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Concrete Containing Recycled Asphalt Pavement for Use in Concrete Pavement

Permanent Link: http://ufdc.ufl.edu/UFE0022618/00001

Material Information

Title: Concrete Containing Recycled Asphalt Pavement for Use in Concrete Pavement
Physical Description: 1 online resource (118 p.)
Language: english
Creator: Hossiney, Nabil
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: Civil and Coastal Engineering -- Dissertations, Academic -- UF
Genre: Civil Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Our study evaluated the feasibility of using concrete containing recycled asphalt pavement (RAP) in concrete pavement applications. Concrete containing 0, 10, 20, and 40% of RAP were produced in the laboratory, and evaluated for their properties which are relevant to performance of concrete pavements. Using the measured properties of these concretes containing RAP, finite element analysis was then performed to determine how the concretes containing different amounts of RAP would perform if it were used in a typical concrete pavement in Florida. Results of the laboratory testing program indicate that compressive strength, splitting tensile strength, flexural strength and elastic modulus of the concrete decrease as the percentage of RAP increases. The coefficient of thermal expansion appears to increase slightly with the use of one RAP, and decrease slightly with the use of a second RAP. The drying shrinkage appears to increase slightly with increasing RAP content. When analysis was performed to determine the maximum stresses in a typical concrete pavement in Florida under critical temperature and load conditions, the maximum stress in the pavement was found to decrease as the RAP content of the mix increases, due to a decrease in its elastic modulus. This indicates that using a concrete containing RAP can result in improvement in the performance of concrete pavements.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Nabil Hossiney.
Thesis: Thesis (M.S.)--University of Florida, 2008.
Local: Adviser: Tia, Mang.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0022618:00001

Permanent Link: http://ufdc.ufl.edu/UFE0022618/00001

Material Information

Title: Concrete Containing Recycled Asphalt Pavement for Use in Concrete Pavement
Physical Description: 1 online resource (118 p.)
Language: english
Creator: Hossiney, Nabil
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2008

Subjects

Subjects / Keywords: Civil and Coastal Engineering -- Dissertations, Academic -- UF
Genre: Civil Engineering thesis, M.S.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: Our study evaluated the feasibility of using concrete containing recycled asphalt pavement (RAP) in concrete pavement applications. Concrete containing 0, 10, 20, and 40% of RAP were produced in the laboratory, and evaluated for their properties which are relevant to performance of concrete pavements. Using the measured properties of these concretes containing RAP, finite element analysis was then performed to determine how the concretes containing different amounts of RAP would perform if it were used in a typical concrete pavement in Florida. Results of the laboratory testing program indicate that compressive strength, splitting tensile strength, flexural strength and elastic modulus of the concrete decrease as the percentage of RAP increases. The coefficient of thermal expansion appears to increase slightly with the use of one RAP, and decrease slightly with the use of a second RAP. The drying shrinkage appears to increase slightly with increasing RAP content. When analysis was performed to determine the maximum stresses in a typical concrete pavement in Florida under critical temperature and load conditions, the maximum stress in the pavement was found to decrease as the RAP content of the mix increases, due to a decrease in its elastic modulus. This indicates that using a concrete containing RAP can result in improvement in the performance of concrete pavements.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Nabil Hossiney.
Thesis: Thesis (M.S.)--University of Florida, 2008.
Local: Adviser: Tia, Mang.

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2008
System ID: UFE0022618:00001


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1 CONCRETE CONTAINING RECYCLED ASPHA LT PAVEMENT FOR USE IN CONCRETE PAVEMENT By NABIL HOSSINEY A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2008

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2 2008 Nabil Hossiney

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3 To all my family members and fr iends for loving and supporting me

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4 ACKNOWLEDGMENTS I would like to express my imme nse gratification to my supe rvisory committee chair, Prof. Mang Tia, for continuously guiding and supporting me at the Univer sity of Florida. Appreciation is also extended to my committee members, Dr. Reynaldo Roque and Dr. Fazil T. Najafi for their help and support. I am also thankful to Florida Department of Transportation [FDOT] for sponsoring the research that made it complete. I am grateful to all FDOT office pers onnel particularly to Michael Bergin, Charles Ishee, Richard DeLorenz o, Craig Roberts, and Luke Goolsby. Gratitude is also conveyed to the staff of the department of civil and coastal engi neering, especially Nancy Been, Carol Hipsley, Doretha Ray, Chuck Broward a nd others. I am also thankful for the help provided by George Lopp, Guangming Wang, Christopher Ferraro and Chen Yu. I would like to express my deep appreciation to all my friends at Univer sity of Florida, as well as my friends at the Bahai Student Associ ation at the University of Florida and all the Bahai members of Gainesville for the kind support and love. Finally, I am thankful to all my family members for understanding and helping me throughout my time during the research at the University of Florida.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4 LIST OF TABLES................................................................................................................. ..........8 LIST OF FIGURES.......................................................................................................................11 ABSTRACT...................................................................................................................................15 CHAP TER 1 INTRODUCTION..................................................................................................................16 1.1 Background.......................................................................................................................16 1.2 Hypothesis of Research....................................................................................................17 1.3 Research Objectives..........................................................................................................17 1.4 Research Approach...........................................................................................................17 2 LITERATURE REVIEW.......................................................................................................18 2.1 Strength of Concrete.........................................................................................................18 2.1.1 Effects of Aggregate on Strength of Concrete.......................................................18 2.1.2 Effects of Water to Cement Ratio on Strength of Concrete ................................... 19 2.2 Elastic Modulus of Concrete............................................................................................ 20 2.3 Coefficient of Thermal Expansion of Concrete................................................................ 21 2.3.1 Effects of Aggregate on Coefficient of Therm al Expansion of Concrete.............. 21 2.3.2 Effects of Moisture Content on Coeffici ent of Ther mal Expansion of Concrete... 23 2.4 Shrinkage of Concrete......................................................................................................23 2.4.1 Effects of Aggregate on Shrinkage of Concrete..................................................... 24 2.4.2 Effects of Water to Cement Ratio on Shrinkage of Concrete ................................25 2.5 Strength of Recycled Concrete.........................................................................................26 2.6 Behavior of RAP in Concrete........................................................................................... 27 2.6.1 Strength of Concrete Containing RAP...................................................................27 2.6.2 Secant Modulus of Concrete Containing RAP.......................................................29 3 MATERIALS AND TEST METHODS................................................................................. 31 3.1 Introduction............................................................................................................... ........31 3.2 Concrete Mix Proportions................................................................................................. 31 3.3 Mix Ingredient Properties................................................................................................. 33 3.4 Fabrication and Curing of Concrete Specimen.................................................................40 3.4.1 Concrete Preparation..............................................................................................41 3.4.2 Sample Preparation.................................................................................................41 3.5 Tests on Fresh Concrete.................................................................................................... 45 3.6 Tests on Hardened Concrete............................................................................................. 47

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6 3.6.1 Compressive Strength and Elastic Modulus Test................................................... 47 3.6.2 Flexural Strength Test............................................................................................ 49 3.6.3 Splitting Tensile Strength Test............................................................................... 52 3.6.4 Free Shrinkage Test................................................................................................ 54 3.6.5 Coefficient of Thermal Expansion (CTE) Test......................................................55 4 CONCRETE TEST RESULTS AND DISCUSSION ............................................................ 59 4.1 Introduction............................................................................................................... ........59 4.2 Analysis of Compressive Stre ngth Test Results and Discussion...................................... 59 4.2.1 Compressive Strength Test Results........................................................................ 59 4.2.2 Effects of RAP on Compressi ve Strength of Concrete ..........................................60 4.2.3 Effects of Water to Cement Ratio on Com pressive Strength of Concrete............. 62 4.3 Analysis of Elastic Modulus Test Results and Discussion ............................................... 65 4.3.1 Elastic Modulus Test Results.................................................................................65 4.3.2 Effects of RAP on Elastic Modulus of Concrete.................................................... 66 4.3.3 Effects of Water to Cement Rati o on Elastic Modulus of Concrete ....................... 67 4.4 Analysis of Flexural Strengt h Test Results and Discussion ............................................. 68 4.4.1 Flexural Strengt h Test Results ................................................................................ 68 4.4.2 Effects of RAP on Flexur al Strength of Concrete .................................................. 69 4.4.3 Effects of RAP on Modulus of Toughness of Concrete......................................... 71 4.5 Analysis of Splitting Tensile Stre ngth Test Results and Discussion ................................ 73 4.5.1 Splitting Tensile Strength Test Results.................................................................. 73 4.5.2 Effects of RAP on Splitting Te nsile Strength of Concrete .....................................74 4.6 Analysis of Free Shrinkage Test Results and Discussion ................................................. 75 4.6.1 Free Shrinkage Test Results................................................................................... 75 4.6.2 Effects of RAP on Free Shrinkage of concrete...................................................... 76 4.7 Analysis of Coefficient of Thermal Expansion Test Results ............................................ 77 4.7.1 Coefficient of Thermal Expansion Test Results..................................................... 77 4.7.2 Effects of RAP on Coefficient of Ther mal Expansion of Concrete....................... 78 4.8 Summary of Test Results.................................................................................................. 80 5 EVALUATION OF POTENTIAL PERFORMANCE OF CONCRETE CONTAINING RAP IN PAVEMENT ............................................................................................................. 81 5.1 Finite Element Model Used to Perform Stress Analysis.................................................. 81 5.2 Results of Stress Analysis using FEACONS IV Analysis................................................ 83 5.3 Effects of RAP on Stress-Strength Ratio of Concrete Pavement.....................................92 5.3.1 Effects of RAP-1 on Stress-Stre ngth Ratio of Concrete Pavem ent........................ 92 5.3.2 Effects of RAP-1 on Stress-Strength Ratio of Concrete Pavem ent with Varying Water to Cement Ratio................................................................................95 5.4 Observation on Results of Stress Analysis....................................................................... 98

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7 6 CONCLUSIONS AND RECOMME NDATIONS................................................................. 99 6.1 Conclusions.......................................................................................................................99 6.2 Recommendations.............................................................................................................99 APPENDIX A FEACONS IV PROGRAM.................................................................................................. 101 B STRENGTH TEST DATA................................................................................................... 108 LIST OF REFERENCES.............................................................................................................114 BIOGRAPHICAL SKETCH.......................................................................................................118

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8 LIST OF TABLES Table page 2-1 Effect of aggregate content on coefficient of Therm al expansion..................................... 22 2-2 Coefficient of linear thermal expansion of various aggregates .........................................23 3-1 Concrete mixes containing RAP-1 to be evaluated........................................................... 31 3-2 Concrete mixes containing RAP-2 to be evaluated........................................................... 32 3-3 Mix proportions for conc rete containing RAP-1 ...............................................................32 3-4 Mix Proportions for conc rete containing RAP-2 ...............................................................33 3-5 Physical properties of Portland cement.............................................................................. 33 3-6 Chemical properties of Portland cement............................................................................ 34 3-7 Specific gravity and water ab sorption of virgin aggregates...............................................34 3-8 Results of Sieve analysis on the virgin aggregate.............................................................. 34 3-9 Specific gravity and water absorption of RAP.................................................................. 35 3-10 Results of Sieve analysis on RAP-1................................................................................... 36 3-11 Results of sieve analysis on RAP-2................................................................................... 37 3-12 Tests performed on concrete samples................................................................................ 40 3-13 Standards for fresh concrete tests...................................................................................... 46 3-14 Properties of fresh concrete using RAP-1..........................................................................46 3-15 Properties of fresh concrete using RAP-2..........................................................................46 4-1 Compressive strength of the concrete using RAP-1.......................................................... 59 4-2 Compressive strength of the concrete using RAP-2.......................................................... 60 4-3 Elastic modulus of the concrete using RAP-1................................................................... 65 4-4 Elastic modulus of the concrete using RAP-2................................................................... 65 4-5 Flexural strength of th e concrete using RAP-1 ..................................................................69 4-6 Flexural strength of th e concrete using RAP-2 ..................................................................69

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9 4-7 Modulus of toughness of concrete using RAP-2 at 14-day............................................... 71 4-8 Modulus of toughness of concrete using RAP-2 at 28-day............................................... 71 4-9 Modulus of toughness of concrete using RAP-1 at 90-day............................................... 72 4-10 Splitting tensile strength of the concrete using RAP-1 and RAP-2 ................................... 73 4-11 Free shrinkage of the concrete using RAP-1.....................................................................75 4-12 Free shrinkage of the concrete using RAP-2.....................................................................76 4-13 Coefficient of thermal expansi on of the concrete using RAP-1 ........................................ 77 4-14 Coefficient of thermal expansi on of the concrete using RAP-2 ........................................ 78 5-1 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-1 with RAP-1 at 14-day............................. 84 5-2 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-1 with RAP-1 at 28-day............................. 85 5-3 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-1 with RAP-1 at 90-day............................. 86 5-4 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-2 with RAP-1 at 14-day............................. 87 5-5 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-2 with RAP-1 at 28-day............................. 88 5-6 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-2 with RAP-1 at 90-day............................. 89 5-7 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-3 with RAP-1 at 14-day............................. 90 5-8 Computed maximum stresses and stress-strength ratios in concrete pavem ent subjected to a 22-kip single axle lo ad for set-3 with RAP-1 at 28-day............................. 91 A-1 Input guide for FEACONS IV program...........................................................................101 B-1 Results of compressive strength tests (psi) ......................................................................108 B-2 Results of elastic modulus tests (6psi)....................................................................... 109 B-3 Results of flexural strength tests (psi)..............................................................................110 B-4 Results of splitting tens ile strength tests (psi).................................................................. 111

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10 B-5 Results of free shrinkage tests (10-6 in/in).......................................................................112 B-6 Results of coefficient of thermal expansion tests (10-6/F)..............................................113

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11 LIST OF FIGURES Figure page 2-1 Relationship between Compre ssive strength and w/c ratio ............................................... 20 2-2 Stress-strain relations for cemen t paste, aggregate and concrete. ...................................... 21 2-3 Autogenous shrinkage resulting with ch anging w/c ratio and equivalen t water amount................................................................................................................................25 2-4 Propagation of crack through aggreg ate with and without asphalt film ............................ 27 2-5 Compressive strength of concre te with varying percent of RAP ....................................... 28 2-6 Split tensile strength of concre te with varying percent of RAP.........................................28 3-1 Gradation chart for virgin aggregate.................................................................................. 35 3-2 Gradation chart for RAP-1 material................................................................................... 36 3-3 Gradation chart for RAP-2 material................................................................................... 37 3-4 Combined gradation curve for conc rete m ixtures containing 10% RAP........................... 38 3-5 Combined gradation curve for conc rete m ixtures containing 20% RAP........................... 39 3-6 Combined gradation curve for conc rete m ixtures containing 40% RAP........................... 39 3-7 Combined gradation curve for concre te m ixtures containing different RAP-2 contents..............................................................................................................................40 3-8 Weighing scale used........................................................................................................ ..42 3-9 Concrete mixer used........................................................................................................ ..43 3-10 Table vibrator used to consolidate cylinder samples......................................................... 43 3-11 Internal vibrator used to consolidate beam samples.......................................................... 44 3-12 Polythene sheets used to cover samples............................................................................. 44 3-13 Samples in standard moist room........................................................................................ 45 3-14 Material Testing System 810............................................................................................. 48 3-15 Failure of concrete cylinder in Com pressive strength test.................................................48 3-16 Test setup used for flexural strength test........................................................................... 51

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12 3-17 Failure of the beam without RAP material........................................................................ 52 3-18 Failure of the beam containing RAP material.................................................................... 52 3-19 Test setup for splitti ng tensile strength test........................................................................53 3-20 Failure of concrete cyli nders in indirect tension ................................................................ 54 3-21 Mold for free shrinkage test.............................................................................................. .55 3-22 Setup for shrinkage test.................................................................................................. ....55 3-23 Setup for coefficient of thermal expansion test................................................................. 57 3-24 Saw used for cutting concrete cylinder sam ples................................................................57 3-25 Grinder used for grinding concrete cylinder samples ........................................................ 58 4-1 Effect of RAP-1 on compressive strength at 14-day with 0.53 W /C ratio........................ 61 4-2 Effect of RAP-1 on compressive strength at 28-day with 0.53 W /C ratio........................ 61 4-3 Effect of RAP-1 on compressive strength at 90-day with 0.53 W /C ratio........................ 62 4-4 Effect of water to cementitious material s on com pressive strength at 14-day with 40% RAP...........................................................................................................................63 4-5 Effect of water to cementitious material s on com pressive strength at 28-day with 40% RAP...........................................................................................................................63 4-6 Effect of water to cementitious material s on com pressive strength at 14-day with 20% RAP...........................................................................................................................64 4-7 Effect of water to cementitious material s on com pressive strength at 28-day with 20% RAP...........................................................................................................................64 4-8 Effect of RAP on elastic modulus of concrete with 0.53 W/C ratio.................................. 66 4-9 Effect of water to cementitious materi als on elastic m odulus at 14-day with 40% RAP....................................................................................................................................67 4-10 Effect of water to cementitious materi als on elastic m odulus at 28-day with 40% RAP....................................................................................................................................67 4-11 Effect of water to cementitious materi als on elastic m odulus at 14-day with 20% RAP....................................................................................................................................68 4-12 Effect of water to cementitious materi als on elastic m odulus at 28-day with 20% RAP....................................................................................................................................68

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13 4-13 Effect of RAP on flexural streng th of concrete of 0.53 W /C ratio.................................... 70 4-14 Decrease in strength of th e concrete containing RAP-1 .................................................... 70 4-15 Stress-strain plots for mixtures with different RAP-2 contents from beam test................ 72 4-16 Stress-strain plots for mixtures with different RAP-2 contents from beam test................ 72 4-17 Stress-strain plots for mixt ures with different RAP-1 c ontents from beam test and 0.53 W/C ratio................................................................................................................. ...73 4-18 Effect of RAP-1 on splitting te nsile strength for 0.53 W /C ratio...................................... 75 4-19 Decrease in the strength of concrete containing RAP-1 fo r 0.53 W /C ratio...................... 75 4-20 Free shrinkage strain for concrete m ixtures with different RAP contents.........................77 4-21 Coefficient of thermal expansion for c oncrete with different RAP contents and 0.53 W /C ratio............................................................................................................................79 5-1 Finite element model used in FEACONS IV analysis....................................................... 82 5-2 22-kip wheel load at sl ab corner and m iddle edge............................................................. 82 5-3 Example input file input us ed for the FEACONS IV program .......................................... 83 5-4 Average Stress-strength ratios at the slab corn er with +20F temperature differential and 0.53 W/C ratio............................................................................................................. 93 5-5 Average Stress-strength rati os at the m iddle edge of the slab with +20F temperature differential and 0.53 W/C ratio.......................................................................................... 93 5-6 Average Stress-strength ratios at the slab corn er with -20F temperature differential and 0.53 W/C ratio............................................................................................................. 94 5-7 Average Stress-strength rati os at the m iddle edge of the slab with -20F temperature differential and 0.53 W/C ratio.......................................................................................... 94 5-8 Average Stress-strength ratios at the middle edge of the slab with 0F temperature differential and 0.53 W /C ratio.......................................................................................... 95 5-9 Stress-strength ratios at the slab corn er with +20F temperature differential and varying W/C ratio.............................................................................................................. 96 5-10 Stress-strength ratios at the middle edge of the slab with +20F tem perature differential and varying W/C ratio..................................................................................... 96 5-11 Stress-strength ratios at the slab corn er with -20F temperature differential and varying W/C ratio.............................................................................................................. 97

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14 5-12 Stress-strength ratios at the middle edge of the slab with -20F tem perature differential and varying W/C ratio..................................................................................... 97 5-13 Stress-strength ratios at the middle edge of the slab with 0 F temperature differential and varying W/C ratio........................................................................................................ 98 A-1 Example of number of nodes and elem ents.....................................................................107

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15 Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science CONCRETE CONTAINING RECYCLED ASPHA LT PAVEMENT FOR USE IN CONCRETE PAVEMENT By Nabil Hossiney August 2008 Chair: Mang Tia Major: Civil Engineering Our study evaluated the feasibility of usi ng concrete containing recycled asphalt pavement (RAP) in concrete pavement applic ations. Concrete containing 0%, 10%, 20% and 40% of RAP were produced in the laboratory, and ev aluated for their properties which are relevant to performance of concrete pavements. Using the measured properties of these concretes containing RAP, finite element analysis was th en performed to determine how the concretes containing different amounts of RAP would perform if it were used in a typical concrete pavement in Florida. Results of the laborat ory testing program indi cate that compressive strength, splitting tensile strengt h, flexural strength a nd elastic modulus of th e concrete decrease as the percentage of RAP increases. The coeffi cient of thermal expansion appears to increase slightly with the use of one RAP, and decrease slightly with th e use of a second RAP. The drying shrinkage appears to increase slightly with increasing RAP content. When analysis was performed to determine the maximum stresses in a typical concrete pavement in Florida under critical temperature and load conditions, the maximum stress in the pavement was found to decrease as the RAP content of the mix increases, due to a decrease in its elastic modulus. This indicates that using a concrete containing RAP can result in improvement in the performance of concrete pavements.

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16 CHAPTER 1 INTRODUCTION 1.1 Background The m odulus of elasticity of concrete is known to have a major effect on the performance of concrete pavements. Modulus of elasticity of concre te is an important input parameter to the AASHTO Mechanistic Empirical Pavement Design Gu ide. Concrete pavements using concrete with a lower modulus of elasticity would have a lower stress due to the same applied load and thus could have a lower chance of cracking. In an investigation of the performance of I-75 concrete pavements in Sarasota and Manatee counties [Tia et al 1989], it was reported that the percent cracked slabs increased w ith an increase in modulus of elasticity of the concrete. In another research study on pavement concrete, it was reported that the optimal concrete mixture for concrete pavement was not nece ssarily a concrete with a high flexural strength, but a concrete with a proper combination of low modulus of elasticity, low coefficient of thermal expansion and adequate flexural streng th [Tia et al, 1991]. Every year in the United States, more th an 100 million tons of reclaimed asphalt pavements (RAP) are generated by asphalt paveme nt (AC) rehabilitation and reconstruction [Collins and Ciesielski, 1994]. Some have been recycled into new asphalt mixtures; some have been used as pavement base materials. However, a large quantity of RAP still remains unutilized and needs to be put into good use. An alternative use of RAP is to use it as an aggregate in Portland cement concrete (PCC). RAP has been used as an aggregat e in Portland cement concrete (PCC) to improve the toughness and ductility of the PCC. According to studies by Huang [Huang et al, 2006] RAP aggregate coated with asphalt forms a film with a thickness about 6 to 9 um. This asphalt film acts as asph alt interface layer between aggregate and cement mortar, which can blunt or even arrest the micro-cracking and de lay the widening and

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17 propagating of the micro-cracki ng. Delwar [Delwar et al, 1997] examined the stress-strain behavior of PCC containing RAP and found that PCC containing a higher amount of RAP fails at a higher strain level indicating that RAP ma y contribute to the ductility of PCC. 1.2 Hypothesis of Research Incorporation of Recycled Aspha lt Pavem ent (RAP) in concrete can reduce the modulus of elasticity of concrete mixture a nd can reduce the load induced stre sses in concrete pavements. RAP added to concrete mixtures reduce the flexur al strength only slightly. Addition of RAP to concrete can reduce the stress-s trength ratio and thus improve the performance of concrete pavement at critical temp erature and load condition. 1.3 Research Objectives The m ain research objectives of this study are as follows: 1. To evaluate the potential use of RAP in conc rete and its effects on the mechanical and thermal properties of concrete. 2. To determine the performance of concrete cont aining different amounts of RAP when used in a typical concrete pavement in Florida. 1.4 Research Approach The following approach es are used in this research: 1. Perform a literature review on past and present studies on the use of RAP in concrete. 2. Prepare concrete mixtures containing natura l aggregates and RAP ma terial with varying proportions. 3. Evaluate the properties of conc rete containing different amo unts of RAP in the laboratory. 4. Perform stress analyses on hypothetical conc rete pavements under critical load and temperature conditions in Florida, if these pavements were made with these concretes containing different amounts of RAP. Eval uate the potential performance of these hypothetical pavements based on the ratio of computed maximum stress to the flexural strength of the concrete

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18 CHAPTER 2 LITERATURE REVIEW 2.1 Strength of Concrete Strength is the m ost important property of c oncrete and it is affe cted by many factors. Some of the major factors are type of aggregat e, water cement ratio, and degree of compaction. The following information provides a literature re view of effects of aggregate and water cement ratio on the strength of concrete. 2.1.1 Effects of Aggregate on Strength of Concrete Aggregate type plays an im portant role in a ffecting the strength of concrete. Different aggregates can have different stre ngths. Even the same type of aggregate from different locations can have different effects on strength of concrete. Ke-Ru Wu [Wu et al, 2001] found that strength of concrete increases with the increasing strength of aggregate. He also concluded that high strength concrete with lower brittleness can be made by selecting hi gh strength aggregate with low brittleness. Turan zturan [zturan, 1997] concluded that the tensile strength is mainly determined by the mortar strength whereas compre ssive strength is influenced significantly by the strength of coarse aggregat e in the mix. Aitcin and Mehta [Aitcin and Mehta, 1990] found some results which showed that diabase and limestone aggregates pr oduced concretes with higher strength compared with granite and river gravel. Sarkar [Sarkar et al, 1990] did some research on petrological examina tion of different aggregates a nd found that participation of aggregate in the strength is a critical parameter for strength development of concrete. It has been demonstrated by the authors that some of the fact ors like textural flaws, presence or absence of fatigue zones, intra-angular fissures, and decomposition of constituent minerals can lead to loss of strength in concrete. Therefor e, petrological examination is essential for the selection of aggregates. Defects in aggregate which can re present up to 45% of the concrete volume can

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19 result in the weakening of th e concrete. Williams [Williams, 1972] stated that for a dry lean concrete mix, the flexural strength was approxima tely one-tenth of the compressive strength. However, materials can affect th is relationship. For instance, highe r values of flexural strength were obtained with crushed rock aggregate, especially limestone. Franklin and King [Franklin and King, 1971] targeted to interrelate the cube strength and cylindrical compressive strength and found that their interrelations hip were markedly influenced by the type of aggregate used. Hence, the type of aggregate can affect the strengths and their interrelationship. Generally, recycled aggregates produce lower quality concrete (lower strength) but can be useful in nonstructural applications. Sommer [1993] found that flexural strength of the concrete containing crushed stone and asphalt was lower than that of normal concrete made w ith natural aggregates. Chehadeh [Chehadeh, 1967] revealed that the pres ence of other materials like silt and clay can increase the values of optimum water content, density and shrinkage, but lower the values of strength and modul us of elasticity. 2.1.2 Effects of Water to Cement Ratio on Strength of Concrete Water to cem ent ratio is an important factor affecting the strength of concrete. Excessive water added to the paste is problematic by reducing ultimate strength of the concrete. This is because of the reduced density and increased porosity. Low water to cement ratios provides higher ultimate strengths by reducing porosity and limiting the ability of free water to penetrate [Hodgson 2000]. For a fully compacted concrete, its st rength is inversely re lated to its water to cement ratio. This relation was establishe d by Duff Abrams in 1919. Figure 2-1 shows the relationship between compressive strength and water to cement ra tio of concrete. Generally, the compressive strength is higher at a lower water to cement ratios and decreases at higher water to cement ratios. However, at low water to cement ratio, the curve deviates from the expected values since full compaction is no longer possibl e. The actual point of departure depends on the

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20 means of compaction available. Porosity of hard ened concrete paste can also be determined by its water to cement ratio, which will directly a ffect the voids in concrete and ultimately the strength of concrete. Figure 2-1 Relationship between Compressive strength and w/c ratio [Neville, A.M., 1996] 2.2 Elastic Modulus of Concrete Modulus of elasticity is considered to be an im portant property for concrete pavements because the stress developed in a cemented laye r is a function of the modulus values of the various layers. A base layer with a high modulus material will have a high value of stress under a given wheel-load. The most importa nt factor affecting the elasti c modulus of concrete is the aggregate used. Modulus of elasticity of a concrete is highly affected by the aggregate content and aggregate type in a mix. Ke-Ru Wu [Wu et al, 2001] found that th e elastic modulus of concrete increases with the increasing elastic modulus of aggregat e. He also concluded that high elastic modulus concrete can be made by selecting aggregates with highe r modulus of elasticity. From Figure 2-2 it can be seen that the elastic modulus of hardened cement paste is different from the elastic modulus of concrete which is highly affected by the elastic modulus of aggregate. Therefore, for a given mix, a higher ag gregate content would resu lt in a higher elastic

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21 modulus of the concrete [Neville, A.M., 1996]. Coarse aggregate type is a very important factor affecting the elastic modulus of hardened concrete. Zhou, Lydon and Barr [Zhou et al, 1995] found that coarse aggregate type has a considerable influence on the elastic modulus of concrete. In their study, effects of mortar, expanded clay, sint fly ash, limestone, gravel, glass and steel on the elastic modulus of concrete were investigated. They found that the elastic modulus of concrete increases with the increase in elastic modulus of aggregate. Williams [Williams, 1972] also found that the modulus of elasticity of c oncrete was affected by the condition of aggregate in the mix. Clean or washed (processed) aggreg ates produced concrete with high modulus of elasticity values compared with those which were used without reprocessing or cleaning. Chi [Chi et al, 2003] found that elas tic modulus of concrete was aff ected by the different proportions and types of aggregate in the concrete. Figure 2-2 Stress-strain relations for cement past e, aggregate and concrete [Neville, A.M., 1996]. 2.3 Coefficient of Thermal Expansion of Concrete 2.3.1 Effects of Aggregate on Coefficient of Thermal Expansion of Concrete The coefficient of therm al expansion of aggregat e influences the value of the coefficient of concrete containing the given aggregate. For a given mix, the higher the coefficient of the

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22 aggregate is, the higher the coefficient of the concrete will be. However, it also depends on the aggregate content in the mix and on the mix proportions in general. It has al so been found that if the coefficient of thermal expansion of the cemen t paste and that of aggregate differ too much, a large change may introduce differential movement and a break in the bond between the cement paste and the aggregate which affects the durabil ity of concrete [Neville 1996]. In Table 2-1, it is clear that the coefficient of thermal expansi on decreases with the intr oduction of aggregate and further reduces with the increase in the amount of aggregate. Aggregate type also plays a major role in affecting the coefficien t of thermal expansion. The coefficient of thermal expansion of various types of rocks is directly related to their quartz conten t. Rocks such as quartzite and sandstone, which are quartz rich, have the highest coefficients, about 6.7 10-6 per F (12 10-6 per C). Those with no quartz or with very little quartz such as limestone and marble have the lowest coefficients averaging 2.8 10-6 per F (5 10-6 per C). Granite and basalt, which are igneous rocks and have medium quartz content, have intermediate values [American Concrete Institute, 1971]. Emmanuel [E mmanuel and Hulsey, 1977] found th at siliceous rocks have the highest coefficient, carbonate rocks the lowest and igneous rocks usually have intermediate value. Table 2-2 presents the values of average coefficient of linear th ermal expansion based on type of rock. Browne [Browne, 1972] also conc luded that the coeffici ent of linear thermal expansion of concrete is largely dependent on the composition and quantity of aggregate. Table 2-1 Effect of aggregate content on coeffi cient of Thermal expansion [Neville A.M., 1996] Cement/sand ratio Linear coefficient of thermal e xpansion at the age of 2 years 10-6 perC 10-6 perF Neat cement 18.5 10.3 1:1 13.5 7.5 1:3 11.2 6.2 1:6 10.1 5.6

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23 Table 2-2 Coefficient of linear thermal expansion of various aggregates [Dettling Heinz, 1964] Type of Rock Average coefficient of linear thermal expansion (10-6 perC) Quartzite/ Silica shale 11.8 Sandstones and gravels 11.0 Clay shale 10.1 Granite 7.4 Limestone 4.5 Marbles 4.5 2.3.2 Effects of Moisture Content on Coeffici ent of Thermal Expansion of Concrete The m oisture content of the conc rete has been considered to be one of the important factors affecting the coefficient of linear thermal expa nsion of concrete [Neville, A.M., 1996]. Sellevold [Sellevold et al, 2006] stated that coefficien t of thermal expansion can be controlled by controlling the moisture content of the concrete and can be reduced by maintaining concrete in a wet state. This is because when concrete is in a wet state (completely saturated) there is no internal moisture movements caused by a change in the capillary forces, produced due to variation in temperature [Dettli ng, 1964]. Therefore, a completely saturated specimen has little apparent linear thermal expansion compared to a partially saturated which has maximum apparent thermal expansion. Dry or zero saturated concrete at a temperature range of 15 to 70F has an essentially constant co efficient of linear expansion, wh ile moist or nearly saturated concrete shows a significant increase in coeffici ent with increase in temperature [Mitchell, 1966]. Coefficient of thermal expans ion of partially saturated concrete is generally greater than that of saturated concre te [Browne, 1972]. 2.4 Shrinkage of Concrete Withdrawal of water from concrete stored in unsaturated air causes drying shrinkage [Neville, 1996]. One of the causes for the premature failure of concrete is excessive shrinkage. This is because at the early age, low strength of the concrete cannot resist the stresses induced due to shrinkage. Shrinkage is highly affected by the type of material used in concrete. The

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24 shrinkage behavior of concrete is greatly affect ed by coarse aggregate content, coarse aggregate type and water content in a mix. Shrinkage increases with an increase in cement content of mix, and an increase in volume of aggregate in concrete will reduce shrinkage. 2.4.1 Effects of Aggregate on Shrinkage of Concrete Aggregate is one of the importa nt factors affecting shrinkage of concrete. Both aggregate content and aggregate type play an important role in shrinkage of concrete. Pickett [ Pickett, G., 1956] reported that the shrinkage of concrete in creases significantly as the aggregate content decreases. This is because, for a mixture with hi gh aggregate content, the coarse aggregate form a very stiff skeleton in the conc rete matrix. This causes point to point contacts between the coarse aggregates and makes it effective in resi sting stresses caused by cement paste shrinkage. Hobbs [Hobbs, 1974] found that aggregates act as a rigid non shrinking incl usion that restrains the deformation of the paste. The higher the aggreg ate content is, the more rigid the structure will be. Consequently, a significant initial deformati on of the paste will not result in an equivalent initial deformation of the concrete, since it occurs when the rigidity of th e paste is low. Hansen [Hansen et al, 1965] carried out some research work on the influence of aggregate properties on concrete shrinkage, and found that the amount of aggregate highly affects the shrinkage of the concrete. Troxell, Raphael and Davis [Troxell et al, 1958] conducted some tests to study the effects of coarse aggregate types on shrinkage behavior of concrete. They concluded that different aggregates have diffe rent modulus of elas ticity, and the elasti c properties of the aggregate determine the degree of restraint to the concrete. In general, co ncrete using dolerites, basalts, greywackes, mudstones and gravels c ontaining these rock types, tended to have excessive shrinkage. Granite, limest one, flint, quartzite, and fresh felsite were found to give low shrinkage [Pike, 1990].

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25 2.4.2 Effects of Water to Cement Ratio on Shrinkage of Co ncrete Figure 2-3 shows the results by Holt [Holt, 2004] who conducted a study to determine autogenous shrinkage at different durations with varying water to cement ratio. The water to cement ratio was changed from 0.30 to 0.45, while the water amount was held constant at 275 kg/m3. The mixtures with the lowest water to cement ratio had th e greatest amount of autogenous shrinkage. This was due to the higher cement cont ent at the lower water to cement ratios, which resulted in larger autogenous shrinkage due to contribution of chemical shrinkage. Neville [Neville, 1996] stated that the shrinkage of hydrat ed cement paste is higher at a higher water to cement ratio, because there is more water in th e cement paste. The water content of concrete affects shrinkage because it reduces the volume of restraining aggregate. Thus, in general, the water content of a mix would indica te the order of shrinkage to be expected, but it is not the only factor. Mixes having the same water content, but widely varying composition, may exhibit different values of shrinkage. Figure 2-3 Autogenous shrinkage resulting with ch anging w/c ratio and equivalent water amount [Erika Holt, 2004]

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26 2.5 Strength of Recycled Concrete Strength of recycled aggregate is highly dependent on the type of recycled aggregate used. Usually, th e use of recycled aggregate will pr oduce lower strength concrete compared with natural aggregate. Recycled aggr egates are often composed of material with highly variable properties resulting in product appl ication limitations. Etxeberria [Etx eberria et al, 2007] states that, based on his findings, concrete made with 100% of recycled coarse aggregates has 20% less compressive strength than conventional conc rete at 28 days, with the same effective w/c ratio (w/c = 0.50) and cement quantity. Concrete made with 100% of coar se recycled aggregate requires a high amount of cement to achieve a high compressive strength and consequently is not an economic proposition as it is not cost effective. Moreover, the adhered mortar in recycled aggregates is lower in strength than that in conventional aggregates. Medium compressive strength (4350 psi) concrete made with 25% of recycled coarse aggregates achieves the same mechanical properties as that of conven tional concrete employing the same quantity of cement and the equal effective w/c ratio. Medium compressive strength concrete made with 50% or 100% of recycled coarse aggregates needs 4% lower effective w/c ratio and 5% more cement than conventional concrete to achieve the same compression strength at 28 days. The modulus of elasticity is lower than that of conventional concrete. Ho wever, the tensile strength of recycled aggregate concrete can be higher than th at of conventional concrete. Standard deviation of compressive strength of concrete using 100% recycled aggregat e is 50% higher than that of the control concrete due to th e heterogeneity of recycled aggregates. Gonzlez-Fonteboa [Gonzlez-Fonteboa, 2007] observed a reduction in sta tic elastic modulus for all recycled concrete. Even the introduction of silica fume, which increased the compressive strength of recycled concrete, did not affect the modulus of elasticity to greater extent. Few differences were observed in the splitting tensile st rength of recycled concrete.

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27 2.6 Behavior of RAP in Concrete RAP (Recycled Asphalt Pavem ent) is a combin ation of both aged asphalt and aggregate, which is removed from existing distressed asphalt pavements. The use of RAP as an aggregate in concrete has been experimented by Huang [Hua ng et al, 2006]. It was found that the toughness and crack resistance of the concre te could be improved by the addi tion of RAP into concrete. In concrete made with RAP, asphalt forms a thin film at the interface of cement mortar and aggregate as shown in Figure 2-4. This thin film can be useful in resisting the crack propagation going along that direction. Thus, a crack would propagate around th e aggregate rather than going through it, during which more energy can be di ssipated [Huang et al, 2006]. Generally, for a concrete with a high percentage of RAP, the conc rete does not separate after failure but tries to sustain load even after initial failure. Figure 2-4 Propagation of crack through aggregate with and without asphalt film [B.Huang et al, 2006] 2.6.1 Strength of Concrete Containing RAP It has been observed that, for a concrete incorporating RAP th e strength generally decreases with an increase in the content of RAP [B.Huang, et al, 2006]. Figure 2-5 and Figure 2-6 present the com pressive stre ngth and splitting tensile streng th of concrete with varying percent of RAP. Numbers 1 to 4 are the concre te mix with different RAP composition. Number 1 was the control mix and number 4 was a mix with maximum percentage of RAP [B.Huang et al,

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28 2006]. Results from a study by Delwar [Delwar et al, 1997] showed similar trends. Table 2-3 presents the compressive strength of concrete containing RAP from this study. Concrete made with natural aggregates yielded the highest co mpressive strength. At 28 days, a compressive strength of 3180 psi was obtained for a mixture that contained 100 pe rcent gravel and 100 percent RAP fines, as compared with a comp ressive strength of 5300 psi for a control mix [Murshed Delwar et al 1997]. For a beam with 50 percent gravel, 50 pe rcent coarse RAP, 100 percent fine RAP and 0.40 w/c, the modulus of rupture was about 685 psi. [Murshed Delwar et al 1997]. Figure 2-5 Compressive strength of concrete w ith varying percent of RAP [B.Huang et al, 2006] Figure 2-6 Split tensile strength of concrete with varying percent of RA P [B.Huang et al, 2006]

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29 Table 2-3 Compressive strength of concrete containing RAP [Murshed Delwar et al, 1997] Aggregate Composition Comp ressive strength range (psi) Percent w/c = 0.5 w/c = 0.4 Fine RAP-100 750 1600 Coarse RAP-100 Fine RAP-50 1300 1800 Sand-50 Coarse RAP-100 Fine RAP-25 1600 2000 Sand-75 Coarse RAP-100 Sand-100 1700 2300 Coarse RAP-100 Fine RAP-100 900 1700 Coarse RAP-100 Fine RAP-100 1800 1900 Gravel-50 Coarse RAP-50 Fine RAP-100 2100 2600 Gravel-75 Coarse RAP-25 Fine RAP-100 2700 3200 Gravel-100 Gravel-100 3800 5300 Sand-100 (Note: Above strengths are not the exact values obtained by the authors, they have been rounded to nearest upper or lower whole digit number) 2.6.2 Secant Modulus of Concrete Containing RAP Table 2-4 presents the secant m odulus values of concrete with different percentage of RAP from a study by Delwar [Delwar et al, 1997]. For a concrete made with 100% fine and 100% coarse RAP the secant modulus was 1.39 106 psi, while for a concrete with 100% sand and 100% gravel the secant modulus was 3.56 106 psi with a same water to cement ratio of 0.5. The

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30 secant modulus for concrete made with 100% coarse and fine RAP was 1.18 106 psi, while for concrete with 100% sand and gravel it was 4.24 106 with 0.4w/c rati o. Therefore secant modulus increases with decrease in water to cement ratio for bot h the concretes with and without RAP. Table 2-4 Secant modulus of concrete cont aining RAP [Murshed Delwar et al, 1997] Aggregate Composition Secant modulus (psi) Percent w/c = 0.5 w/c = 0.4 Coarse RAP-100 1,392,000 1,185,455 Fine RAP-100 Coarse RAP-50 1,555,555 1,536,000 Gravel-50 Fine RAP-100 Gravel-100 2,846,753 2,958,140 Fine RAP-100 Coarse RAP-100 1,266,666 1,453,763 Sand-50 Fine RAP-50 Coarse RAP-100 1,710,000 2,340,000 Sand-100 Gravel-100 3,568,421 4,240,000 Sand-100

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31 CHAPTER 3 MATERIALS AND TEST METHODS 3.1 Introduction This chapter provides the details of m ix proportion and mix ingredients used for the concrete mixtures in this research. It also ex plains the standard method of preparation of the concrete mixture in laboratory, fabrication procedure and standard ASTM testing methods performed in this research study. 3.2 Concrete Mix Proportions The percentages of RAP to be in co rporated in different concre te mixtures to be evaluated are as shown in Table 3-1 and Table 3-2. The mix proportions for these different mixtures are shown in Table 3-3 and Table 3-4. Table 3-1 Concrete mixes contai ning RAP-1 to be evaluated Mix W/C Cement Virgin coarse Co arse Virgin fine Fine Total number ratio (lb/cy) aggregate RAP aggregate RAP RAP 1 0.53 508 100 0 100 0 0 2 0.53 508 90 10 90 10 10 3 0.53 508 80 20 80 20 20 4 0.53 508 60 40 60 40 40 1 1 0.53 508 100 0 100 0 0 2 0.53 508 90 10 90 10 10 3 0.53 508 80 20 80 20 20 4 0.53 508 60 40 60 40 40 1 0.53 508 100 0 100 0 0 2 0.51 508 90 10 90 10 10 3 0.48 508 80 20 80 20 20 4 0.43 508 60 40 60 40 40 (Note: Coarse aggregate and coarse RAP are vol ume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by to tal fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1

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32 Table 3-2 Concrete mixes contai ning RAP-2 to be evaluated Mix W/C Cement Virgin coarse Coarse Virgin fine Fine Total number ratio (lb/cy) aggregate RAP aggregate RAP RAP 1 1 0.53 508 100 0 100 0 0 2 0.53 508 90 10 90 10 10 3 0.53 508 80 20 80 20 20 4 0.53 508 60 40 60 40 40 1 0.48 562 82 18 77 23 20 2 0.48 562 66 34 47 53 40 3 0.43 628 82 18 76 24 20 4 0.43 628 67 33 44 56 40 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by to tal fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Table 3-3 Mix proportions for concrete containing RAP-1 Mix number W/C ratio Cement (lb/cy) Water (lb/cy) Virgin fine aggregate (lb/cy) Virgin coarse aggregate (lb/cy) Coarse RAP (lb/cy) Fine RAP (lb/cy) 1 0.53 508 270 1239 1782 / / 2 0.53 508 270 1115 1604 167 103 3 0.53 508 270 991 1426 335 205 4 0.53 508 270 743 1069 670 410 1 0.53 508 270 1239 1782 / / 2 0.53 508 270 1115 1604 167 103 3 0.53 508 270 991 1426 335 205 4 0.53 508 270 743 1069 670 410 1 0.53 508 270 1239 1782 / / 2 0.51 508 260 1115 1604 167 103 3 0.48 508 245 991 1426 335 205 4 0.43 508 215 743 1069 670 410 Set-1 RAP#1 Set-1 RAP#2 Set-2 RAP#2 Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1

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33 Table 3-4 Mix Proportions for concrete containing RAP-2 Mix number W/C ratio Cement (lb/cy) Water (lb/cy) Virgin fine aggregate (lb/cy) Virgin coarse aggregate (lb/cy) Coarse RAP (lb/cy) Fine RAP (lb/cy) 1 0.53 508 270 1239 1782 / / 2 0.53 508 270 1115 1604 167 103 3 0.53 508 270 991 1426 335 205 4 0.53 508 270 743 1069 670 410 1 0.48 562 270 833 1563 221 337 2 0.48 562 270 452 1304 445 673 3 0.43 628 270 776 1544 219 331 4 0.43 628 270 385 1351 438 664 3.3 Mix Ingredient Properties Mix ingredient used for the concrete was supplied by FDOT [Florida Departm ent of Transportation]. Tests were performed on mix i ngredients by FDOT personnel to determine the different properties. Following are the deta ils of the mix ingredient properties. Water: Normal tap water supplied locally by city water supply system was used. Clean water was used without allowing any unwanted impurities to get into it. Cement: Portland cement type I/II supplied by Fl orida Rock Industry was used. Table 3-5 and Table 3-6 shows the physical and chemical properties of the cement determined by Florida Department of Transportation [FDOT, 2007]. Table 3-5 Physical properties of Portland cement [FDOT, 2007] Test Standard specification Cement Loss of Ignition ASTM C114 0.30% Autoclave expansion ASTM C151 0.04% Time of setting (initial) ASTM C266 190 min Time of setting (final) ASTM C266 290 min Set-1 RAP#2 Set-2 RAP#2

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34 Table 3-6 Chemical properties of Portland cement [FDOT, 2007] Constituents Percent Silicon Dioxide 20.50% Aluminum Oxide 5.20% Ferric Oxide 3.80% Magnesium Oxide 0.60% Sulfur Trioxide 2.80% Tricalcium Aluminate 7% Tricalcium Silicate 54% Total Alkali as Na2O 0.25% Virgin aggregate: Silica sand from Goldhead of Flor ida was used as fine aggregate and number 57 Miami Oolite limestone was used as co arse aggregate. Physic al properties of this aggregate were obtained by Florida Department of Transportation pe rsonnel. The results of these properties for fine and coarse aggregate are s hown in Table 3-7 and Ta ble 3-8. Figure 3-1 shows the gradation chart for the fi ne and coarse aggregate. Table 3-7 Specific gravity and water abso rption of virgin aggregates [FDOT, 2007] Coarse aggregate Fine aggregate SSD Specific Gravity 2.37 2.64 Dry Bulk Specific Gravity 2.28 2.63 Dry Apparent Specific Gravity 2.52 2.65 Absorption 4.31% 0.30% Table 3-8 Results of Sieve anal ysis on the virgin aggregate Sieve size Sieve size (mm) Percent passing coarse aggregate Percent passing fine aggregate 1" 25.0 100 / 1/2" 12.5 50 / #4 4.75 8 100 #8 2.36 5 97 #16 1.18 / 85 #30 0.60 / 57 #50 0.30 / 18 #100 0.15 / 1 #200 0.075 / / Fineness modulus 2.41

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35 Figure 3-1 Gradation chart for virgin aggregate Recycled Asphalt Pavement (RAP): RAP was obtained from a RAP stockpile at an asphalt plant owned by Whitehurst & Sons, Inc. in Gainesville. RAP material was separated into coarse portion and fine portion using a #4 sieve. Tests were run on the RAP to determine their specific gravity, water absorption and gradation. Two different RAP materials obtained from the same plant at two different times were used. Th e results of sieve analys is on RAP material are shown in Table 3-10 and Table 311. Gradation charts for different RAP materials is shown in Figure 3-2 and Figure 3-3. Results of specific grav ity and water absorption of RAP materials are shown in Table 3-9. Table 3-9 Specific gravity a nd water absorption of RAP Coarse RAP-1 Fine RAP-1 Coarse RAP-2 Fine RAP-2 SSD Specific Gravity 2.231 2.185 2.309 2.325 BSG Specific Gravity 2.186 2.125 2.259 2.283 ASG Specific Gravity 2.290 2.261 2.377 2.383 Absorption 2.08% 2.84% 2.20% 1.77%

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36 Table 3-10 Results of Sieve analysis on RAP-1 Sieve size Sieve size(mm) Percent passing Coarse RAP Percent passing Fine RAP Recovered aggregate 2" 50.0 100.00 / / 3/2" 37.5 98.30 / / 1" 25.0 97.07 / / 3/4" 19.0 87.47 / / 1/2" 12.5 67.40 / 100 3/8" 9.5 50.97 / 98 #4 4.75 0.00 100 76 #8 2.36 / 80.95 60 #16 1.18 / 60.71 51 #30 0.60 / 37.5 40 #50 0.30 / 12.1 24 #100 0.15 / 1.98 9 #200 0.075 / 0 5.2 Fineness modulus / 3.07 / Asphalt content / 6.30% Figure 3-2 Gradation chart for RAP-1 material

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37 Table 3-11 Results of sieve analysis on RAP-2 Sieve size Sieve size(mm) Percent passing Coarse RAP Percent passing Fine RAP Recovered aggregate 2" 50.0 100.00 / / 3/2" 37.5 100.00 / / 1" 25.0 100.00 / / 3/4" 19.0 96.00 / 100 1/2" 12.5 80.00 / 92.74 3/8" 9.5 60.00 / 79.58 #4 4.75 14.00 100 43.79 #8 2.36 8.00 81 34.31 #16 1.18 / 61 29.51 #30 0.60 / 40 25.24 #50 0.30 / 20 19.42 #100 0.15 / 5 11.33 #200 0.075 / 1 6.53 Fineness modulus / 3.92 / Asphalt content / 5.40% Figure 3-3 Gradation chart for RAP-2 material

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38 Combined gradation curve: Figures 3-4 to 3-7 shows the combined gradation cure for concrete mixtures containing different percentage of RAP. The combined gradation curve shows the difference in the gradation of RAP-1, RAP-2 and virgin aggregate when incorporated in a concrete mixture. It shows that mixtures cont aining RAP are more dense graded compared to mixtures without RAP. Following observations were made from gradation curves. 1. Combined aggregate (virgin aggregate and RAP) with 40% RAP-2 is much finer than the combined aggregate (virgin aggregate and RAP) with 40% RAP-1. 2. Combined aggregate (virgin aggregate and RA P) with 40% coarse RAP-2 and 40% fine RAP-2 is much finer than combined aggregate (virgin aggregate and RA P) with 33% coarse RAP-2 and 56% fine RAP-2. 3. Combined aggregate (virgin aggregate and RA P) with 10% and 20% RAP-2 had very less difference than combined aggregate (virgin aggregate and RAP) with 10% and 20% RAP-1. Figure 3-4 Combined gradation curve for concrete mixtures containing 10% RAP

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39 Figure 3-5 Combined gradation curve for concrete mixtures containing 20% RAP Figure 3-6 Combined gradation curve for concrete mixtures containing 40% RAP

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40 Figure 3-7 Combined gradation curve for concrete mixtures containing di fferent RAP-2 contents 3.4 Fabrication and Curing of Concrete Specimen Concrete m ixtures were produced in the labora tory using a drum mixe r with a capacity of nine cubic feet, as shown in Figure 3-9. For each concrete mix, about five cubic feet of fresh concrete was produced to fabricate twelve cylind ers (4" 8"), six cylin ders (6" 12"), four beams (6" 6" 12") and three prisms (3" 3" 11.25"). Table 3-12 shows the details of tests performed on concrete samples with va rious specimen size and curing periods. Table 3-12 Tests performed on concrete samples Test Specimen size Curing period Compressive and 4" 8" 14 days, 28 days Elastic modulus Cylinder and 90 days Flexural strength 6" 6" 12" 14 days, 28 days Beam and 90 d ays Splitting tensile 6" 12" 14 days, 28 days strength Cylinder and 90 days

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41 Table 3-12. Continued Test Specimen size Curing period Coefficient of 4" 8" 14 days, 28 days thermal expansion Cylinder and 90 days Drying shrinkage 3" 3" 11.25" 14 days, 28 days Prism and 90 days 3.4.1 Concrete Preparation The following steps were followed to produce concrete in the laboratory. 1. Fill c loth bags with the aggregates and RAP required for mix. 2. Dry the fine aggregates for at least 24 hours in an oven at 23 0 F, and then let it cool for another 24 hours. 3. Soak the coarse aggregate and RAP material fo r at least 48 hours and let it sit outside the tank for at least 30 minutes before weighing. 4. Based on the mix design, weigh the coarse aggregat e, fine aggregate, coarse RAP, fine RAP, cement and water using a weighing scale as shown in Figure 3-8. 5. Place the coarse aggregate, fine aggregate, co arse RAP and fine RAP in a drum mixer as shown in Figure 3-9. 6. Run the mixer for 30 seconds 7. Add more than half of the mixing water and mix it for 1 minute 8. Place cement and mix it for 3 minutes, followed by a 2 minute rest, followed by a 3 minute mixing. 9. Perform fresh concrete property te sts as presented in Section 3.5. 3.4.2 Sample Preparation After concrete was produced, som e portion of the concrete was immediately used for conducting tests to determine fresh concrete properties as discu ssed in Section 3.5.The remaining concrete was used to fabricate different samples as follows:

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42 1. Place concrete in molds such that they are half filled. 2. Place the molds on a vibrating table and vi brate for 45 seconds. Then fill the molds completely and vibrate it for another 45 seconds. 3. Beams were vibrated using a hand equipped internal vibrator as shown in Figure 3-11 and cylinders were vibrated using tabl e vibrator as shown in Figure 3-10. 4. Finish the concrete surface with a hand trowel. 5. Cover the concrete with polythene sheets as shown in Figure 3-12. 6. Remove the samples from the molds after 24 hours and place them in a moist curing room as shown in Figure 3-13. Figure 3-8 Weighing scale used

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43 Figure 3-9 Concrete mixer used Figure 3-10 Table vibrator used to consolidate cylinder samples

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44 Figure 3-11 Internal vibrator used to consolidate beam samples Figure 3-12 Polythene sheets used to cover samples

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45 Figure 3-13 Samples in standard moist room 3.5 Tests on Fresh Concrete Table 3-13 provides the list of ASTM standard tests perform ed on the fresh concrete used in this study. The properties of the fresh concrete mixtures are presented in Table 3-14 and Table 3-15. Slump Test: This test was run in accordance with ASTM C143. This test is very useful in detecting variations in the uniformity of a mix of given nom inal proportions; it is a measure of consistency of the fresh concrete. This test is conducted immediately after the concrete has been made. Unit Weight Test: This test was used to verify the de nsity of concrete mixtures as per the procedures of ASTM C138 standard. Air Content Test: Air content test by volumetric method was run in accordance with ASTM C173 to determine the air co ntent of freshly mixed concrete. Temperature Test: This test was run in accordance with ASTM C1064. It measures the temperature of freshly mixed concrete.

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46 Table 3-13 Standards for fresh concrete tests Test Standard Slump ASTM C143 Unit weight ASTM C138 Air content ASTM C173 Temperature ASTM C1064 Table 3-14 Properties of fres h concrete using RAP-1 Mix number W/C ratio Cement (lb/cy) Water (lb/cy) Slump (inches) Unit weight (lbs/ft3) Air content (percent) Temperature (F) 1 0.53 508 270 4.25 142 1.20 73 2 0.53 508 270 5.25 143 2.20 73 3 0.53 508 270 6.20 143 1.00 73 4 0.53 508 270 7.00 139 1.50 73 1 0.53 508 270 4.75 143 2.00 75 2 0.53 508 270 5.00 142 1.75 77 3 0.53 508 270 7.50 141 1.50 76 4 0.53 508 270 6.25 139 1.50 75 1 0.53 508 270 5.75 143 2.25 73 2 0.51 508 260 5.50 142 1.75 75 3 0.48 508 245 4.00 141 2.50 73 4 0.43 508 215 1.25 133 3.25 73 Table 3-15 Properties of fr esh concrete using RAP-2 Mix number W/C ratio Cement (lb/cy) Water (lb/cy) Slump (inches) Unit weight (lbs/ft3) Air content (percent) Temperature (F) 1 0.53 508 270 6.00 142 1.50 72 2 0.53 508 270 7.00 140 2.00 73 3 0.53 508 270 8.50 141 2.00 75 4 0.53 508 270 8.50 140 4.50 79 1 0.48 562 270 3.75 138 2.25 77 2 0.48 562 270 8.75 134 3.25 77 3 0.43 628 270 5.75 137 2.00 76 4 0.43 628 270 7.75 133 2.75 75 Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1 Set-1 RAP#2 Set-2 RAP#2

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47 3.6 Tests on Hardened Concrete 3.6.1 Compressive Strength and Elastic Modulus Test The standard test procedures of ASTM C39 and ASTM C469 were followed in running the com pressive strength and elastic m odulus test on 4" 8" cylindrical specimens. The two ends of the specimen were grinded evenly before testing to insure even loading during test. Two 4-inch displacement gages, held by four springs we re mounted on the sides of the specimen. The specimen was then placed in a MTS 810 material testing system as shown in Figure 3-14 and Figure 3-15. The testing machine was hydraulic controlled with a maximum capacity of 220 kips. Load was applied to the specimen at a cons tant loading rate of 26 kip/minute until complete failure occurred. The outputs from the displacem ent gages and the load cell from the testing machine were connected to a data acquisition syst em, which records the data during the test. The average displacement reading was used to calculate the strain, and reading from the load cell was used to calculate the stress. Maximum stress re ading was used as the compressive strength for the concrete. The modulus of elasticity was calculated as follows: )000050.0( 1 )(2 12 SSE Where E = Chord modulus of elasticity, psi S2 = Stress corresponding to 40% of ultimate load S1 = Stress corresponding to a longitudinal strain, 1, of 50 millionths, psi and 2 = Longitudinal strain produced by stress S2

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48 Figure 3-14 Material Testi ng System 810 [Guang Li, 2004] Figure 3-15 Failure of concrete cylind er in Compressive strength test

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49 3.6.2 Flexural Strength Test The flexural strength test wa s run in accordance with ASTM C78. 6" 6" 12" beam specimens were tested at each age and the aver age strength was computed. Before testing, the two loading surfaces were grounded evenly by using a grinding stone to support the applied load uniformly. The flexural strength was calculated acco rding to the type of fracture in the beam as follows: 1. If the fracture initiates in th e tension surface within the middle third of the span length, calculate the modulus of rupture as follows R = PL/bd2 Where R = modulus of rupture, psi P = maximum applied load indicated by the testing machine, lbf L = span length, in, or mm, b = average depth of specimen, in, or mm, at the fracture, and d = average depth of specimen, in, or mm, at the fracture. 2. If the fracture occurs in the tension surface outside of the middle third of the span length by not more than 5% of the span length, cal culate the modulus of rupture as follows R = 3Pa/bd2 Where R = modulus of rupture in psi P = maximum applied load indicated by the testing machine in lbf a = average distance between lin e of fracture and the nearest support measured on the tension surface of the beam, in, or mm. b = average depth of specimen, in, or mm, at the fracture, and d = average depth of specimen, in, or mm, at the fracture.

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50 3. If the fracture occurs in the tension surface outside of the middle third span length by more than 5% of the span length, discard the results of the test. Test procedure: The following steps were followed to run the beam test on an Instron 3384 loading frame as shown in Figure 3-16. 1. Smoothen the beam surfaces (top and botto m) with sand paper and clean it with acetone. 2. Glue one strain gage on each of the smoothened top and bottom surfaces with special Loctite 454 glue. 3. Allow the glue to dry to get a perfect bond between the strain gage and the beam. 4. Secure the wires in the area where they c onnect to the strain gages using a normal tape. 5. Place the beams properly centered on the lo ading frame, such that the one third marks accurately align with the loading platens as shown in the Figure 3-16. 6. Attach the strain gages to the SCXI-1000 unit using a quart er bridge configuration. 7. Run the testing machine at a rate of 30 lbs/sec while acquiring both voltage data (from the strain gages) and the load cell data. Data analysis: The following steps are followed in calculating stresses and strains in the flexural strength tests: 1. Determine Vo, from the voltage output data using the following equation, Ve ViVr Vo Where Vr = Variable voltage in volt, Vi = Initial voltage in volt, Ve = Excitation voltage in volt. 2. Calculate the strain us ing following equation, )21( 4VoGF Vo

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51 Where GF = Gage factor 3. Find the stress from the load output data using following equations I c M* Where c = Half of the depth in inch, I = Moment of inertia. 6 L PM Where P = Applied load in psi, L = Span length in inch, 4. Determine the maximum stress at the failure and note it down as flexural strength of the beam. Figure 3-16 Test setup used fo r flexural strength test

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52 Figure 3-17 Failure of the b eam without RAP material Figure 3-18 Failure of the beam containing RAP material 3.6.3 Splitting Tensile Strength Test The splitting tensile strength of concrete was run in accordance with ASTM C496. Cylindrical specimens (6 12) were used to de termine splitting tensile strength. Four lines were drawn along the centre of th e cylinder to mark the edges of the loaded plane and to help align the test specimen before the application of load. Figure 3-19 shows a typical setup of the

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53 cylinder during testing. A strip of wood, 3mm thick and 25mm wide, was inserted between the cylinder and the platens; this helped the applie d force to be uniformly distributed. Load was applied and increased until failure by indirect tension in the form of splitting along vertical diameter took place. The splitting tensile stre ngth of a cylinder specimen was calculated using the following equation: DL P T 2 Where T = splitting tensile strength of cylinder in psi, P = Maximum applied load in lbf, L = Length of cylinder in inch, D = Diameter of cylinder in inch. Figure 3-19 Test setup for spli tting tensile strength test

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54 Figure 3-20 Failure of concrete cylinders in indirect tension 3.6.4 Free Shrinkage Test The free shrinkage measurement was made in accordance with ASTM C157 using 3 X 3 X 11.25 square prism specimens. Figure 3-21 show s a mold used to cast the sample. Steel end plates with a hole at their centers were used to install gage studs at both ends of the specimen. The specimens were removed from the molds at an age of 23 h (after the addition of water to cement during the mixing operation) and then placed in lime-saturated water which was maintained at 73.4 1 F (23.0 0.5C) for a minimum of 30 min. At an age of 24 h, the specimens were removed from water storage one at a time, and wiped with a damp cloth. An initial reading was immediately taken with a length comparator. The specimens were then stored in the drying room and comparat or readings were taken of each specimen after curing age of 14 days, 28 days and 90 days. Figure 3-22 shows th e test set-up of the free shrinkage test. The length change of a specimen at any age after th e initial comparator reading was calculated as follows: 100 G CRD initial CRD Lx Where xL Length change of specimen at any age, %,

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55 CRD = Difference between the comparator reading of the specimen and the reference bar, G = gage length. Figure 3-21 Mold for free shrinkage test Figure 3-22 Setup fo r shrinkage test 3.6.5 Coefficient of Thermal Expansion (CTE) Test The CTE test was run in accordance with AAS HTO TP60. The test set-up is shown in Figure 3-23. The samples were sawed using a sa wing machine as shown in Figure 3-24 and then grinded using a grinding machine as shown in Figur e 3-25. This helped the samples to be in the desired length (7 0.1 inch ) required for the test. The procedure for the CTE test is as follows:

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56 1. Place the support frame, with LVDT attached, in the water bath and fill the bath with cold tap water. Place the four temperature sensors in the bath at locations that will provide an average temperature for the bath as a whole. To avoid any sticking at the points of contact with specimen, put a ve ry thin film of silicon gr ease on the end of the support buttons and LVDT tip. 2. Remove the specimen from the moisture room and measure its length at room temperature to the nearest 0.1 mm (0.004 in .). After measuring the length, place the specimen in the support frame located in the controlled temperature bath, making sure that the lower end of the specimen is firmly seated against the support buttons, and the LVDT tip is seated against th e upper end of the specimen. 3. Connect the LVDT and temperature sensors to a data acquisition system which is connected to a laptop computer. 4. Set the temperature of the water bath to 10 1 C (50 2 F). When the bath reaches this temperature, allow the bath to remain at this temperature until thermal equilibrium of the specimen has been reached, as indicated by cons istent readings of LVDT to the nearest 0.00025 mm (0.00001 in.) taken every 10 mi nutes over a one-half hour period. 5. Record the temperature readings from the four sensors to the nearest 0.1 C (0.2 F). Record the LVDT reading to the nearest 0. 00025 mm (0.00001 in.). These are the initial readings. 6. Set the temperature of the wate r bath to 50 1C (122 2 F ). When the bath reaches this temperature, allow the bath to remain at this temperature until thermal equilibrium of the specimen has been reached as indicated by consistent readings of LVDT to the nearest 0.00025 mm (0.00001 in.). 7. Record the temperature readings from the four sensors to the nearest 0.1 C (0.2 F). Record the LVDT reading to the nearest 0. 00025 mm (0.00001 in.). These are the second readings. 8. Set the temperature of the water bath to 10 1 C (50 2 F). When the bath reaches this temperature, allow the bath to remain at this temperature until thermal equilibrium of the specimen has been reached. 9. Record the temperature readings from the four sensors to the nearest 0.1 C (0.2 F). Record the LVDT reading to the nearest 0. 00025 mm (0.00001 in.). These are the final readings. The CTE of one expansion or c ontraction test segment of a concrete specimen is calculated as follows: CTE= ( La/L0) / T

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57 Where La = actual length change of specimen during temperature change, mm or in. L0 = measured length of specimen at r oom temperature, mm or in.; and T = measured temperature change (a verage of the four sensors), C. The test result is the averag e of the two CTE values obtained from the expansion test segment and contraction test segment, and is calculated as follows: 2 exp tion CTEcontrac ansion CTE CTE Figure 3-23 Setup for coefficien t of thermal expansion test Figure 3-24 Saw used for cutting concrete cylinder samples

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58 Figure 3-25 Grinder used for gri nding concrete cylinder samples

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59 CHAPTER 4 CONCRET E TEST RESULTS AND DISCUSSION 4.1 Introduction This chapter presents the results of comp ressive strength, elastic modulus, flexural strength, splitting tensile strength, free shrinka ge and coefficient of thermal expansion tests on the different concrete mixtures evaluated in this study. The effects of RA P on the properties of concrete are discussed. 4.2 Analysis of Compressive Strength Test Results and Discussion 4.2.1 Compressive Strength Test Results The average compressive strengths at various curing periods of different concrete mixtures are presented in Tables 4-1 and 4-2. The individual compressive strength values are shown in Table B-1 in Appendix B. Table 4-1 Compressive strength of the concrete using RAP-1 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggr egate RAP aggregate RAP RAP 14 28 90 Co mpressive s trength (psi) 1 0.53 100 0 100 0 0 5445 5596 6033 2 0.53 90 10 90 10 10 4484 4936 4976 3 0.53 80 20 80 20 20 3188 3778 3957 4 0.53 60 40 60 40 40 2444 2521 2657 1 0.53 100 0 100 0 0 5683 5779 6353 2 0.53 90 10 90 10 10 4643 4746 5230 3 0.53 80 20 80 20 20 3338 3365 3783 4 0.53 60 40 60 40 40 2336 2240 2766 1 0.53 100 0 100 0 0 5196 5928 2 0.51 90 10 90 10 10 3868 5127 3 0.48 80 20 80 20 20 3470 4794 4 0.43 60 40 60 40 40 3388 3900 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1

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60 Table 4-2 Compressive strength of the concrete using RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregat e RAP aggregate RAP RAP 14 28 C ompressive s trength (psi) 1 0.53 100 0 100 0 0 5644 7073 2 0.53 90 10 90 10 10 4304 4604 3 0.53 80 20 80 20 20 4029 4273 4 0.53 60 40 60 40 40 1952 / 1 0.48 82 18 77 23 20 4471 2970 2 0.48 66 34 47 53 40 3114 3152 3 0.43 82 18 76 24 20 3274 4687 4 0.43 67 33 44 56 40 2516 3342 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) 4.2.2 Effects of RAP on Compressive Strength of Concrete Results shown in Figures 4-1 through 4-3 show a reduction in comp ressive strength of concrete mixes made with RAP compared to the reference mix. The strength of concrete made with maximum percentage of e qual proportion of coarse RAP and fine RAP decreased the most among all the concrete mixtures. For a 0.53 water to cement ratio at 14-day, the strengths of Mix-2, Mix-3 and Mix-4 were 70% 60% and 40% of that of reference mix, respectively. At 28day, the strengths of Mix-2, Mix-3 and Mix-4 were 76%, 62% and 42% of that of reference mix, respectively. At 90-day, the st rengths of Mix-2, Mix-3 and Mi x-4 were 80%, 60% and 45% of that of reference mix, respectively. There is a consistent reduction in the strength of the mix containing RAP at differe nt curing periods. The reduction of the strength in the mix containing RAP could be due to the lower strength of the RAP as compared with the aggregate. Another possible cause could be the weaker bonding between aged asphalt f ilm and the concrete matrix. Set-1 RAP#2 Set-2 RAP#2

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61 Figure 4-1 Effect of RAP-1 on compressive strength at 14-day with 0.53 W/C ratio Figure 4-2 Effect of RAP-1 on compressive st rength at 28-day with 0.53 W/C ratio

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62 Figure 4-3 Effect of RAP-1 on compressive st rength at 90-day with 0.53 W/C ratio 4.2.3 Effects of Water to Cement Ratio on Compressive Strength of Concrete The compressive strength of concrete at a gi ven age is usually depe ndent primarily on the water to cement ratio. In this study, for the concrete mixes using 20% RAP-1 and 40% RAP-1 by volume of the mix, the effects of water to cementit ious materials ratio on co mpressive strength at ages of 14 days and 28 days are shown in Figures 4-4, 4-5, 4-6 and 47. Figures 4-4 and 4-5 show the effect of water to cement ratio on th e compressive strength for a mix containing 40% RAP-1. Figures 4-6 and 4-7 show the effect of water to cement ratio on the compressive strength for a mix containing 20 % RAP-1. In general, th e compressive strength tends to decrease as water to cementitious materials ratio increases.

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63 Figure 4-4 Effect of water to cementitious materi als on compressive strength at 14-day with 40% RAP Figure 4-5 Effect of water to cementitious materi als on compressive strength at 28-day with 40% RAP

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64 Figure 4-6 Effect of water to cementitious materi als on compressive strength at 14-day with 20% RAP Figure 4-7 Effect of water to cementitious materi als on compressive strength at 28-day with 20% RAP

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65 4.3 Analysis of Elastic Modulus Test Results and Discussion 4.3.1 Elastic Modulus Test Results The average elastic moduli at various curing pe riods of different c oncrete mixtures are presented in Tables 4-3 and 4-4. The individual elastic modulus va lues are shown in Table B-2 in Appendix B. Table 4-3 Elastic modulus of the concrete using RAP-1 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregate RAP aggregate RAP RAP 14 28 90 Elas tic modulus (106 psi) 1 0.53 100 0 100 0 0 4.44 4.78 4.72 2 0.53 90 10 90 10 10 3.82 4.00 4 .13 3 0.53 80 20 80 20 20 3.35 3.40 3 .57 4 0.53 60 40 60 40 40 2.31 2.35 2 .50 1 0.53 100 0 100 0 0 4.60 4.90 4.76 2 0.53 90 10 90 10 10 4.17 4.51 4 .55 3 0.53 80 20 80 20 20 3.41 3.75 3 .53 4 0.53 60 40 60 40 40 2.27 2.30 2 .62 1 0.53 100 0 100 0 0 4.27 4.90 2 0.51 90 10 90 10 10 4.11 4.03 3 0.48 80 20 80 20 20 3.31 3.50 4 0.43 60 40 60 40 40 2.77 2.79 (Note: Coarse aggregate and coarse RAP are volume per cent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Table 4-4 Elastic modulus of the concrete using RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregate RAP aggreg ate RAP RAP 14 28 Ela stic modulus (106 psi) 1 0.53 100 0 100 0 0 4.26 4.60 2 0.53 90 10 90 10 10 3.76 3.75 3 0.53 80 20 80 20 20 3.12 3.22 4 0.53 60 40 60 40 40 2.60 / 1 0.48 82 18 77 23 20 3.17 2.81 2 0.48 66 34 47 53 40 2.30 2.27 3 0.43 82 18 76 24 20 3.23 3.90 4 0.43 67 33 44 56 40 2.25 3.29 (Note: Coarse aggregate and coarse RAP are volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1 Set-1 RAP#2 Set-2 RAP#2

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66 4.3.2 Effects of RAP on Elas tic Modulus of Concrete Figure 4-8 presents the results of elastic modulus test. It show s that there is a systematic reduction of elastic modulus of concrete contai ning RAP. For RAP-1 with 0.53 water to cement ratio at 14-day, the elastic modulus of Mix-2, Mix-3 and Mix-4 were 88%, 75% and 54% of that of reference mix, respectively. For RAP-1 with 0.53 water to cement ratio at 28-day, the elastic modulus of Mix-2, Mix-3 and Mix-4 were 86%, 73% and 49% of that of reference mix, respectively. For RAP-1 with 0.53 water to cement ratio at 90-day, the elastic modulus of Mix-2, Mix-3 and Mix-4 were 79%, 70% a nd 55% of that of reference mix, respectively. Therefore consistent reduction in the elas tic modulus for mixtures cont aining RAP at different curing periods was observed. It is we ll known that elastic modulus of concrete is highly affected by modulus of elasticity of aggregate and the content of aggreg ate in a mix. RAP being softer than the natural aggregate de monstrates a lower modulus of elasticity and decreases the elastic modulus of concrete. Thus an increase in the content of RAP in the mix will further reduce the elastic modulus of the concrete. Figure 4-8 Effect of RAP on elastic modul us of concrete with 0.53 W/C ratio

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67 4.3.3 Effects of Water to Cement Ratio on Elastic Modulus of Concrete For the concrete mixtures using 20% RAP1 and 40% RAP-1 by volume of the mix, the effects of water to cementitious materials ratio on elastic modulus at ages of 14 days and 28 days are shown in Figures 4-9, 4-10, 4-11 and 4-12. Figures 4-9 and 4-10 show the effect of water to cement ratio on the elastic modulus of a mix containing 40% RAP-1. While Figure 4-10 and Figure 4-11 shows the effect of water to cement ratio on the elastic modulus of a mix containing 20 % RAP-1. It can be seen that the elastic modulus increases with a decrease in water to cement ratio of the concrete. Figure 4-9 Effect of water to cementitious mate rials on elastic modulus at 14-day with 40% RAP Figure 4-10 Effect of water to cementitious ma terials on elastic modulus at 28-day with 40% RAP

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68 Figure 4-11 Effect of water to cementitious ma terials on elastic modulus at 14-day with 20% RAP Figure 4-12 Effect of water to cementitious ma terials on elastic modulus at 28-day with 20% RAP 4.4 Analysis of Flexural Strength Test Results and Discussion 4.4.1 Flexural Strength Test Results The average flexural strengths at various curi ng periods of different concrete mixtures are presented in Tables 4-5 and 4-6. The individual flexural strength values are shown in Table B-3 in Appendix B.

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69 Table 4-5 Flexural strength of the concrete using RAP-1 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregate RAP aggregate RAP RAP 14 28 90 Flexural strength (psi) 1 0.53 100 0 100 0 0 883 940 976 2 0.53 90 10 90 10 10 807 940 8 45 3 0.53 80 20 80 20 20 829 750 7 56 4 0.53 60 40 60 40 40 715 570 6 77 1 0.53 100 0 100 0 0 802 969 763 2 0.53 90 10 90 10 10 781 868 5 72 3 0.53 80 20 80 20 20 705 709 5 53 4 0.53 60 40 60 40 40 578 640 5 10 1 0.53 100 0 100 0 0 535 570 2 0.51 90 10 90 10 10 558 534 3 0.48 80 20 80 20 20 520 / 4 0.43 60 40 60 40 40 465 517 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Table 4-6 Flexural strength of the concrete using RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregate RAP ag gregate RAP RAP 14 28 Flexura l strength (psi) 1 0.53 100 0 100 0 0 608 543 2 0.53 90 10 90 10 10 552 513 3 0.53 80 20 80 20 20 430 441 4 0.53 60 40 60 40 40 400 / 1 0.48 82 18 77 23 20 477 482 2 0.48 66 34 47 53 40 393 410 3 0.43 82 18 76 24 20 484 539 4 0.43 67 33 44 56 40 394 404 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) 4.4.2 Effects of RAP on Flexural Strength of Concrete Figure 4-13 presents the results of flexural strength test. For RAP-1 with 0.53 water to cement ratio at 14-day, the flexural strength of Mix-2, Mix-3 and Mi x-4 were 93%, 90% and Set-1 RAP#1 Set-2 RAP#1 Set-3 RAP#1 Set-1 RAP#2 Set-2 RAP#2

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70 75% of that of reference mix, respectively. For RAP-1 with 0.53 water to cement ratio at 28day, the flexural strength of Mix-2, Mix-3 and Mix-4 were 95%, 75% and 65% of that of reference mix, respectively. For RAP-1 with 0.53 water to cement ratio at 90-day, the flexural strength of Mix-2, Mix-3 and Mix-4 were 80% 75% and 70% of that of reference mix, respectively. Figure 4-14 shows the reductions in strength for concrete containing RAP-1. For 0.53 water to cement ratio, average reductions in compressive strength at different curing periods were 18%, 38% and 58% for Mix-2, Mix-3 and Mix-4 respectively. For 0.53 water to cement ratio, average reductions in fle xural strength at different curing periods were 10%, 20% and 30% for Mix-2, Mix-3 and Mix4 respectively. The reductions in co mpressive strength are higher than the reductions in flexural strength fo r all the mixtures containing RAP-1. Figure 4-13 Effect of RAP on flexural strength of c oncrete of 0.53 W/C ratio Figure 4-14 Decrease in strength of the concrete c ontaining RAP-1

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71 4.4.3 Effects of RAP on Modulus of Toughness of Concrete Tables 4-7, Table 4-8 and Ta ble 4-9 show the values of modulus of toughness. It shows that for all the mixtures containing RAP, the modulus of toughness was hi gher than the reference mixture. The modulus of toughness was calculated us ing stress-strain curve from the beam test. Figure 4-15, Figure 4-16 and Figure 4-17 show the stress strain plot s for mixtures with different RAP contents for beam test, with different curi ng periods, and water to cement ratio of 0.53. Increase in the modulus of toughness could be due to the high ductility of the RAP material in the concrete mixtures. In a conc rete made with RAP, the asphalt around the aggregate is softer and causes an increase in the ductility of the mix. For a water cement ratio of 0.53, at 90-day, the modulus of toughness of Mix-2, Mix-3 and Mix-4 in tension zone were 108%, 250% and 255% of that of Mix-1. This shows th at there is a considerable incr ease in modulus of toughness for the mixtures containing RAP. Table 4-7 Modulus of toughness of concrete using RAP-2 at 14-day Mix W/C Coarse Coarse Fine Fine Total Modulus of number ratio aggregate RAP aggregate RAP RAP toughness (lb-in /in3) 1 0.53 100 0 100 0 0 0.04 2 0.53 90 10 90 10 10 0.03 3 0.53 80 20 80 20 20 0.06 4 0.53 60 40 60 40 40 0.09 Table 4-8 Modulus of toughness of concrete using RAP-2 at 28-day Mix W/C Coarse Coarse Fine Fine Total Modulus of number ratio aggregate RAP aggregate RAP RAP toughness (lbin/in3) 1 0.53 100 0 100 0 0 0.04 2 0.53 90 10 90 10 10 0.14 3 0.53 80 20 80 20 20 0.10 4 0.53 60 40 60 40 40 / Set-1 RAP#2 Set-1 RAP#2

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72 Table 4-9 Modulus of toughness of concrete using RAP-1 at 90-day Mix W/C Coarse Co arse Fine Fine Total Modulus of toughness number ratio aggregate RAP aggregate RAP RAP (lb-in/in3) Tension Compression 1 0.53 100 0 100 0 0 0.13 0.05 2 0.53 90 10 90 10 10 0.14 0.04 3 0.53 80 20 80 20 20 0.32 0.08 4 0.53 60 40 60 40 40 0.33 0.11 Figure 4-15 Stress-strain plots for mixtures with different RAP-2 contents from beam test Figure 4-16 Stress-strain plots for mixtures with different RAP-2 contents from beam test Set-1 RAP#1 Set-2 RAP#1

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73 Figure 4-17 Stress-strain pl ots for mixtures with different RAP-1 contents from beam test and 0.53 W/C ratio. 4.5 Analysis of Splitting Tensile Stre ngth Test Results and Discussion 4.5.1 Splitting Tensile Strength Test Results The average split tensile strengths at various cu ring periods of different concrete mixtures using RAP-1 and Rap-2 are shown in Table 4-10. Individual splitting tens ile strength values are shown in Table B-4. Table 4-10 Splitting tensile strength of the concrete using RAP-1 and RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggreg ate RAP aggregate RAP RAP 14 28 Splitting t ensile strength (psi) 1 0.53 100 0 100 0 0 512 475 2 0.51 90 10 90 10 10 370 4 85 3 0.48 80 20 80 20 20 260 3 69 4 0.43 60 40 60 40 40 310 3 40 Set-1 RAP#1

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74 Table 4-10 Continued 1 0.53 100 0 100 0 0 533 607 2 0.53 90 10 90 10 10 387 4 17 3 0.53 80 20 80 20 20 364 3 60 4 0.53 60 40 60 40 40 211 / 1 0.48 82 18 77 23 20 378 3 35 2 0.48 66 34 47 53 40 281 3 00 3 0.43 82 18 76 24 20 365 4 44 4 0.43 67 33 44 56 40 289 3 12 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) 4.5.2 Effects of RAP on Splitting Tensile Strength of Concrete Figure 4-18 presents the results of split tensil e strength test. For 0.53 water to cement ratio at 14-day, the splitting tensile strength of Mix-2, Mix-3 and Mix-4 were 74%, 70% and 40% of that of reference mix, respectively. For 0.53 wate r to cement ratio at 28-day, the splitting tensile strength of Mix-2 and Mix-3 were 77% and 67%, of that of refe rence mix, respectively. Figure 4-19 shows the decrease in the strength of concre te with increase in percentage RAP. For 0.53 water to cement ratio, average reductions in co mpressive strength at different curing periods were 18%, 38% and 58% for Mix-2, Mix-3 and Mix-4 respectively. For 0.53 water to cement ratio, average reductions in fle xural strength at different curing periods were 10%, 20% and 30% for Mix-2, Mix-3 and Mi x-4 respectively. For 0.53 water to cement ratio, average reductions in splitting tensile strength at diffe rent curing periods were 25%, 30% and 60% for Mix-2, Mix-3 and Mix-4 respectively. Reduction in splitting tensile strength is higher than that in flexural strength for this set of mixtur es containing RAP-1. It also sh ows that the concrete using RAP performs much better in te nsion than in compression. Set-2 RAP#1 Set-3 RAP#2

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75 Figure 4-18 Effect of RAP-1 on splitting tensile strength for 0.53 W/C ratio Figure 4-19 Decrease in the strength of conc rete containing RAP1 for 0.53 W/C ratio 4.6 Analysis of Free Shrinkage Test Results and Discussion 4.6.1 Free Shrinkage Test Results The average free shrinkage values at various cu ring periods of different concrete mixtures are presented in Table 4-11 and Table 4-12. Th e individual free shrinkag e strain values are shown in Table B-5 in Appendix B. Table 4-11 Free shrinkage of the concrete using RAP-1 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggreg ate RAP aggregate RAP RAP 14 28 90 Shrinkag e (10-6 in/in) 1 0.53 100 0 100 0 0 73 250 / 2 0.53 90 10 90 10 10 85 215 / 3 0.53 80 20 80 20 20 73 120 277 4 0.53 60 40 60 40 40 67 187 337 Set-1 RAP#1

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76 Table 4-11 Continued 1 0.53 100 0 100 0 0 150 287 353 2 0.53 90 10 90 10 10 103 240 3 53 3 0.53 80 20 80 20 20 220 283 3 90 4 0.53 60 40 60 40 40 210 327 5 07 1 0.53 100 0 100 0 0 147 290 2 0.51 90 10 90 10 10 135 174 3 0.48 80 20 80 20 20 123 235 4 0.43 60 40 60 40 40 137 / (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Table 4-12 Free shrinkage of the concrete using RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggregate RAP aggreg ate RAP RAP 14 28 Shrink age (10-6 in/in) 1 0.53 100 0 100 0 0 133 230 2 0.53 90 10 90 10 10 125 165 3 0.53 80 20 80 20 20 193 273 4 0.53 60 40 60 40 40 183 / 1 0.48 82 18 77 23 20 127 276 2 0.48 66 34 47 53 40 140 300 3 0.43 82 18 76 24 20 153 260 4 0.43 67 33 44 56 40 140 273 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) 4.6.2 Effects of RAP on Free Shrinkage of concrete Figure 4-20 shows the comparison of the free sh rinkage strains of the concrete mixtures with different RAP-1 contents having 0.53 wate r to cement ratio. The concretes containing 10% and 20% RAP-1 appear to have lower shrinkage than the control mix. However for mix-4 with 40% RAP-1, the shrinkage is high er than the control mix. It al so shows that shrinkage strain develops much faster at early ages than at the later ages. Shrinkage for the mixtures containing a low content of RAP was lower as compared with the shrinkage of mixtur es containing a higher Set-2 RAP#1 Set-3 RAP#1 Set-1 RAP#2 Set-2 RAP#2

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77 content of RAP. This is because shrinkage is highly affected by the type of aggregate and quantity of aggregate in a mix. Usually, shrink age decreases with the aggregate having higher elastic modulus. RAP being softer than the normal aggregate experiences higher shrinkage strain values. However this was not true for the mixes with lower RAP content which had lower shrinkage values compared to the control mix. Figure 4-20 Free shrinkage strain for concrete mixtures wi th different RAP contents 4.7 Analysis of Coefficient of Thermal Expansion Test Results 4.7.1 Coefficient of Thermal Expansion Test Results The average coefficients of thermal expans ion at various curing periods of different concrete mixtures are shown in Table 4-13 and Table 4-14. Individual co efficient of thermal expansion values are shown in Table B-6. Table 4-13 Coefficient of thermal expa nsion of the concrete using RAP-1 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio a ggregate RAP aggregate RAP RAP 14 28 90 Coefficient of thermal expansion (10-6/F) 1 0.53 100 0 100 0 0 5.97 6.05 6 .19 2 0.53 90 10 90 10 10 6.00 6.07 6. 27 3 0.53 80 20 80 20 20 5.85 6.43 6. 12 4 0.53 60 40 60 40 40 6.36 6.20 6. 29 Set-1 RAP#1

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78 Table 4-13 Continued 1 0.53 100 0 100 0 0 5.79 5.55 5.79 2 0.53 90 10 90 10 10 5.85 5.96 5. 63 3 0.53 80 20 80 20 20 5.81 5.72 5. 86 4 0.53 60 40 60 40 40 5.97 6.13 5. 99 1 0.53 100 0 100 0 0 4.93 4.67 2 0.51 90 10 90 10 10 / 5.02 3 0.48 80 20 80 20 20 4.75 5.02 4 0.43 60 40 60 40 40 5.00 5.33 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) Table 4-14 Coefficient of thermal expa nsion of the concrete using RAP-2 Mix W/C Coarse Coarse Fine Fine Total Age of testing (days) number ratio aggreg ate RAP aggregate RAP RAP 14 28 Co efficient of Therm al expansion (10-6/F) 1 0.53 100 0 100 0 0 5.39 / 2 0.53 90 10 90 10 10 5.09 / 3 0.53 80 20 80 20 20 4.93 / 4 0.53 60 40 60 40 40 5.05 / 1 0.48 82 18 77 23 20 6.49 5.75 2 0.48 66 34 47 53 40 5.74 5.90 3 0.43 82 18 76 24 20 6.03 6.34 4 0.43 67 33 44 56 40 5.94 6.17 (Note: Coarse aggregate and co arse RAP are volume percent by to tal coarse aggregate, fine aggregate and fine RAP are volum e percent by total fine aggregate. Total RAP is the total percentage replacement of coarse RAP and fine RAP) 4.7.2 Effects of RAP on Coefficient of Thermal Expansion of Concrete Figure 4-21 shows the results of coefficient of thermal expansion for concrete with different RAP contents. It shows that coefficient of thermal e xpansion for concrete mixtures containing RAP is higher than the reference mixture. Coefficient of thermal expansion of a mix mainly depends on the aggregate type and the am ount of aggregate in a mix. Limestone is known to have the lowest coefficients of thermal expansion compared to rocks such as sandstone and Set-2 RAP#1 Set-3 RAP#1 Set-1 RAP#2 Set-2 RAP#2

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79 granite. Since RAP contains as phalt, it would tend to have a higher coefficient of thermal expansion as compared with the aggregate in the mix. However it is very difficult to predict the exact difference in coefficient of thermal between the RAP mix and the reference mix. This was due to the variation in coefficient of thermal expansion for the different mixes at different curing period. For instance, at 14-day curing period, the coefficient of thermal expansion of mixes containing 20 % RAP was lowest among all the mi xes. Similarly at 28-day and 90-day curing period, the coefficient of thermal expansion of mixes containing 0% and 10% RAP were lowest among all the mixes, respectively. Mixtures cont aining 40% RAP had the hi ghest coefficient of thermal. For the mixtures containing RAP-1 the in crease in coefficient of thermal expansion was within 5% of that of reference mix at differe nt curing periods. For the mixtures containing RAP2 there was decrease in coefficient of therma l compared to reference mix. At 14-day, the reductions were 5%, 8% and 6% for Mix-2, Mix-3 and Mix-4 respectively. Figure 4-21 Coefficient of therma l expansion for concrete with different RAP contents and 0.53 W/C ratio

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80 4.8 Summary of Test Results Following is the summary of all the test resu lts based on the findings of this research 1. Compressive strength, flexural strength, sp lit tensile strength a nd elastic modulus of concrete decreases as the percentage of RAP increases in a concrete mix. 2. Reduction in flexural stre ngth of the concrete containing RAP was lower than compressive strength and split tensile strength of the concrete mix containing RAP. 3. The shrinkage strain of the concrete incr eases slightly with increasing RAP content 4. The coefficient of thermal expansion appears to increase slightly with the use of one RAP and decrease slightly with the use of a second RAP.

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81 CHAPTER 5 EVAL UATION OF POTENTIAL PERFORMANCE OF CONCRETE CONTAINING RAP IN PAVEMENT 5.1 Finite Element Model Used to Perform Stress Analysis Analysis was done to determin e how each of the four concre te mixes with different RAP content would perform if it were used in a typi cal concrete pavement in Florida. Using the measured elastic modulus and the coefficient of thermal expansion to model the concrete, analysis was performed to determine the maximum stresses in the concrete slab if it were loaded by a 22-kip wheel applied at the critical loading positions, at the slab corner and middle edge as shown in Figure 5-2. Temper ature differentials of +20F, 0F and -20F in the concrete slab were used in the analyses. The FEACONS IV (Finite Element Analysis of Concrete Slabs version IV) program was used to perform the stress analysis. The FEACONS program was written in the FORTRAN-77 language and can be run on any computer sy stem with a FORTRAN-77 compiler and an adequately large core memory. The program ha s been run successfully on an IBM 9001 desk-top computer and a digital equipment corporation VAX mini-computer using FORTRAN-77 compilers. The FEACONS program was previously developed at the University of Florida for FDOT for the analysis of PCC pavements subj ected to load and thermal effects, and had demonstrated to be a fairly effective and reli able tool for this type of analysis. Figure 5-1 shows the finite element model us ed to perform the stress analysis. Figure 5-3 shows the details of input guide used for FEACONS IV program. The following parameters were used to model the concrete pavement. (1) Slab thickness = 10 in; slab lengt h = 15 ft; slab width = 12 ft (2) Subgrade modulus, ks = 0.3 kci; edge stiffness, ke = 30 ksi (3) Joint linear stiffness, kl = 500 ksi; Joint tors ion stiffness kt = 1000 k-in/in

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82 Figure 5-1 Finite element model used in FEACONS IV analysis Figure 5-2 22-kip wheel load at slab corner and middle edge

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83 Figure 5-3 Example input file input used for the FEACONS IV program 5.2 Results of Stress Analysis using FEACONS IV Analysis Analysis using the FEACONS model was performed to determine stresses in a 10-inch concrete pavement slab if it were loaded by 22kip axle load at two critical loading positions, namely at the slab corner and at the middle of th e slab edge. The middle of the slab edge is the most critical loading position in the day time when the temperature differential in the slab is positive, while the slab corner is the most critic al loading position at night when the temperature differential is negative. Using the stresses calculated by FEACONS IV program and the determined flexural strength, stress-strength rati os were calculated to compare the performance of the concrete with RAP.

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84Table 5-1 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-1 with RAP-1 at 14-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4440 883 387 450 0.44 0.51 2 0.53 90 10 90 10 10 6.00 3820 807 371 408 0.46 0.50 3 0.53 80 20 80 20 20 6.00 3350 829 354 376 0.43 0.45 4 0.53 60 40 60 40 40 6.00 2310 715 297 296 0.42 0.41 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4440 883 310 292 0.35 0.33 2 0.53 90 10 90 10 10 6.00 3820 807 276 260 0.33 0.32 3 0.53 80 20 80 20 20 6.00 3350 829 249 234 0.30 0.28 4 0.53 60 40 60 40 40 6.00 2310 715 182 174 0.25 0.24 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4440 883 161 177 0.18 0.20 2 0.53 90 10 90 10 10 6.00 3820 807 154 171 0.19 0.21 3 0.53 80 20 80 20 20 6.00 3350 829 149 165 0.18 0.20 4 0.53 60 40 60 40 40 6.00 2310 715 135 149 0.19 0.21 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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85Table 5-2 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-1 with RAP-1 at 28-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4780 940 398 470 0.42 0.50 2 0.53 90 10 90 10 10 6.00 4000 940 373 421 0.39 0.45 3 0.53 80 20 80 20 20 6.00 3400 750 356 380 0.47 0.51 4 0.53 60 40 60 40 40 6.00 2350 639 298 299 0.47 0.47 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4780 940 328 308 0.35 0.33 2 0.53 90 10 90 10 10 6.00 4000 940 286 269 0.30 0.27 3 0.53 80 20 80 20 20 6.00 3400 750 252 237 0.34 0.32 4 0.53 60 40 60 40 40 6.00 2350 639 185 176 0.32 0.28 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4780 940 164 181 0.17 0.19 2 0.53 90 10 90 10 10 6.00 4000 940 157 173 0.17 0.18 3 0.53 80 20 80 20 20 6.00 3400 750 150 166 0.20 0.22 4 0.53 60 40 60 40 40 6.00 2350 639 135 150 0.24 0.23 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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86Table 5-3 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-1 with RAP-1 at 90-day Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4720 976 396 467 0.41 0.48 2 0.53 90 10 90 10 10 6.00 4130 845 376 429 0.44 0.51 3 0.53 80 20 80 20 20 6.00 3570 756 362 392 0.48 0.52 4 0.53 60 40 60 40 40 6.00 2500 677 307 311 0.45 0.46 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4720 976 324 305 0.33 0.31 2 0.53 90 10 90 10 10 6.00 4130 845 293 276 0.35 0.33 3 0.53 80 20 80 20 20 6.00 3570 756 262 246 0.35 0.33 4 0.53 60 40 60 40 40 6.00 2500 677 195 184 0.29 0.27 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4720 976 164 180 0.17 0.18 2 0.53 90 10 90 10 10 6.00 4130 845 158 174 0.19 0.21 3 0.53 80 20 80 20 20 6.00 3570 756 152 168 0.20 0.22 4 0.53 60 40 60 40 40 6.00 2500 677 137 153 0.20 0.23 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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87Table 5-4 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-2 with RAP-1 at 14-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4600 801 392 459 0.49 0.57 2 0.53 90 10 90 10 10 6.00 4170 780 378 432 0.48 0.55 3 0.53 80 20 80 20 20 6.00 3410 704 356 381 0.51 0.54 4 0.53 60 40 60 40 40 6.00 2270 558 296 292 0.53 0.52 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4600 801 319 300 0.40 0.37 2 0.53 90 10 90 10 10 6.00 4170 780 296 278 0.38 0.36 3 0.53 80 20 80 20 20 6.00 3410 704 252 237 0.36 0.34 4 0.53 60 40 60 40 40 6.00 2270 558 180 171 0.32 0.31 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4600 801 163 179 0.20 0.23 2 0.53 90 10 90 10 10 6.00 4170 780 159 175 0.20 0.22 3 0.53 80 20 80 20 20 6.00 3410 704 150 166 0.21 0.24 4 0.53 60 40 60 40 40 6.00 2270 558 134 149 0.24 0.27 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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88Table 5-5 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-2 with RAP-1 at 28-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 969 402 478 0.42 0.49 2 0.53 90 10 90 10 10 6.00 4510 867 389 453 0.45 0.52 3 0.53 80 20 80 20 20 6.00 3750 709 369 403 0.52 0.57 4 0.53 60 40 60 40 40 6.00 2300 640 297 295 0.46 0.46 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 969 334 314 0.35 0.32 2 0.53 90 10 90 10 10 6.00 4510 867 314 295 0.36 0.34 3 0.53 80 20 80 20 20 6.00 3750 709 272 256 0.38 0.36 4 0.53 60 40 60 40 40 6.00 2300 640 182 173 0.28 0.27 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 969 166 182 0.17 0.19 2 0.53 90 10 90 10 10 6.00 4510 867 162 178 0.19 0.21 3 0.53 80 20 80 20 20 6.00 3750 709 154 170 0.22 0.24 4 0.53 60 40 60 40 40 6.00 2300 640 135 149 0.21 0.23 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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89Table 5-6 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-2 with RAP-1 at 90-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4760 763 397 469 0.52 0.61 2 0.53 90 10 90 10 10 6.00 4550 572 390 457 0.68 0.80 3 0.53 80 20 80 20 20 6.00 3530 553 361 389 0.65 0.70 4 0.53 60 40 60 40 40 6.00 2620 510 316 321 0.62 0.63 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4760 763 327 307 0.43 0.40 2 0.53 90 10 90 10 10 6.00 4550 572 316 297 0.55 0.52 3 0.53 80 20 80 20 20 6.00 3530 553 259 244 0.47 0.47 4 0.53 60 40 60 40 40 6.00 2620 510 203 191 0.40 0.40 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 90-day Mean 90-day Mean 90-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4760 763 165 181 0.22 0.24 2 0.53 90 10 90 10 10 6.00 4550 572 162 170 0.28 0.30 3 0.53 80 20 80 20 20 6.00 3530 553 151 167 0.27 0.30 4 0.53 60 40 60 40 40 6.00 2620 510 139 154 0.27 0.23 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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90Table 5-7 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-3 with RAP-1 at 14-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4270 535 380 439 0.71 0.82 2 0.51 90 10 90 10 10 6.00 4110 558 376 428 0.67 0.77 3 0.48 80 20 80 20 20 6.00 3310 520 351 374 0.68 0.72 4 0.43 60 40 60 40 40 6.00 2770 465 323 333 0.69 0.72 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4270 535 301 283 0.56 0.53 2 0.51 90 10 90 10 10 6.00 4110 558 292 275 0.52 0.49 3 0.48 80 20 80 20 20 6.00 3310 520 246 232 0.47 0.45 4 0.43 60 40 60 40 40 6.00 2770 465 213 200 0.46 0.43 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 14-day Mean 14-day Mean 14-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4270 535 160 176 0.30 0.33 2 0.51 90 10 90 10 10 6.00 4110 558 158 174 0.28 0.31 3 0.48 80 20 80 20 20 6.00 3310 520 149 164 0.29 0.32 4 0.43 60 40 60 40 40 6.00 2770 465 141 157 0.30 0.34 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the total pe rcentage replacement of coarse RAP and fine RAP)

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91Table 5-8 Computed maximum stresses and st ress-strength ratios in concrete pavement subjected to a 22-kip single axle load for set-3 with RAP-1 at 28-day Temperature difference of +20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 570 402 478 0.71 0.84 2 0.51 90 10 90 10 10 6.00 4030 534 373 423 0.70 0.79 3 0.48 80 20 80 20 20 6.00 / / / / / / 4 0.43 60 40 60 40 40 6.00 2790 517 324 335 0.63 0.65 Temperature difference of -20F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 570 334 314 0.59 0.55 2 0.51 90 10 90 10 10 6.00 4030 534 288 237 0.54 0.44 3 0.48 80 20 80 20 20 6.00 / / / / / / 4 0.43 60 40 60 40 40 6.00 2790 517 214 201 0.41 0.39 Temperature difference of 0F between top and bottom Mix No W/C Coarse Coarse Fine Fine Total Mean 28-day Mean 28-day Mean 28-day Computed Stress ratio Agg. RAP Agg. RAP RAP Water-saturated Modulus of Modulus of Stress (psi) Ratio CTE (10-6/F) Elasticity (ksi) Rupture (psi ) Corner Middle Corner Middle Edge Edge 1 0.53 100 0 100 0 0 6.00 4900 570 166 182 0.29 0.32 2 0.51 90 10 90 10 10 6.00 4030 534 157 173 0.29 0.32 3 0.48 80 20 80 20 20 6.00 / / / / / / 4 0.43 60 40 60 40 40 6.00 2790 517 141 157 0.27 0.30 (Note: Coarse aggregate and coarse RAP ar e volume percent by total coarse aggregate, fine aggregate and fine RAP are volume percent by total fine aggregate. Total RAP is the tota l percentage replacement of coarse RAP and fine RAP)

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92 5.3 Effects of RAP on Stress-Streng th Ratio of Concrete Pavement 5.3.1 Effects of RAP-1 on Stress-Strength Ratio of Concrete Pavement Analysis using the FEACONS model was perf ormed to determine maximum stresses in 10-inch concrete slab if it were loaded by 22-ki p axle load at two critical loading positions, namely at the slab corner and at the middle of the slab edge. The middle of the slab edge being more critical had maximum stresses compared to the slab corner. Using the stresses calculated by FEACONS IV program and the de termined flexural strength, stress-strength ratios were calculated to compare the performance of the conc rete with RAP. Figure 5-4 to Figure 5-8 shows the stressstrength ratios at the corn er and middle edge of the slab with +20F, -20F and +0F temperature differential. It shows that stress-str ength ratio reduces for all the concrete mixtures containing 40% RAP-1 at the middle edge of the slab compared to other mixtures with 10% and 20% RAP and reference mix. There was no reduction in stress-strength ratio for all the mixtures containing 10% and 20% RAP-1 compared to reference mixture. Fo r 0.53 water to cement ratio, at 14-day, with +20F temperatur e differential the stress-strength ra tio for the concrete containing 40% RAP-1 at the middle edge of the slab was 87% of the reference mix. For 0.53 water to cement ratio, at 28-day, with +20F temperature differential the stress-strength ratio for the concrete containing 40% RAP-1 at the middle edge of the slab was 93% of the reference mix. For 0.53 water to cement ratio at 90-day, with +20F temperature differential the stress-strength ratio for the concrete containi ng 40% RAP-1 at the middle edge of the slab was 100% of the reference mix. Figure 5-4 shows an increase in stress-strength ratio for the concrete containing RAP at the slab corner with +20 F temperat ure differentials and 0.53 water to cement ratio. Figure 5-6 shows some decrease in stress-strengt h ratio for the concrete containing 40% RAP at the slab corner with -20 F temperature di fferentials and 0.53 water to cement ratio.

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93 Figure 5-4 Average Stressstrength ratios at the slab corner with +20F temperature differential and 0.53 W/C ratio. Figure 5-5 Average Stress-stre ngth ratios at the middle edge of the slab with +20F temperature differential and 0.53 W/C ratio.

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94 Figure 5-6 Average Stressstrength ratios at the slab corner with -20F temperature differential and 0.53 W/C ratio. Figure 5-7 Average Stress-stre ngth ratios at the middle edge of the slab with -20F temperature differential and 0.53 W/C ratio.

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95 Figure 5-8 Average Stress-stre ngth ratios at the middle edge of the slab with 0F temperature differential and 0.53 W/C ratio. 5.3.2 Effects of RAP-1 on Stress-Strength Ratio of Concrete Pavement with Varying Water to Cement Ratio Figure 5-9 to Figure 5-13 shows the stressstrength ratios at the corner and middle edge of the slab with +20F, -20F and +0F temperature differen tial. It shows that stress-strength ratio reduces for the concrete containi ng RAP-1 at the middle edge and co rner of the slab. For all the mixtures containing RAP-1 there was reduction in stress strength ratio compared to reference mix. At 14-day, with +20F temperature differentia l, the stress-strength ratio at the middle edge of the slab for the concrete mixtures with 0. 51 water to cement ratio and 10% RAP-1, 0.48 water to cement ratio and 20% RAP-1 and 0.43 water to cement ratio and 40% RAP-1 were 94%, 87% and 87% of the reference mix. At 28-day, with + 20F temperature differential, the stress-strength ratio at the middle edge of the slab for the conc rete mixtures with 0.51 water to cement ratio and 10% RAP-1 and 0.43 water to cement ratio and 40 % RAP-1 were 94% and 77% of the reference mix. Reduction in stress-strength ratio was obser ved due to lower water to cement ratio for the mixtures containing higher percentage of RAP.

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96 Figure 5-9 Stress-strength rati os at the slab corner with +20F temperature differential and varying W/C ratio. Figure 5-10 Stress-strengt h ratios at the middle e dge of the slab with +20F temperature differential and varying W/C ratio.

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97 Figure 5-11 Stress-strength ratio s at the slab corner with -20F temperature differential and varying W/C ratio. Figure 5-12 Stress-strengt h ratios at the middle e dge of the slab with -20F temperature differential and varying W/C ratio.

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98 Figure 5-13 Stress-strengt h ratios at the middle e dge of the slab with 0F temperature differential and varying W/C ratio. 5.4 Observation on Results of Stress Analysis From the results presented in Tables 5-1 thr ough Table 5-8, it can be seen that the most critical loading condition, which results in the maximum computed stress, was the condition when the 22-kip axle load was applied at the middle edge of the slab when the temperature differential is +20F. Thus the observation of poten tial performance of the various concrete mixes will be focused mainly on the computed st ress-strength ratio at this condition. From the results presented in Table 5-1 th rough Table 5-8, which present the analysis results for concrete using RAP-1, it can be seen that a reduction in the co mputed stressstrength was generally obtained as a resu lt of incorporation of RAP in the concrete mix. Though the flexural strength of the concrete was reduced due to the incorporation of RAP, the loadtemperature induced stresses were reduced due to reduction in elastic modulus. A lower stress to strength indicate that the concrete will be able to sustain higher number of load repetition before fatigue failure, and thus s hould have a better potential performance in service.

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99 CHAPTER 6 CONCLUSI ONS AND RECOMMENDATIONS 6.1 Conclusions This study evaluated feasibility of using conc rete containing recycled asphalt pavement (RAP) in concrete pavement applications. C oncrete containing 0%, 10%, 20% and 40% of RAP were produced in the laboratory and evaluated for their proper ties which are relevant to performance of concrete pavements. Results of the laboratory testi ng program indicate that compressive strength, sp litting tensile strength, flexural st rength and elastic modulus of the concrete decrease as the percentage of RAP incr eases. The coefficient of thermal expansion appears to increase slightly when the first RAP was incorporated, a nd to decrease slightly when a second RAP was used. The drying shrinkage appears to increase slightly w ith the use of RAP in concrete. When a finite element analysis was performed to determine the maximum stresses in typical concrete pavements in Florida under cr itical temperature a nd load conditions, the maximum stresses in the pavement were found to decrease as the RAP c ontent of the content increases, due to a decrease in the elastic modul us of the concrete. T hough the flexural strength of the concrete decreases as RAP was incorporated in the concrete, the resulting maximum stress to flexural strength ratio for th e concrete was reduced as compared with that of a reference concrete with no RAP. This indicates that using a concrete containing RAP can result in improvement in the performance of concrete pavements. 6.2 Recommendations The results of this limited laboratory testing program and finite elem ent analysis indicate that the use of RAP as aggregate replacement in pavement concrete appears to be not only feasible but also offers the possi bility of improving the performance of concrete pavement. It is

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100 thus recommended that further research be conduc ted in this area to further substantiate this finding. It is recommended th at further research work be done in the following areas: 1. To conduct a full factorial experiment to inves tigate the properties of concrete containing RAP as affected by (a) the mechanical propert ies of the RAP, (b) the gradation of the RAP, (c) properties of the vi rgin aggregate, (d) w/c of the concrete and (e) mineral admixtures such as fly ash and ground blast-furnace slag. 2. To evaluate the potential perfor mance of the various concrete mixes tested in the factorial experiment using finite elemen t analysis where the maximum stresses in typical concrete pavements in Florida under critical temperat ure and load conditions would be determined using the measured properties. The results of these analyses can then be used to develop a method for optimizing a concrete mix design incorporating RAP. 3. To conduct accelerated pavement testing on conc rete pavement slabs made with concrete containing RAP to evaluate the actual field pe rformance of these concrete mixes.

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101 APPENDIX A FEAC ONS IV PROGRAM Input Guide for FEACONS IV Program There are two types of input to the FEACONS IV program they are: 1. The input data which describe the problem. 2. The command statements which give specific instructions for execution of the program. Both the input data and the command statements must appear in the i nput file in the same order as specified. All of the input data are freeformatted so that the data are not limits to any specific columns. Adjoining data must be se parated by a blank or a comma. However, a command statement must start at the first column of each line. Inputs to th e program are listed in Table A-1. Table A-1 Input guide for FEACONS IV program Item Input Mandato ry (M) or Optional (O) 1. Number of runs M 2. Number of x-divisions on slab #1 M Number of x-divisions on slab #2 Number of x-divisions on slab #3 Number of y-divisions 3. Number of bonded layers (1 or 2) M 4. Thickness of top layer (in inches), M Elastic modulus of top layer (in ksi), Poissons ratio of both layers 1. Skip if number of bonded layers = 1, otherwise Thickness of second layer (in inches) Elastic modulus of second layer (in ksi) 2. Thickness of subbase (in inches) Elastic modulus of subbase layer (ksi) (e nter 0, 0 if not used) M

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102 3. x-coordinates of nodes along the x axis (in inches) M 4. y-coordinates of nodes along the y axis (in inches) M 5. Command LINEAR (for linear sub-grade), or M NONLINEAR (for nonlinear sub-grade) 6. Subgrade modulus in kci (if LINEAR), or M Coefficient A, Coefficient B (if NONLINERAR) (The force-deflection relationship is: F = Ad + Bd2, where F = force/area in ksi, and d = deflection in inches) 7. Command GAP (if initial gaps are to be read), or NO GAP M 8. Skip if NO GAP. Otherwise, input: M Number of gaps Node number, Depth of gap in inches (Use one line for each node with gap) 9. Command CONC FORCE (if con centrated loads are to be read in), M or NO CONC FORCE 10. Skip if NO CONC FORCE, Otherwise: M Number of Concen trated Forces (on one line) Node number, Magnitude of load in kips (use one line for each node) 11. Command UNIF LOAD (if uniform load is to be read in), M or NO UNIF LOADS 12. Skip if NO UNIF LOAD. Otherwise: M Number of elements with uniform loads (on one line) Element number, Uniform load in ksi (use one line for each element) 13. Density of 1st layer (in pcf) M 14. Skip if number of layers = 1, otherwise M Density of 2nd layer (in pcf) 15. Command TEMPERATURE EFFECT (if effects of M temperature differentials are to be considered) or No TEMPERATURE EFFECT (Temperature effect can not be considered if a subba se layer is used.)

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103 16. Skip if NO TEMPERATURE EFFECT. Otherwise: M Coefficient of thermal expansion (in 1 .F), Temperature at the top of the slab (in .F) Temperature at th e bottom of the slab (in .F) 17. Spring coefficient for the edges (in ksi) M 18. Linear spring coefficient for the joints (in ksi), M Torsional spring coefficient for the joints (in k-in) 19. Linear spring coefficient for the dowel joints (in ksi), M Torsional spring coefficient for the dowel joints (in k/in) SLIP (in inches) 20. Number of load increments to compute the effects of slab weight, M Number of load increments to compute the effects of temperature Differentials, Number of load increments to compute the effects of applied loads 21. Command PRINT INITIAL DEFLECTION (if deflection caused O by the combined effects of slab weight and temp erature differentials are to be printed) 22. If the command PRINT INTIAL DEFLEC TION is read in, O read in: Total number of sets of nodes to be printed, Starting node number, Ending node number, Increment between the nodes (the last three numbers represent a node set. The next node set follows here if there is more than one node set) 23. Command PRINT DEFLECTION (i f deflections caused by O applied loads are to be printed) 24. If PRINT DEFLECTION is read in, read in: O Total number of sets of nodes to be printed, Starting node number, Ending node number, Increment between the nodes (Similar to No.26) 25. Command PRINT MAXIMUM DEFLECTION, read in: O (If maximum deflections betw een specific nodes are to be printed)

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104 26. If PRINT MAXIMUM DEFLECTION, read in: O Number of sets of nodes, Starting node number, Ending node number, Increment (Similar to No.26) 27. Command PRINT MOMENTS (If moments at the nodes are to be printed) 28. If PRINT MOMENTS, read in: O Number of sets of nodes, Starting node number, Ending node number, Increment (Similar to no.26) 29. Command PRINT MAXIMUM MOMENTS O if maximum mo ments between specific nodes are to be printed) 30. If PRINT MAXIMUM MOMENTS, read in: O Number of sets of nodes, Starting node number, Ending node number, Increment (Similar to No.26) 31. Command PRINT TOP STRESSES O (If stresses at the to p of the slabs are to be printed) 32. If PRINT TOP STRESSES, read in: O Number of sets of nodes, Starting node number, Ending node number, Increment (Similar to No.26) 33. Command PRINT BOTTOM STRESSES O (If stresses at the botto m of the slabs are to be printed) 34. If PRINT BOTTOM STRESSES, read in: O (Similar to No.26) 35. Command PRINT MAXIMUM STRESSES O (If maximum stresses betw een specific nodes are to be printed)

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105 36. If PRINT MAXIMUM STRESSES, then read in: O Number of sets of nodes, Starting node number, Ending node number, Increment (Similar to No.26) 36A. Command PRINT 1STLAYER BOTTOM ST RESSES O (if stresses at the bottom of the top layer are to be printed) 36B. If PRINT 1STLAYER BOTTOM ST RESSES is read in, read in: Total number of sets of nodes to be printed, Starting node number, Ending node number, Increment between the nodes. (This is similar to item 26) 37. Command PRINT PRINCIPAL STESSES O (If principal stresses are to be printed) 38. If PRINT PRINCIPAL STRESSES, then r ead in: O Number of sets of nodes, DEG, Starting node number, Ending node number, Increment (If DEG = 1, angles will be in degrees. If DEG = 2, angles will be in radians.) (The last four numbers represent a node set. The next node set follows here if there is more than one node set) 38A. Command PRINT 2NDLAYER TOP STRESSES O (if stresses at the top of the bottom layer are to be printed) 38B. If PRINT 2NDLAYER TOP STRESS ES is read in, read in: O Total number of se ts of nodes to be printed, Starting node number, Ending node number, Increment between nodes. (This is similar to item 26) 38C. Command PRINT SUBBASE TOP STRESSES O (if stresses at the top of th e unbonded subbase layer are to be printed)

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106 38D. If PRINT SUBBASE TOP STRESSES read in, read in: O Total number of sets of nodes to be printed, Starting node number, Ending node number, Increment between the nodes. (This is similar to item 26) 39. Command PRINT MAXIMUM STRESSES 1STLAYER TOP O (if maximum stresses at the t op of the top layer, between specific nodes, are to be printed) [revised] 40. If PRINT MAXIMUM STRESSES 1STLAYER TOP, then r ead in: O Total number of sets of nodes to be printed, Starting node number, Ending node number, Increment between the nodes. (Similar to No.26) [revised] 40A. Command PRINT MAXIMUM STRESSES 1STLAYER BOTTOM (if maximum stresses at the bottom of the t op layer, between specific nodes, O are to be printed) 40B. If PRINT MAXIMUM STRESSES 1STLAYER BOTTOM, then O (inputs similar to item 26) 40C. Command PRINT MAXIMUM STRESSES 2NDLAYER BOTTOM (if maximum stresses at the bottom of the bottom layer, between specific nodes, O are to be printed) 40D. If PRINT MAXIMUM STRESSES 2NDLAYER BOTTOM, then O (inputs similar to item 26) 40E. Command PRINT MAXIMUM STRESSES 2NDLAYER TOP (if maximum stresses at the top of the bottom layer, between specific nodes, O are to be printed) 40F. Command PRINT MAXIMUM STRESSES SUBASE TO P (if maximum stresses at the top of the unbonded subbase layer, O between specific nodes, are to be printed) 41. Command FINISH (This is to mark the end of a set of data. M The next set of data in the same formats as items (2) through (39) follows here, if there is more than one run to be made.)

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107 Numbering of Nodes and Element In using the FEACONS IV program it is essential that the nodes and the elements of the chosen finite-element mesh are numbered prop erly. The nodes and elements are numbered from left to right and from bottom to top such that they start at the lower left corner of the first slab, and proceed up in the vertical di rection for the full width of the slab. The number of nodes and the y coordinates of the chosen nodes in the y dir ection (along the width) in each slab should be the same as those of the other slabs. Howeve r, the number of nodes and distances between two nodes in the x direction (al ong the length) may vary from one slab to another. Figure A-1 Example of number of nodes and elements

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108 APPENDIX B STRENGTH TEST DATA Table B-1 Results of compre ssive strength tests (psi) Age of testing (d ays) Mix No 14 28 90 1 2 3 1 2 3 1 2 3 Set-1 RAP#1 1 5315 5548 5472 5818 5434 5536 6349 5717 4213 2 4527 4239 4685 4999 4867 4942 5228 4909 4773 3 3084 3269 3210 3711 3807 3818 3981 3910 3981 4 2436 2381 2516 2693 2371 2497 2527 2768 2677 Set-2 RAP#1 1 5621 5745 / 5810 5670 5857 6538 6881 5641 2 4663 / 4623 4431 4411 5396 4969 5741 4981 3 3300 3594 3120 3385 3623 3088 3495 4016 3839 4 2212 2221 2575 2251 2013 2457 2498 3038 2763 Set-3 RAP#1 1 4540 5690 5359 5879 6100 5806 2 4370 4075 3160 5170 4980 5230 3 3230 3470 3710 5371 4365 4647 4 2946 3700 3520 3883 4207 3644 Set-1 RAP#2 1 5836 5673 6025 7000 7119 7101 2 4300 4150 4462 4523 4543 4746 3 3758 4360 3970 4136 4141 4543 4 2000 1904 / / / / Set-2 RAP#2 1 4640 4391 4383 2548 2271 4090 2 2769 3257 3316 2961 3451 3045 3 2554 4632 2637 4555 4792 4716 4 2203 2699 2647 3358 3206 3464

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109 Table B-2 Results of elastic modulus tests (6psi) Age of testing (days) Mix No 14 28 90 1 2 3 1 2 3 1 2 3 Set-1 RAP#1 1 4.12 4.81 4.40 / 4.71 4.85 4.62 4.57 4.97 2 3.71 3.90 3.86 3.98 / 4.02 3.95 4.20 4.23 3 3.29 3.45 3.31 / 3.34 3.45 3.56 3.71 3.43 4 2.46 2.17 2.32 2.35 2.35 / 2.59 2.30 2.60 Set-2 RAP#1 1 4.47 4.73 / 4.99 5.25 4.47 4.89 4.89 4.5 0 2 4.10 / 4.24 4.23 4.13 5.18 / 4.45 4.64 3 3.19 3.42 3.61 3.21 3.38 4.65 3.37 3.77 3.44 4 2.31 2.15 2.34 2.33 2.32 2.24 2.95 2.52 2.39 Set-3 RAP#1 1 4.74 3.95 4.13 5.41 4.83 4.44 2 4.03 3.80 4.52 4.07 3.98 4.03 3 3.40 3.45 3.09 3.81 3.26 3.45 4 2.77 2.75 2.79 3.02 2.69 2.66 Set-1 RAP#2 1 4.05 4.25 4.50 4.39 4.73 4.68 2 3.86 3.51 3.93 3.99 3.51 3.77 3 2.93 3.34 3.09 3.25 2.91 3.51 4 2.98 2.21 / / / / Set-2 RAP#2 1 3.16 3.35 3.00 2.80 2.82 2.81 2 2.06 2.44 2.40 2.32 2.39 2.10 3 3.16 3.30 / 3.85 3.95 3.91 4 2.32 2.23 2.21 3.30 3.23 3.35

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110 Table B-3 Results of flexur al strength tests (psi) Age of testing (days) Mix No 14 28 90 1 2 1 2 1 2 Set-1 RAP#1 1 843 923 879 1001 1003 949 2 839 775 808 1074 848 841 3 903 755 707 793 723 790 4 682 748 558 582 533 821 Set-2 RAP#1 1 802 / 969 970 807 719 2 840 721 900 836 568 576 3 760 649 766 653 513 592 4 599 557 564 716 523 496 Set-3 RAP#1 1 547 524 572 568 2 569 548 534 / 3 520 / / / 4 423 509 538 496 Set-1 RAP#2 1 550 608 550 537 2 513 552 484 543 3 463 430 457 424 4 378 400 / / Set-2 RAP#2 1 488 466 455 510 2 381 406 419 402 3 466 502 546 532 4 440 347 412 396

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111 Table B-4 Results of splitting te nsile strength tests (psi) Age of testing (days) Mix No 14 28 1 2 3 1 2 3 Set-1 RAP#1 1 572 497 454 492 503 416 2 332 389 390 484 489 490 3 206 267 310 401 327 395 4 307 330 316 326 336 391 Set-2 RAP#2 1 509 524 568 577 609 636 2 410 367 / 351 432 468 3 342 346 405 354 359 370 4 197 243 196 / / / Set-3 RAP#2 1 361 377 413 375 346 294 2 292 247 316 292 293 322 3 314 434 365 459 424 467 4 262 330 289 325 318 306

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112 Table B-5 Results of free shrinkage tests (10-6 in/in) Age of testing (days) Mix No 14 28 90 1 2 3 1 2 3 1 2 3 Set-1 RAP#1 1 60 130 30 180 410 160 / / / 2 80 90 / 220 210 / / / / 3 60 50 110 140 80 140 300 190 340 4 130 60 10 280 170 110 360 330 320 Set-2 RAP#1 1 140 140 170 270 270 320 360 330 370 2 60 90 160 200 230 290 350 320 390 3 210 200 250 290 260 300 440 350 380 4 240 180 210 380 280 320 540 430 550 Set-3 RAP#1 1 200 110 130 260 310 300 2 140 110 150 180 150 190 3 135 110 / 230 220 250 4 150 140 120 120 130 130 Set-1 RAP#2 1 100 110 190 190 220 280 2 140 110 / 180 150 / 3 200 150 230 310 260 250 4 190 210 150 / / / Set-2 RAP#2 1 150 130 110 250 290 270 2 160 140 130 250 230 250 3 140 130 150 240 210 290 4 180 160 150 280 310 320

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113 Table B-6 Results of coefficient of thermal expansion tests (10-6/F) Age of testing (days) Mix No 14 28 90 1 2 3 1 2 3 1 2 3 Set-1 RAP#1 1 5.70 6.17 6.04 6.34 6.07 5.76 6.43 6.08 6.06 2 6.58 5.47 5.98 5.80 6.15 6.23 6.14 6.35 6.32 3 5.35 5.84 6.36 5.92 6.85 6.50 5.92 6.03 6.40 4 6.13 6.43 6.53 5.60 6.51 6.48 5.97 6.04 6.85 Set-2 RAP#1 1 5.53 5.67 6.19 5.41 5.45 5.79 5.64 5.61 6.14 2 5.78 5.80 5.98 5.88 6.01 5.99 5.29 5.73 5.87 3 5.79 5.60 6.04 5.69 5.65 5.82 5.88 5.75 5.95 4 5.73 6.03 6.16 5.86 5.89 6.64 5.97 5.83 6.16 Set-3 RAP#1 1 5.17 4.82 4.79 5.33 5.00 5.76 2 / / / 5.08 5.33 4.64 3 5.06 4.94 4.75 5.39 4.78 4.88 4 5.23 4.98 4.79 5.45 5.35 5.25 Set-1 RAP#2 1 5.56 5.52 5.11 / / / 2 5.44 5.20 4.64 / / / 3 5.02 4.97 4.79 / / / 4 5.12 5.30 4.75 / / / Set-2 RAP#2 1 6.52 6.64 6.32 5.97 5.81 5.46 2 5.68 5.48 6.05 6.15 5.75 5.79 3 6.07 6.33 5.70 6.24 6.30 6.49 4 6.32 5.79 5.71 6.57 5.95 5.98

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114 LIST OF REFERENCES Alexander, M.G., and Addis, B.J., 1992, Propert ies of High Strength Concrete Influenced by Aggregate and Interfacia l Bond. Bond in concrete: From Re search to Practice, Proceeding of the CEB International Confer ence held at Riga Technical University, Riga, Latvia, oct. 15-17, v.2, p.4-19 to p.4-26. Aitcin, P.C., and Mehta P.K., 1990, Effect of Co arse aggregate Characteristics on Mechanical Properties of High Strength Concrete, ACI Material Journal, v.87, no.3, p.103-107. American Concrete Institute, 1971, Temperat ure and Concrete, SP-25, Detroit, Michigan: American Concrete Institute. Browne, R.D., 1972, Thermal Movement of Concre te, The Journal of the Concrete Society, London, v.6, no.10, p.51-53. Chehadeh, W., 1967, A Laboratory Investigatio n of the Relative Properties of Dry Lean Concrete using as Raised or Washed Coarse Aggregate, Univ ersity of Surrey, Guidford, UK. Chi, J.M., Huang, R., Yang, C.C., Chang, J.J ., 2003, Effect of Aggregate Properties on the Strength and Stiffness of Light weight Concrete, Cement and Concrete Composites, no.25, p.197-205. Collins, R.J., and S. K. Ciesielski, 1994, Recycling and Use of Waste Materials and By-Products in Highway Construction NCHRP Symthesis 199, TRB, Washington, D.C. Delwar, M., Fahmy, M., Taha, R., 1997, Use of R eclaimed Asphalt Pavement as an Aggregate in Portland Cement Concrete. ACI Materials Journal. Dettling Heinz, 1964, The Thermal Expansion of Hardened Cement Paste, Aggregates, and Concrete, Bulletin no.164, Berlin. Emmanuel, Jack H., and J. Leroy Hulsey, 1977, Prediction of the Thermal Coefficient of Expansion of Concrete, ACI Journal, Title no.74-14, p.149-155. Etxeberria, M., Vazquez, E., Man, A., and Ba rra, M., 2007, Influence of Amount of Recycled Coarse Aggregates and Production Process on Pr operties of Recycled Aggregate Concrete, Cement and Concrete Research, v.37, issue no.5, p.735-742. FDOT, 2007, Properties of Portla nd Cement and Virgin Aggregat e, Gainesville, Florida. Franklin, R.E., and King, T.M.J., 1971, Relations between Compressive and Indirect tensile Strength of Concrete, RRL Report LR 412, Ro ad Research Laborator y, Crowthorne, UK. Gonzelez-Fonteboa, B., and Martinez-Abella, 2007, Concretes with Aggregates from Demolition Waste and Silica Fume Materials and Mechanic al Properties, Building and Environment, v.43, issue.4, p.429-437.

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115 Guang Li, 2004, The Effect of Moisture Content on the Tensile Strength Properties of Concrete, Thesis Presented to the Graduate School of University of Florida. Guoqiang Li., Michael A. Stubblefield., Gregor y Garrick., John Eggers., Christopher Abadie., Baoshan Huang., 2004, Development of Wast e Tire Modified Concrete, Cement and Concrete Research, no.34, p.2283-2289. Hansen T., Nelsen K., 1965, Influence of A ggregate Proportions on Concrete Shrinkage, American Concrete Institute, 62(7), p.783-794. Hermite, R.L., 1960, Volume Changes of Concre te, Chemistry of Cement, Washington DC, p.659-694. Hobbs, D.W., 1974, Influence of Aggregate restra int on the Shrinkage of Concrete, American Concrete Institute 71(9), p.445-450. Hodgson, Shells, S., 2000, The Effect of Wate r/Cement Ratio and Air Entraining on Portland Cement Concrete Freeze/Thaw Durability Civil and Environmental Engineering Department, University of WisconsinMadison. Hoff, G.C., 1979, Chemical, Polymer and Fibe r Additives for Low Maintenance Highways, Chemical Technology Review no.130. Holt Erika, 2004, Contribution of Mixture Design to Chemical and Autogenous Shrinkage of Concrete at Early Ages, Ce ment and Concrete Research, v.35, issue no.3, p.464-472. Huang, B., Shu, X., Burdette, E.G., 2006, Mechanical Properties of Concrete Containing Recycled Asphalt Pavement, Magazine of Concrete research, v.58, no.5, p.313-320. Imtiaz Ahmed, 1993, Use of Waste Materials in Highway Construction, Library of Congress Catlog, p.92-541. Leming, M.L., 1990, Comparison of Mechanical Properties of High Strength Concrete made with Different Raw Materi als, Transportation Research Record, no.1284, p.23-30. Llewellin, J.D., 1988, Concrete for Pavements, Edited by A.F.Stock in Concrete Pavements, 1988, Elsevier Applied Science, p.57-103. Mitchell, L.J., 1966, Hardened Concrete, Thermal Properties, Insigni ficance of Tests and Properties of Concrete and Concrete Ma king Materials, ASTM Special Technical Publication, no.169A, Philadelphia, PA: Amer ican Society for Testing and Materials, p.202-210. Murshed Delwar, Mostafa Fahmy, and Ramzi Ta ha, 1997, Use of Reclaimed Asphalt Pavement as an Aggregate in Portland Cement Concre te, ACI Materials Journal, v.94, no.3, p.251257. Neville, A.M., 1996, Properties of Concrete, Four th and Final Edition, New York, J.Wiley.

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116 zturan Turan and Cengizhan Cecen, 1997, Effect of Coarse Aggregate Type on Mechanical Properties of Concretes with Different Streng ths, Cement and Concrete Research, v.27, no.2, p.165-170 Pickett.G. 1956, Effect of Aggregate on Shrinkage of Concrete and Hypothesis Concerning Shrinkage, Journal of American Concrete Institute, no.52, p.581-590. Pike, D.C., 1990, Standards for Aggregate, Ellis Horwood Series in Applied Geology. Sarkar, S.L., and Atcin, P.C., 1990, The Im portance of Petrological, Petrographical and Mineralogical Characteristics of aggregates in Very High-Strength Concrete, Petrography Applied to Concrete and Concrete Aggregates, ASTM STP 1061, p.129-158. Sellevold, E.J., Bjntegaard, ., 2006, Coefficien t of Thermal Expansion of Cement Paste and Concrete: Mechanisms of Mois ture Interaction. Materials and Structures, no.39, p.809-815. Shideler, J.J., 1957, Lightweight Aggregate Concre te for Structural use, Journal of American concrete Institute, no.54, p.229-328. Stock A.F., Hannant D.J., and Williams, R.I.T., 1979, The Effect of Aggregate Concentration upon the Strength and Modulus of Elasticity of Concrete, Magazine of concrete Research, v.31, no.109, p.225-234 Tia, M., Bloomquist, D., Alungbe G.D., and Richardson, D., 1991, Coefficient of Thermal Expansion of Concrete Used in Florida, Research Report, Univ ersity of Florida, June 1991. Tia, M., Wu, C.L., Ruth, B.E., Bloomquist, D., and Choubane, B., 1989, Field Evaluation of Rigid Pavement Design System--Phase IV, Research Report, University of Florida, August 1989. Troxell, G.E., Raphael, J.M., and Davis, R.E., 1958, Long-Time Creep and Shrinkage Tests of Plain and Reinforced Concrete, Proc. ASTM, no.58, p.1101-1120. Wilburn, David.R., and Goonan, Thomas. G., 1998, Aggregates from Natural and Recycled Sources, Economic Assessments fo r construction Appli cationa Material Flow Analysis, US Geological Survey Circular 1176. Williams, R.I.T., 1986, Cement Treated Pavements, Materials, Design and Construction, p.340. Williams, R.I.T., 1972, Properties of cement Stab ilized Materials, Journal, Institution of Highway Engineers, 19(2), p.5-19. Wu Ke-Ru, Bing Chen, Wu Yao, Dong Zang, 2001, Effect of Coarse Aggregate Type on Mechanical Properties of High Performance concrete, Cement and Concrete Research, no.31, p.1421-1425. Zhou, F.P., Lydon, F.D., and Barr, B.I.G., 1995, E ffect of Coarse Aggregate on Elastic Modulus and Compressive Strength of High Performan ce Concrete, Cement and Concrete Research, v.25, no.1, p.177-186.

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117 Zhang, M.H., Tam, C.T., and Leow, M.P., 2003, Effect of Water-toCe mentitious Materials Ratio and Silica Fume on the Autogenous Shrinkage of Concrete, Cement and Concrete Research, v.33, issue no.10, p.1687-1694.

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118 BIOGRAPHICAL SKETCH Nabil J. Hossiney was born in Kolhapur, India. He went to Shivaji University in September 2001 to pursue his bachelors degr ee. He earned his bachelors degree in civil engineering in April 2005. He was admitted to pursue his masters degree in civil engineer ing at the University of Florida in fall 2006. He received a research assistantship in spri ng 2007 and started working on his research program on concrete materials. He graduated from the University of Florida in summer 2008 and continued for his PhD program in ci vil engineering at Univ ersity of Florida.