International conference on transportation and development 2018 airfield and highway pavements

Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Airfield and Highway Pavements Papers from Sessions of the International Conference on Transportation and Development 2018 Pittsburgh, Pennsylvania July 15–18, 2018 Edited by Yinhai Wang, Ph.D Michael T McNerney, Ph.D., P.E Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved INTERNATIONAL CONFERENCE ON TRANSPORTATION AND DEVELOPMENT 2018 AIRFIELD AND HIGHWAY PAVEMENTS SELECTED PAPERS FROM THE INTERNATIONAL CONFERENCE ON TRANSPORTATION AND DEVELOPMENT 2018 July 15–18, 2018 Pittsburgh, Pennsylvania SPONSORED BY The Transportation & Development Institute of the American Society of Civil Engineers EDITED BY Yinhai Wang, Ph.D Michael T McNerney, Ph.D., P.E Published by the American Society of Civil Engineers Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Published by American Society of Civil Engineers 1801 Alexander Bell Drive Reston, Virginia, 20191-4382 www.asce.org/publications | ascelibrary.org Any statements expressed in these materials are those of the individual authors and not necessarily represent the views of ASCE, which takes no responsibility for any statement made herein No reference made in this publication to any specific method, product, process, or service constitutes or implies an endorsement, recommendation, or warranty thereof by ASCE The materials are for general information only and not represent a standard of ASCE, nor are they intended as a reference in purchase specifications, contracts, regulations, statutes, or any other legal document ASCE makes no representation or warranty of any kind, whether express or implied, concerning the accuracy, completeness, suitability, or utility of any information, apparatus, product, or process discussed in this publication, and assumes no liability therefor The information contained in these materials should not be used without first securing competent advice with respect to its suitability for any general or specific application Anyone utilizing such information assumes all liability arising from such use, including but not limited to infringement of any patent or patents ASCE and American Society of Civil Engineers—Registered in U.S Patent and Trademark Office Photocopies and permissions Permission to photocopy or reproduce material from ASCE publications can be requested by sending an e-mail to permissions@asce.org or by locating a title in ASCE's Civil Engineering Database (http://cedb.asce.org) or ASCE Library (http://ascelibrary.org) and using the “Permissions” link Errata: Errata, if any, can be found at https://doi.org/10.1061/9780784481554 Copyright © 2018 by the American Society of Civil Engineers All Rights Reserved ISBN 978-0-7844-8155-4 (PDF) Manufactured in the United States of America International Conference on Transportation and Development 2018 Preface Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved It is our great pleasure to welcome you to the ASCE International Conference on Transportation and Development (ICTD 2018)! Organized by Transportation and Development Institute (T&DI), ICTD is ASCE’s flagship conference in transportation and development The conference theme, Emerging Technologies: Impacts on Transportation and Development, represents our vision and goal for future endeavors in transportation and development research, education, and practice ASCE ICTD 2018 awaits your active participation and contribution at the beautiful and scenic Wyndham Grand Pittsburgh Downtown Hotel from July 15 through 18, 2018 Pittsburgh is historically known as “the Steel City.” Now, about 1,600 technology firms, including Google, Apple, Bosch, Facebook, Uber, Nokia, Autodesk, and IBM, have landed in Pittsburgh, making it an important technology hub and one of the eleven most livable cities in the World Being the host city of ASCE ICTD 2018, Pittsburgh offers many unique real-world examples for transportation and development professionals to feel, think, and learn ASCE ICTD 2018’s technical program is featured with four plenary sessions:     Opening Plenary Session: Keynote Speeches from Federal, State, and Local Government Leaders Private Sector CEO Forum: Impacts of Connected & Autonomous Vehicles on Transportation & Development - Perspectives of Leaders from the Private Sector State DOT CEO Forum: Impacts of Connected & Autonomous Vehicles on Transportation & Development - Perspectives of Leaders from the Public Sector The Advent of CAVs - A Global Perspective: Current Status of Deployment and Future of Connected and Autonomous Vehicles Around the World The program covers deeper technical content on multiple modes and topics in transportation and development in eight (8) concurrent tracks It also includes a variety of special events such as the T&DI Board of Directors’ Town Hall Meeting, Younger Members’ “The Best Advice I Ever Received” session, icebreaker reception, and an Awards Banquet The conference is preceded with four (4) associated workshops:     Mobility as a Service Workshop University Transportation Center Technology Transfer Workshop NSF Civil Infrastructure Systems Workshop ASCE Ethics Workshop All these workshops are carefully designed to enhance fruitful experience of participants Last but not the least, conference attendees get the opportunity to attend over 15 technical committee meetings of ASCE as preconference event, covering all areas of transportation and development In addition, partnering with Transportation Research Board (TRB), two TRB committees have chosen to host their mid-year meeting at ICTD 2018, giving conference attendees additional exposure to technical discussions and content © ASCE iii International Conference on Transportation and Development 2018 It is exciting to announce that ASCE ICTD 2018 attracted huge interests as indicated by the record high quality contributions and the rich technical program A total of 146 papers were accepted for publication in the proceedings These published papers went through a rigorous review and quality assurance process in the process of becoming a publication of ASCE – the world’s largest publisher of Civil Engineering content The proceedings for this conference have been organized in four (4) different volumes based on the topical distribution as follows: Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved     Volume I: Connected & Autonomous Vehicles and Transportation Safety Volume II: Traffic & Freight Operations and Rail & Public Transit Volume III: Airfield & Highway Pavements Volume IV: Planning, Sustainability, and Infrastructure Systems All these accomplishments are due to the excellent team efforts of our Conference Steering Committee, and the terrific support from ASCE-T&DI staff We would like to express our sincere gratitude to all the authors and conference participants for their solid contributions We are also grateful to all paper reviewers for their outstanding volunteer efforts Finally, our special thanks goes to the entire Conference Steering Committee, Local Organizing Committee, T&DI technical committee volunteers, ASCE-T&DI staff members, sponsors, exhibitors, invited speakers, and session chairs for their hard work and great efforts to help lead ASCE ICTD 2018 on track to a great success! ASCE ICTD has been an excellent platform for information exchange, experience sharing, and professional networking since it was launched in 2011 We hope ASCE ICTD 2018 to be another wonderful and rewarding experience in your memory Wish you a very pleasant stay in Pittsburgh! ASCE ICTD 2018 Co-Chairs & Proceedings Editors Yinhai Wang, Ph.D., M.ASCE University of Washington © ASCE Michael T McNerney, Ph.D., P.E., M.ASCE University of Texas at Arlington iv International Conference on Transportation and Development 2018 Acknowledgements Conference Steering Committee Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Yinhai Wang, Ph.D., M.ASCE (Co-Chair & Proceedings Editor) University of Washington Michael T McNerney, Ph.D., M.ASCE (Co-Chair & Proceedings Editor) University of Texas at Arlington Chris Hendrickson, Ph.D., Hon.M.ASCE (Chair, Local Organization Committee) Carnegie Mellon University Randall (Randy) S Over, P.E., F.ASCE, Retd (Chair, Sponsorships & Exhibits) 2014 President of ASCE, Ohio DOT Brian McKeehan, P.E., F.ASCE (Past-Chair) Gresham, Smith and Partners Katherine Kortum (Track Chair, Development) Transportation Research Board (TRB) Robert Bryson, P.E., M.ASCE Retd (Track Chair, Roadways) City of Milwaukee Walt Kulyk, P.E., M.ASCE, Retd (Track Chair, Rail & Public Transit) Federal Transit Administration Rich Thuma, P.E., M.ASCE (Track Chair, Aviation) Crawford, Murphy & Tilly Zhanmin Zhang, Ph.D., M.ASCE (Track Chair, Mode Spanning) University of Texas at Austin Jianming Ma, P.E., M.ASCE (Track Chair, Connected & Autonomous Vehicles’ Impacts) Texas Department of Transportation Local Organizing Committee Chris Hendrickson, Ph.D., Hon.M.ASCE (Chair, Local Organization Committee) Carnegie Mellon University David DiDiogia, P.E., M.ASCE McMahon Associates © ASCE v International Conference on Transportation and Development 2018 Sean Qian, Ph.D., M.ASCE (Student & Younger Member Activities) Carnegie Mellon University Stan Caldwell, Ph.D., M.ASCE Carnegie Mellon University Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Julie Vandenbossche, Ph.D., M.ASCE University of Pittsburgh Paper Reviewers Ahmed Abdeldayem Renju Abraham Burns & McDonnell Engineering Company, Inc Emmanuel Adanu University of Alabama Nithin Agarwal University of Florida Baabak Ashuri Georgia Tech University Husain Abdul Aziz Oak Ridge National Laboratory Joel Barnett Department of Transportation Geoff Baskir Federal Aviation Administration Ricardo Aitken Ahmad Al-Akhras Public Transport Authority of Riyadh, Saudi Arabia Majed Al-Ghandour North Carolina DOT Priyanka Alluri Florida International University Panagiotis Anastasopoulos University at Buffalo Michael Anderson University of Alabama in Huntsville Justice Appiah Virginia DOT Ricardo Archilla University of Hawaii Warda Ashraf Purdue University © ASCE Rahim Benekohal University of Illinois at Urbana-Champaign Abhinav Bhattacharyya University of California, Berkeley Richard Boudreau Boudreau Engineering, Inc Georges Bou-Saab Iowa State University David Brill Federal Aviation Administration Robert Bryson Ayres Associates Lei Bu Jackson State University Qing Cai University of Central Florida Samuel Cardoso vi International Conference on Transportation and Development 2018 Consultant on Airports and Airfield Pavements Silvia Caro Universidad de los Andes, Columbia Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Halil Ceylan Iowa State University Karim Chatti Michigan State University Nspire Green Kakan Dey West Virginia University Sunanda Dissanayake Kansas State University Kimberly Eccles VHB Larry Emig Ghassan Chehab American University of Beirut Deogratias Eustace University of Dayton Peter Chen Santa Clara Valley Transportation Authority Ahmed Faheem Temple University Subeh Chowdbury University of Auckland Wei Fan UNC Charlotte Mashrur Chowdhury Clemson University Muhammad Farhan Imam Abdulrahman Bin Faisal University Eleni Christofa University of Massachusetts, Amherst Luis Ferreras David Clarke University of Tennessee, Knoxville Julius Codjoe State of Louisiana Alison Conway City College of New York Seosamh Costello University of Auckland Velvet Fitzpatrick The National Academy of Sciences, Engineering, and Medicine Scott Forbes Mike Frabizzio Advanced Infrastructure Design, Inc Jason Frank Garver Robert Costigan Ryan Fries Southern Illinois University Edwardsville Qingbin Cui University of Maryland James Gallagher Resolution Management Consultants, Inc Jordan Daniell HNTB Corporation Christopher Garlick Michael Garvin Veronica Davis © ASCE vii Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Virginia Polytechnic Institute and State University Jungyeol Hong University of Seoul Nasir Gharaibeh Texas A&M University Kamal Hossain University of Illinois at Urbana-Champaign Scott Gibson Regional Transportation Commission of Washoe County, Nevada Mohammad Imran Hossain Bradley University Konstantina Gkritza Purdue University Salil Gokhale Dynatest Nima Golshani University of Illinois at Chicago Yaobang Gong University of Central Florida © ASCE Mustaque Hossain Kansas State University Jill Hough North Dakota State University Jia Hu University of Virginia Hai Huang Penn State University Jozef Grajek EJG Aviation Mouyid Islam Center for Urban Transportation Research, University of South Florida Feng Guo Virginia Polytechnic Institute and State University Reza Jafari Road Safety and Transportation Solutions, Inc Jim Hall Applied Research Associated, Inc Mohammad Jalayer Rutgers University Thomas Hall Purdue University Steven Jones University of Alabama John Harvey UC Davis Ganesh Karkee City of Sunnyvale, California David Hein Applied Research Associated, Inc Kurt Keifer Gorrondona & Associates, Inc Brendon Hemily Hemily and Associates Vivek Khanna WSP Chris Hendrickson Carnegie Mellon University Myungseob Kim Western New England University Frank Hermann Sonny Kim University of Georgia viii Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Ronald Knipling Safety for the Long Haul, Inc Min Liu NC State University Kristin Kolodge J.D Power Cheryl Lowrance VHB Alexandra Kondyli University of Kansas Jianming Ma Texas Department of Transportation Eleftheria Kontou National Renewable Energy Laboratory Wanjing Ma Katherine Kortum Transportation Research Board Gregory Krueger HNTB Corporation Emin Kutay Michigan State University Samuel Labi Purdue University Hyung Lee Applied Research Associated, Inc Kang-Won Lee University of Rhode Island © ASCE Matthew Mace Hill International Rajib Mallick Worcester Polytechnic Institute Angel Mateos University of California, Berkeley Akhilesh Maurya Indian Institute of Technology Guwahati Mehran Mazari California State University, Los Angeles Leslie McCarthy Villanova University Matthew Lesh Brian McKeehan Gresham Smith & Partners Yingfeng Li Center for Infrastructure-Based Systems Magaret McNamara University of Alabama Zhenning Li University of Hawaii Sue McNeil University of Delaware John Lieswyn ViaStrada Mike McNerney University of Texas at Arlington Lei Lin University at Buffalo Richard Meininger Department of Transportation Huiyuan Liu University of Nebraska-Lincoln Mariely Mejias US Army Corps of Engineers Jun Liu Deb Mishra ix International Conference on Transportation and Development 2018 407 average, 16% greater compressive strength than the control and 12% higher compressive strength than the non-sonicated PBA blended concrete mix RCA-PBA This would indicate that sonication can be effective in dispersing the fine PBA particles within a PCE-water solution to yield significant gains in compressive strength within Recycled Aggregate Concrete 45.0 Compressive Strength (MPa) Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved 50.0 40.0 28-day 110-day 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 RCA-C RCA-PBA RCA-PBA-S Figure Mean compressive strength of the recycled aggregate concrete mixes The strength activity of the RCA-PBA mix at 28 and 110 days was 104% and 116% at 28 and 110 days for the RCA-PBA-S mix The strength activity is defined here as the ratio of the compressive strength of the control specimen and treatment specimen (with PBA) The recycled aggregate concrete compressive strength activity is shown to be similar to comparable PBA mortar blends tested in Oruji et al (2017); where PBA mortar strength activity was shown to vary from 103% and 113% depending on powder fineness, age, and cement replacement dosage f 'c ,treatment ( withPBA) Strength Activity  f 'c , control ( noPBA) The compressive strength activity enhancement observed in the treated mix RCA-PBA-S compares well against other published treatment methods: i) Pulverized fly ash-115% (Ann et al., 2008), HCL acid treatment-112% and mechanical scrubbing-116% (Purushothaman et al., 2015), metakaolin-110% and silica fume-110% (Kou et al., 2011), ground granulated blast furnace slag-112% (Berndt, 2009), and PVA impregnation-107% (Kou and Poon, 2010) Optical Microscopy: Concrete Microstructure Optical images were taken of sliced prismatic specimens for each of concrete mix to further investigate the microstructure of the cement matrix, recycled concrete aggregate, and the interfacial transition zone The images are shown in Fig 6–7 Fig shows the images from the RCA-C cross-section, and magnified images of the new and old mortar that encapsulates the old coarse and fine aggregate; the three major components that make up the recycled concrete aggregate Fig shows the images from RCA-PBA-S cross-section The X1000 magnification images reveal that the new mortar within the RCA-C specimens contain a coarser porous structure than the RCA-PBA-S specimens which may partially explain the increased mechanical strength within the RCA-PBA-S specimens © ASCE Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Figure (a) Sliced cross-section, (b) Sliced cross-section at X200 magnification, (c) Sliced cross-section X1000 magnification of the RCA-C prismatic specimen Figure (a) Sliced cross-section, (b) Sliced cross-section at X200 magnification, (c) Sliced cross-section X1000 magnification of the RCA-PBA-S prismatic specimen © ASCE 408 International Conference on Transportation and Development 2018 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved CONCLUSION A landfilled sub-bituminous coal bottom ash was reclaimed, pulverized, and reutilized as a cement replacement to enhance the mechanical properties of a recycled aggregate concrete using a modified two-stage mixing approach The results of this study have led to the following conclusions:  The introduction of a well dispersed fine pulverized coal bottom ash can increase the recycled aggregate concrete compressive strength by 16%  Sonication treatment is shown to significantly impact the concrete compressive strength activity; the non-sonicated bottom ash blended concrete mixes only yield a 4% increase in compressive strength  Microscopic analysis revealed finer pore structure in the cement mortar matrix in the samples treated with the well dispersed pulverized bottom ash solution and revealed interfacial debonding zones in the control mix REFERENCES American Coal Ash Association (2015) News Release Coal Ash Production and Use https://www.acaa-usa.org/Portals/9/Files/PDFs/News-Release-Coal-Ash-Production-andUse-2015.pdf Ann, K.Y., Moon, H.Y., Kim, Y.B., Ryou, J (2008) “Durability of recycled aggregate concrete using pozzolanic materials”, Waste Management, 28 993–999 ASTM C39 / C39M-17b (2017) “Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C136 / C136M-14 (2014) “Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C33 / C33M-16e1 (2016) “Standard Specification for Concrete Aggregates”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C150 / C150M-17 (2017) “Standard Specification for Portland Cement”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C109 / C109M-16a (2016) “Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in or [50-mm] Cube Specimens)”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C778-17 (2017) “Standard Specification for Standard Sand”, ASTM International, West Conshohocken, PA, 2017, www.astm.org ASTM C204-16 (2016) “Standard Test Methods for Fineness of Hydraulic Cement by AirPermeability Apparatus”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C188-16 (2016) “Standard Test Method for Density of Hydraulic Cement”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C127-15 (2015) “Standard Test Method for Relative Density (Specific Gravity) and Absorption of Coarse Aggregate”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C128-15 (2015) “Standard Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate”, ASTM International, West Conshohocken, PA, www.astm.org ASTM C29 / C29M-17a (2017) “Standard Test Method for Bulk Density (“Unit Weight”) and © ASCE 409 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Voids in Aggregate”, ASTM International, West Conshohocken, PA, www.astm.org Townsend, T., (2017) “The benefits of construction and demolition materials recycling in the United States.” Construction and Demolition Recycling Association http://www.cdrecycling.org/assets/docs/cdd%202014%20executive%20summary.pdf Berndt, M.L (2009) “Properties of sustainable concrete containing fly ash, slag, and recycled concrete aggregate” Construction and Building Materials, 23, (2009) 2606–2613 Cheriaf, M., J Rocha, J., Péra, J (1999) “Pozzolanic properties of pulverized coal combustion bottom ash,” Cement and Concrete Research, 29(9), 1387–1391 Dilbas, H, Simsek, M, Çakır, Ư (2014) “An investigation on mechanical and physical properties of recycled aggregate concrete (RAC) with and without silica fume” Construction and Building Materials, 61, 50–59 Fedorka, W., Knowles, J., Castleman, J (2015) “Reclaiming and Recycling Coal Fly Ash for Beneficial Reuse with the STAR Process”, Proceedings In World of Coal Ash (WOCA), Nashville, TN, May 5–7 Kurama, H., Kaya, M (2008) “Usage of coal combustion bottom ash in concrete mixture,” Construction and Building Materials, 22, 1922–1928 Kou, S.-C., Poon, C.-S (2010) “Properties of concrete prepared with PVA-impregnated recycled concrete aggregates.” Cement and Concrete Composites, 32, 649–654 Kou, S.-C., Poon, C.-S., Agrela, F (2011) “Comparisons of natural and recycled aggregate concretes prepared with the addition of different mineral admixtures.” Cement and Concrete Composites, 33, 788–795 Kou, S.-C., Bao-jian, Z., S.-C, Poon, C.-S (2014) “Use of a CO2 curing step to improve the properties of concrete prepared with recycled aggregates”, Cement and Concrete Composites, 45, 22–28 Mukharjee, B.B, Barai, S.V (2014) Influence of incorporation of nano-silica and recycled aggregates on compressive strength and microstructure of concrete Construction and Building Materials, 71, 570–578 Oruji, S., Brake, N.A., Nalluri, L., Guduru, R (2017) “Strength activity and microstructure of blended ultra-fine coal bottom ash-cement mortar.” Construction and Building Materials, 317–326 Purushothaman, R Amirthavalli, R.,Karan, L (2015) “Influence of Treatment Methods on the Strength and Performance Characteristics of Recycled Aggregate Concrete”, J Mater Civ Eng., 27(5): 04014168 Silva, R.V., de Brito, J., Dhir, R.K (2014) “Properties and composition of recycled aggregates from construction and demolition waste suitable for concrete production.” Construction and Building Materials, 65, 201–217 Tam, V.W.Y., Tam, C.M., Wang, Y (2007) “Optimization on proportion for recycled aggregate in concrete using two-stage mixing approach,” Construction and Building Materials, 21, 1928–1939 Worrell, E., Kermeli, K., and Galitsky, C (2013) “Energy Efficiency Improvement and Cost Saving Opp for Cement Making An ENERGY STAR Guide for Energy/Plant Mngrs.” United States Environmental Protection Agency, Doc # 430-R-13–009 Wongkeo, W., Thongsanitgarn, P., Pimraksa, K., Chaipanich, A (2012) “Compressive strength, flexural srength, and thermal conductivity of autoclaved concrete block made using bottom ash as cement replacement materials,” Materials and Design, vol 35, pp 434–439, 2012 © ASCE 410 International Conference on Transportation and Development 2018 Mechanistic Evaluation of Effect of PPA on Moisture-Induced Damage Using SFE and XRF S A Ali1 ; R Ghabchi2 ; M Zaman3; R Steger4; S Rani5; and M A Rahman6 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Graduate Research Assistant, School of Civil Engineering and Environmental Science, Univ of Oklahoma, 202 West Boyd St., Room 334, Norman, OK 73019 (corresponding author) E-mail: syed.a.ali@ou.edu Assistant Professor, Dept of Civil and Environmental Engineering, 132 Crothers Engineering Hall, South Dakota State Univ., Brookings, SD 57007 E-mail: rouzbeh.ghabchi@sdstate.edu David Ross Boyd Professor and Aaron Alexander Professor of Civil Engineering, Alumni Chair Professor of Petroleum and Geological Engineering, and Director, Southern Plains Transportation Center, Univ of Oklahoma, 202 West Boyd St., Room 334, Norman, OK 73019 E-mail: zaman@ou.edu Platform Manager, Pavement Rehabilitation, Ingevity, 1540 N 107th E Ave., Tulsa, OK 74116 E-mail: richard.steger@ingevity.com Graduate Research Assistant, School of Civil Engineering and Environmental Science, Univ of Oklahoma, 202 West Boyd St., Room 334, Norman, OK 73019 E-mail: shivani.rani@ou.edu Graduate Research Assistant, School of Civil Engineering and Environmental Science, Univ of Oklahoma, 202 West Boyd St., Room 334, Norman, OK 73019 E-mail: shovon0701001@gmail.com ABSTRACT The modification of binder using poly-phosphoric acid (PPA) to improve high-temperature properties is not a new concept to asphalt industries However, there are some concerns over the moisture-induced damage potential of asphalt pavements with PPA-modified binder The present study was undertaken to explore the effect of PPA modification on the moisture-induced damage potential of an Oklahoma binder A commercially available PPA was collected and blended with a PG 76-28 binder The amount of PPA was kept constant at 1.5% by weight of the binder The surface free energy (SFE) components and the chemical constituents of the binders were determined using dynamic wilhelmy plate (DWP) test and X-ray fluorescence (XRF) test, respectively The bonding characteristics as well as the moisture-induced damage potential of the PPA-modified binder with a limestone aggregate were evaluated using the SFE technique The PPA modification was found to increase the moisture-induced damage potential of the asphalt mix with limestone aggregate In this study, an attempt has been made to explain the changes in SFE components using the results of elemental analysis from XRF test INTRODUCTION Asphalt binder modification has become an integral part of asphalt production to improve performance of asphalt pavements over the last few decades The use of different types of modifiers such as polymers, crumb rubber, and polyphosphoric acid (PPA) have increased significantly with the advent of Superpave specification (Baumgardner, 2010) The use of PPA in binder modification to change the high temperature rheological properties was first reported on early 1970s (Baumgardner, 2010) A number of studies has reported increase in the hightemperature performance grade (PG) of the neat binder with negligible effect on the lowtemperature properties with the addition of PPA (Baumgardner, 2010; Fee et al., 2010; © ASCE 411 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 D'Angelo, 2010) Also, PPA can be added to polymer-modified binder as a cross-linking agent or as a partial replacement for polymer modification (Arnold et al., 2009; D'Angelo, 2010) Although the use of PPA has a long history with pavement industries, highway agencies are concerned about the long-term performance of PPA-modified binder and limited it’s use in a number of states (Maurer and D'Angelo, 2012) One of the major concern for the PPA-modified binder is its performance in presence of moisture Arnold et al (2009) reported that, at a higher level of PPA modification, the sensitivity of the binder to moisture absorption increased significantly Several studies have reported increased moisture-induced damage potential of asphalt mixes with PPA-modified binder (Fee et al., 2010; Orange et al., 2004; Al-Qadi et al., 2014) Also, there is a need to study the effect of the addition of PPA on the moisture-induced damage potential of polymer-modified binders A number of test methods such as indirect tensile strength ratio (TSR), resilient modulus ratio, stripping inflection point (SIP) from Hamburg wheel tracking (HWT) test and fracture energy ratio is currently being used for evaluating the moisture-induced damage potential of asphalt mixes (Bagampadde et al., 2006; Gorkem and Sengoz, 2009; Ghabchi et al., 2015; Mirzababaei, 2016) However, none of these test methods was found adequate to explain the failure mechanisms of the moisture-induced damage phenomena of asphalt pavements Mechanistic evaluation of the bond strength between asphalt binder and aggregate in presence of water is important to assess the moisture-induced damage potential of asphalt mixes The thermodynamic theory or adhesion due to surface free energy (SFE) approach is gaining popularity to mechanistically quantify the bonding between aggregate and binder (Bhasin et al., 2006; Hefer et al., 2006; Bhasin et al., 2007; Wasiuddin et al., 2007; Wasiuddin et al., 2008; Buddhala et al., 2011; Ghabchi et al., 2013) To understand the effect of PPA on the binder’s performance properties, it is important to examine the interaction between PPA and the binder constituents As binder is a very complex material with thousands of compounds, the interaction with PPA is also very complex and needs different approaches to explain pertinent physical and chemical phenomena (Fee et al., 2010) Baumgardner et al (2005) analyzed the chemical compositions of PPA-modified binders using different chemical analysis tools and concluded that the mechanism of PPA action depends on the constituents of the base binder Baumgardner et al (2005) also mentioned different possible mechanisms of PPA reaction with the binder, such as acidolysis of alkyl-aromatics and nucleophilic displacement, alkylation of aromatics, cyclization of carboxylic acids and alcohols, and formation of an amino-phosphate salt and ionic cluster However, a general mechanism reported by Fee et al (2010) is based on the notion that the PPA reacts with various functional groups in the binder and breaks the asphaltene agglomerates into smaller fractions and disperse them in the maltene phase Those smaller asphaltene units form long-range networks and affect the rheology and physical characteristics of the binder Recently, researchers are using various chemical analysis tools such as X-Ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, nuclear magnetic resonance (NMR), atomic force microscopy (AFM) and X-ray photo electron spectroscopy (XPS) to analyze the chemical constituents of asphalt binder (Le Guern et al., 2010; Hossain et al., 2012; Hesp and Shurvell, 2013) In the present study, a relatively easy and less time-consuming XRF technique was used to determine the effect of PPA on a polymer-modified binder Reinke and Glidden (2010) have used XRF technique to detect the amount of phosphorus in the binder and to quantify PPA content Also, the XRF has been used to ensure the quality of asphalt binder by conducting elemental analysis (Hesp and Shurvell, 2010; Hesp and Shurvell, © ASCE 412 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 413 2013) In the present study, moisture susceptibility of an Oklahoma binder with 1.5% PPA was evaluated through measuring the surface free energies and chemical composition of the binder The specific objectives of this study were as follows: i Determining the SFE components of an polymer-modified binder with 1.5% PPA by using dynamic wilhelmy plate (DWP) test ii Assessing the effect of 1.5% PPA on the chemical composition of binder using XRF iii Evaluating the relationship between the SFE components and binders’ chemical composition iv Evaluating the moisture-induced damage potential of asphalt mixes containing asphalt binder modified with PPA and an limestone aggregate based on energy parameters SURFACE FREE ENERGY (SFE) The SFE of a solid is generally defined as the work required to increase the surface of that solid by a unit area under vacuum (Van Oss et al., 1988) The SFE of a material can be divided into three independent components, namely an apolar or Lifshitz-van der Waals component, a monopolar acidic component, and a monopolar basic component (Van Oss et al., 1988) The total SFE of a material can be expressed by Equations (1) and (2) LW (1) ΓTotal  Γ AB A A  ΓA   Γ AB A  (Γ A *Γ A ) (2) where,   = Lewis acid component,  - = Lewis base component, LW = Lifshitz-van der Waals component, and Total = Total SFE components For convenience, subscripts A, L, S, and W are used to represent asphalt binder, probe liquids, aggregate and water, respectively Work of adhesion (WA/S): The tendency of the asphalt and aggregate to bind together in a dry condition can be represented by the work of adhesion The WA/S of an asphalt-aggregate system can be calculated from Equation (3) using the SFE components of the asphalt binder and aggregate Generally, a higher WA/S value indicates a stronger bond between asphalt binder and aggregate at a dry condition LW     WAS  (Γ LW A Γ S )  (Γ A Γ S )  (Γ AΓ S ) (3) wet Work of debonding ( W ASW ): In presence of water, the amount of work required for debonding of the asphalt binder from the aggregate surface is defined as work of debonding ( wet wet ) and can be determined using Equation (4) Generally, the value of WASW is negative WASW indicating an overall reduction in free energy of the system due to debonding of the asphalt binder from aggregate interface in presence of water Therefore, debonding of asphalt binder from aggregate is a thermodynamically favorable phenomenon (Bhasin et al., 2007) wet (4) WASW  Γ AW  ΓSW  Γ AS where, ΓAW, ΓSW, and ΓAS represent the interfacial energy between asphalt binder and water, aggregate and water and asphalt binder and aggregate, respectively The interfacial energy between materials i and j can be determined using Equation (5) © ASCE International Conference on Transportation and Development 2018 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved     Γij  Γi  Γ j  (ΓiLW Γ LW j )  (Γi Γ j )  (Γi Γ j ) 414 (5) Wettability (SA/S): The tendency of the binder to spread and coat the surface of the aggregate can be determined using the wettability or spreading coefficient (SA/S) The spreading coefficient is generally a positive value A higher magnitude of spreading coefficient is required to ensure a better coating of the binder to the surface of aggregate (Buddhala et al., 2011) The SA/S can be calculated using Equations (6) (6) S A/ s  ΓS  Γ AS  Γ A Energy ratio (ER1): The ratio of the work of adhesion and work of debonding is defined as the energy ratio (ER1) and can be calculated using Equation (7) This parameter was introduced wet by Bhasin et al (2007) to quantify the effects of WA/S and WASW into a single value ER1  WAS wet WASW (7) MATERIALS AND METHODS Materials: A polymer-modified PG 76-28 asphalt binder was collected from a local refinery in Oklahoma The type and amount of polymer-modification was unknown as the refinery did not share that information Also, a commercially available poly-phosphoric acid (P1) was collected from its vendor The PPA was added to the binder at an amount of 1.5% by weight of asphalt binder The mixing of the binder and the PPA was conducted using a high shear mixer at a speed of 1,000 rpm for 45 minutes at a temperature of 170 °C The oxidation and aging of binders similar to that of mixing in the asphalt plant and compacting in the field were simulated using a rolling thin film oven (RTFO) following the AASHTO T 240-13 test method For the convenience, the PPA modified binder is called PG 76-28+1.5% P1 Methods Dynamic Wilhelmy Plate (DWP) test The contact angles of the PG 76-28 and PG 7628+1.5% P1 asphalt binders with different probe liquids were determined using the dynamic wilhelmy plate (DWP) test The contact angles of the asphalt binders with three different probe liquids, namely water, glycerin and formamide were measured using a dynamic contact angle analyzer (DCA) The test procedure described by Ghabchi et al (2013) was used for this purpose The SFE components of the binders were calculated from the contact angles using Equation (8) Five replicates were tested with each solvent to ensure consistency and repeatability In this study, advancing contact angles from DWP tests were used for further analysis, as they have been found more consistent than the receding contact angles (Hefer et al., 2006) LW     ΓTotal (8) 1  cos   2(ΓLW L A Γ L  Γ AΓ L  Γ AΓ L ) XRF Test on Asphalt Binders The X-ray fluorescence test for this study was conducted in the chemical laboratory of Ingevity using a Rigaku NexCG X-Ray Fluorescence Device The elemental analysis of the RTFO-aged PG 76-28 and PG 76-28+1.5% P1 binders using the XRF device was used to determine the effect of PPA modification The emission of characteristic "secondary" (or fluorescent) X-rays from the test sample excited by high-energy X-rays was used to identify the chemical compositions of the binders The working principles and mechanism of the XRF technique can be found elsewhere (Hesp and Shurvell, 2010; Hesp and Shurvell, 2013) © ASCE International Conference on Transportation and Development 2018 415 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved Elements ranging from sodium (Na) to uranium (U) of varying concentrations can be detected using the XRF device For consistency, three samples were tested from each binder and the average value was reported Table presents the test matrix for asphalt binders tested for this study Table Test Matrix of the PG 76-28 and PG 76-28+1.5% P1 Binders DWP Tests of Binders Material PG 76-28 PG 76-28+1.5% P1 Solvent Type No of Samples Water Glycerin Formamide 10 10 10 XRF Tests of Binders PG 76-28 PG 76-28+1.5% P1 3 RESULTS AND DISCUSSIONS Surface Free Energy of Asphalt Binders Contact Angles of Asphalt Binders Table presents the contact angles of RTFO-aged PG 76-28 and PG 76-28+1.5% P1 binders The wettability of a material with a specific solvent can be determined from the contact angle between the material and that solvent Typically, a contact angle of less than 90º indicates solvent’s ability to wet the surface of that material, whereas a contact angle of greater than 90º indicates that the solvent will not be able to wet the surface (Buddhala et al., 2011) From Table 2, the contact angles of PG 76-28 with water, glycerin and formamide were found to be 114.37º, 101.17º and 97.45º, respectively The addition of 1.5% PPA to the PG 76-28 binder was found to increase the contact angles with all probe liquids The contact angles of RTFO-aged PG 76-28+1.5% P1 binder were 117.70°, 108.83° and 106.10° for water, glycerin and formamide, respectively The increase in contact angles of the binder with the addition of PPA are expected to reduce the wettability of the probe liquids on the surface of the binder Reactions between the binder’s chemical components with the PPA are expected to be responsible for the increase in contact angles Also, the oxidation during short-term aging process may affect the contact angles of the binder Table Contact Angles of the PG 76-28 and PG 76-28+1.5% P1 Binders Advancing Contact Angle (Degree) Binder Type Glycerin Formamide Mean Standard Deviation Mean Standard Deviation Mean Standard Deviation 114.37 0.26 101.17 0.20 97.45 0.39 PG 76-28+ 1.5% P1 117.70 1.14 108.83 0.41 106.10 0.80 PG 76-28 © ASCE Water Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 416 Surface Free Energy (SFE) Components of Asphalt Binder Typically, a change in the SFE components of binder resulted in a change in the moisture-induced damage potential of asphaltaggregate system The SFE components of RTFO-aged PG 76-28 and PG 76-28+1.5% P1 are presented in Table The acid (Γ+) and the nonpolar Lifshitz-van der Waals (ΓLW) components of the PG 76-28 binder was found to decrease with the addition of 1.5% PPA For example, the Γ + component was observed to reduce to 0.88 mJ/m2 from 1.28 mJ/m2 with the addition of PPA The ΓLW component of the PG 76-28 binder was 7.67 mJ/m2, which reduced to 4.81 mJ/m2 (approximately 37% reduction) for binder with PPA However, the base (Γ -) components of the PG 76-28 binder increased with the addition of the 1.5% PPA The Γ- component was found to increase from 0.29 mJ/m2 to 0.79 mJ/m2 with the addition of PPA The total SFE (Γ Total) components of the PG 76-28 binder also decreased from 8.90 mJ/m2 to 6.49 mJ/m2 with the addition of the 1.5% PPA As a result of the addition of PPA, the Γ +/Γ- component of the PG 7628 binder was found to reduce from 4.41 to 1.11 indicating a substantial increase in basic behavior with the addition of PPA Al-Qadi et al (2014) also reported an increase in the basic SFE components of the binder with an increase in PPA As noted by Bhasin et al (2006), the acid component of the asphalt binder acts as a scale factor in calculation of dry adhesive bond strength Therefore, the addition of PPA may result in a weak bonding with aggregates which exhibits higher basic component than acid component As in the case of contact angles, the reactions of the polymer and PPA with binder’s chemical components are likely reasons for such changes in the binder’s surface energy properties Table SFE Components of the Tested Binders and Aggregate Surface Free Energy Components (mJ/m2) Binder Type Γ+ Γ- ΓLW ΓAB ΓTotal Γ+/Γ- PG 76-28 1.28 0.29 7.67 1.22 8.90 4.41 PG 76-28+ 1.5% P1 0.88 0.79 4.81 1.67 6.49 1.11 Surface Free Energy Components (mJ/m2) of Aggregate (Ghabchi et al., 2014) Aggregate Type Limestone Γ+ Γ- ΓLW ΓAB ΓTotal Γ+/Γ- 17.5 741.4 51.4 227.8 279.2 0.024 XRF Tests Results of Asphalt Binder Figure presents the results of the XRF tests conducted on the RTFO-aged PG 76-28 and PG 76-28+1.5% P1 binders In Figure 1, the chemical compositions of the tested binders are presented in a unit of particles per million (ppm) During XRF tests, all elements were scanned initially Then those elements that were not detected, or spectrum could not be seen, were deleted Each analysis was then re-calculated with the detected elements The primary constituent of the binder, as mentioned by Hefer et al (2005), is lightweight, oily or waxy fraction of long carbon chains and rings saturated with hydrogen For both the tested binders, oily constituents were found to be more than 95% of the total binder The oily constituent of the PG 76-28 binder was found to be 97.1%, which reduced to 96.9% with the addition of the PPA The presence of Aluminium (Al, 1.49 keV), Silicon (Si, 1.74 keV), Phosphorus (2.01 keV), Sulfur (S, 2.31 keV), Chlorine (Cl, 2.62 keV), Calcium (Ca, 3.69 keV), Vanadium (V, 4.95 keV), Iron (Fe, 6.40 keV), Nickel (Ni, 7.48 keV), Copper (Cu, 8.05 keV), Zinc (Zn, 8.64 keV), © ASCE Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Strontium (Sr, 14.17 keV), Tin (Sn, 25.27 keV) and Lead (Pb, 10.55 keV) were detected on the XRF spectrum The elements detected in the XRF are consistent with the studies conducted by Hesp and Shurvell (2010) and Hesp and Shurvell (2013) From Figure 1, it can be observed that the amount of S (28,666 ppm) was the highest among all the elements detected for the PG 76-28 binder from the XRF spectrum According to their composition from the highest to the lowest, other detected elements can be listed as Al (241 ppm), Fe (183 ppm), Si (116 ppm), P (80.1 ppm), Cl (46.3 ppm), V (45.2 ppm), Ca (26.1 ppm), Ni (25.2 ppm), Sn (14.5 ppm), Zn (8.36 ppm), Cu (3.29 ppm), Pb (2.46 ppm), and Sr (1.16 ppm) Analyzing the XRF spectrum of the PG 76-28+1.5% P1 binder, the addition of PPA can be easily detected from the increase in phosphorus content of the binder The amount of phosphorus increased from 80.1 ppm to 3385 ppm with the addition of PPA to the PG 76-28 binder Reinke and Glidden (2010) also reported presence of phosphorus element in the binder sample after PPA modification from XRF test Furthermore, nuclear magnetic resonance (NMR) test used by Baumgardner et al (2005) detected phosphorous compounds in the precipitated asphaltenes from the PPA-modified asphalt binders The amount of Al, Si, and Sn exhibited an increase in amount with an addition of 1.5% PPA For example, the Al was found to increase from 241 ppm to 264 ppm upon the addition of 1.5% PPA On the other hand, S, Cl, Fe and Ni was found to decrease with PPA addition Figure Chemical components of the RTFO-aged PG 76-28 and PG 76-28+1.5% P1 binders According to Hefer et al (2005), the oily fractions are nonpolar in character and made up from single C-H and C-C bonds These nonpolar molecules interact through van der Waals forces The reduction in the nonpolar Lifshitz-van der Waals component (ΓLW) of the PG 76-28 binder with the addition of PPA was found to be consistent with the reduction of oily fraction of the binder The XRF results showed that the phosphorus content increased significantly with PPA addition, which can be misinterpreted as an increase in the acidic component of the binder With the addition of PPA, the acid to base ratio of the polymer-modified PG 76-28 binder was found to decrease Reinke and Glidden (2010) reported that the acid functionality of the PPA is responsible for the binder properties, not the phosphorus The acid reaction with the binder constituents can be neutralized by presence of other compounds without affecting the phosphorus content Also, the oxidation from the RTFO-aging can affect the polarity of the binder As the © ASCE 417 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 418 base binder’s constituents, functional groups and type and amount of polymer are unknown, it is difficult to comment on the mechanism behind this phenomenon Further studies involving different amount of PPA and aging processes are needed to properly understand this characteristic Compatibility of Binders with Limestone Aggregate: A limestone aggregate with a known SFE components from a previous study was selected to determine the compatibility with the tested binders The SFE components of the aggregate are presented in Table It can be observed that the selected limestone aggregate is primarily a basic aggregate Table presents the spreading coefficient (SA/S), work of adhesion (WA/S), work of debonding wet ( WASW ) and ER1 values of the PG 76-28 and PG 76-28+1.5% P1 binders with limestone aggregate From Table 4, the SA/S was found to decrease with an increase in the PPA content The PG 76-28 binder containing 1.5% PPA was found to exhibit a SA/S of 77.1 mJ/m2 which is approximately 12.5% less than the SA/S of the neat binder This observation indicated that the use of PPA is expected to reduce binder’s ability to wet and coat the surface of the limestone aggregate It was observed that the WA/S for PG 76-28 binder reduced due to the addition of 1.5% PPA The work of adhesion for PG 76-28 binder containing 1.5% PPA was found to be 105.9 mJ/m2, wet whereas the PG 76-28 binder exhibited a WA/S of 90.1 mJ/m2 Also, the magnitude of the WASW wet was found to increase upon the addition of PPA The | WASW | for the PG 76-28 binder with limestone aggregate was found to be 175.5 mJ/m , whereas the same for the PPA-modified wet binder was 187.5 mJ/m2 Based on the results of the WA/S and WASW , it can be concluded that the addition of PPA may reduce the resistance of an asphalt mix containing limestone aggregate to moisture-induced damage The ER1 also reduces with the addition of PPA As in the case of WA/S wet and WASW , it can be concluded that the PPA addition is expected to reduce the resistance to moisture-induced damage of the asphalt binder–aggregate systems The reduction in the moisture damage resistance of a PPA-modified binders with limestone aggregate was also reported in other studies (Al-Qadi et al., 2014; Reinke et al., 2012) Use of an anti-stripping agent with PPAmodified binder was recommended for a better moisture resistance performance (Fee et al., 2010) Table Energy Parameters of Asphalt Binders and Limestone Aggregate Binder Type Work of Adhesion, WA/S Work of Debonding, wet W ASW Wettability, SA/S ER1 PG 76-28 105.9 -175.5 88.1 0.50 PG 76-28+1.5% P1 90.1 -187.5 77.1 0.41 *all units are in mJ/m2 CONCLUSIONS The effect of PPA modification on a polymer-modified PG 76-28 binder was evaluated in this study using the SFE and XRF techniques The SFE components of the binders were determined using DWP test Elemental analyses were performed to determine the chemical characteristics of the binders using XRF technique Based on the results and discussions © ASCE Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 presented in the preceding sections, the following conclusions can be drawn: i The contact angles of the PG 76-28 binder increased with the addition PPA for all probe liquids ii The addition of PPA to a polymer-modified binder reduced the ΓLW, Γ+ and ΓTotal SFE components of the binder The Γ- component increased significantly, which in turn resulted in a reduction in acid to base ratio (Γ+/Γ-) of PG 76-28 binder The reaction between the polymer, PPA and the base binder constituents are likely responsible for such characteristics The oxidation during RTFO-aging and use of high PPA content can be another reason for this kind of phenomena iii From the XRF results, presence of a large amount of phosphorus was detected in the PPA modified binder However, it was difficult to comment on the moisture-induced sensitivity of the binder based on only XRF results iv Addition of PPA to the PG 76-28 binder reduced the WA/S and increased the magnitude of wet the WASW with limestone aggregate and resulted in a lower ER1 value Therefore, an asphalt mix with limestone aggregate and PPA-modified PG 76-28 binder is expected to exhibit higher susceptibility to moisture-induced damage than the mix with only PG 7628 binder RECOMMENDATIONS FOR FUTURE STUDY Considering the limited scope of the present study, the following recommendations are made: Future studies may focus on the determination of chemical characteristics and surface energy properties of polymer-modified binders with different amounts of PPA Such studies will provide a better understanding of the effects of PPA ii The mechanisms behind the interactions between PPA, polymer and base binder components need be studied to understand the effect of PPA on the SFE properties as well as moisture-induced damage potential of binders i ACKNOWLEDGEMENTS The financial supports provided by the Oklahoma Department of Transportation (ODOT) and the Southern Plains Transportation Center (SPTC) are gratefully acknowledged The authors also extend their appreciation to the binder suppliers, Ingevity and Valero refinery (Ardmore, Oklahoma) for their support Finally, the authors to the members of the OU Asphalt Group for their assistance and support REFERENCES Al-Qadi, I L., Abauwad, I M., Dhasmana, H., and Coenen, A R (2014) Effects of various asphalt binder additives/modifiers on moisture-susceptible asphaltic mixtures.” Illinois Center for Transportation Research Report FHWA-ICT-14-004 Arnold, T S., Needham, S P., and Youtcheff Jr, J S (2009) “Use of phosphoric acid as a modifier for hot-mix asphalt.” Transportation Research Circular E-C160, Polyphosphoric Acid Modification of Asphalt Binders, 40-51 Bagampadde, U., Isacsson, U., and Kiggundu, B M (2006) “Impact of bitumen and aggregate composition on stripping in bituminous mixtures.” Materials and structures, 39(3), 303-315 Baumgardner, G L., Masson, J F., Hardee, J R., Menapace, A M., and Williams, A G (2005) “Polyphosphoric acid modified asphalt: proposed mechanisms.” J of the Assoc of Asphalt © ASCE 419 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 Paving Techno., 74, 283-305 Baumgardner, G L (2010) “Why and how of polyphosphoric acid modification–an industry perspective.” J of the Assoc of Asphalt Paving Techno., 79 Bhasin, A., Masad, E., Little, D., and Lytton, R (2006) “Limits on adhesive bond energy for improved resistance of hot-mix asphalt to moisture damage.” Transportation research record: Journal of the Transportation Research Board, 1970, 3-13 Bhasin, A., Little, D N Vasconcelos, K L., and Masad, E (2007) “Surface free energy to identify moisture sensitivity of materials for asphalt mixes.” Transportation Research Record: Journal of the Transportation Research Board, 2001, 37-45 Buddhala, A., Hossain, Z., Wasiuddin, N M and Zaman, M (2011) “Effects of an amine antistripping agent on moisture susceptibility of sasobit and aspha-min mixes by surface free energy analysis.” J of Test and Eval., 40(1), 1-9 D'Angelo, J (2010) “Effect of poly phosphoric acid on asphalt binder properties.” Asphalt Paving Technology-Proceedings Assoc of Asphalt Techno., 79, 679 Fee, D., Maldonado, R., Reinke, G., and Romagosa, H (2010) “Polyphosphoric acid modification of asphalt.” Transportation Research Record: Journal of the Transportation Research Board, 2179, 49-57 Ghabchi, R., Singh, D., Zaman, M., and Tian, Q (2013) “Mechanistic evaluation of the effect of WMA additives on wettability and moisture susceptibility properties of asphalt mixes.” J of Test and Eval., ASTM, 41(6), 1-10 Ghabchi, R., Singh, D., and Zaman, M (2014) “Evaluation of moisture susceptibility of asphalt mixes containing RAP and different types of aggregates and asphalt binders using the surface free energy method.” Construction and Building Materials, 73, 479-489 Ghabchi, R., Singh, D., and Zaman, M (2015) “Laboratory evaluation of stiffness, lowtemperature cracking, rutting, moisture damage, and fatigue performance of WMA mixes.” Road Materials and Pavement Design, 16(2), 334-357 Gorkem, C., and Sengoz, B (2009) “Predicting stripping and moisture induced damage of asphalt concrete prepared with polymer modified bitumen and hydrated lime.” Construction and Building Materials, 23(6), 2227-2236 Hefer, A W., Little, D N., and Lytton, R L (2005) “A synthesis of theories and mechanisms of bitumen-aggregate adhesion including recent advances in quantifying the effects of water.” J of the Assoc of Asphalt Paving Techno., 74, 139-196 Hefer, A W., Bhasin, A., and Little, D N (2006) “Bitumen surface energy characterization using a contact angle approach.” J of Materials in Civil Eng., ASCE, 18(6), 759-767 Hesp, S A., and Shurvell, H F (2010) “X-ray fluorescence detection of waste engine oil residue in asphalt and its effect on cracking in service.” Int J of Pavement Eng., 11(6), 541553 Hesp, S A., and Shurvell, H F (2013) “Quality assurance testing of asphalt containing waste engine oil.” Int J of Pavements Conference, São Paulo, Brazil Hossain, Z., Lewis, S., Zaman, M., Buddhala, A., and O’Rear, E (2012) “Evaluation for warmmix additive-modified asphalt binders using spectroscopy techniques.” J of Materials in Civil Eng., ASCE, 25(2), 149-159 Le Guern, M., Chailleux, E., Farcas, F., Dreessen, S., and Mabille, I (2010) “Physico-chemical analysis of five hard bitumens: Identification of chemical species and molecular organization before and after artificial aging.” Fuel, 89(11), 3330-3339 Maurer, D., and D'Angelo, J A (2012) “Department of transportation perspective: a survey on © ASCE 420 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/03/19 Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 polyphosphoric acid use and issues Transportation Research E-Circular, (E-C160), 8-11 Mirzababaei, P (2016) “Effect of zycotherm on moisture susceptibility of warm mix asphalt mixtures prepared with different aggregate types and gradations.” Construction and Building Materials, 116, 403-412 Orange, G., Martin, J V., Menapace, A., Hemsley, M., and Baumgardner, G L (2004) “Rutting and moisture resistance of asphalt mixtures containing polymer and polyphosphoric acid modified bitumen.” Road materials and pavement design, 5(3), 323-354 Reinke, G., and Glidden, S (2010) “Analytical procedures for determining phosphorus content in asphalt binders and impact of aggregate on quantitative recovery of phosphorus from asphalt binders.” Asphalt Paving Technology-Proceedings Assoc of Asphalt Techno., 79, 695 Reinke, G., Glidden, S., Herlitzka, D., and Veglahn, S (2012) “Polyphosphoric acid–modified binders and mixtures: aggregate and binder Interactions, rutting, and moisture sensitivity of Mixtures.” Transportation Research E-Circular, (E-C160), 52-69 Van Oss, C J., Chaudhury, M K., and Good, R J (1988) “Interfacial Lifshitz –van der Waals and polar interactions in macroscopic systems.” Chemical Reviews, 88(6), 927–941 Wasiuddin, N M., Fogle, C M., Zaman, M., and O’Rear, E A (2007) “Effect of antistrip additives on surface free energy characteristics of asphalt binders for moisture-induced damage potential.” ASTM J of Test and Eval., 35(1), 36–44 Wasiuddin, N M., Zaman, M and O’Rear, E A (2008) “Effect of sasobit and aspha-min on wettability and adhesion between asphalt binders and aggregates.” Transportation Research Record, 2051, 80-89 © ASCE 421 ... ASCE International Conference on Transportation and Development (ICTD 2018) ! Organized by Transportation and Development Institute (T&DI), ICTD is ASCE’s flagship conference in transportation and. .. on 01/03/19 Copyright ASCE For personal use only; all rights reserved INTERNATIONAL CONFERENCE ON TRANSPORTATION AND DEVELOPMENT 2018 AIRFIELD AND HIGHWAY PAVEMENTS SELECTED PAPERS FROM THE INTERNATIONAL. .. Copyright ASCE For personal use only; all rights reserved International Conference on Transportation and Development 2018 pavements and plan potential CapEx interventions for 1935 sections of pavement