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Green Concrete in Developing Economies

Permanent Link: http://ufdc.ufl.edu/UFE0041608/00001

Material Information

Title: Green Concrete in Developing Economies Assessing the Potential for Using Low Cost Cement Substitutes
Physical Description: 1 online resource (91 p.)
Language: english
Creator: Terrell, Christian
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: analysis, cement, concrete, cycle, developing, economies, green, life, organic, substitutes
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: GREEN CONCRETE IN DEVELOPING ECONOMIES: ASSESSING THE POTENTIAL FOR USING LOW COST CEMENT SUBSTITUTES Christian Terrell 904-484-4156 / cavguns@ufl.edu Rinker School of Building Construction Dr. Esther Obonyo Master of Science in Building Construction May 2010 Keywords: Green concrete; Developing economies; Organic cement substitutes; Life cycle analysis Concrete is second only to water as the most consumed substance on earth, with nearly three tons used annually for each person on the planet. The building industry and the natural environment in developed and developing economies can benefit from building low-cost and sustainable structures with green concrete. The aim of this study is to assess the potential and structural performance of using cement substitutes. Specifically, low cost cement substitutes that are renewable and locally available in the developing world will be tested for strength and durability according to American Society for Testing and Materials (ASTM) standards. The specific research objectives of the study are: 1. To review existing practices with respect to green cement substitutes in developed and developing countries. 2. To determine the potential for using animal bone char, fly ash, and volcanic ash as substitutes for portland cement in the manufacture of green concrete. 3. To characterize the material properties performance of the resulting concrete based on durability, compressive strength and tensile strength tests by ASTM standards. 4. To characterize the impact of using the proposed concrete in building envelope performance against sustainability metrics using BEES (Building for Environmental and Economic Sustainability) software. Current practices in the manufacture of both traditional and green concrete in developed and developing economies will be examined. The ethical obligations of developed economies to preserve a baseline well-being of humanity and assist developing economies in building practices and alternative energy technologies will also be introduced to outline the importance of sustainability in the developing world. Following laboratory testing of green cement substitutes, recommendations for further study and research will be made for use in future sustainable building projects.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Christian Terrell.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Obonyo, Esther.
Local: Co-adviser: Kibert, Charles J.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041608:00001

Permanent Link: http://ufdc.ufl.edu/UFE0041608/00001

Material Information

Title: Green Concrete in Developing Economies Assessing the Potential for Using Low Cost Cement Substitutes
Physical Description: 1 online resource (91 p.)
Language: english
Creator: Terrell, Christian
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2010

Subjects

Subjects / Keywords: analysis, cement, concrete, cycle, developing, economies, green, life, organic, substitutes
Building Construction -- Dissertations, Academic -- UF
Genre: Building Construction thesis, M.S.B.C.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: GREEN CONCRETE IN DEVELOPING ECONOMIES: ASSESSING THE POTENTIAL FOR USING LOW COST CEMENT SUBSTITUTES Christian Terrell 904-484-4156 / cavguns@ufl.edu Rinker School of Building Construction Dr. Esther Obonyo Master of Science in Building Construction May 2010 Keywords: Green concrete; Developing economies; Organic cement substitutes; Life cycle analysis Concrete is second only to water as the most consumed substance on earth, with nearly three tons used annually for each person on the planet. The building industry and the natural environment in developed and developing economies can benefit from building low-cost and sustainable structures with green concrete. The aim of this study is to assess the potential and structural performance of using cement substitutes. Specifically, low cost cement substitutes that are renewable and locally available in the developing world will be tested for strength and durability according to American Society for Testing and Materials (ASTM) standards. The specific research objectives of the study are: 1. To review existing practices with respect to green cement substitutes in developed and developing countries. 2. To determine the potential for using animal bone char, fly ash, and volcanic ash as substitutes for portland cement in the manufacture of green concrete. 3. To characterize the material properties performance of the resulting concrete based on durability, compressive strength and tensile strength tests by ASTM standards. 4. To characterize the impact of using the proposed concrete in building envelope performance against sustainability metrics using BEES (Building for Environmental and Economic Sustainability) software. Current practices in the manufacture of both traditional and green concrete in developed and developing economies will be examined. The ethical obligations of developed economies to preserve a baseline well-being of humanity and assist developing economies in building practices and alternative energy technologies will also be introduced to outline the importance of sustainability in the developing world. Following laboratory testing of green cement substitutes, recommendations for further study and research will be made for use in future sustainable building projects.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Christian Terrell.
Thesis: Thesis (M.S.B.C.)--University of Florida, 2010.
Local: Adviser: Obonyo, Esther.
Local: Co-adviser: Kibert, Charles J.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2010
System ID: UFE0041608:00001


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GREEN CONCRETE IN DE VELOPING ECONOMIES: ASSESSING THE POTENTIAL FOR USING LOW COST C EMENT SUBSTITUTES By CHRISTIAN B. TERRELL A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN BUILDING CONSTRUCTION UNIVERSITY OF FLORIDA 2010

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2 2010 Christian B. Terrell

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3 To my father and to all those who have been struck down by cancer

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4 ACKNOWLEDGMENTS I would like to thank my family and close friends for their unwavering support over the years. I would also like to thank my professors at the M.E. Rinker, Sr. School of Building Construction at the University of Florida for imparting their knowledge of t he construction industry, particularly my thesis committee chair Dr. Esther Obonyo and my thesis committee members Dr. Charles Kibert and Dr. Mang Tia in the UF Civil Engineering Department for their guidance and support of this project.

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5 TABLE OF CONT ENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ ............ 7 LIST OF FIGURES ................................ ................................ ................................ .......... 8 ABSTRACT ................................ ................................ ................................ ................... 12 1 INTRODUCTION ................................ ................................ ................................ .... 14 Background ................................ ................................ ................................ ............. 14 Aims and Objectives ................................ ................................ ............................... 15 Outline of the Remainder of the Thesis ................................ ................................ ... 16 2 LITERATURE REVIEW ................................ ................................ .......................... 17 Introduc tion ................................ ................................ ................................ ............. 17 ................................ ................................ ...................... 18 Review of Existing Trends in Green Concrete ................................ ........................ 21 Overview of Organic Animal Waste Materials as Potentia l Cement Substitutes: Bone ................................ ................................ ................................ .................... 24 Bone Char: Definition, Usages, Production process, Recent Studies ..................... 25 The Case for Using Bone Char in Concrete ................................ ............................ 26 Bone Meal: Definition, Usages, Production process, Recent Studies ..................... 27 The Case for Using Bone Meal in Concrete ................................ ............................ 29 Review of Portland Cement Manufacturing Process ................................ ............... 29 Climate Change in Developing Economies ................................ ............................. 34 .................. 36 The Need for Sustainable Industries in Developing Economies ............................. 37 Cost Comparisons Between Traditional and Green Concrete ................................ 40 Ethics and Sustainability ................................ ................................ ......................... 42 Summary ................................ ................................ ................................ ................ 45 3 METHODOLOGY ................................ ................................ ................................ ... 46 Introduction ................................ ................................ ................................ ............. 46 Scope ................................ ................................ ................................ ...................... 47 Experimental Approach ................................ ................................ ........................... 48 Experimental Data Entry ................................ ................................ ......................... 49 ASTM C19 2: Making and Curing Concrete Test Specimens in the Laboratory ................................ ................................ ................................ ..... 49 ASTM C39: Compressive Strength of Cylindrical Concrete Specimens .......... 51 ASTM C496: Splitting Tensile Strength of Cylindrical Concrete Specimens .... 52

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6 ASTM C1585 04e1: Standard Test Method for Measurement of Rate of Absorption of Water by Hydraulic Cement Concretes ................................ ... 53 Equipment Used ................................ ................................ ................................ ..... 54 Concrete Mixer (Pa n Type) ................................ ................................ .............. 54 Full Automatic Compression Machine ................................ .............................. 55 Vibrating Table ................................ ................................ ................................ 56 Environmental Performance Data Entry: BEES Software ................................ ....... 56 4 RESULTS ................................ ................................ ................................ ............... 61 Introduction ................................ ................................ ................................ ............. 61 Concrete Mix Design ................................ ................................ ............................... 61 Concrete Testing Results: Wet Compressive Strength ................................ ........... 66 Concrete Testing Results: Dry Compressive Strength ................................ ............ 68 Concrete Testing Results: Tensile Strength ................................ ............................ 69 Concrete Testing Results: Water Absorption ................................ .......................... 71 Environmental Impact Assessment: BEES Results ................................ ................ 73 5 DISCUSSION AND CONCLUSIONS ................................ ................................ ..... 76 Summary ................................ ................................ ................................ ................ 76 Discussion ................................ ................................ ................................ .............. 77 Green Cement Substitut es ................................ ................................ ............... 77 Potential for Bone Char, Fly Ash, and Volcanic Ash as Cement Substitutes .... 77 Materials Performance Testing ................................ ................................ ......... 78 BEES Building Envelope Performance ................................ ............................. 79 Conclusions ................................ ................................ ................................ ............ 80 Further Research ................................ ................................ ................................ .... 81 APPENDIX : ADDITIONAL BEES DATA RESULTS ................................ ...................... 83 LIST OF REFERENCES ................................ ................................ ............................... 88 BIOGRAPHICAL S KETCH ................................ ................................ ............................ 91

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7 LIST OF TABLES Table page 2 1 Mineral composition of bone charcoal (J.A. Wilson, et al. 2002). ....................... 27 2 2 Mineral composition of bone meal (Meriter Health Services, 2009). ................... 28 4 1 Computerized mix design used to create the three batches of concrete mixtures. ................................ ................................ ................................ ............. 62 4 2 ............................. 63 4 3 Mineral composition of Miracle Gro Organic Choice bone meal (Fertilizer Product Information, 2009). ................................ ................................ ................ 65 4 4 Max wet compressive strength of concrete cylinders achieved after 28 days of curing. ................................ ................................ ................................ ............. 67 4 5 Max d ry compressive strength of concrete cylinders achieved after 28 days of curing. ................................ ................................ ................................ ............. 68 4 6 Max tensile strength (psi) and spitting ten cylinders achieved after 28 days of curing. ................................ ......................... 70 4 7 Weight of concrete cylinders after intervals of 5 minutes, 10 minutes of water immersion. ................................ ................................ ................................ .......... 72 4 8 Weight of concrete cylinders after intervals of 20 minutes, 1 hour and 2 hours of water immersion. ................................ ................................ ............................ 72

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8 LIST OF FIGURES Figure page 2 1 Quarry and dry process cement plant with environmental, social and economic impacts (World Business Council For Sustainable Development, 2002). ................................ ................................ ................................ ................. 20 2 2 Projected CO 2 emissions (in millions of metric tons) from the global cement industry through 2050, assuming no change in current practices (World Business Council For Sustainable Development, 2002). ................................ .... 23 2 3 Global cement production in millions of metric tons annually. Rising cement demand will increase the need for fuels and raw materials (World Business Council For Sustainable Development, 2002). ................................ ................... 23 2 4 A concrete industry advertisement depicting the green benefits of concrete (Jeffries, 2 009). ................................ ................................ ................................ ... 24 2 5 Production flow chart of typically manufactured concrete without cement substitutes (BFRL: Office of Applied Economic s, 2007). ................................ .... 3 0 2 6 substitutes (BFRL: Office of Applied Economics, 2007). ................................ .... 31 2 7 Materials and content used in portland cement manufacturing (BFRL: Office of Applied Economics, 2007). ................................ ................................ ............. 32 2 8 Concrete constituent quantities by cement blend and compressive strength of concrete (BFRL: Office of Applied Economics, 20 07). ................................ ........ 33 2 9 Energy requirements for portland cement manufacturing (BFRL: Office of Applied Economics, 2007). ................................ ................................ ................. 34 2 10 (a) Global annual emissions of anthropogenic GHGs from 1970 to 2004.5 (b) Share of different anthropogenic GHGs in total emissions in 2004 in terms of CO 2 eq. (c) Share of different sectors in total anthropogenic GHG emissions in 2004 in terms of CO 2 eq. (Intergovernmental Panel on Climate Change, 2007). ................................ ................................ ................................ ................. 35 2 11 Buildings can account for a significant reduction in CO 2 emissions per year. (Intergovernmental Panel on Climate Change, 2007) ................................ ......... 37 2 12 These windmills, part of a $90 million project, have sprung up on the edge of Lake Nicaragua in Rivas, Nicaragua (Press, 2009). ................................ ........... 39 2 13 Wind turbines on the shores of Lake Nicaragua with Ometepe Island volcano in the distance (Aleman, 2008). ................................ ................................ .......... 40

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9 2 14 Animal Numbers, Cattle Production by Country in 1,000 HEAD (Animal Numbers, Cattle Production by Country in 1000 HEAD, 2009). .......................... 41 3 1 4in. x 8in. concrete cylinders that were used to make laboratory specimens. .... 50 3 2 Rodding and vibrating the concrete specimens in the laboratory. ...................... 50 3 3 The concrete specimens curing and immersed in water for 28 days. ................. 50 3 4 Sketch showing typical failure modes of compression testing: (a) splitting; (b) shear (cone); and (c) splitting and shear ................................ ............................ 51 3 5 Hardened concrete specimen failure in the compression machine after destructive testing. ................................ ................................ .............................. 52 3 6 Hardened concrete (volcanic ash) specimen failure in the compression machine after splitting tensile strength testing. ................................ ................... 52 3 7 Moisture movement into concrete cylinder from surface contact with water. ...... 54 3 8 The tray and chicken wire apparatus used to test the hardened concrete specimens for water absorption. Bricks were used to steady the wire base and provide an even water level across the cylinders. ................................ ....... 54 3 9 Concrete mixer and tray used to mix the batches. ................................ .............. 55 3 10 Typical compression machine ................................ ................................ ............ 55 3 11 Typical vibrating table ................................ ................................ ......................... 56 3 12 BEES screenshot showing first step of analysis: setting up performance parameters. ................................ ................................ ................................ ........ 57 3 13 BEES screenshot showing second step of analysis: selecting building elements for comparison. ................................ ................................ ................... 57 3 14 BEES screenshot showing third step of analysis: selecting product alternatives. ................................ ................................ ................................ ........ 58 3 15 BEES screenshot showing fourth step of analysis: selecting product transportation distance. ................................ ................................ ...................... 58 3 16 BEES screenshot showing fifth step of analysis: computing results. .................. 59 3 17 BEES screenshot show ing sixth step of analysis: selecting tables and graphs to depict the product data. ................................ ................................ .................. 59 3 18 BEES screenshot showing seventh step o f analysis: final graphs and charts depicting performance of product comparisons. ................................ ................. 60

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10 4 1 Class F fly ash used in the lab tests. ................................ ................................ .. 63 4 2 Volcanic pumice ash obtained from local pet store. ................................ ............ 64 4 3 Miracle Gro Organic Choice bone meal. ................................ ............................. 64 4 4 The three sets of concrete cylinders curing for 24 hours. ................................ ... 65 4 5 The three sets of concrete cylinders curing for 28 days. ................................ .... 66 4 6 A bone meal concrete cylinder being tested for wet compressive strength. ....... 66 4 7 Concrete cylinders drying in oven for 48 hours. ................................ .................. 66 4 8 Graph of max wet compressive strength of concrete cylinders achieved after 28 days of curing. ................................ ................................ ............................... 67 4 9 Concrete cylinders after removal from the oven. ................................ ................ 68 4 10 A volcanic ash concrete cylinder being tested for dry compressive strength. ..... 68 4 11 Graph of max dry compressive strength of concrete cylinders achieved after 28 days of curing. ................................ ................................ ............................... 69 4 12 A volcanic ash concrete cylinder being tested for tensile strength. ..................... 70 4 13 The tray and chicken wire apparatus used to test the hardened concrete specimens for water absorption. ................................ ................................ ......... 71 4 14 Concrete cylinders after exposure to water and being weighed on electronic scale for water absorption. ................................ ................................ ................. 71 4 15 Graph depicting water absorption of concrete cylinders at specified time intervals. ................................ ................................ ................................ ............. 72 4 16 BEES overall performance results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ ................................ ............ 74 4 17 BEES environmental performance results of 100% portland cement (baseline), 20% fly Ash, and silica fume mixes. ................................ .................. 74 4 18 BEES economic performance results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ ................................ .... 75 6 1 Schematic diagram of ASTM C1585 testing procedure. ................................ ..... 82 A 1 BEES environmental performance by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ........................ 83

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11 A 2 BEES specific environmental performance results of 100% portland cement (ba seline), 20% fly ash, and silica fume mixes. ................................ .................. 83 A 3 BEES global warming by life cycle stage results of 100% portland cement (baseli ne), 20% fly ash, and silica fume mixes. ................................ .................. 84 A 4 BEES fossil fuel depletion by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ ..... 84 A 5 BEES ecological toxicity by life cycle stage results of 100% portland cemen t (baseline), 20% fly ash, and silica fume mixes. ................................ .................. 85 A 6 BEES human health by life cycle stage results of 100% portland cement (ba seline), 20% fly ash, and silica fume mixes. ................................ .................. 85 A 7 BEES global warming by flow results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ ................................ .... 86 A 8 BEES fossil fuel depletion by flow results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ .................. 86 A 9 BEES embodied energy by fuel renewability results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. ................................ .................. 87 A 10 BEES summary results of 100% portland cement (baseline), 20% fly ash, and silica fume. ................................ ................................ ................................ ... 87

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12 Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science in Building Construction GREEN CONCRETE IN DE VELOPING ECONOMIES: ASSESSING THE POTENTIAL FOR USING LOW COST C EMENT SUBSTITUTES By Christian B. Terrell May 2010 Chair: Esther Obonyo Cochair: Charles Kibert Major: Building Construction Concrete is second only to water as the most consumed substance on earth, with nearly three tons used annually for each person on the planet. The building industry and the natural environment in developed and developing economies can benefit from buildin g low cost and sustainable structures with green concrete. The aim of this study is to assess the potential and structural performance of using cement substitutes that c oncrete. Specifically, low cost cement substitutes that are renewable and locally available in the developing world will be tested for strength and durability according to American Society for Testing and Materials (ASTM) standards. The specific research objectives of the study are: 1. To review existing practices with respect to green cement substitutes in developed and developing countries. 2. To determine the potential for using animal bone char, fly ash, and volcanic ash as substitutes for portland cement i

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13 3. To characterize the material properties performance of the resulting concrete based on durability, compressive strength and tensile strength tests by ASTM standards. 4. To characterize the impact of using the proposed c oncrete in building envelope performance against sustainability metrics using BEES ( B uilding for E nvironmental and E conomic S ustainability) software. The developing economies of the world will play a key role in the future of sustainable construction practices. It is imperative that the natural resources and ecology found within these countries are preserved due to the ever increasing human impacts on r esource depletion. Many economies in the developing world have natural climate, oxygen and weather patterns. Additionally, these countries are experiencing record popula tion growth, growing economies, and resource depletion on a massive scale that is unsustainable under traditional building methods. These factors can lead to massive soil runoff, desertification, greenhouse gas emissions, polluted drinking water, and an ov erall detrimental effect on human health. developed and developing economies will be examined. The ethical obligations of developed economies to preserve a baseline wel l being of humanity and assist developing economies in building practices and alternative energy technologies will also be introduced to outline the importance of sustainability in the developing world. tutes, recommendations for further study and research will be made for use in future sustainable building projects.

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14 CHAPTER 1 INTRODUCTION Background In re unavoidable consequence of a combination of natural planetary warming cycles and human activities through the increased use of fossil fuels and destruction of the biosphere. The b uilt environment has been no exception in contributing to an increase in the burning of fossil fuels for building energy needs, an increase in construction waste in landfills, an increase in negative effects on human health, as well as contamination of wat er resources, agriculture and natural ecosystems. It is imperative to human survival that all professionals associated with the building industry begin implementing new construction techniques and utilizing sustainable building materials that will reverse potentially catastrophic harm to future generations. At the same time, it is imperative to incorporate alternative energy technologies in power generation in the built environment to reduce energy consumption, reduce reliance on a finite supply of fossil fuels and to mitigate the human contribution to climate change and pollution. Developed economies have a moral and ethical obligation to the developing economies of the world that lack infrastructure, resources and technical applications to share knowledg e of sustainable building practices and technologies. Any delay in sharing this information will have potentially irreversible effects on future generations depletion of na tural resources and potential poisoning of natural ecosystems which are crucial to human survival.

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15 This introduction presents an overview of the objectives of this thesis study. Some of the information to be presented in this study will be the follo wing: a definition of cement substitutes; a review of current unsustainable cement manufacturing processes; rations in producing sustainable cement substitutes; and an overview the ethical framework of sustainable construction. This study will then test the structural performance of organic cement substitutes in a laboratory setting and present the data obtained Aims and Objectives The aim of this study is to assess the potential and structural performance of using environmentally sustainable concrete. The specific research objectives of the study are: 1. To review existing practices with respect to green cement substitutes in developed and developing economies. 2. To determine the potential for using animal bone char, fly ash, and volcanic concrete. 3. To characterize the material properties performance of the resulting concrete based on durability, compressive strength and tensile strength tests. 4. To characterize the impact of using the proposed concrete in building envelope performance again st sustainability metrics using BEES ( B uilding for E nvironmental and E conomic S ustainability) software.

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16 Outline of the Remainder of the Thesis The remainder of this thesis will present the methodology and research data results that were conducted to deter mine the materials properties and environmental performance of using sustainable cement substitutes in developing economies. A literature review has been conducted on these issues and the results are discussed in Chapter 2. Chapter 3 provides the m ethodology used to conduct this research. Chapter 4 provides the results of the laboratory experiments performed on the concrete specimens with regard to compressive strength, tensile strength and durability (water absorption) testing as well as environme ntal performance with BEES software. The final Chapter 5discusses and analyzes the laboratory results, provides a conclusion of the research and results, and provides opportunities for further research in the field of sustainable construction.

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17 CH APTER 2 LITERATURE REVIEW Introduction This literature review presents an overview of the current information available about sustainable concrete. Green concrete will be defined as a sustainable building material that contains locally available, renewable and low cost cement substitutes. Organic, animal based materials of bone char and bone meal will be defined and current studies reviewed in terms of current applications as water filtration sources. The potential applications of bone char and bone meal a s cement substitutes will be presented in terms of their mineral composition. The traditional manufacturing process of concrete and portland cement will be presented in terms of materials content and energy consumption. The need for green concrete in deve loping economies will then be defined with respect to current trends in the building industry and projected effects on climate change. An overview of climate change in developing economies will be presented with respect to projected increases in carbon emi ssions and projected increases in the need for traditional concrete for building projects. The sustainable industries currently being employed to combat carbon emissions and to improve local economies will be presented. Particular attention will be paid to developing Central American economies which contain different economic scenarios while at the same time sharing much potential for sustainable building practices. Finally, the underpinning reasons for producing green concrete will be discussed in terms of an ethical framework of sustainability and its effects on future generations.

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18 In order to define green concrete and its material properties, one must first nstruction industry the typical construction industry term to describe new or uncured concrete). Most sustainable building materials can be classified into five sep arate categories and are best for the environment if they contain characteristics of all five, of which green concrete is included. These categories are (1) materials made with salvaged, recycled, or agricultural waste content; (2) materials that conserve natural resources; (3) materials that avoid toxic or other emissions; (4) materials that save energy or water; (5) materials that contribute to a safe, healthy, built environment (Lazarus, 2002). Green concrete is typically made from recycled aggregate that reduces the need for mining and extracting virgin aggregate and reduces toxic contamination of water supplies from leaching (Lazarus, 2002) The use of recycled aggregate as well as orga nic cement substitutes requires less cement in the concrete mixtures, which reduces the embodied energy and carbon footprint of green concrete due to less need for quarried materials extraction and fossil fuel processing. This in turn reduces the amount o f greenhouse gas emissions into the atmosphere. Additionally, the use of and structures. Its thermal mass is highly efficient in reducing the energy needed to hea t and cool buildings, and it also contains a high level of air tightness. Green concrete is highly durable, needs minimal maintenance, and has a long lifespan which leads to lower life cycle costs. This durability means that a building can preserve its co ncrete foundation or concrete exterior while replacing less durable parts like windows,

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19 insulation and plumbing. Its mass and damping qualities allow good acoustic performance while minimizing movement and reducing floor vibration. Green concrete is also non combustible, has a slow rate of heat transfer making it a highly effective fire barrier, and is resilient to flood damage (The Concrete Centre, 2009) Both traditional and green concrete are second only to water as the most consumed substance o n earth, with nearly three tons used annually for each person on the planet. Cement is the critical ingredient in green concrete, locking together the sand and gravel cement substitutes in an inert matrix. Both traditional and green concrete are a critica been used extensively for over 2000 years (World Business Council For Sustainable Development, 2002) Cement used in traditional and green concrete is made by heating limestone with small quantities of other materials (such as clay) to 1450C in a kiln. The into a powder to make Ordinary Portland Cement (OPC), the most commonly used type of c ement (Figure 2 1). Many users require cement with particular properties, and these can be made by grinding additional constituents with the cli nker. Typical green cement substitutes include slag and fly ash, by products from blast furnaces and power generation. Another is pozzolan a type of finely ground volcanic slag that is mixed with lime and act s like OPC and will set under water. Due to its use in construction, green cement is made to strict standards. These standards can v ary by region and may limit the type and am ount of additive materials used (World Business Council For Sustainable Development, 2002)

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20 Figure 2 1. Quarry and dry process cement plant with env ironmental, social and economic impacts (World Business Counc il For Sustainable Development, 2002). Green concrete is also beneficial to the environment because the raw materials to produce it are prevalent in most parts of the world, which means it can be locally sourced and reduce CO 2 emissions from transportation while employing nearby workers in concrete factories. The cement, aggregates, and reinforcing steel used to make green concrete and the raw materials used to manufactur e cement are usually obtained from sources within 300 miles of the concrete plant (Jeffries, 2009). Green c oncrete can be recycled as fill or road base, can be reused to protect shorelines in seawalls, and can be reused as aggregate in new concrete. However, its recyclability can be limited because its chemical properties deg rade over time (Jeffries, 2009)

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21 Review of Existing Trends in Green Concrete Developed economies are taking steps to reduce the amount of carbon in the production of concrete and its transport to the construction site, which developing economies can emula concrete has a high thermal mass and can reduce heating energy consumption by 2 15%. Well designed combinations of heating, natural ventilation, solar shading and building design can re duce energy use for cooling and related CO 2 emissions by up to CO 2 efficient design (The Concrete Centre, 2009). In the UK, the embodied CO 2 associated with the production and transport of an average ton of concrete is 95kg of CO 2 When the total CO 2 emitted by the UK concrete industry is conside red, cement is estimated to account for around 85% of these emissions. The rest arises from the production and transport of the other raw materials and from the mixing of concrete and its transport to the construction site. During cement production about 60% of the CO 2 emissions arise from the chemical reaction which takes place in the kiln; the other 40% come from the combustion of fuels. Through a significant investment in energy efficient technologies and by using biomass and other waste derived fuels, the UK cement sector has reduced its CO 2 emissions by 27% since 1990, which has lowered CO 2 emissions by over 3.7 million tons since 1990 (The Concrete Centre, 2009) The UK concrete industry has also been successful in reducing the embodied CO 2 of concrete through the extensive use of fly ash in concrete mixes and through the use of factory made composite cements. The use of these materials can lower the

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22 embodied CO 2 of a concrete mix by up to 40%. Carbon emissions from sites manufacturing precas t and ready mixed concrete have also been reduced by 6.4% between 1990 and 2006. This has resulted in a 27% overall reduction in CO 2 emissions achieved by the cement industry in the UK and has greatly contributed to the n emissions by a minimum of 80% by the year 2050 (The Concrete Centre, 2009) However, global cement production will be increasing through 2050 and will lead to an increase in CO 2 emissions if developing nations are not included in carbon reduction policie s (Figure 2 2). Even with the current steps taken to promote energy efficiency and carbon reduction in the production of typical concrete mixes in developed countries, further research and emphasis should be placed on locally available and organic ce ment. New technologies may be able to achieve a carbon negative manufacturing process. For example, the California based company Calera has been able to filter carbon dioxide emissions through seawater to create a carbonate byproduct that is then mixed with aggregate and water to create concrete, lowering carbon emissions and avoiding the need to heat the ingredients (Jeffries, 2009) Bu t these sustainable concrete mixes and India, which are consuming concrete at unprecedented levels on large building projects (Figure 2 3). And worldwide CO 2 reduct subsidizing the industry in poor countries (Jeffries, 2009). Concrete plants in the developing world, where the industry continues to expand and develop new sites, may be cleaner and more efficient than those in the developed world which were built ten, twenty or even thirty years ago. In many developed countries, market growth is slow or

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23 even stagnant. In developing markets, growth rates are more rapid and a large fraction is sold as a bagged product to individual c ustomers. Figure 2 2. Projected CO 2 emissions (in millions of metric tons) from the global cement industry through 2050, assuming no change in current practices (World Business Council For Sustainable Development, 2002). Figure 2 3. Global cement prod uction in millions of metric tons annually. Rising cement demand will increase the need for fuels and raw materials (World Business Council For Sustainable Development, 2002). China is the fastest growing market today (World Business Council For Sustainabl e Development, 2002) Existing practices in the production of concrete are not truly 4) without a combination of new technology, energy efficiency in the manufacturing process, and locally available, renewable additives.

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24 Figure 2 4. A concrete industry advertisement depicting the green benefits of concrete (Jeffries, 2009). Overview of Organic Animal Waste Materials as Potential Cement Substitutes: Bone As the BEES data regarding environmental and economic performance of concrete show s, the amount of portland cement must be reduced and substituted with carbon footprint of concrete. In recent years, alternative materials have been added to reduce the cement content of the concrete which can reduce its overall carbon footprint without increasing cost or decreasing its structural properties. As previously mentioned in this literature review, these material cement substitutes have been thoroughly tes ted and used on numerous construction projects and usually consist of recycled or down cycled industrial materials like fly ash, blast furnace slag, volcanic pumice, or recycled s that are locally available, easily renewable, environmentally friendly, and cost effective must be tested in a lab setting for their potential use in the industry. have seen no significant laboratory testing are organic animal bone charcoal and bone meal. In developing countries, livestock (particularly cattle) are a widely used source of food and a significant segment of the local economy for subsistence farmers. Howeve r,

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25 once these animals are slaughtered or die of natural causes, their bones may be used for only a few small purposes like water filtration, simply composted, or not used at all. Bone Char: Definition, Usages, Production process, Recent Studies Meat wast e management from livestock continues to be an important issue in pollution management. Large quantities of meat waste materials like blood, hair, tail, horns and bones have to be thoroughly and effectively treated through methods like composting prior to their disposal. In recent years, an emphasis has been placed in the livestock industry on reusing animal waste materials like meat and bone meal for production processes. Bone meal was widely recommended and used in animal feeds until the Small Bowel Enter oclysis (SBE) (Mad Cow disease) occurrence and micro incinerated and made into bone char to prevent any disease from spreading. However, recent studies have discovered that heavy me tal absorption through the use of charred animal bones appears to be one of the most promising applications of re using meat waste materials for pollution management and mitigation, particularly in the area of potable water filtration (Ioannis S. Arvanitoy annis, 2007) Recent studies have also tested meat and bone char ashes obtained from specific incineration (laboratory) and from co incineration (industrial process). In these studies, the industrial ashes contained much more heavy metals than laboratory ash and th e amounts of leached elements into potential water supplies were low, especially for laboratory ash which can be classified as an inert waste. From these results, possibilities other than landfilling could be considered to give economic value to these ash es (Marie Coutanda, et al. 2008)

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26 A recent study conducted by the Department of Chemistry at the University of Glasgow in 2002 tested animal bone charcoal as a treatment for decontaminating polluted water (J.A. Wilson, et al. 2002) This study sought to determine the use of bone charcoal as a low cost treatment for decontaminating polluted water particularly in developing countries in Africa In particular, its potential to remove metals like copper (Cu) and zinc (Zn) fro m contamin ated water supplies was examined through sorption testing. This type of testing is also used to determine the water absorption rate of concrete materials. The Case for Using Bone Char in Concrete The 2002 University of Glasgow study provided the theoret ical basis for this thesis countries. As the study states, b one charcoal is being developed as a treatment for decontaminating polluted water and it is a n inexpensive yet ef fi cient absorbent of heavy metals and aids in fluoride removal. Bone charcoal has been used to remove color from water since the early nineteenth century and it is widely used in the sugar industry to remove color and contaminants due to its mineral conten t (Table 2 1) However, it is difficult to recharge or reuse in the water filtration process and eventually needs disposal. Since the mineral content of bone char contains a significant amount of calcium carbonate (CaCO 3 ), a bonding agent essentially the s ame as limestone that is 72% of the total mass of portland cement: (see Figure 2 11), it should be tested as a cement substitute to reduce the amount of portland cement needed in the mix. If bone char is used in concrete, it can also solve the ecological problem of having to dispose of bone char that has run its useful course in filtering water for a small village or town.

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27 Table 2 1 Mineral composition of bone charcoal (J.A. Wilson, et al. 2002). Mineral/Material %Content Hydroxyapatite 70 76 wt.% Carbon 9 11 wt.% CaCO 3 CaSO 4 Fe 2 O 3 Acid insoluble ash 7 9wt.% 0.1 0.2wt.% < 0.3 wt.% 3wt.% max The University of Glasgow study concluded that b one charcoal has a hig h capacity for the removal of copper and zinc from water and further study must be completed to understand the absorption mechanisms of bone charcoal in a real world setting. Bone charcoal may be a readily available source of cement substitutes in developing nations due to prevalent subsistence farming economies and a large avail ability of local livestock, particularly cattle. However, little research has been completed about its structural properties as a cement substitute in concrete. Bone Meal: Definition, Usages, Production process, Recent Studies Similarly, bone meal could a lso be a readily available, local source of cement substitutes in developing economies. Bone meal is a waste byproduct resulting from the slaughter of animals, especially beef cattle, by meat processors. It is produced by either raw or steamed animal bone s that are removed of fat and dried, then ground into a white powder. Bone meal is commonly used as a fertilizer due its negligible pH effect on soils and content of approximately 20% 30% phosphorus, 2 4% nit rogen, 18% calcium (see Table 2 2 for bone meal mineral content), with small traces of copper, iodine, iron, manganese and zinc. It is an inexpensive form of phosphoric acid and is fed to farm animals to supply important minerals like calcium phosphorus, iron, magnesium and zinc It also contains a significant amount of protein due to the amount of tendon and muscle left on the ground bones (Alternative Medicine Encyclo pedia,

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28 2010) Some of the trace elements contained in bone meal can also be beneficial to human health as a dietary supplement for calcium intake. However, concerns about bone meal's high lead content and possible elevated mercury levels raise questions a bout using bone meal as a supplement. Typical lead content in bone meal is significantly higher than that in refined calcium carbonate (CaCO3), which is a laboratory processed calcium. Table 2 2 Mineral composition of bone meal (Meriter Health Services, 2009). Mineral/Material %Content Calcium (Ca) 30.71 Phosphoric Acid (P 2 O 5 ) 12.86 Nitrogen (N) Sodium (Na) Sulfur (S) Magnesium (Mg) Potassium (K) 6.00 5.69 2.51 0.33 0.19 A 2005 study conducted at the Universit Paul Sabatier in Castres, France sought to determine the physical properties, chemical composition, and potential environmental effects of incinerated bone meal in response to the recent bovine spongiform encep halopathy (BSE) crisis in the European beef industry. The results of the study showed that meat and bone meal combustion residues were calcium (30.7%) and phosphate (56.3%) rich compounds, mainly a mixture of Ca10(PO4)6(OH)2 and Ca3(PO4)2. Significant l evels of sodium (2.7%), potassium (2.5%) and magnesium (0.8%) were also observed. Ash particles were relatively small, from a few millimeters to a micrometer, with almost 90% of them smaller than 1 mm. The researchers stated the recent need for incineratin g animal waste products in the meat industry for health as a result of the bovine spongiform encephalopathy (BSE) crisis in the

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29 the European Community (EU), lead ing to a need for the elimination or safe recycling of low risk MBM (Deydier E., et al. 2005) The Case for Using Bone Meal in Concrete Could low risk meat and bone meal (MBM) that is properly sterilized be safely cement substitute in developed and developing economies ? Like bone char, t here is little, if any, previous research about using these organic substances as cement substitutes and further research is necessary to determine the structural and environmental properties of MBM in concrete us es. And like bone char, bone meal may be a readily available source of cement substitutes in developing nations due to prevalent subsistence farming economies and a large availability of local livestock, particularly cattle. Its high amount of calcium may aid in the concrete bonding and curing process but further research is needed. Review of Portland Cement Manufacturing Process This section of the literature review contains detailed economic and environmental information about the manufacturi ng of portland cement to make concrete that is widely used in the building industry in the developed world. This information was obtained from the materials analysis section of BEES (Building for Environmental and Economic Sustainability) software which is used in the selection of cost effective, environmentally preferable building products. BEES was developed by NIST (National Institute of Standards and Technology) Building and Fire Research Laboratory and is used by designers, building contractors and product manufacturers in the construction industry (BFRL: Office of Applied Economics, 2007). The following pages contain written analysis, charts and tables of information relating to portland cement concrete are excerp ted from the BEES 4.0 software.

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30 Flow diagrams (Figures 2 5 and 2 6) are an effective means of depicting the major elements of portland cement production with or without the use of cement substitutes like fly ash, slag and limestone. Figure 2 5. Production flow chart of typically manufactured concrete without cement substitutes (BFRL: Office of Applied Economics, 2007 ).

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31 Figure 2 substitutes (BFRL: Office of Applied E conomics, 2007). As Figure 2 5 shows, concrete in developed economies is typically made from a mixture of raw materials including portland cement, fine aggregate and course 6 to reduce the carbon fo otprint of concrete are typically fly ash, slag, and 5% limestone blended cement with an equal amount of replacement by weight for portland cement. Mix

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32 designs and strength will vary depending on the aggregates and cement used and Figure 2 7 shows the typ ical amounts of materials used in the manufacture of portland cement. Figure 2 7. Materials and content used in portland cement manufacturing (BFRL: Office of Applied Economics, 2007). Figure 2 8 shows quantities of concrete constituents for t hree compressive strengths (fly ash, slag, and limestone). Fly ash is a waste material that results from burning coal to produce electricity and has an environmental outflow of coal combustion with an environmental inflow of concrete production, which esse ntially makes it an environmentally "free" waste material. Slag cement is a waste material from steel production and is similar to fly ash with an environmental outflow of steel production and an environmental inflow of concrete production. However, slag must be processed at the steel mill and transported to a grinding facility before it can be added to concrete mixes. Other materials that are sometimes added, such as silica fume and chemical admixtures, are not shown in the table

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33 Figure 2 8. Concrete constituent quantities by cement blend and compressive strength of concrete (BFRL: Office of Applied Economics, 2007). Cement plants located throughout North America at locations with ample supplies of raw materials are used in the concrete manufactu ring process Major raw materials for cement manufacture inc lude limestone, cement rock shale, and clay. portland cement is manufactured using one of four processes: wet, long dry, preheater, or precalciner. Figure 2 9 presents the average energy use of portland cement factories by process and fuel types. Emissions from portland cement factories include carbon dioxide ( CO 2 ), carbon monoxide (CO), sulfur oxides (SOx), nitrogen oxides (NOx), total hydrocarbons, and h ydrogen chloride (HCl). The major waste m aterial from cement manufacturing is cement kiln dust (CKD). An industry average of 38.6 kg of CKD is generated per metric ton (93.9 lb/ton) of cement. Of this, 30.7 kg (74.6 lb) is landfilled and 7.9 kg (19.3 lb) is reused on site. Once portland cement co ncrete has reached the end of its useful life,

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34 the majority of it in the United States is recycled in urban areas as fill and road base (BFRL: Office of Applied Economics, 2007) Figure 2 9. Energy requirements for portland cement manufacturing (BFRL: Office of Applied Economics, 2007). Climate Change in Developing Economies According to the Intergovernmental Panel on Climate Change, climate change refers any change in climate over time, whether due to natural variability o r as a result of human activi ty The planet is gradually warming, as evidenced by increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea levels. Additionally, greenhouse gas emissions due to human activity have increa sed 70% between 1970 and 2004 (Figure 2 1 0 ) due to growth in energy supplies, transport, industry, agriculture and particularly residential and commercial buildings Global increases in carbon dioxide ( CO 2 ) are also attributed to human activity through burning of fossil fuels. Atmospheric concentrations of CO 2 in 2005 far exceed the natural range measured through ice core samples over the last 250,000 years (Intergovernmental Panel on Climate Change, 2007).

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35 Figure 2 10. (a) Global annual emissions of anthropogenic GHGs from 1970 to 2004.5 (b) Share of different anthropogenic GHGs in total emissions in 2004 in terms of CO 2 eq. (c) Share of different sec tors in total anthropogenic GHG emissions in 2004 in te rms of CO 2 eq. (Intergovernmental Panel on Climate Change, 2007). Climate change will affect developing nations in the near and long term for several reasons. In Latin America, the increases in temperature and resulting decreases in soil water are projec ted to lead to gradual replacement of tropical forest by savanna in the eastern areas of the Amazon in Brazil, a country that has seen explosive economic growth in the last ten years. In countries like Costa Rica, Nicaragua and Panama which have tropical rainforest ecosystems, climate change poses a risk of significant biodiversity loss through species extinction. Deforestation and climate change are thought to be causing loss of significant levels of biodiversity in tropical rainforests and worldwide, wi th estimates over the next 2 0 years predicting a loss of 20% of existing species (Kibert, 2008). Rainforests are thought to contain more than 500,000 spe cies while consisting of only 6% areas w ould be devastating to water and soil resources, pollution breakdown and

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36 absorption, wood products, medicinal resources and potential sources of new foods, medicines and new technologies (Kibert, 2008). In these same countries and throughout Latin Americ a, cropand livestock productivity is expected to suffer significant declines which will lead to food shortages and an increase in the number of people at risk of hunger. Changes in precipitation patterns due to loss of glaciers are expected to cause sever e water shortages for human consumption, agriculture, and energy generation. This loss of water access will severely affect Costa Rican and Nicaraguan energy production since a significant portion of energy is generated by hydroelectric dams in these cou ntries (Intergovernmental Panel on Climate Change, 2007). In the developed countries of Europe, buildings are estimated to consume roughly 50% of all energy produced. Lighting and heating carbon dioxide emissions while the production of building materials accounts for a further 10%. The construction industry generates one third of all waste in Britain, while 20% of new building materials on an average bu ilding site are simply thrown away at the end of the job. The greatest contribution to embodied carbon for housing comes from cement based materials (poured concrete, concrete blocks and pre cast concrete elements) which contribute in excess of 50% of the carbon footprint in construction (DMG World Media Dubai, 2009). This contribution is widespread and similar in all developed countries since concrete extraction and manufacturing use the same processes. In the United States, constructing to reduce the carbon footprint of the built environment is exacerbated by current unsustainable trends in which commercial and residential buildings use almost 40% of the primary energy and approximately 70% of the electricity in the United States (Annual Energy Review 2004, 2005) This massive

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37 consumption of energy leads to massive carbon emissions, and b uildings account for an (Emissions of Greenhouse Gases in the United States 2007, November 2008) Developed countries must not continue on the same path of the developed world if true reduction or elimination of fossil fuel use combined with energy efficient buildings and alternative energy technologies is to be realized. In order for developing countries to spur economic growth through the built environment that is environmentally beneficial, sustainable materials must be extracted, produced and used in the latest building projects. Sustainable concrete that uses organic cement substitutes that reduces the amount of cement needed in the concrete mixture will produce less carbon and will be economically beneficial to local suppliers and builders. The Need for Sustainable Industries in Developing Economies The Intergovernmental Panel on Climate Change (IPCC) provides several reasons for the need for renewable energy technology in developing countries and how to implement it (Figure 2 11) Renewable energy like solar, wind, geothermal, biomass Figure 2 11 Buildings can account for a significa nt reduction in CO 2 emissions per year. (Intergovernmental Panel on Climate Change, 2007)

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38 and tidal energy employed on a large scale can provide significant reductions in greenhouse gas emissions and lead to the eventual goal of complete elimination of fos sil fuel use. According to the IPCC, n o single technology can provide all of the carbon mitigati on potential in any sector. E nergy efficiency in buildings combined with utiliz ation of renewable energy offer the best synergies with sustainable development In least developed countries, energy substitution can lower mortality and morbidity by reducing indoor air pollution, reduce the workload for women and children, and decrease the unsustainable use of wood for fuel and related deforestation (Intergovernm ental Panel on Climate Change, 2007) The IPCC also recommends enacting governmental policies that provide a real price of carbon in order to create incentives for producers and consumers to invest in low greenhouse gas products, technologies and processe s. In developed countries, there is growing implementation of climate response options in several industrial sectors to realize synergies and avoid conflicts with other dimensions of sustainable development. Climate change policies enacted by nati onal governments on a wide scale that are related to energy efficiency and renewable energy are often economically beneficial, improve energy security and reduce local pollutant emissions. These policies can result in reducing the loss of natural habitat and deforestation, can have significant biodiversity, soil and water conservation benefits, and can be implemented in a socially and economically sustainable manner. For example, forestation and bio energy plantations can restore degraded land, manage wat er runoff, retain soil carbon and benefit rural economies (Intergovernmental Panel on Climate Change, 2007)

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39 To illustrate the potential of sustainable technologies in developing countries, one can look to the proliferation of alternative sources of energy in the Central American nation of Nicaragua. The use of wind turbines as an alternative power source is growing rapidly in Nicaragua with a 19 turbine, $90 million project located on the shores of Lake Nicaragua, the largest lake in Central America and a direct recipient of over three hundred days of strong offs hore winds per year (Figure 2 12 ). Figure 2 12. These windmills, part of a $90 million project, have sprung up on the edge of Lake Nicaragua in Rivas, Nicaragua (Press, 2009). The 410 foot high windmills, installed by Suzlon Energy Ltd. of Pune, India, were set up on the edge of Lake Nicaragua and will generate 40 megawatts or 6% of the count ries per capita in the western hemisphere, yet its government has decided to think in bigger terms and reduce its dependence on foreign oil, of which nearly 80% is currently provided at a discount by Venezuela. Nica ragua currently produces over 35 % of its energy needs from alternative sources like geothermal from volcanoes, hydroelectric generated by rivers and sugarcane based ethanol (Associated Press, 2009). Wind is part of Nicaragua's efforts to reduce its dependenc e on oil based energy to just 3% by 2 013 (Figure 2 13 ). Ernesto Martinez, executive president of the Nicaraguan Energy Company, said recently that Russia will finance and build two

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40 geothermal plants in Nicaragua with the capacity to produce 250 megawatts (Aleman, 2008) Figure 2 1 3 Wind turbines on the shores of Lake Nicaragua with Ometepe Island volcano in the distance (Aleman, 2008). Cost Comparisons Between Traditional and Green Concrete In order for green concrete to be a viable building material, its cement substitutes will need to b e low in cost and easily renewable in order to compete with traditional portland cement concrete. Traditional plain portland cement concrete with no admixtures delivered to a jobsite in the United States typically costs around $75 per cubic yard, which is about 2 cents per pound.. Portland cement itself after processing costs less than 4 cents per pound. However, using green cement substitutes in the concrete mix does not usually increase the cost of the concrete, which shows that renewable green cement sub stitutes are cost effective. Diluting the portland cement with a less costly waste product like fly ash typically costs only 1.5 cents per pound, which is profitable for power plants since the fly ash would be landfilled if not re used in concrete. Ground granulated blast furnace slag costs about 3 cents per pound, which can be mixed and combined with portland cement, fly ash, and the slag to make a cost effective and green concrete. The total cost of an air entrained 6 bag (564 lb) concrete

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41 mix made using gravel coarse aggregate (1800 lb) and sand fine aggregate (1250 lb) is about $75 per cubic yard, even when recycled waste materials like fly ash or ground granulated blast furnace slag are included. Therefore, green concrete is just as cost effective as tr aditional concrete, while having better environmental benefits (Pistilli, 2010) As Figure 2 14 shows, the potential for using organic animal bone char in both developed and developing economies as a potential green cement substitute shows great promi se based on the sheer number of cattle processed in each of these countries. Figure 2 1 4 Animal Numbers, Cattle Production by Country in 1,000 HEAD (Animal Numbers, Cattle Production by Country in 1000 HEAD, 2009). Developing economies in India and Bra zil are leading producers of cattle and may be able to use the processed cattle bones in green concrete instead of discarding them. And the previously mentioned developing economy of Nicaragua is a leading producer of cattle as the graph shows, so bone cha r made from processed cattle bones could

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42 also be a low cost and local material for green cement production for concrete building projects. The unit cost of processed cattle bones varies by each country, so more cost research would be needed to determine th e exact price for using cattle bone char in green concrete. Ethics and Sustainability In terms of sustainable development, ethical principles provide a set of rules of t (World Commission on Environment and Development, 1987) This set of ethical principles is also referred to as intergenerational justice and must be applied more widely in terms of sustainable developm ent since values must be applied across generations to be effective (Kibert, 2008) The choices of the present generation will affect future generations through availability of resources, biodiversity, and environmental quality. Present decisions about h an understanding of and willingness to accept risk; and (3) the economic costs of imple (Kibert 2008). With regard to developing countries, the ethical principle of protecting the vulnerable applies. People in poorer countries may be vulnerable to the decisions of wealthier and influential countries t hat have economic and governmental influence. This power arrangement places developing countries in a subordinate position to wealthier, developed countries and those in power have a moral obligation to protect the vulnerable and dependent population. Ad ditionally, future generations are vulnerable to the actions of present generations and sustainble steps must be taken to ensure their

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43 on the current generation and is made more difficult by global poverty in developing countries (Kibert, 2008). The ethical challenges presented by climate change and the destruction of the natural environment by human activity are vast. Specifically, developing nations are inc reasingly dependent on the actions of developed nations to act in an ecologically sound manner and to share the knowledge necessary to negate the harmful effects of G8 nati ons and Brazil, China and India signed a statement in 2005, outlining the reality of global climate change and calling on world leaders at the G8 Summit in July 2005 to enact specific and far reaching changes to reverse the effects. This report called att ention to the fact that over the next 25 years world primary energy is expected to increase by almost 60% and fossil fuels are expected to provide 85% of this demand (Joint Science Academies, 2005). The report concluded that even with lowered emission rates targeted by developed nations through agreements like the Kyoto Protocol, humans will be experiencing the impacts of climate change throughout the et greenhouse gas emissions now, will cause even further hardship for future generations trying to make significant changes in fossil fuel emissions (Joint Science Academies, 2005) The most important point made by this report is that any developing natio ns that lack the infrastructure or resources to respond to the impacts of climate change will be the most affected and will have to rely solely on the goodwill of developed nations, with little opportunity to make meaningful change on their own behalf.

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44 will suffer the most. Since the problem of climate change is well defined, the science academies report goes on to provide a list of suggested actions for world leaders to take to begin adapting and reversing its effects. Leaders worldwide must devise and from a wide range of experts, including physical and natural scientists, engineers, social scientists, medical scientists, those in the humanities, business leaders and (Joint Science Academies, 2005) The Joint Academies report provide s the following steps for developed and developing nations to adapt toand reverse the detrimental effects of climate change Steps number three and four are particularly relevant to ethical principles of sustainability in developing countries: 1. Identify cost effective steps that can be taken now to contribute to substantial and long term reduction in net global greenhouse gas emissions. 2. Recognize that delayed action will increase the risk of adverse environmental effects and will likely incur a greater cost. 3. Work with developing nations to build a scientific and technological capacity bes t suited to their circumstances, enabling them to develop innovative solutions to mitigate and adapt to the adverse effects of climate change, while explicitly recognizing their legitimate development rights. 4. Show leadership in developing and deploying cle an energy technologies and approaches to energy efficiency, and share this knowledge with all other nations.

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45 5. Mobilize the science and technology community to enhance research and development efforts, which can better inform climate change decisions. As evi denced by these steps, developing nations have the most to gain from sharing knowledge of sustainable technologies and building techniques that are best suited to their local ecology and climates and may have the greatest impact on climate change and apply ing the ethical principle of protecting the vulnerable. The ultimate problem to be solved by ethical principles and sustainability is to figure out how all inhabitants of the planet can have a decent quality of life without esources and biodiversity. If developed countries can dramatically reduce resource and energy consumption, particularly in the built environment that is materials and energy heavy, then developing countries may be able (Kibert, 2008) Summary The world has a finite supply of natural resources, particularly fossil fuels, and mankind will not survive if it does not find new ways to reduce its energy consumption and to use renewable sources o f energy. One way to achieve this is to use organic, locally available renewable cement substitutes in concrete manufacturing in both developed and developing economies. Animal waste materials, particularly in the form of bone char, may provide a promising new substitute.

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46 CHAPTER 3 METHODOLOGY Introduction The aims and objectives of the study, as listed in Chapter 1, to be followed through the course of the laboratory experimentation were as follows: 1. To review existing practices with respect t o green cement substitutes in developed and developing countries. 2. To determine the potential for using animal bone char, fly ash, and volcanic ash as substitutes for portland cement in the manufacture of 3. To characterize the material prop erties performance of the resulting concrete based on durability, compressive strength and tensile strength tests. 4. To characterize the impact of using the proposed concrete in building envelope performance against sustainability metrics using BEES ( B uildin g for E nvironmental and E conomic S ustainability) software. This thesis provided the ethical underpinnings for researching and providing alternative building materials technologies to developing countries. It was determined through the course of t his study that in order for humanity to combat ecosystem atmosphere through the burning of fossil fuels that can lead to global climate change, developing economies must p reserve their natural resources and native ecosystems. These countries must use alternative sources of fuel as well as sustainable, local building materials to lower their carbon output and preserve their local resources. The

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47 key issues in promoting and ut ilizing sustainable building materials and practices in these countries were found to be: the availability, cost, and durability of local materials. These elements are crucial in promoting and utilizing sustainable building materials and practices in the c onstruction of commercial buildings and residential homes. This thesis then provided further research about various types of sustainable cement substitutes including bone char and bone meal (MBM). Three sustainable cement substitutes (fly ash, volcanic as h, bone meal) were then mixed and poured into eight (8) cylinders of 4 x 8 inch size for each mix type, resulting in a total number of minimum 24 cylinders. The concrete cylinders were allowed to cure for 28 days and then tested by the American Society for Testing and Materials (ASTM) standards for compression strength, tensile strength and water absorption, and data results were obtained and analyzed. The resulting concrete material types were then tested for environmental and economic performance based on BEES (Building for Environmental and Economic Sustainability) software which measures the performance of building products by using the life cycle assessment approach. Scope The methodology followed in this research was determined by the objective of the study and the hypotheses statements listed in Chapter 1. The steps taken to conduct the thesis research and to obtain quantifiable results were as follows: 1. A literature review was performed on sustainable building materials for the construction industry as well as the ethical basis for providing developing countries with the knowledge and means to employ sustainable building 2. The data needed for the analysis was identified.

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48 3. The sources of data were ide ntified. 4. Standard ASTM concrete testing for the three selected cement substitutes (fly ash, volcanic ash, bone meal) was identified. 5. The three concrete types were mixed and poured into 8 cylinders of 4 x 8 inch size for each mix type, resulting in a total number of 24 cylinders and tested in the laboratory by ASTM standards to obtain the data. 6. Analytical and descriptive statistics were generated to assess the significance of the laboratory results sought. 7. The concrete data for the three different cement su bstitutes was compared with BEES metrics according to economic performance (first cost and future c osts) with a discount rate of 3% availability in their local environments (within 300 miles of the project site), and environmental performance based on sev eral parameters: global warming, fossil fuel depletion, ecological toxicity, human health, embodied energy by fuel renewability. Economic and environmental performance were given equal 50% weightings in the study to obtain a clear average and detailed anal ysis. Experimental Approach The following experimental specifications were taken into account when designing and testing the compressive strength of the three concrete mixtures: 1. Characteristics of the mixture 2. Maximum size aggregate 3. Minimum cement content 4. Characteristics of the cement, water aggregates and admixtures

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49 5. Characteristics of the plastic and/or hardened concrete 6. Compressive and/or flexural strength 7. Tensile Strength 8. Water absorption coefficient Experimental Data Entry The following ASTM standard methods for testing concrete were conducted in the laboratory setting to make the three sustainable concrete mixtures, to determine their compressive strength, to determine their tensile strength, and to determine the water abso rption coefficient of the three mixtures after twenty eight (28) days of curing. Detailed results of the testing are contained in Chapter 4: Data Analysis. The following standard tests were used to obtain the concrete mixture data for the three samples co nsisting of 8 cylinders for each mix type of 4 x 8 inch size, resulting in a total number of minimum 24 cylinders: ASTM C192: Making and Curing Concrete Test Specimens in the L aboratory The size of the cylinder to be tested is typically 6 x 12 for 1 inch or greater max size course aggregate; 4 x 8 for inch or less size course aggregate (Figure 3 1) as used in this study. ASTM C192 provides standardized requirements for preparation of materials, mixing concrete, and making and curing concrete test specimens under laboratory conditions. The concrete cylinder specimens were mixed and rodded 20 times and vibrated for 1 minute each to ensure uniform mixing of the cement substitutes (Figure 3 2). Lab specimens were cured for 28 days in a completely sat urated limewater tank (Figure 3 3).

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50 Figure 3 1. 4in. x 8in. concrete cylinders that were used to make laboratory specimens. Figure 3 2. Rodding and vibrating the concrete specimens in the laboratory. Figure 3 3. The concrete specimens curing and immersed in water for 28 days.

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51 ASTM C39: Compressive Strength of Cylindrical Concrete Specimens This test is also known as destructive testing of hardened concrete. The strength of the concrete to be tested is affected by the length to diameter (L/D ) ratio of the cylinder and the condition of the ends of the cylinder samples is noted to determine the failure mode of the concrete (Figure 3 4). The loading rate of the compression machine is typically between 20 50 psi/sec. The concrete strength testi ng for each class of concrete placed is conducted under the following circumstances: not less than once per day, not less than once for each 150 cubic yard (cy) of concrete placed, and not less than once for each 5000 square feet (sq. ft.) of surface area for slabs and walls (Figure 3 5). The results of this test method are used as a basis for quality control of concrete proportioning, mixing, and placing operations; determination of compliance with specifications; control for evaluating effectiveness of a dmixtures; and similar uses. In this study, both the wet compressive strength of the moist concrete after 28 days of curing and dry compressive strength of the hardened concrete after 28 days and 48 hours of drying in an oven were tested. Figure 3 4. Sk etch showing typical failure modes of compression testing: (a) splitting; (b) shear (cone); and (c) splitting and shear

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52 Figure 3 5. Hardened concrete specimen failure in the compression machine after destructive testing. ASTM C496: Splitting Tensile Str ength of Cylindrical Concrete Specimens This ASTM test method covers the determination of the splitting tensile strength of cylindrical concrete specimens. This method consists of applying a diametral compressive force along the length of a cylindric al specimen. This loading induces tensile stresses on the plane containing the applied load. Tensile failure occurs rather than compressive failure. Plywood strips are used so that the load is applied uniformly along the length of the cylinder. The maximum load is divided by appropriate geometrical factors to obtain the splitting tensile strength. The concrete cylinders were placed in the compression machine with bearing strips 2 each, 1/8 in. thick plywood strips, 1 in. wide (the length shall be slightl y longer than that of the specimens). The bearing strips were placed between the specimen and the upper and lower bearing blocks of th e testing machine (see Figure 3 6). Figure 3 6. Hardened concrete (volcanic ash) specimen failure in the compression mac hine after splitting tensile strength testing.

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53 The load was applied continuously at a constant rate of 100 to 200 psi/minute of splitting tensile stress until failure occurred. The maximum load at failure in pounds was then recorded and the splitting tensile strength was calculated (Equation 3 1), where P is the maximum load at failure in pounds, and l and d are the length and diameter of the cylindrical specimen, respectively, in inches: l*d (3 1) ASTM C1585 04e1: Standard Test Method for Measurement of Rate of Absorption of Water by Hydraulic Cement Concretes This test method is used to d etermine the rate of absorption (sorptivity) of water by hydraulic cement concrete by measuring the increase in the mass of a specimen resulting from absorption of water as a function of time when only one surface of the specimen is exposed to water. The e xposed surface of the specimen is immersed in water and water ingress of unsaturated concrete dominated by capillary suction during initial contact w ith water is measured (Figure 3 7). The standard method is to cure the specimens in an oven for three days, at a temperature of 50C and relative humidity of 80%. The relative humidity is achieved using potassium bromide. As an alternative to the standard test method, potassium bromide was not used. The specimens, one sample each of fly ash, volcanic ash, bone meal concrete were cured in the oven for 2 days at a temperature of 108C. All of the samples were kept in the same environmental condition in the laboratory at a constant temperature during the period o f the testing program (Figure 3 8). All sets of samples were cured for 28 days. The properties of each are shown in Chapter 4: Data Analysis.

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54 The readings of the test and the value of the Absorption (I) are found using Equation 3 2: I = mt / (a* d) where mt = the change in mass in grams, at different ti me (t) (3 2) a = ex posed area of the specimen, in d = density of water in g/in Figure 3 7. Moisture movement into concrete cylinder from surface contact with water. Figure 3 8. The tray and chicken wire apparatus used to test the hardened concrete specimens for water absorption. Bricks were used to steady the wire base and provide an even water level across the cylinders. Equipment Used Concrete Mixer (Pan Type) The Pan Concrete Mixer (Figure 3 9) is efficient for mixing quality concrete. Pan type mixer is suitable for the mixing concrete in the laboratory. It is designed to give e fficient mixing of both dry and wet materials. The total effective capacity of the mixer is

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55 56 liters The mixer head lifts clear to provide maximum acc ess to the pan and holds the mixing blades at a constant depth during the mixing operation. The blades can be adjusted to suit the different types and volume of materials to be mixed. Figure 3 9. Concrete mixer and tray used to mix the batches. Full Aut omatic Compression Machine Range of 2000 kN, 3000KN and 4000 kN capacity c ompressio n machine (Figure 3 10) has been designed to meet the need for reliable and consistent testing of concrete samples. The machine feature s the complete automatic test cycle wi th a closed loop digital readout. Once the specimen parameters have b een introduced, it is sufficient to press the START button to complete the test. The compression machine consist s of : a frame, power pack and data acquisition control system. Figure 3 1 0. Typical compression machine

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56 Vibrating Table The Vibrating Table (Figure 3 11) is a compact unit providing controlled vibro compaction with fixed amplitude in the labor atory using cube or cylinder mo lding equipment. Vibrating tables consist of vi brating motor, control unit and clamping assembly (Concrete, 2010) Figure 3 11. Typical vibrating table Environmental Performance Data Entry: BEES Software The concrete data for the three different cement substitutes was compared with BEES metrics according to economic performance (first cost and future c osts) with a discount rate of 3% availability in their local environments (within 300 miles of the project site), and environmental performance based on several parameters: global warming, fossil f uel depletion, ecological toxicity, human health, embodied energy by fuel renewability. Economic and environmental performance were given equal 50% weightings in the study to obtain a clear average and detailed analysis. Figures 3 12 through 3 18 show comp uter screenshots that depict the BEES process and the parameters that were chosen to obtain the computed results.

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57 Figure 3 12. BEES screenshot showing first step of analysis: setting up performance parameters. Figure 3 13. BEES screenshot showing second step of analysis: selecting building elements for comparison.

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58 Figure 3 14. BEES screenshot showing third step of analysis: selecting product alternatives. Figure 3 15. BEES screenshot showing fourth step of analysis: selecting product transpo rtation distance.

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59 Figure 3 16. BEES screenshot showing fifth step of analysis: computing results. Figure 3 17. BEES screenshot showing sixth step of analysis: selecting tables and graphs to depict the product data.

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60 Figure 3 18. BEES screenshot showing seventh step of analysis: final graphs and charts depicting performance of product comparisons.

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61 CHAPTER 4 RESULTS Introduction The specific goals of this study were to determine an optimal mix for organic cement substitutes of fly ash, volcanic ash, and bone meal; to characterize the structural performance of the resulting concrete based on durability and compressive strength tests; and to characterize the impact of using the proposed concrete in building envelope performance ag ainst sustainability metrics and environmental performance using BEES ( B uilding for E nvironmental and E conomic S ustainability) software life cycle approach. As stated in Chapter 3 Methodology, three concrete mixtures were prepared and each mix type was pou red into a minimum of eight (8) cylinders of 4x8 inch size, resulting in a minimum total number of 24 cylinders. Any extra cylinders were used as potential replacements for broken test cylinders or if any problems arose during the testing. Concrete Mix De sign A computerized mix design (Tables 4 1 and 4 2) commonly used in the concrete laboratory at the M.E. Rinker Sr. School of Building Construction at the University of Florida was used to create the three batches yielding 2/3 cubic foot (cf) of concrete This amount was enough concrete to pour into the required minimum of eight 4x8 inch cylinders for subsequent testing. Any extra concrete was poured into remaining cylinders as replacements. The desired compressive strength for the mix design was 3000 psi (a standard minimum in the construction industry for a laboratory setting) and the targeted air content was 2% Standard uniform materials used in all three of the mixes were as follows: #67 coarse aggregate of 0.75 inch (85 lb/cf), fine aggregate

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62 sand wi th 2.09 fineness modulus, water content (W/C) ratio of 0.55, and 6.9cubic centimeters (cc) of water reducing admixture (Daracem 100) to speed up the curing process. Daracem 100 provides improved slump retention in flowable concrete and is ideal for low wat er/cement ratio concrete designed for high early compressive and flexural strengths with exceptional workability and flow characteristics. Table 4 1. Computerized mix design used to create the three batches of concrete mixtures. Properties Amount Required Compressive Strength (psi) 3000 Target Air Content 2 CA Nominal max size (inches) Dry rodded unit weight/bulk density (lb/cf) Gs NMC (%) ABS (%) FA Fineness modulus Gs NMC (%) ABS (%) admixture (fl oz/100lbs cement) w/c ratio slump (inches) water content (lbs) CA content (cf CA/cf concrete) Fly Ash amount replaced (%) Gs Cementitious materials (lbs) 0.75 85.3 2.44 2.5 5.5 2.09 2.63 4 0.5 3 0.55 4 340 0.69 20.0 2.4 618.2 Each of the mixes contained a uniform 20% amount of sustainable cement substitute. The percentages were determined by weight derived from the 2/3 cf concrete mixture in Table 4 2 and amounted to 3.0 lbs each.

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63 Table 4 Ingredient Content Cement (lbs) 12.2 Water (lbs) 8.6 CA (lbs) FA (lbs) water reducer (cc) 40.2 30.4 3.0 6.9 Three sets of 8 concrete cylinders were produced, one set of 20% fly ash concrete, one set of 20% volcanic ash concrete, and one set of 20% bone meal (MBM) concrete. The mixes consisted of the following cement substitutes with the following properties : 1. Fly ash (Figure 4 1) obtained from the M.E. Rinker, Sr. School of Building Construction concrete laboratory and Class F type, which is produced from Eastern U.S. coal plants and commonly used in Florida. Class F greatly reduces the risk of expansion due to sulfate attack that may occur in fertilized soils or near coastal areas, and produces a dense concrete with smooth surface. Figure 4 1. Class F fly ash used in the lab tests. 2. Volcanic pumice ash obtained from a local pet store. Manufactured by Kayt ee Company (Figure 4 2) and is a high quality, natural dusting

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64 powder used for small pets. This product was chosen due to time constraints and since it was readily available in the local area. Figure 4 2. Volcanic pumice ash obtained from local pet store. 3. Bone meal: Due to time and cost constraints in this study, Miracle Gro Organic Choice (Figure 4 3) was chosen as a cement substitute. Bone char cement substitute was not readily available and time constraints did not allow for it to be tested as a substitute. Bone meal however, is locally available at plant nurseries and is an all natural phosphorous supplement to promote root and flower growth. It is enriched with iron for stronger, greener plants and allows for controlled release nitrogen for plan t feeding. Three pounds of bone meal were used in the experimentation according to the computerized mix design. During the curing process, the bone meal cylinders were weaker and easily broke apart when immersed in water, which was a result of high water c ontent and also resulted in lower compressive and tensile strengths during testing. The specific mineral content of this product is also listed in Table 4 3. Figure 4 3. Miracle Gro Organic Choice bone meal.

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65 Table 4 3. Mineral composition of Miracle Gro Organic Choice bone meal (Fertilizer Product Information, 2009). Mineral % Content Metal Parts per Million (ppm) Gypsum & Liming Materials % Content Nitrogen (N) 6.00 Arsenic 0.26 Calcium Carbonate (CaCO 3 ) N/A Phosphoric Acid (P 2 O 5 ) 9.00 Cadmium 0.26 CaCO 3 Equivalent N/A Soluble Potash (K 2 O) Calcium (Ca) Magnesium (Mg) Sulfur (S) Boron (B) Chlorine (Cl) Cobalt (Co) N/A N/A N/A N/A N/A N/A N/A Cobalt Mercury Molybdenu m Nickel Lead Selenium Zinc 1.30 0.0050 1.80 2.73 0.58 1.29 167.00 Magnesium Carbonate(MgCO 3 ) Calcium Sulfate (CaSO 4 2H 2 O) N/A N/A Once poured into the 4x8 in. cylinder forms, the concrete was allowed to cure for 24 hours (Figure 4 5). After 24 hours all of the cylinders were placed together in a large metal tub of water (Figure 4 6) and allowed to cure, completely immersed, for an ad ditional 28 days as per ASTM standards listed in Chapter 3 Methodology. It was initially noted however, that the bone meal concrete cylinders were still very moist after 24 hours of curing and were very fragile when immersing them in water. During the 28 d ay curing process, three of the nine bone meal cylinders broke down and disintegrated in the water, which resulted in fewer testable bone meal samples (only six versus the minimum of eight needed) for the compressive strength, tensile strength and water ab sorption tests. F igure 4 4 The three sets of concrete cylinders curing for 24 hours.

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66 Figure 4 5 The three sets of concrete cylinders curing for 28 days. Concrete Testing Results: Wet Compressive Strength Once the concrete cylinders were cured for 28 days, they were removed from the metal tub of water and inspected for cracking and any material problems. As noted before, three of the nine bone meal cylinders disintegrated in the water while the rest of the cylinders were intact. One cylinder from ea ch batch was tested for wet compressive strength (Figure 4 7) while the remaining cylinders were placed in an oven (Figure 4 8) at 108 degrees Celsius for 48 hours to completely dry. Figure 4 6 A bone meal concrete cylinder being tested for wet compress ive strength. Figure 4 7 Concrete cylinders drying in oven for 48 hours.

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67 The results of the wet compressive strength of each of the concrete cylinders were as follows with compressive strength measured in pounds per square inch (psi): Table 4 4. Max wet compressive strength of concrete cylinders achieved after 28 days of curing. Mix No. S ample ID Diameter (inches) Area (sq. in.) Ultimate Stress ( lbf ) Ultimate Stress (psi) 1 1 1 Average SD Volcanic Ash Bonemeal Fly Ash 4.0 4.0 4.0 12.57 12.57 12.57 27500 4230 42100 20700 17390 2190 336 3350 1650 1384 M ax wet compressive strength @ 28 days of curing Ultimate Stress (psi) Material Additive Figure 4 8 Graph of max wet compressive strength of concrete cylinders achieved after 28 days of curing. As the graph shows, fly ash performed the best with 3350 psi, which achieved the minimum strength of 3000 psi as required by the computerized mix design. Bone meal performed the most poorly with only 336 psi. Volcanic ash performed well with 2190 psi but still did not achieve the minimum 3000 psi standard.

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68 Concrete Testing Results: Dry Compressive Strength After the remaining cylinders were allowed to dry for 48 hours, they were removed from the oven (Figure 4 10), allowed to cool for 2 hours, and three cylinders from each batch were tested for dry compressive strength (Figure 4 11) in the compression machin e. Figure 4 9 Concrete cylinders after removal from the oven. Figure 4 10 A volcanic ash concrete cylinder being tested for dry compressive strength. The results of the dry compressive strength testing are listed in the following table: Table 4 5 M ax dry compressive strength of concrete cylinders achieved after 28 days of curing. Mix No. Sample ID Diameter (inches) Area (sq. in.) Ultimate Stress (lbf) Ultimate Stress (psi) 1 1 1 1 1 1 1 Volcanic Ash 1 Volcanic Ash 2 Volcanic Ash 3 Bonemeal 1 Bonemeal 2 Bonemeal 3 Fly Ash 1 4.0 4.0 4.0 4.0 4.0 4.0 4.0 12.57 12.57 12.57 12.57 12.57 12.57 12.57 276 00 29900 31700 16510 15660 5460 47900 2200 2380 2520 1314 1246 434 3810

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69 1 1 AVG SD Fly Ash 2 Fly Ash 3 4.0 4.0 12.57 12.57 50800 52800 23900 19170 4040 4200 1902 1525 As the graph in Figure 4 11 shows, fly ash performed the best with an average compressive strength of 4017 psi and all three of the fly ash cylinders achieved the minimum strength of 3000 psi as required by the computerized mix design. Bone meal performed better than the wet compressive strength testing and achieved an average of 998 psi, but was still not close to the minimum 3000 psi desired. Volcanic ash performed well with an average compressive strength of 2367 psi but stil l did not achieve the minimum 3000 psi standard. Max dry compressive strength @ 30 days of curing Figure 4 11. Graph of max dry compressive strength of concrete cylinders achieved after 28 days of curing. Concrete Testing Results : Tensile Strength After the remaining cylinders were allowed to dry for 48 hours, three cylinders from each batch were tested for tensile strength in the compression machine (Figure 4 13). However, two bone meal cylinders were not available for testing since they had disin tegrated during the 28 day curing process. This allowed for only one bone meal cylinder to be tested and affected the data results

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70 Figure 4 12. A volcanic ash concrete cylinder being tested for tensile strength. The results of the tensile strength testin g are listed in the following table: Table 4 6. Max tensile strength of concrete cylinders ac hieved after 28 days of curing. Mix No. Sample ID Diameter (inches) Area (sq. in.) U ltimate (lbf) Ultimate Stress (psi) 1 1 1 1 1 1 1 Volcanic Ash 1 Volcanic Ash 2 Volcanic Ash 3 Bonemeal 1* Fly Ash 1 Fly Ash 2 Fly Ash 3 4.0 4.0 4.0 4.0 4.0 4.0 4.0 12.57 12.57 12.57 12.57 12.57 12.57 12.57 12185 16080 22780 6940 14105 25060 12285 969 1279 1812 552 1122 1994 977 242.5 320.1 453.4 138.1 280.8 498.8 244.5 Only one bonemeal cylinder w as available for testing due to disintegration of remaining bonemeal cylinders during curing process. The maximum load at failure for each cylinder was recorded and listed in Table 4 was calculated with the formula from Chapter 3 Methodology table shows, fly ash again performed the best with an average s plitting tensile strength of 341 while volcanic ash was close behind with an average of 339. Bone meal performed the most poorly and achieved a single result of 138 since no other cylinders were available for testing.

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71 Concrete Testing Results: Water Absorp tion After the remaining cylinders were allowed to dry for 48 hours, one cylinder from each batch was tested for water absorption in the laboratory according to ASTM standards listed in Chapter 3 Methodology. The test method was used to determine the rate of absorption (sorptivity) of water by measuri ng the increase in the mass of the specimen s as a function of time when onl y one surface of the specimen was exposed to water. The exposed surface of the specimen was immersed in water (Figure 4 15) with a simple mesh wire device. The density of the specimens were measured at intervals of 5 minutes, 10 minutes, 20 minutes, 1 hour and 2 hours and each time the specimens were removed from the water and weighed on an electronic scale (Figure 4 16), then returne d to the water. Figure 4 13. The tray and chicken wire apparatus used to test the hardened concrete specimens for water absorption. Figure 4 14. Concrete cylinders after exposure to water and being weighed on electronic scale for water absorption. The results of the water absorption testing are listed in the following table:

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72 Table 4 7 Weight of concrete cylinders after intervals of 5 minu tes, 10 minutes of water immersion. Mix No. Sample ID Diameter (inches) Area (sq. in.) Dry Weight ( g ) Weight @ 5 min (g) Weight @ 10 min (g) 1 1 1 Volcanic Ash 1 Bonemeal 1 Fly Ash 1 4.0 4.0 4.0 12.57 12.57 12.57 3398 2612 3273 3402 2614 3281 3403 2614 3283 Table 4 8 Weight of concrete cylinders after intervals of 20 minutes, 1 hour and 2 hours of water immersion. Mix No. Sample ID Weight @ 20 min ( g ) Weight @ 1 hr (g) Weight @ 2 hrs ( g ) Total increase (g) % Increase 1 1 1 Volcanic Ash 1 Bonemeal 1 Fly Ash 1 3405 2613 3286 3406 2614 3298 3407 2612 3312 9 0 39 0.26% 0.00% 1.19% The results of the water absorption testing are depicted in the following graph: Water Absorption of Concrete Cylinders over Time Weight (grams) T ime Figure 4 15. Graph depicting water absorption of concrete cylinders at specified time intervals. The results of the water absorption testing show that fly ash had the greatest absorption and change in mass of 39 grams over the total 2 hour period. Volcanic ash

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73 followed with only 9 grams, and finally bone meal with 0 grams change in mass over the 2 hou r period. The value of absorption (I) was then determined through the following equation described in Chapter 3 Methodology: I = mt / (a* d) where mt = the change in mass in grams, at different time (t) (4 1) a = exposed area of the specimen, cm (12.57 sq. in. = 81.1 sq. cm.). d = density of water in g/cm (0.999 g/cm @ 65 degrees F). 1. For fly ash, the value of absorption I was calculated as follows: I = (39 grams 120 minutes) / (81.1 sq. c m. 0.999) = 57.8 2. For volcanic ash, the value of absorption I was calculated as follows: I = (9 grams 120 minutes) / (81.1 sq. cm. 0.999) = 13.3 3. For bone meal, the value of absorption I was calculated as follows: I = (0 grams 120 minutes) / (81 .1 sq. cm. 0.999) = 0 Environmental Impact Assessment: BEES Results The final stage of the data analysis consisted of determining the environmental and ec onomic performance (Figures 4 16 to 4 18 ) of the 20% alternative concrete materials by comparing them to typically used concrete mixes of 100% portland cement and silica fume concrete. ( Silica fume is an industrial byproduct of electric furnaces and is sold as a mineral admixture in concrete. It consists primarily of silicon dioxide ( Si O 2 ) whose parti cles are approximately 1/100th the size of an average cement particle. Because of its fine particles, large surface area, and the high Si O 2 content, silica fume is a very reactive pozzolan when used in concrete). The data was derived using BEES software an d was entered into the program as a substructure or foundation slab material for comparison purposes. Concrete of this type would typically be used in sub structure or foundation slabs in developing countries since many structures are no more than 2 stor ies in height.

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74 Figure 4 16 BEES overall performance results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure 4 17 BEES environmental performance results of 100% portland cement (baseline), 20% fly Ash, and silica fume m ixes.

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75 Figure 4 18 BEES economic performance results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes.

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76 CHAPTER 5 DISCUSSION AND CONCL USIONS Summary It was determined through the course of this study that in order to combat ecosystem destruction and the effects of increased amounts of carbon and toxins in the preserv e their natural resources and native ecosystems. These countries must use alternative sources of fuel as well as sustainable, local building materials to lower carbon output and preserve local resources. The key issues in promoting and utilizing sustainabl e building materials and practices in these countries were found to be: availability, cost, and durability of local materials. Local materials are crucial to the sustainable construction of commercial buildings and residential homes. Existing practices in the manufacturing of traditional portland cement concrete and existing studies about new forms of sustainable cement substitutes were reviewed, particularly animal meat waste products like bone char and bone meal. Three sustainable cement substitutes (fly ash, volcanic ash, bone meal) were then mixed and poured into eight (8) cylinders of 4 x 8 inch size for each mix type, resulting in a total number of minimum 24 cylinders. The concrete cylinders were allowed to cure for 28 days and then tested by the AST M standards for compressive strength, tensile strength and water absorption and data results were obtained and analyzed. The resulting concrete material types were then tested for environmental and economic performance based on BEES (Building for Environme ntal and Economic Sustainability) software which measures the performance of building products by using the life cycle assessment approach.

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77 Discussion This discussion will refer to the aims and objectives of the study listed in Chapter 1 and determine how the aims and obj ectives were achieved. Green Cement Substitutes 1. To review existing practices with respect to green cement substitutes in developed and developing countries This objective was reached through the extensive review of existing lit erature in Chapter 2. Recent studies about green cement substitutes, current practices in the manufacture of concrete in developed economies, and existing information and studies about the mineral composition and usage of animal bone char and bone meal wer e presented. Potential for Bone Char, Fly Ash, and Volcanic Ash as Cement Substitutes 2. To determine the potential for using animal bone char, fly ash, and volcanic ash as substitutes for portland cement in the manufacture of Due to time and cost constraints in this study, Miracle Gro Organic Choice bone meal was chosen as a substitute for actual bone char cement substitute. It is locally available at plant nurseries and is an all natural phosphorous supplement to promote root and flower growth. It is enriched with iron for stronger, greener plants and allows for controlled release nitrogen for plant feeding. However, it was also noted during the testing that this material is a porcine based product which does not use cow parts. This may h ave affected the mineral content of the bone meal mixture, since typical cow based bone meal contains approximately 30% calcium. The amount of minerals found in the produc t (listed previously in Table 4 3) were listed by the manufacturer (Miracle

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78 Gro) and calcium, a key ingredient in the concrete curing process, was not one of the minerals listed. This may have been an oversight by the manufacturer or perhaps the actual amount of calcium in porcine based bone meal is negligible due to the lack of cow bones in the mixture. Additionally, the manufacturer did not list calcium carbonate CaCO 3 as an ingredient, which would also affect the curing strength of the concrete since calcium carbonate is a key ingredient and bonding agent in portland cement. Bone char is still a very good potential cement substitute since it contains a high amount of CaCO 3 and its strength and durability should be tested in a laboratory setting when time and cost constraints are not a factor. Materials Performance Testing 3. To characteriz e the material properties performance of the resulting c oncrete based on durability, compressive strength and tensile strength tests Three pounds of bone meal was used in the experimentation according to the computerized mix design. During the curing pro cess, the bone meal cylinders were weaker and easily broke apart when immersed in water, which was a result of high water content. This also resulted in lower compressive and tensile strengths during testing. Bone meal material as a cement substitute did not meet the desired targets in terms of compressive strength, tensile strength and water absorption. Bone meal failed to reach the minimum 3000 psi during wet and dry compressive strength testing, was outperformed by fly ash and volcanic ash in tensil e strength testing, and had zero water absorption during testing. This is perhaps due to the high moisture content of the bone

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79 meal concrete mixture evidenced during the 28 day curing process when three of the bone meal cylinders easily broke apart when im mersed in water. Bone meal may be a desirable cement substitute with less than 20% material added to the mixture, as is the case with 5% limestone additive in portland cement. However, the lack of calcium carbonate (CaCO 3 ) in bone meal may negate any effects of reducing the material mixture since CaCO 3 is an effective bonding agent in the curing process. Bone char is still a very good potential cement substitute since it contains a high amount of CaCO 3 and its strength and durability should be tested in a laboratory setting when time and cost constraints are not a factor. BEES Building Envelope Performance 4. To characterize the impact of using the proposed concrete in building envelope performance against sustainability metrics using BEES ( B uilding for E nvironmental and E conomic S ustainability ) software. Several data comparisons and graphs were obtained through the BEES software in terms o f Overall Performance (Figure 4 18), Environmental Performance, and Economic Performance. Since the BEES software does not contain specific m aterials data on volcanic ash, bone char, and bone meal cement substitutes, the fly ash data had to be used and compared to 100% portland cement and silica fume concrete baselines with 4000 psi compressive strengths. Additional g raphs and data showing more specific comparisons through BEES software in areas of global warming, ecological toxicity, fossil fuel depletion, human health and embodied energy were also obtained and are listed in Appendix A. In terms of overall perfo rmance, 20% fly ash as an cement substitute material fared well compared to 100% portland cement and silica fume concrete. According to

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80 BEES, silica fume concrete had by far the best envi ronmental performance (Figure 4 19) with a score of only 1.0 (l ower scores are better), while 20% fly ash scored 21.8 and 100% portland cement scored an even higher 27.1 points. Fly ash scored the best in terms of economic performance (Figure 4 20) with a rating of 15.9, while portland cement scored 16.7 and silica fu me scored the worst with 17.4 points. Fly ash had lower first costs and future costs than either of its competitors. Conclusions A number of conclusions can be made from the results of this study. Sharing practices, particularly with the manufacturing and usage of concrete, may have positive economic effects in developed as well as developing countries. The standard uses of portland cement concrete in the developed world for construction projects mus t be replaced with alternative cement substitutes like fly ash, volcanic ash, silica fume, and other organic materials in order to minimize embodied energy, fossil fuel depletion, environmental damage and to reduce costs. Bone meal material as a ceme nt substitute did not meet the desired targets in terms of compressive strength, tensile strength and water absorption. Bone meal failed to reach the minimum 3000 psi during wet and dry compressive strength testing, was outperformed by fly ash and volcanic ash in tensile strength testing, and had zero water absorption during testing. This is perhaps due to the high moisture content of the bone meal concrete mixture evidenced during the 28 day curing process when the bone meal cylinders easily broke apart. B one meal may be a desirable cement substitute with less than 20% material added to the mixture.

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81 Twenty percent fly ash material as a cement substitute has improved environmental and economic performance compared to 100% portland cement concrete an industrial byproduct from landfilling. However, it is far out performed by silica fume concrete according to the BEES data comparisons in environmental impacts. Bo ne char is still a very good potential cement substitute since it contains a high amount of CaCO 3 and its strength and durability should be tested in a laboratory setting. Simple water absorption tests executed carefully in the laboratory can ide ntify the effect of material cement substitutes on the water absorption of building materials, Further Research Through the course of this study, several opportunities for further research were noted to expand the amou construction industry. Specifically, further environmental impact assessment data using BEES software is needed for organic cement substitutes and alternatives to portland cement concrete. BEES data s howing environmental and economic impacts of alternative cement substitutes like bone meal, fiberglass, volcanic ash is needed to aid The environmental performance of alternative cement substitutes can also be further studied through the Environmental energy efficiency) performance can also be measured and predicted in terms of WUFI) model for moisture and

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82 also be further researched through rigorous laboratory experimentation and analysis by ASTM standards for compressive strength, moisture ab sorption (as used in this study) and also through studies of air tightness (pore structure analysis); Additionally, due to the lack of research and few testing results of bone meal and bone char cement substitutes, these materials can be considered e nvironmentally friendly in concrete mixes due to their organic and renewable content. These materials warrant further durability testing for concrete with less than 20% bone meal cement substitute and a lower moisture content. It is also recommended that f urther water absorption tests follow ASTM C1585 and use the device in Figure 5 concrete specimens. Figure 6 1. Schematic diagram of ASTM C1585 testing procedure

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83 APPENDIX : ADDITIONAL BEES DA TA RESULTS Figure A 1. BEES environmental performance by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure A 2. BEES specific environmental performance results of 100% portland cement (baseline), 20% fly ash, and sili ca fume mixes.

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84 Figure A 3. BEES global warming by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure A 4. BEES fossil fuel depletion by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes.

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85 Figure A 5. BEES ecological toxicity by life cycle stage results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure A 6. BEES human health by life cycle stage results of 100% portland ce ment (baseline), 20% fly ash, and silica fume mixes.

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86 Figure A 7. BEES global warming by flow results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure A 8. BEES fossil fuel depletion by flow results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes.

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87 Figure A 9. BEES embodied energy by fuel renewability results of 100% portland cement (baseline), 20% fly ash, and silica fume mixes. Figure A 10. BEES summary results of 100% portland ceme nt (baseline), 20% fly ash, and silica fume.

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88 LIST OF REFERENCES Administration, E. I. (2008). Emissions of Greenhouse Gases in the United States. Washington, D.C. : U.S. Department of Energy. Aleman, F. (2008, December 25). Nicaragua Wind Power: Another Oil Producing Country Going Green. The Huffington Post p. 1. Alternative Medicine Encyclopedia. (2010). Bone meal definition Retrieved February 2010, from Answers.com: URL: http://www.answers.com/topic/bone meal Animal Numbers, Cattle Production by Country in 1000 HEAD (2009). Retrieved March 2010, from Index Mundi: http://www.indexmundi.com/agriculture/?commodity=cattle&graph=production Annual Energy Review 2004. (2005). Washington, D.C.: U.S. Department of Energy, Energy Information Administration. ASTM C143 (2009). Retrieved 2009, from ASTM C143 / C143M 09 Standard Test Method for Slump of Hydraulic Cement Concrete: http://www.astm.org/Standards/C143.htm ASTM C192 (2009). Retrieved 2009, from ASTM C192 Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory: http://www.astm.org/Standards/C192.htm ASTM C231 (2009). Retrieved 2009, from ASTM C231 09a Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method: http://ww w.astm.org/Standards/C231.htm ASTM C39 (2009). Retrieved 2009, from ASTM C39 / C39M 05e2 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens: http://www.astm.org/Standards/C39.htm BFRL: Office of Applied Economics (2 007, August 20). Retrieved February 2010, from BEES 4.0: http://www.bfrl.nist.gov/oae/software/bees/ Carbon Footprint (2009, October 17). Retrieved October 17, 2009, from What is a Carbon Footprint? : http://www.carbonfootprint.com/carbonfootprint. html Concrete (2010). Retrieved Feb 15, 2010, from Geotechnical Testing Equipment: http://geotechnical equipment.com/Concrete.html Deydier E., G. R. (2005). Physical and chemical characterisation of crude meat and bone meal combustion residue: "waste or raw material?". Journal of Hazardous Materials 141 148.

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89 DMG World Media Dubai. (2009). First Steps: What is construction's carbon footprint? Retrieved 2009, from The Big 5 2009 International Building and Co nstruction Show: http://www.thebig5exhibition.com/page.cfm/link=120 Emissions of Greenhouse Gases in the United States 2007. (November 2008). U.S. Energy Information Administration. Energy Efficiency and Renewable Energy (n.d.). Retrieved September 4, 2009, from U.S. Department of Energy: http://www1.eere.energy.gov/buildings/commercial_initiative/zero_energy_def initions html Fertilizer Product Information (2009). Retrieved February 22, 2010, from Washington State Department of Agriculture: http://agr.wa.gov/pestfert/fertilizers/fertdb/prodinfo.aspx?pname=1991 Intergovernmental Panel on Climate Change. (2007). Climate Change 2007: Synthesis Report. Valencia, Spain : IPCC Plenary XXVII. International Initiative for a Sustainable Built Environment (2009). Retrieved 2009, from International Initiative for a Sustainable Built Environment: http://www.iisbe.org/iisbe/start/iisbe.htm Ioannis S. Arvanitoyannis, D. L. (2007, September 25). Meat Waste Treatment Methods and Potential Uses. International Journal of Food Science & Technology pp. 543 559. J.A Wilson, I. P. (2002). Sorption of Cu and Zn by Bone Charcoal. Glasgow Scotland: Department of Chemistry, University of Glasgow. Jeffries, A. (2009, February 5). Is It Green?: Concrete Retrieved November 19, 2009, from Inhabitat.com: http://www.inhabitat.com/2009/02/05/is it green concrete/ Joint Science Academies. (2005). Joint Science Academies' Statement: Global Response to Climate Change. London: The Royal Society. Kendall, A. G. (2008). Materials design for sustainability through life cycle. Materials and Structures 1117 1131. Kibert, C. J. (2008). Sustainable construction : green building design and delivery. John Wiley & Sons, Hoboken, N.J. Lazarus, N. (200 2). Beddington Zero Fossil Energy Development: Construction Materials Report. Wallington, Surrey, UK: Bioregional Development Group. Marie Coutanda, M. C. (2008). Characteristics of industrial and laboratory meat and bone meal ashes Journal of Hazardous Materials 522 532

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90 Meriter Health Services (2009). Retrieved February 2010, from Bone Meal: http://meriter.staywellsolutionsonline.com/RelatedItems/19,BoneMeal Pistilli, Mike. (2005). The Cost of Doing Business with Concrete Concrete Construction. Retrieved March 2010, from FindArticles.com. http://findarticles.com/p/articles/mi_m0NSX/is_11_50/ai_n15878171/ Press, A. (2009, January 1). Nicaragua Turns to Wind Power Retrieved September 10, 2009, from MSNBC.com: http://www.msnbc.msn.com/id/28421541/ The Concrete Centre. (2009). The Concrete Industry Sustainability Performance Report. Camberley, Surrey, UK: The Concrete Centre. World Business Council For Sustainable Development. (2002). Cement Sustainability Initiative Report. Geneva, Switzerland: World Business Council For Sustainable Development. World Commission on Environment and Development. (1987). Our Common Future. Oxford: Oxford University Press.

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91 BIOGRAPHICAL SKETCH Christian B. Terrell was born in San Francisco, California into a military family and has lived throughout the United States and in Puerto Rico. In 2001 he was awarded a ania and was commissioned an officer in the U.S. Army. Christian served on active duty in the U.S. Army as an AH 64 pilot in scenic places in the United States and overseas. He has worked for international architecture firms on a variety of projects and earned a Master of Science in Building Construction from the University of Florida in May 2010. Christian plans to become a leading design builder in the construction industry focusing on sustainable building practices