1、September 2012 Manual for Emulsion-Based Chip Seals for Pavement Preservation American Association of State Highway and Transportation Officials 444 North Capitol Street, N.W. Suite 249 Washington, DC 20001 www.transportation.org Publication Code: MEBC-1 ISBN: 978-1-56051-530-2 2012 by the American
2、Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.American Association of State Highway and Transportation Officials 444 North Capitol Street, NW , Suite 249 Washington, DC 20001 202-624-5800 phone/202-624-5806 fax www.transp
3、ortation.org 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law. Publication Code: MEBC-1 ISBN: 978-1-56051-530-2 2012 by the American Association of State Highway and Transportation Officials. All rights
4、reserved. Duplication is a violation of applicable law.i AASHTO EXECUTIVE COMMITTEE 20112012 Voting Members Officers: President: Kirk T. Steudle, P .E., Michigan Vice President: Michael P . Lewis, Rhode Island Secretary-Treasurer: Carlos Braceras, Utah Regional Representatives: REGION I: Beverley Sw
5、aim-Staley, Maryland, One-Y ear Term James P . Redeker, Connecticut, Two-Y ear Term REGION II: Robert St. Onge, South Carolina, One-Y ear Term Eugene Conti, North Carolina, Two-Y ear Term REGION III: Kevin Keith, Missouri, One-Y ear Term Mark Gottlieb, Wisconsin, Two-Y ear Term REGION IV: Francis Zi
6、egler, North Dakota, One-Y ear Term John Cox, Wyoming, Two-Y ear Term Non-Voting Members Immediate Past President: Susan Martinovich, Nevada AASHTO Executive Director: John Horsley, Washington, DC 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Du
7、plication is a violation of applicable law. 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.iii AASHTO Subcommittee on Maintenance 20112012 Chair: Carlos Braceras, Utah Vice Chair: Jennifer Brandenburg,
8、 North Carolina Vice Chair: Robert “Chris” Christopher, Washington Secretary: Bryan Cawley, FHW A Liaison: Gummada Murthy, AASHTO State Me Mber S Al AbAmA G. Mike Harper George H. Conner Ronald D. Pruitt Al Ask A Michael Coffey Arizon A Lonnie D. Hendrix Marwan Aouad Dennis G. Halachoff Ark Ans As T
9、ony Sullivan Emanuel Banks CAliforni A Tony Tavares Color Ado David C. WiederSteve Olson Conne CtiCut Vacant d el Aw Are Alastair Probert d istri Ct of Col umbi A Mesfin Lakew Aaron Horton f lorid A Tim Lattner Geor GiA Eric Pitts Rachel Brown HAw Aii John Williams idAHo Greg Laragan illinois Aaron
10、WeatherholtDavid B. Johnson indi An A Jason Jones iow A Bob Y ounie kA ns As Peter Carttar Tim D. Cunningham k entu Cky Nancy B. AlbrightEdward MerrymanJon Wilcoxon l ouisi An A Leslie W . Mix Janice P . Williams William Drake Jr. mAine Dale Doughty mAryl And Russell A. YurekLeonard Schultz 2012 by
11、the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Manual for Emulsion-Based Chip Seals for Pavement Preservation iv mAss ACHuset ts Vacant miCHiGAn Mark GeibSteve Cook minnesot A Steven M. Lund Susan J. Lodahl mi
12、ssissippi Celina Sumrall missouri Don Hillis Elizabeth (Beth) Wright mont An A Jon Swartz n ebr Ask A Michael T. Mattison Craig R. Lind n evAdA Richard J. Nelson Anita Bush n ew H Amps Hire Caleb B. Dobbins Douglas Gosling n ew Jersey Richard M. Shaw n ew mexi Co Dennis Ortiz n ew york Peter Weykamp
13、 n or tH CArolin A Jennifer P . Brandenburg n or tH dAkotA Brad Darr oH io David Ray Halle Jones Capers o kl AHom A Kevin S. Bloss Tom Wadley o re Gon Lucinda M. Moore pennsyl vAni A W . James Smith Charles C. Goodhart rH ode isl And Paul R. Annarummo sout H CArolin A James J. FedaDavid B. Cook sout
14、 H dAkotA Ed Rodgers Jason Humphrey tennessee Mike Doran Greg Duncan Chris Harris tex As Toribio Garza u tAH Carlos Braceras Steven J. McCarthyKevin GriffinLloyd Neeley v ermont Scott A. Rogers Wayne GammellKen Valentine v ir Gini A Erle W . Potter Emmett HeltzelJeffrey Milton wA sHin Gton Robert “C
15、hris” Christopher w est v ir Gini A Steven B. Cole w isConsin David I. Vieth Todd MathesonMark Woltmann w yomin G Kent Ketterling U.S. DOt MeMber f Hw A Christopher Newman Paul Pisano William Beatty Steve Mueller James Stevenson Anwar Ahmad 2012 by the American Association of State Highway and Trans
16、portation Officials. All rights reserved. Duplication is a violation of applicable law.v The research reported herein was performed under NCHRP Project 14-17 by the Department of Construction Management at Colorado State University (CSU) and the department of civil engineering at Texas A Amy Epps-Ma
17、rtin, Associate Professor at TAMU; and Denise Hoyt, M.S. candidate and Research Assistant at TAMU. Additional contributors to this work include Charles Leudders, FHW A Federal Lands Division; Ben Vagher, A-1 Chip Seal; William Trudahl, Washington state DOT; and Roy Guevera, Colorado Department of Tr
18、ansportation. The authors gratefully acknowledge the work and technical assistance of Nikornpon Prapaitrakul, Rongbin Han, Xin Jin, and Charles J. Glover of the Artie McFerrin Department of Chemical Engineering, Texas A and of Rick Canatella of the Texas Transportation Institute McNew Laboratory, Te
19、xas A Crawford F. Jencks, Deputy Director, Cooperative Research Programs; Amir N. Hanna, Senior Program Officer; Eileen P . Delaney, Director of Publications; and Doug English, Editor. NCHr P Pr OJeCt 14-17 PaNeL Field of MaintenanceArea of Maintenance of Way and Structures; Edward J. Denehy, The Go
20、rman Group, Great Barrington, MA (formerly New Y ork State DOT) (Chair); John Vance, Mississippi DOT, Jackson, MS; John W . Col- lins, John W . Collins, LLC, Baton Rouge, LA (formerly Louisiana DOTD); F. M. “Rick” Harvey, Wyoming DOT, Cheyenne, WY; Kevin Kennedy, Michigan DOT, Lansing, MI; Joseph A.
21、 Mickes, Quixote Transportation Safety, Jef- ferson City, MO; Luis Rodriguez, FHW A Liaison; and Frank N. Lisle, TRB Liaison. AUTHOR ACKNOWLEDGMENTS 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law. 2012
22、 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.vii Emulsion-based chip seals are the most commonly used chip seal type in the United States. These seals are frequently used as pavement preservation treatme
23、nts on flexible pavements to seal fine cracks in the underlying pave- ments surface and prevent water intrusion into the base and subgrade. Because chip seals are not expected to provide additional structural capacity to the pavement, benefits ideally are accrued by their application early in a pave
24、ments life before a great degree of distress is exhibited. Although a large body of research is available on chip seal design practices, the design process in the United States remains empirical in naturebased on experience and judgment. Procedures that consider the surface condition of the existing
25、 pavement, traffic volume, environment, and other rel- evant factors in determining the characteristics and application rates of aggregates and binder have not been widely used in the United States. In spite of their apparent benefits, the use of chip seals for pavement preservation in the United St
26、ates is ham- pered by the lack of nationally accepted guidance on their design and construction and appropriate specifications and testing procedures for constituent materials. Thus, research was needed to identify the factors that influence chip seal design and performance and to develop a manual t
27、hat documents design and construction practices and delineates necessary testing and specifications. Such a manual will provide highway agencies with the information necessary for designing and constructing long-lasting chip seals and preserving pavements. Under NCHRP Project 14-17, “Manual for Emul
28、sion-Based Chip Seals for Pavement Preservation, ” Colorado State University of Fort Collins conducted a review of available information relevant to design and construction prac- tices of emulsion-based chip seals, conducted laboratory tests and field investigations to evaluate the factors affecting
29、 chip seal performance, and prepared a manual for designing and constructing chip seals over hot mix asphalt pave- ments together with test methods for evaluating some aspects of chip seal construction. The manual and test methods presented in the NCHRP report will be particularly useful to highway
30、agencies because the manual provides a rational approach for the design of chip seals used in the preservation of pavements and the test methods provide appropriate means for control of chip seal construction. FOREWORD 2012 by the American Association of State Highway and Transportation Officials. A
31、ll rights reserved. Duplication is a violation of applicable law.Manual for Emulsion-Based Chip Seals for Pavement Preservation viii The appendices contained in the research agencys final report provide further elaboration on the work performed in this project. These appendices are not published her
32、ein but are available on the NCHRP Report 680 summary webpage at http:/www.trb.org/Main/Blurbs/164090.aspx. 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.ix 1-1 CHaPter 1 INtr ODUCtION1-1 | 1.1 d efin
33、ition of Chip seals 2-1 CHaPter 2 FaCtOr S aFFeCtINg CHIP Sea L Per FOr MaNCe2-1 | 2.1 pavement behavior and Condition2-2 | 2.2 traffic Characteristics2-3 | 2.3 Geometry2-3 | 2.4 Highway, r esidential, u rban, or r ural2-4 | 2.5 materials2-6 | 2.6 Construction preparation2-6 | 2.7 maintenance 3-1 CH
34、aPter 3 DeSIgN aND CONStr UCtION CONSIDera tIONS3-1 | 3.1 identifying Appropriate pavements to Chip seal3-1 | 3.2 type of seal3-2 | 3.3 Chip seal selection3-2 | 3.4 selecting the Aggregate size3-2 | 3.5 evaluating the pavement3-3 | 3.6 materials Table of Contents 2012 by the American Association of
35、State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Manual for Emulsion-Based Chip Seals for Pavement Preservation x 4-1 CHaPter 4 SeLeCtINg t He aPPr OPr Iate C HIP Sea L4-1 | 4.1 single seal4-1 | 4.2 single seal with Choke stone4-2 | 4.3 d
36、ouble seal 5-1 CHaPter 5 CHIP Sea L Mater IaLS SeLeCtION5-1 | 5.1 Chip Gradation5-1 | 5.2 modified or u nmodified emulsion5-1 | 5.3 f og seal After Chip seal5-2 | 5.4 emulsionAggregate Compatibility 6-1 CHaPter 6 CHIP Sea L DeSIgN6-1 | 6.1 emulsion Application r ate6-9 | 6.2 Aggregate Application r
37、ate6-9 | 6.3 time u ntil sweeping and traffic6-9 | 6.4 o ther Considerations6-9 | 6.5 example d esign 7-1 CHaPter 7 CONStr UCtION7-1 | 7.1 equipment Calibrations7-3 | 7.2 operations 8-1 CHaPter 8 QUaLIty C ONtr OL8-1 | 8.1 Aggregate sieve Analysis8-2 | 8.2 moisture Content of system8-2 | 8.3 embedme
38、nt d epth measurement d uring Construction8-2 | 8.4 f ield v iscosity 9-1 CHaPter 9 Per FOr MaNCe9-1 | 9.1 l ess than o ne year9-1 | 9.2 Greater than o ne year r -1 r eFere NCeS 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a viol
39、ation of applicable law.1-1 CHAPTER 1 Introduction This manual was developed for use in designing and constructing chip seals over hot mix asphalt pavements. It documents best practices based on the findings of research during NCHRP Project 14-17, Manual for Emulsion- Based Chip Seals for Pavement P
40、reservation. In addition, certain subjective or qualitative judgments previously needed during chip seal construction have been eliminated in favor of field and laboratory testing. These include the moisture content of the seal before traffic can be released, judging surface condition so emulsion ap
41、plication rate can be adjusted for surface demand, and measuring the emulsion consistency in the field. The introduction of these new techniques should improve the probability of success when designing and constructing chip seals, but they do not replace the significant judgment required. Also, the
42、success of any chip seal depends on conformance to best prac- tices, and variance or elimination of these practices often leads to disappointing performance. 1.1 Definition of Chip Seals Chip seals described in this manual are based on emulsified asphalt binders and natural mineral aggregate chips.
43、The chip seal is constructed by spraying the asphalt emulsion onto the existing asphalt pavement and then dropping the aggregate chips into the asphalt emulsion. The purpose of the chip seal is to seal minor cracks in the surface of the asphalt pavement and provide additional friction. 2012 by the A
44、merican Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.2-1 CHAPTER 2 Factors Affecting Chip Seal Performance The performance of a chip seal depends on many factors, including the condition of the pavement to which the chip
45、 seal is to be applied, pavement geometry, traffic volume and type, materials, and construction practices. The fol- lowing discussion describes these factors and their effects on the performance of the chip seal. 2.1 Pavement behavior and Condition 2.1.1 Deflection of Substrate The amount of deflect
46、ion is an indication of whether future fatigue can be expected. If deflection is significant, a chip seal may be inappropriate. The maximum level of deflection will vary depending on the traffic volume; however, if fatigue cracking is already present, chip seal performance may be reduced. However, a
47、 chip seal may reduce moisture infiltration into the subgrade, thus reducing the potential for future fatigue. Therefore, the decision to chip seal over existing fatigue cracking requires judgment depending on the performance expectation of the existing pavement. 2.1.2 Cracking Severity Chip seals a
48、re most effective as a pavement preservation technique before cracks are ranked as high severity (Peshkin et al., 2004), defined as a crack width of 3 8 in. Although the chip seal binder has the ability to seal cracks greater than this width, as crack width increases, the emulsion residue is less ef
49、fective at bridging the gap across the crack and sealants should be used to fill these cracks prior to chip sealing. 2.1.3 Flushing/Bleeding Chip seals may be applied to remedy friction loss, but penetration of chips into flushed pavement surfaces may limit effectiveness unless chips can be retained with lower emulsion application rates. Flushing and bleeding of the existing 2012 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.2-2 Manual for Emulsion-Based Chip S
