmental impacts. Furthermore, for
the case of bamboo based construction materials the electricity mix used on their production and the
transport distances play a major role on the variability of the results. On the first stage the LCA data for
bamboo was produced but if a comparative LCA was needed the data for conventional construction
materials was still missing or have different level of detail. A master research project was carried out by
Alex Balzanini and supervised by Prof.Dr. Guillaume Habert and Edwin Zea Escamilla. On this project
LCA data for conventional construction materials like concrete, concrete hollow blocks, bricks, and
alternative construction materials like soil stabilized bricks and ferro-cement panels were generated
applying the same methodology as the one used for bamboo based construction materials. The results
from this project showed that there is less variability on the inputs of these construction materials. In the
case of those materials that contain cement, the main contributor to the variability of the results was the
clinker and the electricity mix and energy source used for its production. Furthermore, they showed that
the transport distances can significantly contribute to the environmental impact.
With these two research projects it was possible to develop a set of LCA data for conventional and
alternative construction materials that were able to represent the global range of production practices.
Moreover, the variability of the results and the main processes contributing to it were identified. These
results were satisfactory but the process of adapting the data sets to specific locations worldwide was
still time consuming and in the case of the transport distances of construction materials there was no
consistent approach to estimate these distances. Moreover, it was considered that the data alone would
solve the main challenge only partially and that a methodology to characterize the data and estimate the
potential transport distances was still needed. Furthermore, it was necessary to understand what were
the limitations to the proposed methodology for data generation and under which conditions the
produced data could be considered as valid.
39
Introduction to the chapter
This chapters introduces the topic of generation of Life Cycle Assessment data for conventional and
alternative construction materials with global validity. This chapter is thematically divided on two major
sections, the first describes the methodological approach to generate LCA data outside the European
context and presents an example for its application on bamboo based construction materials. The second
section presents the results from the work of Alex Bazanini whom supervised by Prof.Dr. Guillaume
Habert and Edwin Zea Escamilla applied the methodology to mineral based construction materials both
conventional and alternative.
The first section will introduce the necessity of a cost effective method to generate LCA data with global
validity and the challenges faced on this process. Furthermore, it will describe the potentials that bamboo
withholds as a construction material and describes five bamboo based construction materials. This
section continues with a description of LCA and its application on the assessment of whole life impacts
of buildings. Moreover, it will present a series of practical and methodological challenges faced when
using LCA and specifically those related to the application of LCA on buildings. It will also present an
overview of the different approaches used to assess the life cycle of bamboo based construction
materials.
After this introduction, the proposed method for data generation will be described. First, the functional
units for each bamboo based construction materials and the boundaries to the studied system will be
described. Furthermore, the data used on the methodology is presented showing the variability of input
and the different sources where the data was obtained. This part closes with a description of the
environmental impact evaluation method selected to test the method and a brief description of the set up
for the uncertainty analysis of the application’s results.
The section continues presenting the results from the application of the proposed method on bamboo
based construction materials. These results present a first view of the environmental impact from the
production of bamboo based construction materials and how the different process contribute to this
impact. Furthermore, the contribution from production process to the variability and uncertainty of the
results are presented. This section finishes by discussing the results considering the most sensitive
premises of the method and proposing a series of key parameters for the development of simplified LCA
of bamboo based construction materials.
40
Environmental impacts from the production of bamboo based construction materials
representing the global production diversity
Journal of Cleaner Production 69 (2014) 117e127
2.1. Environmental impacts from the production of bamboo based construction materials
representing the global production diversity
The construction industry has been recognised as one of the major consumers of resources and energy
and as being responsible for a large proportion of the waste produced worldwide [1, 2]. These three
topics are already of major concern, but if they are considered in light of the staggering urbanisation
process of the last few decades, during which more than 50% of the human population has become urban
[3], it becomes clear that the need for purpose-specific, high-performance construction materials is more
urgent than ever. Moreover, the high levels of CO2 emission coming from the production of
construction materials represents a problem on the global scale [4]. On this respect bio-based
construction materials have an advantage of being not only renewable but also able to sequester CO2
during their growth [5, 6], as well as store it during their use phase. Bamboo can be considered among
the most important bio-based construction materials. However, bio-based materials bring also
challenges for their application. One of the most important is the variability in their growth and yield,
which makes it difficult to accurately estimate their environmental benefits and impacts. This study
focuses on the calculation of the environmental impact associated with the production and use of
bamboo-based construction materials.
Furthermore, it aims to generate data on environmental impact of bamboo based construction materials
representing the global production diversity of these materials. The study provides mean values and
standard deviations for each bamboo-based material and identifies the processes with the greatest
influence on the results, which allows for the identification of those processes requiring additional data
collection.
2.2. Literature review
This literature review contains three main components. First, bamboo is introduced, and the potential
for its use as construction material is described. Then, the methodological challenges of Life Cycle
Assessment are presented, emphasizing those challenges related to data quality and uncertainty. Finally,
the state of the art concerning the application of LCA to bamboo-based construction is presented.
2.2.1. Bamboo as a construction material
Bamboo is a gigantic grass and is the only tribe in the grass family to successfully adapt to life in the
forest [7]. Bamboo grows naturally in Africa, Asia, America and Oceania, and more than 1200 bamboo
species have been catalogued [8]. A common feature among these species is their rapid growth, which
can reach up to 25 cm per day. Of the 1200 species, approximately 20 are considered suitable for
construction purposes [9]. The most important of these are Moso bamboo (Phyllostachys pubescens),
Guadua (Guadua angustifolia Kunth), and Dendrocalamus asper. These species are considered giants
41
among bamboos. Their culms have a diameter of between 10 and 18 cm, and their height ranges from
12 to 20 m. These features vary from one species to another and with the ecology of their growth site.
Due to their great strength, flexibility, and versatility, the culms of bamboo have been widely used for
housing and other construction purposes. The following five bamboo-based construction materials were
identified (ordered from the least to most industrialised material): bamboo pole, flattened bamboo,
woven bamboo mat, glue-laminated bamboo, and laminated woven bamboo mat panel. In countries such
as Colombia, Ecuador, and Peru, where a tradition of building with bamboo exists [9], these materials
have been integrated into engineered constructive systems thanks to extensive research on the
mechanical behaviour of bamboo-concrete composites[10]; glue laminated bamboo [11] and load
bearing wall systems [9, 12]. Building codes for the bamboo used in construction have been available
in Colombia since 2011 [13] and have been more recently introduced in Peru and Ecuador. The
following two general constructive systems are defined in these codes: spatial structures and load-
bearing walls.
The spatial structure system is mainly used in roofs, pavilions, and bridges. This system is used in the
construction of lightweight structures able to cover large spans, as can be seen in figure 2.1. The load-
bearing wall system consists of frames made out of bamboo poles and is mainly used for houses. The
poles are covered with flattened bamboo and then plastered with soil-cement plaster. Figure 2.2 shows
an example of this type of constructive system, which can be used in a wide range of building styles. A
focus on the five aforementioned bamboo based construction materials enables the calculation of the
environmental impact of most buildings in which bamboo in their structure.
Figure 2.1 Example of a spatial structure. Bamboo Bridge in Bogotá, Colombia. Sce: L.F. Lopez
42
2.2.2. Life cycle assessment methodological challenges
To calculate the environmental impact of these five bamboo products, Life Cycle Assessment (LCA)
was used. This assessment method was developed to quantify the material use, energy use, and
environmental impact associated with specific products, services, and technologies. LCA is described
and standardised in ISO1440 [14] and consists of four steps: the definition of goal and scope, the
development of life cycle inventories, impact assessment, and interpretation. LCA is an iterative process
in which the goal and scope are constantly adjusted depending on the data collection limitations and the
insights provided by the impact assessment [15]. The term "environmental impact" is used in LCA to
refer to the effects of the studied system on the environment. These impacts depend directly on the
evaluation method used during the impact assessment step. LCA has been applied in the construction
sector for more than 20 years [16]. Among the difficulties involved in providing accurate environmental
assessments, such as allocation [17, 18], end-of-life scenarios [19, 20], and system boundaries [21], the
quality of the data used all along the supply chain remains a major topic [22, 23]. Indeed, an industrial
material and the data available concerning that material are the result of many different processes. For
instance, the quality of cement data is dependent on the quality of the assessment made for the extraction
and refinement of fuels [24], a process occurring geographically and technologically far removed from
the cement industry.
In LCA, it is common to distinguish foreground data derived directly from the studied process, which
are technical data related to the amount of material and energy used during the specific process, from
background data, which are related to all the upstream processes [25]. The quality of background data
Figure 2.2 Example of a load-bearing structure. Bamboo
house in Ibague, Colombia
43
is difficult and expensive to assess because the data are linked to processes far removed from the
evaluated product. The strategy developed for the EcoInvent database, which involves assessing the
quality of the data through a pedigree matrix, enables the definition of a quantified standard deviation
based on different qualitative assessments [26, 27]. In the construction sector, this strategy has been
used recently with a different tool to provide a usable confidence index for the data [28]. The main focus
in the construction sector is to reduce uncertainty only for those materials that make a large contribution
to the overall environmental impact of a building and for which the uncertainty is significant [29]. For
this reason, Heijungs [30] introduced the concepts of uncertainty and contribution as two parameters to
categorise life cycle inventory data. In the case of industrialised materials, the foreground data is derived
from a standardised process that may be similar in different industrial plants. Thus, the low quality of
background data can be ignored. As a result, assessing the environmental impact of one cement plant
enables generalisation, with a high level of confidence, concerning the environmental impact of a cement
bag produced in another plant, as long as the plants operate under the same processes [31, 32], even if
changes in environmental impact due to intrinsic variability in the processes cannot be avoided [24, 33].
For low-industrialised materials, such as bamboo, which are often produced in rural communities with
low quality control, the potential variability of data is significant. Previous studies of low industrialised
products have highlighted this point for brick or concrete block production [34-36]. Moreover, all bio-
based products have an intrinsic product variability [37, 38]. The environmental assessment of bamboo
products combines the challenges of data quality and high data variability. Therefore, the
methodological approaches used for an environmental assessment must deal with these challenges while
also being easy to apply in different contexts.
2.2.3. LCA of bamboo-based construction materials
LCAs of non-load-bearing, Bamboo-Based Construction Materials (BBCM), such as flooring [39] and
load-bearing materials in the study of bamboo based houses [40, 41]; supporting structures [42, 43];
concrete-bamboo composite beams [44] and load bearing bamboo walls [45] have been conducted. All
of these studies reported the potential of bamboo for use in the construction sector. However, none of
these studies addressed the problem of results variability and the uncertainty related to the production
of BBCM. This omission can be justified because most of the studies focused on industrial-quality
products, whose variability is, a priori, lower. However, the studies also often focused on only one
bamboo species [43, 46].
2.3. Data and methods
In this section, the data collection for the different steps in the life cycle assessment of the materials and
the methodologies for the sensitivity and uncertainty analysis are presented.
2.3.1. Functional unit and system boundaries
The goal of this LCA is to evaluate the environmental impacts related to the production of bamboo-
based construction materials considering the need for values with global representativeness and
44
applicability. This LCA was limited to five BBCM: bamboo pole, flattened bamboo, woven bamboo
mat, glue-laminated bamboo, and woven bamboo mat panel. The results can be used to assess all
bamboo-based constructive systems. The functional unit is defined as 1 m3 of material. The decision to
use 1 m3 is based on experience with the development of LCA data for wood products for the EcoInvent
database [47]. Bamboo and wood present similar methodological challenges for their LCA modelling,
as they both experience a loss of mass throughout their processing. This loss is mainly caused by the
drying process of these bio-based materials. The basic properties of the functional units of the studied
materials are described in table 2-1. The detailed calculation of these functional units can be found on
the Annex B.
Table 2-1 Functional units studied
Products Functional
unit Density
(kg.m-3) Resin content
(wt%)
Low industrialized
products
Bamboo pole 1m3 100 0
Flattened bamboo 1m3 176.8 0
Woven bamboo mat 1m3 178.2 0
Highly
industrialized
products
Woven bamboo mat panel 1m3 723.9 ~ 6.5
Glue laminated bamboo 1m3 885.4 ~ 5
2.3.2. Inventory data
The conceptual framework for the development of life cycle inventories is presented in figure 2.3. Note
that each material interacts with the environment in several ways. First, each has a flow towards the
environment that represents the flow of by-products and emissions. Second, each material has a flow
towards the built environment where it can be used for construction. Finally, a material can also serve
as a resource for a more complex construction material.
45
Figure 2.3 Conceptual framework
Showing the relationship between the different bamboo-based construction materials, the environment and the
built environment
The Life Cycle Inventory (LCI) data were collected through literature review and interviews with
experts. The focus of data collection was on the material, energy, and transport inputs needed to produce
the functional unit. The infrastructure was also considered, representing the machinery and buildings
that are used for the production of each material [48]. With regard to transport, the common calculation
used in EcoInvent was modified because bamboo is a lightweight material. The usual method of
transport calculation is to divide the truck consumption per km by the weight of material that can be
transported to produce an environmental load per ton and km. Because of the light weight of bamboo,
the truck is full before reaching its maximum load capacity. Therefore, it is needed to divide the truck’s
consumption by a smaller maximum weight, leading to a higher impact per mass transported. In this
study, a 16-t lorry from EcoInvent was considered, which has a useful weight capacity of 9.5 tons. The
maximum volume capacity of the lorry is approximately 25 m3. Consequently, when fully loaded with
bamboo poles, the lorry will carry 2.5 tons because 1m3 of bamboo poles has a density of 100 kg/m3
(see table 2-1). This tonnage is 3.8 times less than the weight capacity modelled in EcoInvent. Therefore,
the input value for transport was calculated by multiplying the mass of bamboo transported by the
distance by the correction factor.
46
In the following section, the LCIs for the production of bamboo-based construction materials are
presented, ranging from the least to the most industrialised material. Each table presents three production
scenarios: the best-case, worst-case, and mean.
Although bamboo culm is not itself considered a construction material, the culm is the main input for
all the materials being assessed; thus, its LCI is presented in table 2-2. Each species of bamboo yields
different numbers of culms per year. This number can be influenced by fertiliser use and natural
events[49]. The culms can be extracted manually or using a chainsaw but lack a direct application as a
construction material because their high water content, approximately 40%, and when untreated their
service life is approximately three years [5, 50]
Table 2-2 : LCI of bamboo culm
Products Unit Mean Lower limit Higher limit Source
Bamboo culm, m
3
1
Biomass (branches and leaves) m
3
0.5
Occupation, forest m
2
a18.5 6 31 [a, b, c, d, e, f]
Transformation, to forest m
2
18.5 6 31 [a, b, c, d, e, f]
Bamboo standing at forest m
3
1.5 1.33 1.66 [a, b, c, d, e, f]
Transformation, from pasture and
meadow m
2
18.5 6 31 [a, b, c, d, e, f]
Urea, as N, at regional storehouse kg 0.7 0 1.4 [g]
Potassium chloride, as K2O, kg 0.23 0 0.47 [g]
Single superphosphate, as P2O5 kg 0.7 0 1.4 [g]
Diesel, low-sulphur, kg 0.1 0.07 0.14 [a, b, c, d, e, f]
Power saw, with catalytic converter min 7.65 5 10 [a, b, c, d, e, f]
aDe Flander and Rovers, 2009; bRiaño et al., 2002; cSalz er, 2011; dYang and Hui, 2010; eZea Escamilla et al., 2013; fZea Escamilla and Wallbaum, 2011; gLiu et al., 2011.
Materials / fuels
FertilizerCutting
Functional unit
By-product
Resources
Land use
47
Figure 2.4 Bamboo-based construction materials
a) Bamboo poles b) Flattened bamboo. c) Woven bamboo mat. e) Glue laminated bamboo. e) Woven bamboo mat panels. Sce:
Authors
Table 2-3 shows the LCI for bamboo pole, the first BBCM studied (figure 2.4a). The pole is derived
directly from the bamboo culm and is usually trimmed to between 4 and 6 m and treated against fungi
and pests using boric acid before the water content is reduced by drying to approximately 20%. The
poles are then transported from the treatment plant either to a distributor or to an intermediate processing
facility. This transport is generally local, with a range of between 4 and 120 km. For this material, natural
48
gas was considered the fuel used for the drying process. Bamboo poles can be used directly for the
construction of columns, beams, or struts and are also the main input for other BBCM [39, 42].
Table 2-3 LCI of bamboo pole
aMurphy, et al., 2004; bSalzer, 2011; cvan der Lugt, et al., 2009; dVogtländer, et al., 2010; eZea
Escamilla, et al., 2013
The LCI of flattened bamboo (figure 2.4b), a handcrafted construction material, is shown in table 2-4.
To produce flattened bamboo, a bamboo pole is cracked open and its internodes are removed. The
innermost part of the bamboo is then trimmed down. During this process, some fibres are broken,
rendering the material flexible but still able to maintain its shape. The main application of flattened
bamboo is in load-bearing wall systems, where it is used between bamboo poles to support the soil-
cement mortar with which the walls are plastered [40, 45]
Table 2-4 LCI of flattened bamboo
aMurphy, et al., 2004; bSalzer, 2011; c Zea Escamilla, et al., 2013
To produce woven bamboo mats, a bamboo pole is first flattened and then divided into strips with widths
between 2 and 4 cm. These strips are then peeled into 1- to 2-mm-thick veneers, which are then woven
to form a mat. The entire process is manual and is typically performed in small, rural communities. The
woven bamboo mats are usually used as lightweight walls but have also recently been used for
industrially produced panels [51]. As both flattened bamboo and woven bamboo mats are commonly
Products Unit Mean Lowerlimit Higherlimit Source
Bamboopole m31
Biomass(bambootrimsandsawdust) m30.18
Bamboocul m m31.18 1.12 1. 24 [7,37,38,40,41]
Electrici ty,productionmixCNkWh302337[7,37, 38,40,41]
Sawmill parts 6.69107 5.45E07 7.92E07 [7,37,38,40,41]
Boricacid, anhydrous,powd er kg 19 11 27 [7, 37,38,40,41]
Airco mpressor(screwtype,300kW) parts 4.64E04 4.64E04 4.64E04 [7,37,38,40,41]
Heat, naturalgas,atindustrialfurnace
>100kW MJ 861 795 927 [7,37,38,40,41]
Wood dryinginfrastructure parts 6.09E05 6.09E05 6.09E05 [7,37,38,40,41]
Transport
Lorry>16t, fleetaverage ton*k m 21. 55 1.44 43.09 [7,37, 38,40,41]
Functionalunit
Byproduct
Materials/fuels
TrimmingTreatmentDrying
Products Unit Mean Lowerlimit Higherlimit Source
Flattenedbamboo m3 1
Biomass(bambootrims) m3 0.15
Bamboopo le m3 2.04 2 2.09 [a, b, c]
Functionalunit
Byproduct
Materials
/fuels
49
manufactured in facilities extremely close to the point of extraction and/or treatment, no transport is
included in the inventory. The LCI for the production of woven bamboo mats (figure 2.4c) is shown in
table 2-5.
Table 2-5 LCI of woven bamboo mat
aMurphy, et al., 2004; bSalzer, 2011; cZea Escamilla, et al., 2013
Glue-laminated bamboo (figure 2.4d) has been produced for more than 60 years and is mainly used for
flooring and furniture. Recently, this product has also been used in structural applications [11, 52]. Glue-
laminated bamboo is composed of bamboo slats and a bonding agent. Bamboo poles are split, trimmed,
and then planned to produce the slats, which vary in shape and size depending on the production and
application of the material. The slats are glued, placed in a mould, and hot-pressed to form the laminate
(table 2-6) [39, 50].
Table 2-6 LCI of glue laminated bamboo
aDe Flander and Rovers, 2009; bSalzer, 2011; cvan der Lugt, et al., 2009; dVogtländer, et al.,
2010
Woven bamboo mat panel (figure 2.4e), is currently used as an alternative to plywood, this product has
also shown promise in structural applications [51]. Woven bamboo mat panels are produced in a fashion
similar to that of glue-laminated bamboo. In this process, woven bamboo mats are layered and glued
together with a bonding agent and then hot-pressed to cure the composite material (table 2-7) [41]. Both
glue-laminated bamboo and woven bamboo mat panels are usually transported from the factory to
retailers or distributors. These transport distances can vary between 0 and 600 km.
Products Unit Mean Lowerlimit Higherlimit Source
Bamboomats m3 1
Biomass(bambootrims) m3 0.075
Flattenedbamboo m3 1.075 1.05 1.1 [a, b, c]
Materials
/f