Citation
Evaluating the Feasibility of Using Corn Ash and Wood Ash In Concrete in Florida

Material Information

Title:
Evaluating the Feasibility of Using Corn Ash and Wood Ash In Concrete in Florida
Creator:
Sathe, Ishan Kiran
Place of Publication:
[Gainesville, Fla.]
Florida
Publisher:
University of Florida
Publication Date:
Language:
english
Physical Description:
1 online resource (69 p.)

Thesis/Dissertation Information

Degree:
Master's ( M.S.C.M)
Degree Grantor:
University of Florida
Degree Disciplines:
Construction Management
Committee Chair:
CHINI,ABDOL REZA
Committee Co-Chair:
RIES,ROBERT
Committee Members:
SRINIVASAN,RAVI SHANKAR

Subjects

Subjects / Keywords:
flyash -- portlandcement -- woodash
Construction Management -- Dissertations, Academic -- UF
Genre:
bibliography ( marcgt )
theses ( marcgt )
government publication (state, provincial, terriorial, dependent) ( marcgt )
born-digital ( sobekcm )
Electronic Thesis or Dissertation
Construction Management thesis, M.S.C.M

Notes

Abstract:
The use of fly ash in concrete has seen a steady rise in the last few years. Several government agencies have specified a minimum quantity of fly ash as a substitute for cement in concrete. For example, the Florida Department of Transportation requires a minimum of 18% by weight of the total cementitious materials. In recent years, the generation of fly ash has reduced due to the decreasing reliance on using coal power plants. Therefore, to avoid a situation of fly ash shortage, it is necessary to start looking at alternative options. Wood ash and corn ash have been considered as potential replacements to fly ash in concrete in countries like Nigeria and India. United States is the largest producer of corn with majority of the production in the Midwest. Therefore, there is potential of using corn ash as a substitute for cement and fly ash. The only problem is the availability and the transportation concerns in Florida. Similarly, wood waste is available in plenty in Florida with almost 3 million tons being landfilled. As there are several biomass plants in Florida which use wood biomass to generate electricity, the wood waste can be potentially used to partially satisfy the wood ash as a replacement material to fly ash in concrete. In this study, it is shown that corn ash and wood ash have the potential of meeting 3% and 37% of the quantity of fly ash needed to replace Portland cement in production of 3000 psi concrete in Florida. The environmental impacts of using fly ash along with corn ash and wood ash are also calculated and compared. These impacts consider the energy required to transport wood and corn ash to the concrete gate in Orlando and Miami from their source location. Extensive comparison of all the wastes shows that the transportation energy emissions for wood ash and corn ash are higher than fly ash in Orlando and lower in Miami. Similar study and analysis shows that the cost per ton of wood ash and corn ash are higher than that of fly ash by $4/ton and $25/ton respectively. ( en )
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.
Thesis:
Thesis (M.S.C.M)--University of Florida, 2017.
Local:
Adviser: CHINI,ABDOL REZA.
Local:
Co-adviser: RIES,ROBERT.
Statement of Responsibility:
by Ishan Kiran Sathe.

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
LD1780 2017 ( lcc )

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1 EVALUATING THE FEASIBILITY OF USING CORN ASH AND WOOD ASH IN CONCRETE IN FLORIDA By ISHAN SATHE 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 CONSTRUCTION MANAGEMENT UNIVERSITY OF FLORIDA 2017

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2 2017 Ishan Sathe

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3 To my beloved parents, Kiran Sathe and Anita Sathe who have continuously supp orted egree. To my elder brother, Angad Sathe, for encouraging and believing in me. To all friends and relatives, without whom this would not have been possible.

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4 ACKNOWLEDGMENTS I would like to thank my advisor, Dr. Abdol Chini who has given me di rections throughout my thesis. A t the same time he has given me freedom to pursue my interests. He helped me understand the industry wide research interests in the field of concrete and recyclable materials. My first experience in doing research has been very enjoyable under his guidance. I would also like to exten d my gratitude to Dr. Robert Ries and Dr. Ravi Srinivasan, who agreed to serve as committee members for my thesis. Dr. Ries gave valuable inputs and suggested new ideas. His ideas gave a different approach to my research. Dr. Srinivasan, was very helpful i n giving me constant encouragement. Last but not the least, thanks to the entire academic and industrial fraternity who will read this thesis. I hope my research helps to share and expand the knowledge about concrete and recyclable materials that can be used in the construction industry.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ .. 4 LIST OF TABLES ................................ ................................ ................................ ............ 7 LIST OF FIGURES ................................ ................................ ................................ .......... 8 ABSTRACT ................................ ................................ ................................ ................... 10 CHAPTER 1 INTRODUCTION ................................ ................................ ................................ .... 12 1.1 Concrete Production and Global Warming Emissions ................................ ...... 12 1.2 Objective ................................ ................................ ................................ ........... 14 1.3 Thesis Structure ................................ ................................ ................................ 15 2 LI TERATURE REVIEW ................................ ................................ .......................... 17 2.1 Sustainability and the Concrete Industry ................................ ........................... 17 2.2 Supplementary Cementitious Materials ................................ ............................ 23 2.3 Corn Ash ................................ ................................ ................................ ........... 26 2.4 Fly Ash ................................ ................................ ................................ .............. 31 2.5 Wood Ash ................................ ................................ ................................ ......... 35 2.6 Literature Review Summary ................................ ................................ .............. 38 3 METHODOLOGY ................................ ................................ ................................ ... 39 3.1 Physical a nd Chemical Property Comparison ................................ ................... 39 3.1.1 Properties of wood and corn ash ................................ ............................. 39 3.1.2 Properties of concrete made with wood and corn ash ............................. 39 3.2 Ideal Replacement Percentage of Wood and Corn Ash ................................ .... 39 3.3 Cement Consumption for Low Strength Co ncrete ................................ ............ 40 3.4 Wood Ash Requirement and Availability ................................ ........................... 40 3.5 Corn Ash Requirement and Availability ................................ ............................. 41 3.6 Environmental Impacts ................................ ................................ ..................... 42 3.7 Cost ................................ ................................ ................................ .................. 43 4 RESULTS AND DISCUSSION ................................ ................................ ............... 44 4.1 Corn Ash Analysis ................................ ................................ ............................. 44 4.1.1 Physical Properties of Corn Ash ................................ .............................. 44 4.1.2 Physical Properties of Concrete Made with Corn Ash ............................. 44 4.1.3 Chemical Properties of Corn Ash ................................ ............................ 45 4.2 Wood Ash Analysis ................................ ................................ ........................... 45

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6 4.2.1 Physical Properties of Wood Ash ................................ ............................ 46 4.2.2 Physical Properties of C oncrete Made with Wood Ash ............................ 46 4.2.3 Chemical Properties of Wood Ash ................................ ........................... 46 4.3 Cement Consumption Analysis ................................ ................................ ......... 49 4.4 Wood Ash Demand and Supply Analysis ................................ .......................... 50 4.5 Corn Ash Demand and Supply Analysis ................................ ........................... 51 4.6 Environmental Impacts ................................ ................................ ..................... 54 4.7 Cost ................................ ................................ ................................ .................. 58 5 CONCLUSION AND FUTURE SCOPE ................................ ................................ .. 61 5.1 Conclusion ................................ ................................ ................................ ........ 61 5.2 Research Limitations ................................ ................................ ........................ 63 5.3 Future Scope ................................ ................................ ................................ .... 63 6 LIST OF REFERENCES ................................ ................................ ......................... 64 7 BIOGRAPHICAL SKETCH ................................ ................................ ..................... 69

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7 LIST OF TABLES Table page 4 1 Replacement percentages of wood ash, corn ash and fly ash. ........................... 53 4 2 Calculations of wood ash requirement and availability. ................................ ...... 53 4 3 Calculation of corn ash requirement and availability. ................................ .......... 54 4 4 Transportation Energy Emissions in MTCE/t ................................ ...................... 58 4 5 All materials and their costs ................................ ................................ ................ 60

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8 LIST OF FIGURES Figure page 2 1 Life cycle of concrete ................................ ................................ .......................... 19 2 2 Temperature difference over the last few centuries (adopted from NRMCA Concrete CO 2 fact sheet ) ................................ ................................ .................... 20 2 3 Pie chart with percentage carbon dioxide emissions (adopted from NRMCA Concrete CO 2 fact sheet ) ................................ ................................ .................... 20 2 4 Cement Production in United States and the World (adopted from Statista ) ...... 20 2 5 Domestic Cement Production in the United States (adopted from Statista ) ....... 21 2 6 Global CO 2 emissions in million metric tons (adopted from Statista ) .................. 21 2 7 Production energy of different materials (adopted from: Penttala V. 1997) ........ 22 2 8 ASTM specifications showing maximum percentage replacements (adopted from NRMCA specification ) ................................ ................................ ................ 25 2 9 Production numbers in terms of lbs of cementitious material per cubic yard produced (adopted from NRMCA SCM Survey 2012 ) ................................ ........ 25 2 10 Corn Production Statistics (a dopted from US Department of Agriculture ) .......... 27 2 11 Yield of corn in the United States (adopted from US Department of Agriculture ) ................................ ................................ ................................ ......... 27 2 12 Use of Domestic Corn (adopted from US Department of Agriculture ) ................ 28 2 13 Shows the corn production statistics in Florida by county. (adopted from IFAS) ................................ ................................ ................................ .................. 30 2 14 Typical range of elemental composition for Coal Combustion Products from different coals, wt% (Heidrich et al., 2013) ................................ ......................... 33 2 15 Fly ash requirements per ASTM standards (adopted from NRMCA specification .) ................................ ................................ ................................ ...... 33 2 16 The fly ash production and use statistics (ad opted from American Coal Ash Association ) ................................ ................................ ................................ ........ 34 2 17 The bottom ash production and use statistic in the last 15 years (adopted from American Coal Ash Association ) ................................ ................................ 34

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9 2 18 All the Coal Combustion Products produced and used in 25 years (adopted from American Coal Ash Association ) ................................ ................................ 35 4 1 Comparison of physical properties of wood ash, corn ash and fly ash. .............. 47 4 2 Comparison of physical properties of concrete made with wood ash, corn ash and fly ash. ................................ ................................ ................................ ......... 47 4 3 Comparison of chemical properties of wood ash, corn ash and fly ash. ............. 47 4 4 7, 14 and 28 day compressive strengths of 3000psi concrete with different percentage of wood ash. (adopted from Udoeyo F et al. 2006). ......................... 48 4 5 7, 21 and 28 day compressive strengths of 3000 psi concrete with different percentage of corn ash. (adopted from Oladipupo O. and Festus O. 20 12). ...... 48 4 6 List of all material suppliers near Orlando. ................................ ......................... 55 4 7 List of all material suppliers near Miami ................................ .............................. 55 4 8 Combustion energy coefficients in mBtu/ton ................................ ...................... 56 4 9 Transportation Energy Emissions for one ton of Fly Ash ................................ .... 56 4 10 Transportation Energy Emissions for one ton o f Wood Ash ............................... 57 4 11 Transportation Energy Emissions for one ton of Corn Ash ................................ 57

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10 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 Const ruction Management EVA L U ATING THE FEASIBILITY OF USING CORN ASH AND WOOD ASH IN CONCRETE IN FLORIDA By Ishan Sathe August 2017 Chair: Abdol Chini Major: Construction Management The use of fly ash in concrete has seen a steady rise in the last few years. Several government agencies have specified a minimum quantity of fly ash as a su bstitute for cement in concrete. For example, the Florida Department of Tran sportation requires a minimum of 18% by weight of the total cementitious materials. In recent years, the generation of fly ash has reduced due to the decreasing reliance on using coal power plants. Therefore, t o avoid a situation of fly ash shortage it is necessary to start looking at alternative options. Wood ash and corn a s h have been considered as potential replacements to fly ash in concrete in countries like Nigeria and India. United States is the largest producer of corn with majority of the production in the Midwest. Therefore, there is potential of using corn ash as a substitute for cement and fly ash. The only problem is the availability and the transportation concerns in Florida. Similarly, wood waste is available in plenty in Florida wit h almost 3 million tons being landfilled. As t here are several biomass plants in Florida which us e wood biomass to generate electricity, the wood waste can be potentially used to partially satisfy the wood ash as a replacement material to fly ash in concrete.

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11 In this study, it is shown that corn ash and wood ash have the potential of m eetin g 3 % and 37 % of the quantity of fly ash needed to replace Portland cement in production of 3000 ps i concrete in Florida. Th e environmental impacts of usi ng fly ash along with corn ash and wood ash are al so calculated and compared. These impacts consid er the energy required to transport wood and corn ash to the concrete gate in Orlando and Miami from their source location Extensive comparison of all the wastes shows that the transportation energy emissions for wood ash and corn ash are higher than fly ash in Orlando and lower in Miami Similar study and analysis shows that the cost per ton of wood ash and corn ash are highe r than that of fly ash by $4/t and $25/t respectively.

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12 CHAPTER 1 INTRODUCTION 1.1 Concrete Production and Global Warming Emiss ions Concrete is one of the widely used construction materials in the world today ( Olafusi S. and Olutoge A. 2012 ). It is estimated that concrete production would be around 18 billion tons by 2050 ( Aprianti E et al., 2015 ). This has put a larg e strain on raw materials and non renewable natural resources. Construction is said to be a significant source of greenhouse gas emissions ( Junnila S. and Horvath A. 2003 ). Therefore, increase in concrete production will lead to increase in Greenhouse Gas emissions (GHG). Concrete consists of cement, fine aggregates and coarse aggregates along with water in proper proportions Each of these constituents contributes in the strength of concrete by forming calcium silicate hydrate called as the process of hydration. Ordinary Portland Cement (OPC) is an important ingredient in concrete. The increase in concrete demand has meant th at the cement production has increased causing an increase in carbon emissions. The cement production in 2012 was approximately 3,800 million metric tons while in 2016 it increased to 4,200 million metric tons ( Statista ). T he increase in cement consumption has been because of better infrastructure facilities, improved standard of living caused by increasing population. It is est imated that for every ton of cement produced, a round 0.73 0.99 tons of CO 2 is emitted. ( Hasanbeigi et al., 2012) It is estimated that half of these emissions are due to the combustion of fossil fuels as production of cement requires about 4 5GJ/t on of energy ( Celik K. et al., 2015 ). This increase in carbon emissions has led to expanded efforts on studying alternative materials as a replacement to cement in concrete.

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13 Use of industrial waste like fly ash, blast furnace slag and silica fume in co ncrete has been going on for a long time now. Use of these waste products has prevented 15 million metri c tons from entering landfills Fly ash and blast furnace slag are by products of coal combustion and iron and steel manufacturing process respectively As these are waste products having efficient pozzolan properties, their use in concrete has produced positive results. The government has promoted the use of fly ash in concrete with the Florida Department of Transportation (FDOT) having a minimum 18% requ irement of fly ash in concrete. In recent years, however the gen eration of fly ash has reduced because of the ill effects of coal combustion. But the dema nd for fly ash has remained constant. With the increasing reliance on fly ash in the production of co ncrete, the reduction in the availability of fly ash is a source of concern. Therefore, it has become necessary to look for alternative options as a potential replacement. Corn ash and wood a sh are the relatively new products that have been proposed for us e as partial replacements to cement. These products are found to have good pozzolan properties and can be a good replacement to fly ash in concrete. Wood waste is use d in biomass plants as a raw material for generating renewable energy. These biomass plant s emit wood ash as a byproduct like fly ash in coal combustion process. Thus, the potential of wood ash generatio n is significant. 20% of the solid w aste generated in Florida consists of wood and yard trimmings ( MSW ). Similarly, corn waste generation is significant as United States is the largest producer of corn. Therefore, corn waste can also b e considered for using as a r aw material in biomass plants. The ash generated, can be used as a partial replacement to fly ash in concrete.

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14 1.2 Objective The aim of this thesis was to 1. Review past research in e valuating performance of corn ash and wood ash i n concrete production and c ompare their physical and chemical properties to normal fly ash This past research is further used to find the optimum cement replacement percent of cor n ash and wood ash in production of 3000 psi concrete. 2. Based on the optimum percentage of wood ash an d corn ash determined in part 1, c alculate the amount and availability of wood ash and corn ash require d for concrete production (less than 3500 psi ) in Florida. 3. Calculate and compare environmental impacts in terms of energy required for tr ansporting fly ash, corn ash and wood ash to Orlando and Miami. 4. Find and compare the cost per ton of fly ash corn ash and wood ash delivere d at concrete plants in Orlando and Miami.

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15 1.3 Thesis Structure Research consists of five chapters which are categorized as follows: Chapter 1 : The first chapter consisted of understanding the need for looking at different sources as a replacement to fly ash in concrete. The result for the increase in concrete and cement production is because o f rising population levels. It inc luded studying the demand and supply statistics of fly ash which has made it necessary to look at alternative options like wood and corn ash. Chapter 2 : Literature review covered the inter relationshi p of concrete and sustainable construction It included the contribution of concrete and its raw materials i n producing carbon emissions. Literature covered research done on the use of fly ash, wood ash and corn ash in concrete all over the world. Each materia l was reviewed in detail for their extraction proces s individual characteristic s and the ir properties when used in concrete This section include s the following topics: 1. Interrelationship of concrete and sustainable construction 2. Supplementary Cementitious materials 3. Fly Ash 4. Wood Ash 5. Corn Ash Chapter 3 : Rese arch Methodology included comparison of the physical and chemical properties of concrete with wood ash and corn ash with normal fly ash It also included reviewing literature in finding the optimum replacement p ercentage of corn ash and wood ash to get 3 000 psi strength concrete. The replacement percentages resulted in finding the annual requ irement of corn ash and wood ash in Florida. The focus of the study only covered annual wood ash and corn ash requirement for low strength concrete (less than 3500 ps i). The source of wood ash was the potential wood waste

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16 that would be used in biomass plants to generate electricity. Currently, corn ash is not used as a replacement material in concrete. The corn waste was assumed to be used in biomass plants to generate electricity. Therefore, the source of corn ash was taken as a biomass plant as well. For calculating environmental impacts, two locations were selected: Orlando and Miami. The sources of wood ash, corn ash and fly ash were taken nearest to both the locati ons Environmental impacts of using these waste materials were calculated in terms of the energy required to tra nsport th e materials to the concrete gate in Orlando and Miami The cost per to n of fly ash wood ash and corn ash were obtained to compare the differences. Chapter 4 : This chapter analyzed physical and chemical properties compared i n chapter 3 The chapter also included calculating the annual demand and requirement of wood ash and corn ash for use in low strength concrete in Florida. It analyzed t he e nergy spent in transporting w ood ash and corn ash to concrete gate in Orlando and Miami It also compared the cost per ton of fly ash with that of wood ash and corn ash. Chapter 5: The final chapter discussed the findings of the study. This chapter wi ll end with future recommendations and scope of further research.

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17 CHAPTER 2 LITERATURE REVIEW 2.1 Sustainability and the Concrete Industry The ready mix concrete industry is focused on providing a sustainable development solution to meet the needs of the present generation without affecting the ability of the future generations to meet their own needs. Project owners, developers, contractors and product manufacturers are affected by the challenges of maintaining sustainable development especially since their acti ons have an economic, environmental and social impact on the planet. There are numerous organizations that have focused their attention on developing ways to reduce the carbon footprint of concrete through the development of innovative cement and concrete mixtures. Typically, a concrete mixture is 7 15% cement, 60 75% aggregate and 15 20% water. Figure 2 1 shows the life cycle of concrete which involves material acquisition to product recycling. The manufacture of Portland cemen t is the third most energy intensive process after aluminum and steel. A few of energy reduction process have involved replacement of dry production facilities with wet processing plants. The cement industry has also moved away from petroleum based fuel us e. To produce 1 ton of Portland cement, 1.6 ton of raw materials like limestone and clay are required The concrete industry is one of the two largest producers of CO 2 having 10% of worldwide emissions out of which 50% are from chemical processes and 40% are from burning fuel. The chemical processes include calcination of raw materials which is a part of the manufacturing process. In 2010, U.S was the third largest cement manufacturing country after China 1,814Mt (2,000 million metric tons) and India 191Mt (210 million tons).

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18 The U.S cement industry accounts for 1.5% of U.S CO 2 emission. According to a survey done by the Portland Cement Association (PCA), it was estimated that 1 ton (2205lbs) of cement pr oduces 1 ton (1984 to 2285lbs) of CO 2 The average cement content is 7 15% by weight depending on the concrete mix. The average quantity of cement is 420 lbs. /yd 3 Thus approximately 170 500 lbs. /yd 3 of CO 2 is embodied per cubic yard of concrete. Per the National Ready Mixed Concrete Association (NRMCA), the carbon footprint, embodied energy, potable water, waste and recycled content are the key performance indicators that are measured with regards to product sustainability. Figure 2 2 shows the temperature differences over the last decade because of rising temperatures. Per the data obtained from NRMCA, figure 2 3 sh ows the percentage CO 2 emissions in transportation, residential, industri al and commercial sector. The cement production in the United States and the world is observed in Figure 2 4 and Figure 2 5 The global CO2 emissions have seen a steady rise in the last decade Figure 2 6 From F igure 2 7 concrete and cement require relatively less production energy when compared with other products like steel, aluminum, stainless steel and glass ( Penttala V. 1997 ). The U.S Concrete industry has initiated the P2P (Prescriptive to Performance Specifications for Concrete) initiative which provided concrete manufacturers more flexibility pe r their requirements. It can also help to reduce the environmental impacts. It is observed that the construction industry has unnecessary requirements regarding Portland cement and the limits of using supplementary cementitious materials in concrete. This P2P initiative proposes to eliminate certain prerequisites and evolve the

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19 use of cement and other materials per the specific job requirements. This initiative can help reduce the environmental impact of concrete ( P2P ). Figure 2 1. Life cycle of concrete Material Acquisition Production Construction Product Use Recycling

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20 Figure 2 2. Temperature difference over the last few centuries (adopted from NRMCA Concrete CO 2 fact sheet ) Figure 2 3. Pie chart with percentage carbon dioxide emissions (adopted from NRMCA Concrete CO 2 fact sheet ) Figure 2 4. Cement Production in United States and the World (adopted from Statista )

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21 Figure 2 5. Domestic Cement Product ion in the United States (adopted from Statista ) Figure 2 6. Global CO 2 emissions in million metric tons (adopted from Statista )

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22 Figure 2 7. Production energy of different materials (adopted from: Penttala V. 1997 )

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23 2.2 Supplementary Cementitious Materials divided in two categories based on the type of reaction they undergo: hydraulic and pozzolan Hydraulic materials react directly with water to form cementitious compounds while po zzolan materials react to form C S H gel in the presence of water that has fly ash, slag cement is to reduce the cement content in concrete. Industrial wastes such as fly ash and blast furnace slag along with agricultural wastes like corn cob ash and wood ash are being used as supplementary materials for partial replacement of cement. These materials contain aluminum oxide, silica oxide which react with calcium hydroxide to form compounds having cem entitious properties which are called pozzolan High early strength of concrete can be produced by the highly reactive silica in pozzolan Another required strength character istics of concrete. It is easy to improve the performance of concrete by using them as admixtures as well. By reusing these wastes, it can help reduce cement production resulting in reduction in cost of production of concrete. Use of the waste sent to landfills, reduce raw materials, lesser energy of production and reduced CO 2 emissions. There are large quantities of waste materials all over the world from different sectors like industrial, agricultural both in urban and suburban area s. These wastes if not treated properly can be hazardous. The waste quantity also has gone on to increase tremendously with the increasing population. Large amount of land is lost in landfilling operations to dump these wastes. The diversion of these waste s to useful activities or products can help reduce the burden on waste disposal. It can also help save valuable

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24 land from landfilling. Research has therefore grown a lot as to appropriate utilization of these waste into useful products. Fly ash and blast f urnace slag have proved to be good replacement to cement in concrete. Wood ash and Corn Cob ash have also been used as cement replacement materials in different countries. All the four materials possess cementitious properties which help react with aggrega tes and sand to form concrete. Figure 2 8 gives the limiting values of Supplementary Cementitious Materials. Per a survey by the National ready mix concrete Association, the different cementitious percentage used per cubic yard of concrete was found out. Figure 2 9 shows the the Research conducted by Malhotra (2012) that orm in tests conducted in accordance with ASTM C672/C672M. It is observed that the use of can be beneficial in warm weather conditions like Florida but may be problemat ic in cooler weather. Research has shown that different fly ash samples give significantly different results when 11 different fly ash sources were used to illustrate 20% replacement. ( Malhotra and Ramezanianpour 1994 ). Concrete temperature also influences these properties. Therefore, restricting the percentages does not definitely lead to good properties. Some of the observ 1. Improved resistance to sulfate attack 2. Better concrete durability. 3. Continued improvement in strength at later ages which can improve the life of structures 4. Sustainable construction having lower emissions.

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25 A survey conducted by the American Coal Ash Association in 2012 highlighted different parameters to find out the use of these materials in construction. It observed that there can be a potential increase in the use of SCM from the existing 102lbs to 144 lbs. /yd3 produced. Assuming all the increase is attributed to fly ash and slag cement, and the production levels of concrete continue to rise, the percentage use of fly ash and slag cement will rise from 41% to an all time high of 61%. This will mean a strain on the availability of fly ash and slag cement assuming the current reduction in the supply of these two materials continues. Figure 2 8. ASTM specifications showing maximum percentage replacements (adopted from NRMCA specification ) Figure 2 9. Production numbers in terms of lbs of cementitious material per cubic yard produced (adopted from NRMCA SCM Survey 2012 )

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26 2.3 Corn Ash According to the United States Department of Agriculture, more than 90 million acres of corn plantations are grown in the U.S with the majority of the crop grown in the He artland region. Corn is used majorly for livestock feed, in food and industrial products like starch, sweeteners corn oil, beverage and fuel ethanol. Corn production has increased from a low of 60.2 million in 1983 to more than 90 million in 2015. F igure 2 10 show s the statistics of feed grain production in the year 2016/17. 95% of the production is dominated by corn, while oat, barley and sorghum make up the remaining 5%. F igure 2 11 shows the pro minent rise in the yield of corn over the last century. Although, the area allotted for corn plantation has remained fairly constant which means that better agricultural techniques have helped to improve the yield. Figure 2 12 shows the different types of domestic uses of corn stover like alcohol for fuel use, for livestock feed and other seed and industrial uses. Figure 2 13 provides the production statistics of corn in different counties o f Florida.

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27 Figure 2 10. Corn Production Statistics (adopted from US Department of Agriculture ) Figure 2 11. Yield of corn in the United States (adopted from US Department of Agriculture )

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28 Figure 2 12. Use of Domestic Corn (adopted from US Department of Agriculture ) Corn stover is the combination of stalks, leaves and cobs that is left in the field after corn harvest. Its major use is for ethanol production. Corn stover is also used for cellulosic sugars that can be fermented into ethanol. It is estimated that corn stover could supply as much as 25% of the biofuel needed by 2030 ( Koundinya V. 2009 ). Chemical composition of corn stover includes 70% cellulose and hemicellulose and 15 20% lignin. The cellulose and hemicellulose can be converted into ethanol while lignin can be burned as a boiler fuel for electricity generation in biomass plants. 1 ton of c orn stover was found to include 15 lbs. of nitrogen (N), 6 lbs. of phosphate (P 2 O 5 ), and 25 lbs. of Potash (K 2 O) ( Missouri ). Corn cob and corn stover are used as a biomass feedstock. Due to similar properties, they can be used in biomass plants for electricity generation.

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29 Corn cob is the central thick core on which the grains are borne. It is a waste product that is ultimately crushed and landfilled. The remains of corn cob after removing corn are an agricultural waste. Corn cob ash has pozzolan properties which is therefore a suitable replacement for cement in conc rete production. United States is the largest producer of maize having 52% of the world production Based on the current research, agricultural wastes such as corn cob and wood ash have a wide scope of being used in concrete production in the United States Use of these agricultural waste products can help reduce the disposal problems that end up polluting land, air and water. However, there is potential for more research on the use of corn cob ash in concrete in the United States, despite it being one of t he largest producers of corn. Pinto et al (2012) researched the use of corn cob as a lightweight aggregate for producing co ncrete. This study involved measuring the density, compressive strength and thermal insulation properties of corn cob inducted concrete. Previous research on corn cob has also focused on replacing cement with different percentages of corn cob a sh to check if the concrete is per American Society of Testing Materials (ASTM) and National Institute of Science (NIS) standards. There have also been thermal conductivity and insulation tests on corn cob ash concrete. The results have shown that thermal conductivity decreases with a 25% corn cob ash replacement. The insulation tests have shown that the properties of the CCA concrete improve by replacing cement with corn cob ash ( Adesanya D.A and Raheem A.A 2009 ). It has been found that compressive strength increases with age of curing but decreases with increase in CCA percentage. There is an increase in compressive strength of concret e which has a 10% replacement of cement with CCA. Water requirement was also found to increase with

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30 increase in percentage CCA replacement. In the Cameroon, corn is also used for beer manufacturing and breeding along with human consumption ( Nkayem D. et al. 2016 ). They also noted that corn ash did not attain the required strength at 28 days. It was also observed that the addit ion of admixtures led to improvement in workability and the compressive strength of corn cob ash cement concrete. Use of accelerator helped to increase the strength at early ages ( Raheem A. et al., 2009 ). Figure 2 13: Shows the corn production statistics in Florida by county. (adopted from IFAS )

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31 2.4 Fly Ash Fly ash is one of the by products of coal combustion and is used as a cementitious material in Portland cement concrete. Thermal power plant fly ash is classified in two forms; Class C and F fly ash depending on the properties of coal as well as the combustion pro cess. Fly ash standards are set according to ASTM C618 based on their composition and properties. Class C fly ash is not perm itted for use in concrete. Figure 2 14 provides the minimum chemical requirements in different types of fly ash. Figure 2 15 gives the industry standards of the minimum requirements of fly ash. The minimum silica, aluminum and iron oxide contents is required to be 70%. It is observed that the LOI value is limited to 6%. Although ASTM C618 permits LOI values up to 12% provided there is proper documentation of the service records. The fineness retained on a 45um sieve is limited to 34. There are limits on the sulfur trioxide, moisture content, soundness, strength activity index, water requirement and uniformity requirements. The performance of fly ash depends on the source of coal as well as the physical and chemical properties. It is found that fly ash requires 30 40% more storage space than ordinary Portland cement. Fly ash is spherical in shape increasing the flowability. The government has promoted the use of fly ash over the years to reduce the problem of disposal of fly ash. Per the American Coal Ash Associatio n (ACAA), almost 50% of all ready mix concrete has fly ash as a material. With the industry relying heavily on fly ash as a sustainable material, the decline in production of fly ash is a source of concern for the construction industry. To avoid a situatio n where we end up falling short of fly ash, it is necessary to take measures by researching alternative pozzolan materials as a replacement to fly ash and cement in concrete. Besides concrete, fly ash is also used in

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32 composite materials like metal alloys f or auto parts and synthetic lumber. In recent Generation of fly ash which was constant till 2010 has therefore began to decline as well. The decrease in production of fly as h, has not resulted in a decrease in the use of fly ash. It therefore means that higher percentage of fly ash is reused in concrete. Addition of fly ash in concrete as an admixture has found to increase the early age compressive strength and long term corr osion resisting characteristics of concrete. High volume fly ash can be used to produce high quality pavements in concrete ( Siddique R. 2004 ). Low calcium fly ash can be produced by burning anthracite or bituminous coal and high calcium fly ash can be produced by burning lignite or bituminous coal. Fly ash concrete mixes can be divided into three categories. Simple repla cement method involves direct weight replacement of a part of Portland cement with fly ash with an adjustment for yield of concrete. Addition method involves addition of fly ash to cement replacing partial aggregate in concrete to achieve yield of concrete Third method is divided in two as modified replacement and rational proportioning method. In the modified replacement method fly ash content is modified to compare the properties with parent concrete. Rational proportioning method has a binding efficienc y factor k, with weight of fly ash equivalent to cement having a weight Kf. Figures 2 16 and 2 17 show the fly ash and bottom ash production and use statistics in the last 15 years. As you can se e, the fly ash production has been declining since 2010, but the use of fly ash has remained constant over the years. Hence, the fly ash used as a percent of produced has significantly risen to more than 50%. By this rate, the fly ash production and consum ption will end up being equal and eventually will

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33 lead to a shortage of supply. Similarly, the bottom ash consumption has remained constant while the production has reduced. Although, this is not as alarming as that of fly ash but eventually it will lead t o a similar situation. Figure 2 18 shows all the production and use statistic of all coal combustion products in the United States in the last 25 years. The combustion products usage has gradually increased from 25% in 1991 to almost 55% in 2015 which is a combination of decrease in production as well as increase in the use. Figure 2 14. Typical range of elemental composition for Coal Combustion Products from different coals, wt% ( Heidrich et al., 2013 ) Figure 2 15 Fly ash requirements per ASTM standards (adopted from NRMCA specification .)

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34 Figure 2 16 The fly ash production and use statistics (adopted from American Coal Ash Association ) Figure 2 17 The bottom ash production and use statistic in the last 15 years (adopted from American Coal Ash Association )

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35 Figu re 2 18 All the Coal Combustion Products produced and used in 25 years (adopted from American Coal Ash Association ) 2 .5 Wood Ash Wood ash is the residue generated due to the combustion of wood and its products like chips, saw dust bark etc. Wood ash is a byproduct generated from the combustion in boilers at pulp mills, steam power plants and other thermal power generating facilities. The major problem of u sing timber waste product as a fuel is the generation of ash. Hardwood is observed to produce more ash than softwood while the bark and inner leaves produce more ash as compared to the inner part. Characteristics of the collected wood ash depend on the typ e of wood, the combustion process and the location of ash collection. Wood ash may be a cause of health hazard if it gets air borne with the wind. These health hazards include respiratory problems and irritation to people dwelling near the site. ( Sebastian A. et al. 2016 ). Therefore, care needs to be taken to avoid such problems. Wood ash is an important agricultural waste. As it is a renewable source for energy and an environmentally friendly material, it can be used for energy

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36 production. Therefore, there is large amount of wood waste ash generated and available to be used for different purposes. Almost 70% of the wood was te is deposited in the environment in different forms ( Aprianti E. et al. 2015 ). Biomass which consists of forestry and a gricultural wastes is a considerable source of renewable energy. Landfilling is the most prevalent method accounting for 70% of the ash generated from wood combustion, 20% wood ash is used as soil supplement while the rest is used on miscellaneous jobs. Th e characteristics of this wood ash depend on herbaceous material, wood or bark ( Chowdhury S. et al. 2015 ). The physical and chemical properties of wood ash depend on the species of wood, the combustion temperature, efficiency of the boiler and supplementary fuels used. Ash content yield decreases with increase in temperature of combustion. Etiegni (1990) obtained X ray diffraction data to determine the different oxides like lime, calcite, portlandite and calcium silicate presen t in wood ash. Wood ash contains fine particulate matter which can become airborne after combustion, causing respiratory disorders. It is therefore, important to treat the wood ash properly. The use of wood ash in concrete can reduce the disposal problems and reduce the cost of concrete. High carbon content has limited the use of wood in low and medium strength concrete materials. Etiegni (1990) also studied the effect of combustion temperature on yield and chemical properties. Naik et al (2003) studied the chemical composition of different types of wood ash and found that some of them did not meet ASTM C 618 criteria. Chowdhury et al (2015) studied the compressive, flexural and tensile strengths of concrete with d ifferent percentages (5%, 10%, 15%, 18% and 20%) of blended Wood Ash cement. They observed that these strengths decreased marginally with increase in wood ash contents but recovered at later ages.

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37 Subramaniam P et al. (2015) studied the use of wood ash as a partial replacement to cement for manufacturing concrete blocks. They observed that the compressive strengths of blo cks with 20% wood ash replacement was comparable with the control specimen. The optimum wood ash replacement percent that gave the best results was found to be 15%. ( Sashidhar C. and Rao H. 2010 ) also studied the effects of replacement of cement with wood ash. They observed that H 2 SO 4 attack on wood ash is severe as it resulted in a decrease in strength of concrete. 10% woo d ash replacement had the minimum acid attack. The water absorption capacity was found to decrease with increase in wood ash content from 0 to 30%.

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38 2.6 Literature Review Summary Literature review covered the issue s of global warming emission s associated with increasing population. It also covered the increasing demand of cement consumption and the carbon dioxide emissions associated with it. Literature included the different types of supplementary cementi tious materials used in concrete like fly ash, corn ash and wood ash From the literature, it was observed that there is extensive research on the use of corn ash and wood ash in countries like Nigeria and India. The liter ature has covered the study of compressive and tensile strength s workability, slump, bulk density an d specific gravity of concrete having corn and wood ash. Further tests to check the Aluminum, Silica, Magnesium, Iron, Sulphur and Potassium percentages in corn and wood ash have also been demonstrated

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39 CHAPTER 3 METHODOLOGY 3.1 Physical and Chemical P roperty Comparison The physical and chemical properties of wood ash and corn ash were obtained from the literature. Research included studying articles that focused on using wood ash and corn ash in concrete. 3.1.1 Properties of wood and corn ash Physical properties including pH, moisture content, bulk density and specific gravity are individual properties of wood ash, corn ash and fly ash. Individual fly ash properties were obtained from the U.S. Department of Transp ortation report on coal fl y ash. C hemical properties including silicon, aluminum, iron, calcium, potassium and sodium oxide percentages ar e individual properties of wood ash, corn ash and fly ash 3.1.2 Properties of concrete made with wood and corn ash P hysical properties includi ng compressive strength, initial setting time final setting time soundness and slump were considered for c oncrete containing wood ash, corn ash and fly ash For example: c ompressive strength of wood ash was considered for concrete containing 15% wood ash. Properties including compressive strength, initial setting time, final setting time, soundness and slump for concrete containing fly as h were obtained from the PCA manual C hapter 3. 3.2 Ideal Replacement Percentage of W ood and Corn Ash The ideal replacement percentage s of wood ash and corn ash to achieve 3000 psi concr ete was obtained from the literature The reason for choosing 3000 psi concrete was that the scope of the study involved wood a sh and corn ash availability to use in low strength concrete. Studies were reviewed that tested the compressive

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40 strength of wood ash concrete and corn ash concrete. The tests involved concrete samples with incremental percentages of wood ash or corn ash. The results of the compressiv e strength tests o f corn ash and wood ash used in concrete can be seen in figure s 4 1 and 4 2 respectively 3.3 Cement Consumption for Low Strength C oncrete T he scope of the study involved the calculation of the ash requirement for lo w strength concrete in Florida (less than 3500 psi). To calculate the ash requirement, it was necessary to find the annual cement consumption in Florida. T his was obtained from the Portland Cement Association ( ). This association represents 92% of cement manufacturing in the U nited States The average cement cons umption from 2003 2016 was calculated to obta in more accurate results. The cement consu mption was further narrowed to that used in ready mix concrete production. This wa s obtained from the 2016 data on cement used by a user group ( Statista ) As the scope of study involved low strength concrete, it was necessary to find the annual cement consumption for low strength concrete in Florida. Per a report from the National Ready Mix Concrete Association (NRMCA), it was ob served that 64% of the total concrete production in the south east United States consisted of concrete below 3500 psi strength. Therefore, the an nual cement consumption for low strength concrete was calculated as 64% of the total cement consumption used fo r ready mix concrete in Florida. 3.4 Wood Ash Requirement and Availability The wood ash requirement was calculated by using the wood ash replacement percentage and the annual cement consumption determine d in 3.1 and 3.2 respectively. By k nowing the wood a sh replacement percentage and the annual cement

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41 consumption, it was possible to determine the annual wood ash quantity that woul d be required for low strength concrete in Florida. The calculation of wood ash availability was based on the annual generation of solid wood waste in Florida. These data were obtained from the Florida Department of Environmental Protection which had the annual solid waste statistics. Solid waste consists of wood wa ste, yard trimmings etc It was observed that wood waste and yard trimmings consist of 20% of the total solid waste collected annually ( MSW ). Therefore, the total quantity of wood waste that can potentially be used in biomass pla nts was determined It ha s been reported that 1 t of municipal solid waste generates 481 kWh of electricity ( EIA ). However, the biomass materials burned in the biomass plants accounted for 64% of the weight of the MSW and contributed approximately 51% of the energy. Therefore, the amount o f electricity generated by 1 t of biomass was determined Different biomass plants were studied to find the qua ntity of wood ash gene rated as a function of the power generation capacity of the biomass plant However, none of the biomass plants could provide wood ash generation statistics. Therefore, a conservative estimate of 4% ash gen eration from the bioma ss plan t was assumed to determine the potential quantity of wood ash that would be generated from the biomass plants 3.5 Corn Ash Requirement and Availability A s for wood ash, the annual corn ash requirement for low strength concrete was calculated by using the corn ash replacement percentage and the annual cement consumption determined in 3.1 and 3.2. To calculate the annual corn ash availability, the corn generation statistics of Florida were studied. The annual production of corn in Florida was determined from the

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42 United States Department of Agriculture. The amount of ash generation depends on the quantity of corn stover left after harvest This corn stover consists of bales, stalks, leaves and cob. The amount of corn stover generated per acre was obtained from a feasibility study conducted in the Midwest ( Corn Report ) After determining the quantity of corn stover generated in Florida, it was necessary to determine the ash that can be generated from the corn stover. The ash generation for corn cob, husk, leaves and stalk was studied ( Lizotte P et al. 2015 ). The ave rage ash generation percentages of corn cob, husk, leaves and stalk was taken to calculate t he poten tial corn ash generated from corn stover in Florida. 3.6 Environmental Impacts The environmen tal impacts of wood ash include only t he ene rgy required for transporting ash to the concrete gate. As wood ash is a byproduct of biomass plant s there is no processing energy or non energy emissions associated. Corn stover is currently not used as a raw material in biomass plant. However, the potentia l of using it in biomass plants is significant. To calculate the environmental impacts, it wa s assumed that corn stover is used as a raw material in biomass plant s Therefore, its env ironmental impacts include transportation energy emissions such as wood ash. The environmental impacts of fly ash consist of the transportation energy emissions. The d istance of all waste materials was calculated from their respective power plants. To obtain accurate results, it was decided to calculate the environmental impacts in two locations. Orlando was chosen as one because of its central location in Florida. Miami was selected as the second location because of the increasing construction activity under way in south Florida ( Biz ) Sources of all materials near Orlando and Miami were searched. The source of fly ash was taken as the C.D McIntosh Power Plant in

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43 Lakeland, FL. The wood ash source wa s the Gainesville Renewable Energy Center biomass plant in Gainesville, FL. The corn ash source selected was the I.H.I. Power Service, in Brooksville, FL. Similarly, the sources of corn ash, wood ash and f ly ash near Miami were determined Environmental im pacts of wood and corn ash were compared with those of fly ash. The transportation energy unit to measure the environmental impacts was chosen as metric tons of carbon equivalent per ton of material. 3.7 Cost The cost of all materials was ob tained from ind ustry sources The cost of fly ash was taken from the Florida Department of Transportation website. The cost of corn stover was found to vary depending on the supply and demand characteristics. Due to limitations in availability of sources in Florida, the cost of corn stove r was taken from sources in the Midwest region This cost was found to be in the range of $40 80/ton depending on the location and availability ( Purdue ) The high range of price was because of the reimbursement cost applied by the corn producer s for the nutrients removed with the stover. To obtain a better cost estimate of corn stover a 10% markup was applied due to its limited availability in Florida The cost of wood ash per ton was obtained from an article in Wisconsin.

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44 C HAPTER 4 RESULTS AND DISCUSSION 4.1 Corn Ash Analysi s 4.1.1 Physical Properties of Corn Ash Physical properties including specific gravity, pH, moisture content and bulk density are individual properties of corn ash. These were compared with individual properties of fly ash. The moisture content of corn a sh was found to vary depending on the type of combustion process as well as the percentage of corn cob, leaves and stalks burnt in the biomass plants. The specific gravity and bulk density of corn ash was in the same range as that of fly ash which suggested that the mass to vol ume ratio of corn ash and fly ash was same. 4 .1.2 P hysical Properties of Concrete M ade with Corn Ash This s ection analyzes the physi cal properties of concrete made with corn ash found in the literature with t hose of Portland cement conc rete havin g fly ash These properties include d soundness, initial setting time, final setting time, slump and compressive strength It was observed in figure 4 1 that the initial and final setting time of concrete made with corn ash, i ncreased from 30 to 208 min and 200 to 328 min respectively This wa s because of the reduction in surface area of cement due to increase in corn ash percentages that slowed the hydration process. The s low hydration process reduce d the thermal stresses due to the low rate of heat development. Per figure 4 1 the 28 day compressive strength of concrete with corn ash was ob served to decrease with increa s ing corn ash percentages. The 28 day st rength of co ncrete (2900 psi) with 10% co rn ash replacement, just managed to meet the minimum requirement. The strength increase wa s slow because of the lower percentage of highly reactive

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45 silica reducing the rate of hydration. T he slump of corn ash concrete was like that of normal concrete suggesting that the corn ash does not affect the workability of concrete. 4.1.3 Chemical Propert ies of Corn Ash C hemical property comparison consisted of the ind ividual properties of corn ash and f ly ash. ASTM C 618 requires f ly ash to have more than 70% silica, alumina and calcium content to be a good pozzolan. The American Concrete Institute code (ACI), 318 08 chapter 4 defined the maximum percentage of fly ash to be used in concrete depending on the type of construction. As there wa s no separate specification for corn ash, it wa s compared with ASTM C 618 requirements which specify the use of fly ash in concrete. It was observed in figure 4 2 that the combined percentage of s ilica (SiO 2 ), a lumina (Al 2 O 3 ) and c alcium oxide (CaO) was more than 7 0% which wa s an indication of good pozzolan These compounds wer e responsible for the formation of calcium aluminum hydrates when reacting in the presence of calcium hydroxide and water Thus, as the p ercentage of corn ash increased more silica and alumina content became available for reacting with calcium hydroxide. The Loss of ignition (LOI) value requirement for OPC wa s a maxi mum of 6 under ASTM C 618. It was observed that the LOI value for corn ash wa s high indicating a higher mass change. 4.2 Wood Ash Analysis The literature showed that chemical and physical properties of wood ash depend on the type of wood used and the type of combustion process. Wood waste genera lly consists of sawdust, chips and bark which have different combustion properti es. Wood ash is a byproduct of the biomass plants that use wood waste to generate electricity. Just like coal fly ash, wood ash is also differentiated as wood fly ash and bottom ash.

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46 4.2.1 Physical Properties of Wood Ash Physical properties including specific gravity, pH, moistu re content and bulk density are individual properties of wood ash. These were compared with the individual properties of fly a sh The pH was found to vary between 9 and 13.5 indicating varying levels of alkalinity. The range of specific gravity values (0.16 1.4) was due to the varying percentages of chips, sawdust and bark in the wood waste. The moisture content of wood ash was very low compared to fly ash To produce high quality cement based products incorporating wood ash, not only must the moisture content be kept low but the variability in moisture content must be minim ized. Low moisture content in wood ash wo uld also reduce the transportation cost to the concrete gate. 4.2.2 Physical Properties of Concrete M ade with Wood Ash Just like corn ash, this section analyze s the physical properties of concrete made with wood ash found in the literature with those of Portland cement concrete havin g fly ash These propertie s include d soundness, initial setting time, final setting time, slump and compressive strength The initial and final setting time values of concrete made with wood ash were higher than those of concrete co ntaining fly ash The slump value of concrete containing wood ash was observed to be very low indicating less workable concrete. This indicated that more wate r would be required to increase the workability. 4.2.3 Chemical Properties of Wood Ash Just like corn ash, the chemical property comparison invo lved the comparison of ind ividual properties of wood ash and fly ash The minimum 70% requirement of silicon dioxide, aluminum o xide and iron oxide fell short the combined percentage equaled 63%. Wood ash was observed to swell because of hydration of sili cates an d the lime present in the ash. The los s on ignition was found to be 3 1.6% which is significantly

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47 high than the maximum of 6% required for pozzolan per ASTM C618 specification This was because of the substantial am ount of unburnt carbon present in wood ash. The alkali content (Na 2 O) was found to be higher (6.5%) than the maximum required (1.5%). Figure 4 1. Comparison of physical propert ies of wood ash, corn ash and fly ash. Figure 4 2 Comparison of physical properties of concrete made with woo d ash, corn ash and fly ash. Figure 4 3 Comparison of chemical properties of wood ash, co rn ash and fly ash

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48 Figure 4 3 provides the compressive strength test results for different percentage replacements of cemen t with wood ash. The 28 day strength for 15% replacement is 3150 psi indicating that for 3000 psi concrete, a maximum of 15% cement can be replaced with wood ash. It was observed that there was a significant gain in strength at a later age due to the slow pozzolan activity of wood ash. Figure 4 4 7, 14 and 28 day compressive strengths of 3000psi concrete with different percentage of wood ash (adopted from Udoeyo F et al. 2006). Figure 4 4 provides the different compressive strength test resul ts for different percentage replacements of cement with corn ash in concrete. The 28 day strength for 10% replacement is 2900 psi indicating that for 3000 psi concrete, a maximum of 10% cement can be replaced with corn ash. Figure 4 5 7, 21 and 28 day compressive strengths of 3000 psi concrete with different percentage of corn ash. (adopted from Oladipupo O. and Festus O. 2012 ).

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49 According to the literature concrete with 3000 psi strength, had a maximum of 15% wood ash replacement levels. Increasing the wood ash percentage beyo nd 15% was observed to reduce the strength of concrete mixes. Therefore, the replacement percent age of cement with wood ash that could achieve 3000 psi strength concrete was chosen to be 15%. Similarly, for corn ash, according to the literature concrete with 3000 psi strength, had a maximum replacement level of 10% I ncreasing the corn ash percentag e beyond 10% was observed to achieve less than 3000 psi strength. T he refore, replacement percentage of cement with corn ash that could achieve 3000 psi strength concrete was chosen to be 10%. Th e fly ash replacement level of 2 0% w as chosen from the FDOT fo r low strength concrete mixes. 4.3 Cement Consumption Analysis The annual cement consumption of 6 million tons in Fl orida was obtained from the PCA for 2016 ( PCA ). To obtain accurate results, the average cement consumption from 2003 2016 was calculated Figure 4 6 shows the average cement consumption from 2003 2016. This included the average of 14 years which was equal to 4.8 million tons. Cement consumption for ready mi x concrete composed 70% of the total cement consumption in the United States. Therefore, the an nu al cement consumption for ready mi x concrete was calculated as 3.36 million t The scope of this study was restricted to cement consumption for concrete with less than 3500 psi strength. Per NRMCA data, 64% of the total concrete consumption in the south east region of United States had less than 3500 psi strength. Theref ore, the annual cement consumption for low strength c oncrete was calculated to be 2.15 million t

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50 Figure 4 6. Average Cement Consumption from 2003 2016 4.4 Wood Ash Demand and Supply Analysis T he woo d ash percentage obtained from 3.1 was used to calculate the wood ash requirement for use in low strength concrete. Thus, the annual wood ash d emand in Florida was determined as 322,500 t by replacing 15% of the annual cement consumption de termined in 4.3. Per the Florida Department of Environmental Protection, nearly 14.8 million tons of solid waste is landfilled annually ( Solid Waste in Florida ). From the literature, it wa s observed that 20% of the total solid waste is composed of wood and yard trimmings ( MSW ). Therefore, Florida has approximat ely 3 million t of wood waste t hat is landfilled annually. Per the EIA, 1 t of MSW generates 481kWh of electricity. However, the biomass materials in the MSW that burn in the power plants account for 64% of the weight of MSW and contribute to 51% of the en ergy. Therefore, 1 t of biomass generates 383 kWh of electricity. Therefore, 3 million t of wood waste has a potential of

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51 generating 1,149 GWh e lectricity. The annual electricity consumption in Florida is 17,300 GWh ( U.S EIA ). Thus there is a 7% potential of total electricity generation using biomass plants. Assuming a conservative 4% ash generation from the biomass plant, the potential quantity of wood ash a vaila ble in Florida is 120,000 t From T able 4 2 37% of the annual wood ash requirement can be covered by the potential wood ash generated in Florida. 4.5 Corn Ash Demand and Supply Analysis Just like wood ash, the corn ash replacement percentage obtained from 3.1 was used to determine the annual corn ash requirement. Thus, the annual corn ash demand in Florid a was determined as 215,000 t by replacing 10% of the annual cement consumption obtained in 4.3. To calculate the annual corn ash availability, the corn generation statistics in Florida were studied. Per United States Department of Agriculture, Florida has 40,000 acres of corn produc tion. With 145b u/acre, th ere is a total 5,800,000 bu. of annual corn production in Fl orida ( USDA ). The amount of ash generation depends on the quantity of corn stover remaining after harvest. This corn stover consists of ba les, stalks, leaves and cob. One hundred forty five bushels of corn produce 3.3 dry tons of corn stover per acre ( Corn Report ). Therefore, the total quantity of corn stover generated annu ally in Florida was 1 32,000 t The ash generation for corn cob, husk, leaves and stalk was studied and the average was taken as 5% ( Lizotte P et al. 2015 ). Thus, the potential corn ash gene ration in Florida was 6,600 t which is 3% of the annual requ irement The potential wood ash supply is 37% of the annual requirement. Wood ash can be considered for use as a partia l replacement of fly ash in low strength concrete. However, with the increase in solid waste generation per year, more wood waste is

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52 being landfilled. If such waste is used in biomass plants to generate renewable energy, more wood ash will be generated. It will also help reduce the electricity generated from coal c ombustion, which will help reduce carbon emissions. R enewable electricity generation through biomass has evolved over the years. Electricity generation in biomass plant s involves diffe rent combustion technologies including fixed bed, fluidized bed and pulverized bed ( J ames A et al. 2012 ). Fluidized bed technology is considered the best to burn low quality fuel, obtain high ash content and generate low calorific value ( Saidur R. et al. 2011 ). Therefore, the use of biomass plants is also increasi ng with better techniques for electricity generation. Using wood ash in concrete, will also help reduce the disposal problems of ash generated from these biomass plants. Florida has 18 biomass plants among the most in the United States ( Biomass ). Four of these plants use wood biomass as the main raw material. Therefore, the scope of generating wood ash is increasing every year. The f ollowing is a list of the biomass plants running on wood waste in Florida: 1. Brooksville IHI Power Services: 70MW 2. Gainesville Renewable Energy Center: 102.5MW 3. Multitrade Telogia: 14MW 4. Telogia Power: 14MW Corn ash availability is very low in Flo rida with only 5,800,000 bu. harvested annually. The potential corn ash supply is 3% of the annual requirement making it unfavorable for use. Currently, the primary use of corn stover is as a biofuel in ethanol production. It is also used as a feedstock and as bedding for cattle. According to the Department of Energy, corn stover is expected to be the dominant source for renewable energy generation compared to all other sources of biomass ( Corn Harvest ). With increas ing levels of corn production, the quantity of corn stover generated will increase

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53 in future years. Therefore, the potential of using corn stover in biomass is significant which will increase the qua ntity of ash generated. Most of this corn production is h owever from the Midwest region. Therefore there would be the additional cost of transporting the ash to Florida. Table 4 1. Replacement percentages of wood ash, corn ash and fly ash. No Waste Material Percentage Replacement 1 Wood Ash 15% 2 Corn Ash 10% 3 Fly Ash 20% Table 4 2 C alculations of wood ash requirement and availability. 1 Total Cement production in Florida 4.8 million t 2 Cement consumption for ready mix concrete production (70%) 3.36 million t 3 Cement consumption for low strength concrete (64%) 2.15 million t 4 Wood a sh required (15% replacement) 322,500 t 5 Wood waste l andfilled in Florida 3 million t 6 Ash availability (4% ash generation) 120,000 t

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54 Table 4 3 C alculation of corn ash requirement and availability. 1 Total c ement production in Florida 4.8 million t 2 Cement consumption for ready mix concrete production (70%) 3.36 million t 3 Cement consumption for low strength concrete (64%) 2.15 million t 3 Corn ash r equirement (10%) 215,000 t 4 Corn p roduction 5,800,000 bu. 5 Corn s tover 132,000 t 5 Corn a sh availability (5% ash generation) 6,600 t 4.6 Environmental Impacts The e nviro nmental impacts of all materials we re calculated by comparing t he difference in greenhouse gas emissions as sociated with transporting 1 t of fly ash, wo od ash and corn ash to the concrete plant gate As all materials under considera tion are byproducts the processing energy associate d with acquiring the materials wa s taken as zero. Therefore, the greenhouse gas emissions con sist of only the transportation ene rgy emissions. These emissions we re from the combustion of fossil fuels required to transport the material to the concrete gate. Transportation energy wa s measured in metric tons of carbon equivalent per ton of material t ransported Therefore, t he sources of cement, fly ash, blast furna c e slag, wood ash and corn ash nearest to Orlan do were selected The s ource of wood ash wa s the biomass plant in Gainesville FL. The source of fly ash wa s the coal combustion plant in Lakeland, FL. Currently, corn ash is not pro duced in the United States. It was assumed that the corn waste wa s used in biomass plants to generate corn ash as a byproduct Therefore, the source of corn ash was

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55 taken as the IHI Power Services Corpor ation biomass plant in Brooksville, FL. Figure 4 7 lists all the suppliers and their distance to Orlando. Similarly, Figure 4 8 lists the sources of corn ash, fly ash and wo od ash near Miami. Google Maps was used for calculating the distance. The fuel used for transport was taken as diesel. The transportation combustion energy factor for each material in Figure 4 9 wa s the product of the combustion fa ctor of diesel and the distance travelled. The combustion energy coefficient for diesel was obtained from the US EPA document of l ife cycle greenhouse emissions ( EPA ) Figures 4 9 through 4 12 discuss the transportation energy per ton f or fly ash, wood ash and corn ash in both Orlando and Miami Figure 4 7 List of all material suppliers near Orlando Figure 4 8 List of all material suppliers near Miami

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56 Figure 4 9 C ombustion energy coefficients in mBtu/ t Transport energy emissions we re calculated based on t he energy spent in the combustion of fossil fuels to transport the fly ash to the concrete gate. The fuel specific carbon coefficient and CH 4 emissions we re taken from the EPA document. Based on the combustion coeffi cient of diesel and distance travel ed the transport energy emissions of CO 2 and CH 4 were calculated to obtain the total transportation greenhouse gas emissions. Figure 4 10 Transportation e nergy emissions for 1 t of fly a sh Wood ash is a byproduct of electricity generation in biomass plants. Just like fly ash, fuel specific carbon and CH 4 e mission coefficients are obtained from the EPA document. These coefficients are multiplied by the trans portation energy combu stion coefficients in F igure 4 8 to obtain CO 2 and CH 4 emissions for wood ash.

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57 Figure 4 1 1 Trans portation energy e missions for 1 t of wood a sh Currently, corn stover is not used as a raw material for electricity generation in biomass plants. Its primary use is in ethanol production as a biofuel. However, the hypothesis wa s that the corn stover can be used as a raw material in biomass plants for e lectricity generation. The corn ash generated can be used in concrete. The c hemical composition of corn stover involves nitrogen, calcium and potassium oxide in major proportions. The transportation energy c alculation for corn ash involved similar calculat ions to those of wood ash Biomass plants near Orlando and Miami were searched for the source of corn ash. The distance of these biomass plants to Orlando and Miami was used to calculate the transportation energy emissions Therefore, the transportation en ergy emission of corn ash wa s calculated like wood ash. Figure 4 1 2 Transportation energy emissions for 1 t of corn a sh After calculating the transportation energy emissions of fly ash, wood ash an d corn ash, it was observed in F igures 4 10 through 4 12 that the transportation energy emissions due to CH 4 are negligible as compared to CO 2 emissions. Therefore

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58 neglecting CH 4 emissions, the total greenhouse gas emissions consist of CO 2 emissions. Transportation emissions for corn ash were lower than w ood ash in Orlando but higher in Miami Fly ash had the lowest greenhouse gas emissions in Orlando but the highest emissions in Miami T his wa s because of the proximity of the fly ash source to Or lando. With the current availability of wood and corn ash, t he t r ansportation energy values were higher than fly ash in Orlando In contrast due to the proximity of biomass plants near Miami, the transportation energy values of wood ash and corn ash were l ower than those of fly ash However, if the recent trend in the reduction in fly ash generation continues, the sources of fly ash may become limited. In that scenario, wood and corn ash can be considered as possible replacement options. With upcoming b iomass plants in Florida, it would be possible to reduce the tr ansportation distances and the ene rgy emissions associated with them Table 4 4 Transportation Energy Emissions in MTCE/ t Material Transportation e ner gy emissions travelling to Orlando (MTCE/t ) Tra nsportation e nergy emissions t ravelling to Miami (MTCE/t ) Fly Ash 0.0016 0.0032 Corn Ash 0.0024 0.0024 Wood Ash 0.0034 0.0012 4.7 Cost T he availability and cost play an important role when evaluating the feasibility of using any material s The cement industry is aff ected by regulatory norms because of strict environmental issues. The average price of cement in the United States is $13 0/t

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59 ( Statista ). The reason for the high cement price is the processing energy and raw mat erials spent in manufacturing cement. Cement prices also depend on the current economic situation. Fly ash prices have been steady over the years. However, recent closure of coal plants, has resulted in a decrease in fly ash production. T he cost of fly ash wa s $35/t ( FDOT ) The American Road & Transportation Builders Association report predicted the utilization of fly ash to grow by 2.2% per year. However, the production of fly ash, is projected to grow at only 0.1% per year The fly ash utilization rate was 45% in the United States in 2013 which is predicted to increase to 63% by 2033 ( ACAA ). This difference in production and demand may create availability problems in the future. A reduction in avai lability may lead to increased fly ash prices. Wood ash is generated in biomass plants when wood waste is burned to produce renewable energy The c ost of wood ash wa s taken as $24 38 /t ( Kopecky M et al. 2013 ) Currently corn ash is not used as a raw material in biomass plant s T herefore, the cost of corn ash wa s not available. The c ost of co rn stover in Florida was not available because of limited availability Therefore, the cost of corn stover f rom the Midwest was take n for reference. To get a better estimate of price in Florida, a 10% increase was considered to offset the increase in price due to reduction in availability. Therefore, the co st of corn stover was $45 75/t

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60 Table 4 5. All materials and their costs Mat erial Cost per Ton Cement $13 0 Fly Ash $35 Wood Ash $24 38 Corn Stover $45 75 T he current market cost of wood ash is comparable to fly ash. Therefore, it can be used without affecting the current cost of concrete. The cost of corn stover is found to vary depending on location and market condition. Due to limited availability, this cost is bound to be on the higher side. Using corn stover to replace fly ash will increase the cost per ton of concrete In the absence o f fly ash for cement with blast furnace slag the cost per ton of concrete becomes the highest. In that situation, using corn stover, will help r educe the cost of concrete. In addition using wood ash and corn ash in concrete will reduce the cost of dumpi ng the ash in landfill s The a verage cost of waste disposal prices of $ 30 /t charged by landfill sites or yard trash will help save $ 3.6 mil lion because of the 120,000 t of wood ash generated annually in Fl orida. ( DEP ).

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61 CHA PTER 5 CONCLUSION AND FUTURE SCOPE 5.1 Conclusion The f ollowing were the key findings of the thesis: 1. The physical properties of wood ash and corn ash included the ir individual properties as well as the properties of concrete made with wood ash and corn ash Individual properties including mois ture content, specific gravity and bulk density were compared with those of fly ash. The chemical properti es of wood ash and corn ash including silica, aluminum, calcium and magnesium were compared with those of fly ash. It was observed from the literature that t he silica aluminum and calcium contents of wood and corn ash satisfy the ASTM C 618 requirement s for a pozzolan. 2. Th e physical properties of concrete containing wood ash or corn ash were compared with concrete containing fly ash. These properties included the i nitial and final setting times, slump and compressive strength. The initial and final setting times of concrete with wood or corn ash are higher than those made with concrete having fly ash because of slow reactive a lkalis. This also resulted in slow gain in the compressive and tensile strength of concrete Based on the properti es studied, it wa s observed that wood ash and corn ash can be used for low strength concrete applications up to 3500psi in strength. The problem of low ear ly age strength of concrete containing wood or corn ash can be solved using admixtures. 3. The l iterature was reviewed to determine the maxim um replacement percentage of wood ash and corn ash in low strength concrete. It was found that a maximum 15% wood ash replacement percentage could satisfy the compressive strength requirements of concrete (3000 psi). Similarly, it was found that a maximum 10% corn ash replacement percentage could satisfy the compressive strength require ments of concrete (3000 psi). 4. The average annual cement consumption in Florida was found out to be 4.8 million t From this, t he cement consumption for ready mix concrete pro duction was determined to be 3.36 million t As the scope of study was limited to concrete less than 3500 psi, the cement required for low strength concrete was determined to be 2.15 million t 5. The 10% corn ash replacement obtained in conclusion 3 was used to determine the annu al corn ash requirement for low strength concrete in Florida. Therefore, replacing 10% of the annual cement consumption obtained in conclusion 4 a 215,000 t corn ash requirement was determined. 6. The annual corn harvest in Flori da was found out to be 40,000 acres. With 145 bu. / acre Florida has 5.8 m illion bu. of corn. For 145 bu. 3.3 dry tons per acre of

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62 dry stover is produced. Therefore, 5.8 million bu. of corn production could produce 132,000 t of corn waste. Assuming 5% ash genera tion, t his waste had the potential of generating 6,6 00 t of corn ash annually in Florida. This could satisfy only 3% of the total corn ash required to replace fly ash 7. The 15% wood ash replacement obtained in conclusion 3 was used to determine the annu al wood ash requirement for low strength concrete in Florida. Thus, the annual wood ash requirement was found out to be 322,5 00 tons. T he annual wood waste generation in Florida was determined to be 3 million t Assuming 4% ash generation, the potential wood ash generated annually in Florida was determin ed to be 120,000 t This could satisfy 37 % of the total wood ash required to replace fly ash. 8. The enviro nmental impacts comprised of only the transportation energy emissions of wood ash and corn ash because bot h are byproducts of biomass plants. The emis sions were measured as greenhouse gas emissions of CO 2 and CH 4 The tra nsportation energy emissions of wood ash and corn ash were found to be 0 .0034MTCE/t and 0.0024MTCE/t in Orlando respectively. These were higher than the transportation energy emission of fly ash in Orlando ( 0.0016MTCE/t ) Similarly, the wood ash, corn ash and fly ash emissions in Miami were found to be 0.0012MTCE/t, 0.0024MTCE/t and 0.0032MTCE/t respectively. 9. Similar study and analysis showed that t he cost per ton of wood ash and corn ash was $24 38/t and $45 75/t respectively. The cos t per ton of fly ash was $35/t 10. The wood ash generated from 3 million t in annual wood waste is 120,000 t The average disposal fee charged by land fill sites in Florida is $30/t Therefore, using this wood ash in concrete can reduce the annual landfilling cost by $3.6 million Based on the properties of wood ash and corn ash studied, they can be a suitable replacement to f ly ash in low strength concrete applications The potential availability of wood ash being 3 7 %, it can be used as a partial replacement to fly ash in concrete. However, the potential availability of corn ash is very low (3%). Therefore, it will be necessary to look at additional sources of corn ash, possibly from the Midwest region. However, the cost of transporting this corn ash to Florida would be high and is beyond the scope of the study. The transportation energy emissions of wood ash and corn ash are high becau se of the higher distance of transportation to Orlando. This is because of their low availability compared to fly ash. On the other hand, due to the

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63 proximity of sources near Miami, the transportation emissions of wood ash and corn ash are low compared to fly ash in Miami. The difference in cost per ton of wood ash and f ly ash is only $4/t Therefore, wood ash can be considered as a partial replacement to fly ash. The difference in cost per ton of corn ash and fly ash is $2 5/t which would result in a consi d erable increase in cost of concrete. 5.2 Research Limitations The data used for comparing the physical and chemical properties of concrete containing wood ash and corn ash were not based in Florida. Many papers studied were from outside the United States. T he properties of wood ash and corn ash are dependent on the typ e of wood waste and corn waste. The study did not include the sources of wood ash and corn ash outside Florida because the cost and energy required to transport the materials wou ld be considerable. The cost data used for determining the cost per ton of wood as h was taken from Wisconsin, whereas that of corn ash was taken from Missouri. 5.3 Future Scope The transportation energy emissions are based on the transportation distances o f wood and corn ash from biomass plants. Therefore, using the Geographic Information Syst em to identify the best locations for installing biomass plants not only for the generation of electricity but also for using the byproducts for cement replacement in concrete would help reduce energy emissions. More experimental work such as studying the compressive and tensile strengths of wood ash and corn ash in concrete will help to explain properties of wood ash and corn ash obtained from sources in Florida.

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64 LIST OF REFERENCES Abdullahi, M. (2006). Characteristics of wood ash/OPC concrete. Leonardo Electronic Journal of Practices and Technologies, 8 9 16. Adesanya, D., & Raheem, A. (2009). Development of corn cob ash blended cement. Construction and Building Ma terials, 23 (1), 347 352. Adesanya, D., & Raheem, A. (2009). A study of the workability and compressive strength characteristics of corn cob ash blended cement concrete. Construction and Building Materials, 23 (1), 311 317. American coal ash association. R etrieved 03/18, 2017, from https://www.acaa usa.org/Portals/9/Files/PDFs/News Release Coal Ash Production and Use 2015.pdf Aprianti E., Shafigh, P., Bahri, S., & Farahani, J. N. (2015). Supplementary cementitious materials origin from agricultural wastes A review. Construction and Building Materials, 74 176 187. doi: http://dx.doi.org/10.1016/j.conbuildmat.2014.10.010 Capehart, T. https://www.ers.usda.gov/topics/crops/corn/background/ Celik, K., Meral, C., Petek Gursel, A., Mehta, P. K., Horvath, A., & Monteiro, P. J. M. (2015). Mechanical properties, durability, and life cycle assessment of self consolidating concrete mixtures made with blended portland cements containing fly ash and limestone powder. Cement and Concrete Composites, 56 59 72. doi: http://dx.doi.org/10.1016/j.cemconcomp.2014.11.003 Cheah, C. B., & Ramli, M. (2011). The implementation of wood waste ash as a partial cement replac ement material in the production of structural grade concrete and mortar: An overview. Resources, Conservation and Recycling, 55 (7), 669 685. doi: http ://dx.doi.org/10.1016/j.resconrec.2011.02.002 Chowdhury, S., Maniar, A., & Suganya, O. (2015). Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters. Journal of Advanced Research, 6 (6 ), 907 913. Chowdhury, S., Mishra, M., & Suganya, O. (2015). The incorporation of wood waste ash as a partial cement replacement material for making structural grade concrete: An overview. Ain Shams Engineering Journal, 6 (2), 429 437. doi: http://dx.doi.org/10.1016/j.asej.2014.11.005 Concrete solutions for sustainable development. Retrieved 03/27/2017 http://www.concretepromotion.org/downloads/concrete sustainability brochure.pdf

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65 Crossin, E. (2015). The greenhouse gas implications of using ground granulated blast furnace slag as a cement substitute. Journal of Cleaner Production, 95 101 108. doi: http://dx.doi.org/10.1016/j.jclepro.2015.02.082 Demirbas, A. (2004). Combustion characteristics of different biomass fuels. Progress in Energy and Combustion Sci ence, 30 (2), 219 230. Etiegni, L. (1990). Wood Ash Recycling and Land Disposal, Federal highway administration research and technology. Retrieved 03/18, 2017, from https://www.fhwa.dot.gov/publications/research/infrastructure/structures/97148/bfs3 .cfm Gursel, A. P., Maryman, H., & Ostertag, C. (2016). A life cycle approach to oncrete mixes with rice husk ash. Journal of Cleaner Production, 112 823 836. Halstead, W. J. (1986). Use of fly ash in concrete. NCHRP Synthesis of Highway Practice, (127) Hasanbeigi, A., Price, L., & Lin, E. (2012). Emerging energy efficiency and CO 2 emission reduction technologies for cement and concrete production: A technical review. Renewable and Sustainable Energy Reviews, 16 (8), 6220 6238. Heidrich, C., Feuerborn, H., & Weir, A. (2013). Coal combustion products: A global perspective. 2013 world of coal ash (WOCA) conference. Lexington, KY, Helsel, Z. R., & Wedin, W. (1981). Direct combustion energy from crops and crop residues produced in iowa. Energy in Agriculture, 1 317 329. Iron and steel slag. Retrieved 05/29, 2017, from https://minerals.usgs.gov/minerals/pubs/commodity/iron_&_steel_slag/mcs 2012 fesla.pdf Junnila, S., & Horvath, A. (2003). Life cycle environmental effects o f an office building. Journal of Infrastructure Systems 9 (4), 157 166. Li, G., & Zhao, X. (2003). Properties of concrete incorporating fly ash and ground granulated blast furnace slag. Cement and Concrete Composites, 25 (3), 293 299. Lizotte, P., & Savoie P. (2011). Spring harvest of corn stover. Applied Engineering in Agriculture, 27 (5), 697. Madurwar, M. V., Ralegaonkar, R. V., & Mandavgane, S. A. (2013). Application of agro waste for sustainable construction materials: A review. Construction and Build ing Materials, 38 872 878. doi: http://dx.doi.org/10.1016/j.conbuildmat.2012.09.011

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66 Malhotra, V. M., & Ramezanianpour, A. (1994). Fly ash in concrete Canmet. Marceau, M., Nis bet, M., & VanGeem, M. (2006). Life cycle inventory of portland manufacture cement. Naik, T. R. (1999). Tests of wood ash as a potential source for construction materials. Report NoCBU 1999 09.Milwaukee: UWM Center for by Products Utilization, Department of Civil Engineering and Mechanics, University of Wisconsin Milwaukee, 61. Naik, T. R. (2002). Greener concrete using recycled materials. Concrete International, 24 (7), 45 49. Naik, T. R., Kraus, R. N., & Siddique, R. (2002). Demonstration of manufactu ring technology for concrete and CLSM utilizing wood ash from wisconsin. UWM Centre for by Product Utilization, Naik, T. R., Kraus, R. N., & Siddique, R. (2003). Use of wood ash in cement based materials. Center for by Products Utilization (CBU 2003 19, National slag association. Retrieved 03/18, 2017, from http://www.nationalslag.org/slag availability Nkayem, D. N., Mbey, J., Diffo, B. K., & Njopwouo, D. (2016). Preliminary study on the use of corn cob as pore forming agent in lightweight clay bricks: Physical and mechanical features. Journal of Building Engineering, 5 254 259. Olafusi, O. S., & Olutoge, F. A. (2012). Strength properties of corn cob ash concrete. Journal of Emerg ing Trends in Engineering and Applied Sciences, 3 (2), 297 301. Oner, A., Akyuz, S., & Yildiz, R. (2005). An experimental study on strength development of concrete containing fly ash and optimum usage of fly ash in concrete. Cement and Concrete Research, 3 5 (6), 1165 1171. granulated blast furnace slag on concrete properties a review. Construction and Building Materials, 105 423 434. Pal, S., Mukherjee, A., & Pathak, S. ( 2003). Investigation of hydraulic activity of ground granulated blast furnace slag in concrete. Cement and Concrete Research, 33 (9), 1481 1486. Penttala, V. (1997). Concrete and sustainable development.

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67 Petek Gursel, A., Masanet, E., Horvath, A., & Stade l, A. (2014). Life cycle inventory analysis of concrete production: A critical review. Cement and Concrete Composites, 51 38 48. doi: http://dx.doi.org/10.1016/j.cemconcomp.2014 .03.005 Pinto, J., Vieira, B., Pereira, H., Jacinto, C., Vilela, P., Paiva, A., et al. (2012). Corn cob lightweight concrete for non structural applications. Construction and Building Materials, 34 346 351. doi: http://dx.doi.org/10.1016/j.conbuildmat.2012.02.043 Raheem, A. A., Oyebisi, S. O., Akintayo, S. O., & Oyeniran M. I. Civil engineering department, ladoke akintola university of technology, ogbomoso, nigeria. Raheem, A. A., Oyebisi, S. O., Akintayo, S. O., & Oyeniran, M. I. (2010). Effects of admixtures on the properties of corn cob ash cement concrete. Leonardo Electronic Journal of Practices and Technologies, 16 13 20. Rajamma, R., Ball, R. J., Tarelho, L. A., Alle n, G. C., Labrincha, J. A., & Ferreira, V. M. (2009). Characterisation and use of biomass fly ash in cement based materials. Journal of Hazardous Materials, 172 (2), 1049 1060. Recycled materials resource center. Retrieved 03/18, 2017, from http://rmrc.wisc.edu/ug mat blast furnace slag/ Sarkar, A., Sahani, A. K., Roy, D. K. S., & Samanta, A. K. (2016). Compressive strength of sustainable concrete combining blast furnace slag and fly ash. IUP Journal of Structural Engineering, 9 (1), 17. Saidur, R., Abdelaziz, E. A., Demirbas, A., Hossain, M. S., & Mekhilef, S. (2011). A review on biomass as a fuel for boilers. Renewable and sustainable energy reviews 15 (5), 2262 2289. Sashidhar, C., & Sudarsana Rao, H. (2010). Durability studies on concrete with wood ash additive. Paper presented at the 35th Conference on our World in Concrete and Structures. Http://cipremier. com/100035048, Sebastian A., Manapurath, A. S., Balachandran, D., Sebastian, D. M., & Philip, D. Partial replacement of cement with wood ash. Shafigh, P., Mahmud, H. B., Jumaat, M. Z., & Zargar, M. (2014). Agricultural wastes as aggregate in concrete mixtures A review. Constr uction and Building Materials, 53 110 117. doi: http://dx.doi.org/10.1016/j.conbuildmat.2013.11.074 Siddique, R. (2008). Wood ash. Waste materials and by products in concrete (pp. 303) Siddique, R. (2004). Performance characteristics of high volume class F fly ash concrete. Cement and Concrete Research, 34 (3), 487 493.

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68 Siddique, R. (2012). Utilization of wood ash in concrete manufacturing. Resources, Conservation and Recyclin g, 67 27 33. Slag cement association. Retrieved 03/18, 2017, from http://www.slagcement.org/MemberInfo/WhereToFind.html Subramaniam, P., Subasinghe, K., & Fonseka, W. K. (2015). Wood ash as an effective raw material for concrete blocks. International Journal of Research in Engineering and Technology, 4 (2), 2319 1163. Suresh, D., & Nagaraju, K. (2015). Ground granulated blast slag (GGBS) in concrete A review. 12 (4) Teixei ra, E. R., Mateus, R., Cames, A. F., Bragana, L., & Branco, F. G. (2016). Comparative environmental life cycle analysis of concretes using biomass and coal fly ashes as partial cement replacement material. Journal of Cleaner Production, 112, Part 4 2221 2230. doi: http://dx.doi.org/10.1016/j.jclepro.2015.09.124 Udoeyo, F. F., Inyang, H., Young, D. T., & Oparadu, E. E. (2006). Potential of wood waste ash as an additive in concrete Journal of Materials in Civil Engineering, 18 (4), 605 611. United States Environmental Protection A gency. Retrieved 03/18, 2017, from https://www3.epa.gov/warm/pdfs/Fly_Ash.pdf Unite d states geological survey. Retrieved 03/21/2017, 2017, from https://minerals.usgs.gov/minerals/pubs/commodity/iron_&_steel_slag/ Zych, D. (2008). The viabili ty of corn cobs as a bioenergy feedstock. A Report of the West Central Research and Outreach Center, University of Minnesota,

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69 BIOGRAPHICAL SKETCH The author Ishan Sathe, was born in 1991 in Pune, Maharashtra, India and is currently living in Gainesville Fl. He was inclined towards construction as he had seen his family construction business since childhood. Due to his inclination, he opted to pursue a career in civil e ngineering and completed his bachelors from the University of Pune, India in 2013 Wit h an intention of pursuing higher education, he chose to move to United States. Ishan is currently in his final semester of completing his Master of Science degree in Construction Management from University of Florida in Gainesville Upon completion, he i s looking to pursue a career in the field of construction/project management specializing in residential, commercial or industrial projects.