SUBCOMMITTEE ON MATERIALS€¦ · SUBCOMMITTEE ON MATERIALS ... Consider Task Force. Tech Sec 2B 2016 Mid-Year Minutes Page 2 of 30 Pennsylvania Department of Transportation (Robert

SUBCOMMITTEE ON MATERIALS Mid‐Year Web Meeting

Wednesday, February 17, 2016 1:30 pm – 3:30 pm EST

TECHNICAL SECTION 2b ASPHALT

I. Call to Order and Opening Remarks Maria gave some rules on the web meeting. Eileen will beretiring on September 1, 2016. Lyndi Blackburn (AL) is going to be taking over as the Chair,and Barry Paye (WI) will be taking over as the Vice‐Chair.

II. Roll Call Member attendance marked below. For complete attendance see Appendix A.

Voting Members

Blackburn, Lyndi D Alabama X Tedford, Darin P Nevada X

Burch, Paul and Craig Wilson

Arizona X Boisvert, Denis M. and Baron Black

New Hampshire X

Schiebel, Bill R Colorado Sheehy, Eileen New Jersey X

Connery, James P. Connecticut X Burnett, Robert A. New York

Khan, Wasi U District of Columbia Peoples, Christopher North Carolina X

Bukowski, John R (Matt Corrigan)

FHWA X Lane, Becca Ontario

Nash, Tanya M Florida X Mullis, Cole F. Oregon X

Wu, Peter Georgia X Ramirez, Timothy Pennsylvania X

Shishido, Eric Hawaii Byrne, Michael and Mark Felag

Rhode Island X

Mueller, Matthew W. (Justan Mann)

Illinois X Egan, Brian Tennessee X

Kreider, Richard E. Kansas Hazlett, Darren Texas X

Myers, Allen Kentucky Andrus, Scott (Dave Thomas)

Utah X

Abadie, Chris Louisiana X Ahearn, William and Mladen Gagulic

Vermont X

Bradbury, Richard L Maine Bailey, William R. Virginia X

Barot, Sejal Maryland Farley, Paul M (John Crane and Jimmy Fritz)

West Virginia X

Grieco, John E. and Maggie McDonald

Massachusetts X Paye, Barry Wisconsin X

Strizich, Matt (Oak Metcalfe)

Montana X

Non‐Voting Members

Johnson, Brian AMRL X Arasteh, Michael FHWA

Tech Sec 2B2016 Mid-Year Minutes

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Knake, Maria AMRL X Aschenbrener, Tim FHWA X

John Malusky AMRL X Harman, Tom FHWA

Lutz, Robert AMRL Smith, Michael Ray FHWA

Rothblatt, Evan AASHTO Gallivan, Victor Lee Gallivan Consulting X

III. Approval of Technical Section MinutesRequest discussion and approval of minutes from August 6, 2015 meeting in Pittsburgh,Pennsylvania. TS Chair received a call from Jesus Sandoval (AZ). AZ no longer wants to be onthe single‐edged notch task force. No other changes were suggested. LA approved the minutes,OR seconded. Minutes are approved.

IV. Old BusinessA. SOM Ballot Items

Items 26 – 30 – See Attachment #1 for all comments.

Item 39 ‐ Concurrent ballot item to adopt a new provisional test method for Determination ofPerformance Grade of Physically Aged Asphalt Binder Using Extended Bending Beam Rheometer(BBR) Method. See Appendix D‐1 (pages 18‐26) for the proposed standard and page 3 of the 2015minutes for discussion and motion. 46 Affirmative, 0 negative, 6 No Vote. This item passed. Editorialcomments have been addressed. This is now TP 122.

Item 40 ‐ Concurrent ballot item to adopt a new provisional test method for Measuring AsphaltBinder Yield Energy and Elastic Recovery Using the Dynamic Shear Rheometer. See Appendix D‐2(pages 27‐32) for the proposed standard, Appendix D‐2a for responses to the TS Ballot, and pages 3‐4of the 2015 minutes for discussion and motion. 46 Affirmative, 0 negative, 6 No Vote. There were nonegatives. Task Force considered all comments. Editorial comments have been addressed. OH wasconcerned about precision and bias. TX wanted to do the testing on unaged binder. The Chair feelsthat those are valid comments, but the task force is not sure about making a change on unagedbinder since no one is performing the test on unaged binders at this point. This will be revisited oncepeople start using this standard. This is now TP 123.

Item 41 ‐ Concurrent ballot item to revise TP 102 to keep this standard in line with the NTPEP workplan for asphalt release agents. See Appendix D‐3 (pages 38‐49) for the proposed standard and page4 of the 2015 minutes for discussion and motion. 45 Affirmative, 0 negative, 7 No Vote. Editorialcomments were addressed. Task Force considered all comments. This item passed. Proposedchanges have been forwarded to the Chair, and they appear to be all editorial in nature. Thecomments are included in Attachment 1 of the agenda.

Item 42 ‐ SOM ballot item to revise M 320 to base PAV temperatures on climate when switchinggrades due to traffic or blending with other asphalt (RAP/RAS). See Appendix D‐4 (pages 50‐55) forthe proposed standard and page 4 of the 2015 minutes for discussion and motion. 45 Affirmative, 0negative, 7 No Vote. Comments from Kentucky, Massachusetts, and Oklahoma stating that footnotef is confusing. See Attachment #2 for some other potential wording. The Chair tried to proposewording to help eliminate the confusion. She also tried to add a table to help make it clearer. Lyndiwill work on another revision to clear this up. She will email her revision out to the technical sectionto get comments before sending it to ballot.

Item 43 ‐ Reconfirm R028‐12 as a full standard. 45 Affirmative, 0 negative, 7 No Vote. DiscussPennsylvania comment. Consider Task Force.

Tech Sec 2B 2016 Mid-Year Minutes

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Pennsylvania Department of Transportation (Robert D Horwhat) ([email protected])

Affirmative but please review and respond to our comment: ------------------------------------------------------------------- We have had problems with Section 6.1.2.3 during our AMRL Surveillance audits. Our previous PAV was not able to release pressure in a "linear rate" and was written up by the AMRL auditor. We had to purchase new PAVs from a different PAV manufacturer to solve this problem. Can this section be reviewed to see if the rate of release needs to be in a linear rate? If the concern is excessive foaming of the sample, will de-gassing take care of that?

"6.1.2.3: A slow release bleed valve that allows the pressure in the vessel at the completion of the conditioning procedure to be reduced at an approximately linear rate from 2.1 MPa to local atmospheric pressure within 9 ± 1 min."

Matt Corrigan stated that the Binder ETG (Dave Anderson) has been looking at this, and he found that neither of the main PAV manufacturers conform to this requirement. ETG is looking at whether this is going to make a difference in the condition of the material. The TS will wait for a report from the ETG.

Item 44 Reconfirm T313‐12 as a full standard. 45 Affirmative, 0 negative, 7 No Vote. No comments.



Item 47 Reconfirm TP078‐09 (2013) as a provisional standard. 45 Affirmative, 0 negative, 7 No Vote. No comments. TP 78 (Detecting the Presence of Phosphorous in Asphalt Binder) is coming to the end of its life as a provisional standard. Consider adopting as a full standard or deleting. There is a question as to whether people are still using this and if the SOM should still maintain it. This will be balloted at the TS level for removal to see if there is any real interest in maintaining this standard.

Item 48 Reconfirm TP101‐12 (2015) as a provisional standard. 45 Affirmative, 0 negative, 7 No Vote. No comments.

Item 48 Reconfirm TP102‐12 (2015) as a provisional standard. 45 Affirmative, 0 negative, 7 No Vote. Since this standard was balloted for change this year, the reconfirmation is moot.

B. TS letter ballots

No TS Ballots since the August meeting.

C. Task Force Reports

Single Edge Notched Bending Test ‐ Task force goal was to determine if this standard shouldbe considered for adoption as provisional test method. The membership of the task force isTravis Wallbeck (West Virginia) (Chair), Bill Hurguy (Arizona), and Becca Lane (Ontario). WVis no longer interested, and no one at the meeting showed interest in working on this testmethod. The Chair will sunset this task force, and if someone wants to resurrect this item inthe future, it will be handled as new business.


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Binder Yield Energy and Elastic Recovery Test –The membership of the task force is Oak Metcalfe (Montana) (Chair), Bill Scheibel (Colorado), Barry Payee (Wisconsin), Mike Santi (Idaho), and Scott Andrus (Utah). The standard was balloted and adopted. Task Force can be closed. The Chair thanked the members of the task force for their efforts.

TP 102 – The task force member ship is Richard Williammee (Texas) (Chair), Jim Trapanier (Illinois), Barry Paye (Wisconsin), and Bill Ahearn (Vermont). The standard was balloted and adopted. Task force considering all comments. The Chair thanked the members of the task force for their efforts.

Task Force 15‐01 (T 48) – Task Force members are Eileen Sheehy (New Jersey) (Chair), Maria Knake (AMRL), Bill Bailey (Virginia), Jerry Peterson (Texas), and Ron Horner (North Dakota). Task Force to consider rewrite of T 48. Eileen is almost finished with a first draft and will send out to the task force in the next few weeks.

Task Force 15‐02 (M 320) – Task force was formed to explore the issue of extending the range of PG grades in M 320 for specialty uses. Members of the task force are Eileen Sheehy (New Jersey) (Chair), John D’Angelo (consultant), Jesus Sandoval‐Gil (Arizona), Ala Mohseni (Pavement Systems), and Bill Bailey (Virginia). Eileen will contact the members of the task force to see if they can set up a conference call to discuss this item.

V. New BusinessA. Research Proposals – Chris Abadie is the TS 2b Research Liaison. Chris is leaving so we are looking for

a new research liaison. No one volunteered at the meeting, but they can contact the Chair if theywould like to act in this capacity. Please support the TS 2b research proposal 2017‐D‐04 on binderaging if you are also participating in SCOR. TX submitted a synthesis statement on rejuvenation. VTasked that people consider NCHRP proposals for adhesion of asphalt and non‐oxidative hardening.

B. AMRL/CCRL Issues – Discuss any new comments.

John Malusky – AMRL has gathered some information regarding the MSCR testingand PSP data. John will have a presentation of findings. John reviewed the latestresults of the MSCR and discussed differences between manufacturers on % difference inJnr, Jnr at 0.1 kPa, % difference in recovery, and % recovery at 0.1 kPa. He also mentionedthat % difference may not be a good way to evaluate conformance for laboratoryaccreditation purposes. One manufacturer recommended that AMRL use a differentmethod of analysis for the MSCR (ASTM D4460). This is not appropriate because it isintended to establish precision estimates when the results are obtained using test methodsthat have their own precision estimates. Please submit any feedback and recommendationsto John Malusky at [email protected]. The Chair thanked John for working on this after theissue was brought up during the last meeting. The presentation is in Appendix B of theseminutes.

C. NCHRP IssuesD. Correspondence, calls, meetings/ Presentation by Industry

Rick Bradbury (Maine) – See Attachment #3. NEAUPG is looking at R 15 Asphalt Additivesand Modifiers. The Chair will follow up with them regarding any proposed changes. Nothingto review at this time.

Tim Ramirez (Pennsylvania) – T 51 Ductility of Asphalt Materials refers to ASTM D113‐07which has been withdrawn. Action is needed on T 51. We can leave it as is or update thestandard to an A standard. No one volunteered to take this on. Maria (AMRL) indicated thatthis standard will be reinstated at ASTM.

Darren Hazlett (Texas) – Texas has developed a PG Binder type specification for surfacetreatments. See Attachment #4 for the proposed standard and Attachment #5 for apresentation. TS to consider this proposed new standard. TX uses a lot of these materialsand surface treatments on their roads. TX looked at how these are being used, climate,


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performance, etc. and came up with some specifications. Colin (RI) said that the ETF is also working on this. The Chair asked if there is any interest in TS 2b pursuing this. Eric (OH) is also interested. Darin (TX) reminded everyone that this is being proposed at this TS because this is hot‐applied binder instead of just emulsified asphalts. Bill (VT) commended the work of TX. OR approved the motion to put this out to a TS ballot. VT seconded this motion. Colin asked if there is something that can be shared with the TS on emulsions (2a) so they know what is going on. Eileen said that this will be brought up and has been shared with the Chair of 2a, Ron Horner (ND). Peter (GA) said that GA is seeing something similar to what TX is doing. No one objected to having this balloted as a TS ballot.

Matt Corrigan (FHWA)o Elastic Response with MSCR – See Appendix D. The ETG is proposing a separate

standard practice for evaluating elastic response: The ETG is asking the TS toconsider accepting this draft standard as a provisional standard or making the non‐mandatory information in M332 required language and accepting this draftstandard as a full standard. Since most people probably did not have a chance toreview this draft thoroughly, and no one had questions or comments. Tanya (FL)volunteered to take a look at this draft standard. Eileen (NJ) and Barry (WI) will alsobe involved in this new Task Force with Matt (FHWA). Tanya will be assigned as theChair of this new TF.

o ETG’s activities: See Appendix E for presentation. NAPA is now housing all themeeting information for the ETG (www.asphaltetgs.org). ETG is looking at negativepercent recoveries on MSCR due to creep cycle inertia and would like to propose arecommendation to the MSCR test to address this situation. The same task force(Tanya (FL), Eileen (NJ), Barry (WI), and Matt (FHWA)) will look at thisrecommendation.

o REOB and ΔTC: The ETG found that for REOB materials, aging is accelerated andthere seems to be a loss of cracking resistance. ΔTC could be used to trackperformance and is readily available in the existing data. The amount of REOBgenerally affects the ΔTC, but not on all materials. High RAS and RAP/RAS binderreplacement can result in more negative values of ΔTC. A 40‐hour PAV requirementis being considered.

o LTPP Bind – New version and Beta testing. This will go live in July 2016. Weatherand environmental data can be enhanced using MERRA data from NASA. FHWA islooking for volunteers to test out this latest version of LTPP Bind. Please [email protected] to get involved. The ETG is also looking at setting a limit onmaximum recycle binder ratio values for RAS mixtures. The idea would be that ifsomeone wanted to go over that limit, they would have to test ΔTC.

E. Proposed New Standards The following standards will be considered by the TS:

PG Binder specification for Surface Treatment (TXDOT sponsored)

Elastic Response with MSCR (Binder ETG sponsored)F. Proposed New Task Forces

Task Force 16‐01 ‐ Tanya (FL), Eileen (NJ), Barry (WI), and Matt (FHWA) – Review ETGrecommendations for elastic response, T 350, and M 332.

G. Standards Requiring Reconfirmation – See Appendix C for the list of standards.H. SOM Ballot Items (including any ASTM changes). To be determined at summer meeting.

VI. Open Discussion

VII. Adjourn


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Appendix A ‐ Attendance

SOM TS 2b - 2016 Mid Year Web Meeting

Last Name First Name Email AddressAbadie Chris [email protected] Chandra [email protected] Mike [email protected] Tim [email protected] Charles [email protected] William [email protected] Tom [email protected] Eric [email protected] Lyndi [email protected] Denis [email protected] Paul [email protected] Mike [email protected] Eliana [email protected] Matthew [email protected] Rob [email protected] John [email protected] Steve [email protected] Joe [email protected] Stacey [email protected] Mike [email protected] Charles [email protected] Frank [email protected] Mark [email protected] Mladen [email protected] Tom [email protected] Darren [email protected] Brian [email protected] Sungho [email protected] Troy [email protected] Robert [email protected] John [email protected] Justan [email protected] Maggie [email protected] Oak [email protected] Cole [email protected] Tanya [email protected] Charlie [email protected] Barry [email protected] Chris [email protected] Ron [email protected]


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Appendix A ‐ Attendance

Ramirez Timothy [email protected] Mike [email protected] Scott [email protected] Eileen [email protected] Mike [email protected] Darin [email protected] Dave [email protected] Brett [email protected] Peter [email protected] Merrill [email protected] Larry [email protected] John [email protected] Evan [email protected]


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Appendix B

Evaluation of Laboratory Performance in MSCR Testing (T350/D7405) Using AMRL PSP Data

JOHN J. MALUSKY, PROGRAM MANAGER,

AMRL PROFICIENCY SAMPLE PROGRAM

The Issue: Laboratories are receiving satisfactory ratings (3,4,5s) on percent

recovery and Jnr values at 0.1 and 3.2 kPa, but receiving low ratings(0,1,2s)on the percent differences (recovery and Jnr). Jnr – amount of residual strain in a specimen after a creep and recovery cycle

divided by the stress applied.


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Appendix B

Concerns:

From a DSR manufacturer (urged from users) State DoTs (New England) and Universities (AMRL Feedback

and SOM Meeting) Private testing laboratories (AMRL Feedback and ASTM

Meetings)

AMRL’s Evaluation of the Issue:

From the initial feedback and comments we determined that thiswas an isolated event happening in one PSP round. Caused by thedifference in values between the “+5s and the -5s”.

Not the case:


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Appendix B

Evaluation Continued: Updated PSP Data sheet for PGB rounds to provide DSR

Manufacturer and Software information. Discussed at SOM in Pittsburgh.

One round of PGB 241/242 (Fall 2015) data has been collected andthe data has been analyzed.

Looking for Bias or Something:(Posed by DSR Manufacturer)

Regardless of the manufacturer, all data appears to be normallydistributed. Individually or grouped together

Evaluation of normal probability show r2 values > 0.9. Indication that manufacturer bias is not present (no skewness)

“Welch’s t” test was conducted to check for statistical significance(difference) between manufacturers (“Big Three”).

Statistics indicate there is a difference between some of themanufacturers for some of the test parameters.


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Appendix B

Statistical Significance:

Odd Even

73.6 72.41

Average Results

Odd Even

61.41 61.62

Average Results

Odd Even

72.99 72.31

Average Results

Statistically Significant Differences:

Out of the six reporting parameters in T350/D7405, statisticaldifferences existed between manufacturers (A, B, & C) for thesefour test parameters:

% Recovery at 0.1 kPa (A – B)

% Difference in Recovery (A – B)

Jnr at 0.1 kPa (A – B)

% Difference in Jnr (A – B – C)


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Appendix B

A Second Look: Looking back on our first thought - “difference between a +5 and a -5”.

It doesn’t matter where the data falls when calculating a % difference.

0.1 kPa 3.2 kPa % Diff

40 60 50

Lab 1


30 45 50

Lab 2


10 15 50

Lab 3


60 90 50

Lab 4

-5

-5

+5 -2 -2

-4 +5

AVG = 50 1s = 10

+2

The % Difference Parameters: % Difference recovery and in Jnr may not be a good way to

evaluate laboratory performance for accreditation purposes. Percent difference values are determined using intermediate test

data. Intermediate data can be from anywhere about the distribution

regardless of the proximity from the “true value”.

Satisfactory ratings will be received as long as the ratio between thedifference (numerator) and the denominator is within thedetermined 1s.

+5-2 -2 +2


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Appendix B

The AMRL PSP Analysis: The method analyzes the data it is given. The analysis process covers any form of bias between

manufacturers due to the methodology and includes all randomand systematic error associated with the test.

The manufacturer who has voiced concerns has indicated that theAMRL PSP analysis should be performed in accordance with ASTMD4460 (Standard Practice for Calculating Precision Limits Where Values are Calculated from Other Test Methods)

Only covers precision limits (development of a precision statement) -PSP is measuring accuracy of participants.

Used when a new standard in question is using test values from othertest standards with established precision estimates. MSCR was notdeveloped from other standards.

Looking Ahead:

We will continue to solicit for test data for all reporting parameters inthe MSCR (T350/D7405).

Administrative Task Group has been informed of the situation.

AAP’s proposal is to the ATG is to not evaluate % difference in recoveryand % difference in Jnr for accreditation purposes.

Still look at % recovery and Jnr values at 0.1 and 3.2 kPa, respectively.

Continue to evaluate the data after each PSP round and look forissues (check model and software version).

Feedback from you? John Malusky ([email protected])


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Appendix B

Questions?


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Standards AssignmentsTech Section 2b

Appendix C-Standards

STATE AASHTO TYPERECONFIRM REQUIRED TITLE NOTES

OK M 226-80 (2012) A 2016 Viscosity Graded Asphalt CementGA M 320-16 A 2019 Performance Graded Asphalt Binder Former MP1 & MP1a.

FHWA M 332-14 A 2018 Performance Graded Asphalt Binder Using Multiple Stress Creep Recovery (MSCR) Former MP 19

IN R 15-00 (2012) A 2016 Asphalt Additives and Modifiers CT R 26-01 (2013) A 2017 Certifying Suppliers of Performance Graded Asphalt

Binders Former PP26. CO R 28-12 (2015) A 2019 Accelerated Aging of Asphalt Binder Using a

Pressurized Aging Vessel Former PP1. AZ R 29-15 A 2019 Grading or Verifying the Performance Grade of an

Asphalt Binder Former PP6. TN R 49-09 (2013) A 2017 Determination of Low-Temperature Performance

Grade (PG) of Asphalt Binders Former PP 42 (Original adoption 2001.) HI T 44-14 B 2018 Solubility of Bituminous MaterialsWI T 48-06 (2015) C 2019 Flash and Fire Points by Cleveland Open Cup Consider rewriting as an "A" standard based on T

79.IL T 49-15 C 2019 Penetration of Bituminous MaterialsKS T 51-09 (2013) C 2017 Ductility of Bituminous Materials Consider rewriting as an "A" standard based on T

300.ME T 53-09 (2013) C 2017 Softening Point of Bitumen (Ring-and-Ball

Apparatus)LA T 102-09 (2013) A 2017 Spot Test of Asphaltic MaterialsNH T 111-11 (2015) A 2019 Inorganic Matter or Ash in Bituminous MaterialsRI T 179-05 (2013) B 2017 Effect of Heat and Air on Asphalt Materials (Thin-

Film Oven Test)VA T 201-15 C 2019 Kinematic Viscosity of Asphalts (Bitumens)AR T 202-15 C 2019 Viscosity of Asphalts by Vacuum Capillary

ViscometerID T 228-09 (2013) C 2017 Specific Gravity of Semi-Solid Bituminous Materials

UT T 240-13 B 2017 Effect of Heat and Air on a Moving Film of Asphalt (Rolling Thin Film Oven Test)

WY T 313-12 (2015) A 2019 Determining the Flexural Creep Stiffness of Asphalt Binder Using the Bending Beam Rheometer (BBR)

Former TP1. MA T 314-12 (2015) A 2019 Determining the Fracture Properties of Asphalt

Binder in Direct Tension (DT) Former TP3. MD T 315-12 (2015) A 2019 Determining the Rheological Properties of Asphalt

Binder Using a Dynamic Shear Rheometer (DSR) Former TP5. NV T 316-13 A 2017 Viscosity Determination of Asphalt Binder Using

Rotational Viscometer Former TP48. SC T 350-14 A 2018 Multiple Stress Creep Recovery (MSCR) Test

of Asphalt Binder Using a Dynamic Shear Rheometer (DSR) Former TP 70

KY TP 78-09 (2015) A XXXX Detecting the Presence of Phosphorus in Asphalt Binder

First published in 2009. Needs to be adopted as full standard or deleted.

TP 92-14 A 2017 Determining the Cracking Temperatures of Asphalt Binder Using the Asphalt Binder Cracking Device (ABCD) First published in 2011

TP 101-12 (2015) A 2017 Estimating Fatigue Resistance of Asphalt Binders Using the Linear Amplitude Sweep

First published in 2012TP 102-16 A 2018 Evaluation of Asphalt Release Agents

First published in 2012TP 113-15 A 2017 Determination of Asphalt Binder Resistance to

Ductile Failure Using Double-Edge-Notched Tension (DENT) Test First published in 2015

TP 122-16 A 2018 Determination of Performance Grade of Physically Aged Asphalt Binder Using Extended Bending Beam Rheometer (BBR) Method First published in 2016

TP 123-16 A 2018 Measuring Asphalt Binder Yield Energy and Elastic Recovery Using the Dynamic Shear Rheometer First published in 2016


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Appendix D

Standard Practice for

Evaluating the Elastic Behavior of Asphalt Binders Using the Multiple Stress Creep Recovery (MSCR) Test

AASHTO Designation: PP xx-yy

American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001


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TS-2b AASHTO PP xx-yy Page 1

Standard Practice for

Evaluating the Elastic Behavior of Asphalt Binders Using the Multiple Stress Creep Recovery (MSCR) Test

AASHTO Designation: PP xx-yy

1. SCOPE

1.1. This practice provides a means of evaluating the elastic behavior of an asphalt binder by using the results (percent recovery and non-recoverable creep compliance) from the Multiple Stress Creep Recovery (MSCR) test. The MSCR test is conducted using the Dynamic Shear Rheometer (DSR) at a specified temperature. It is primarily intended for use with residue from T 240 (Rolling Thin-Film Oven Test (RTFOT)), but may also be run on residue from R 28 (Pressurized Aging Vessel (PAV)).

1.2. The elastic behavior of an asphalt binder can provide insight to the technologist indicating to what extent, if any, the binder could be modified with an elastomeric polymer.

1.3. This practice may be used in conjunction with M 320, Specification for Performance-Graded Asphalt Binder, or M 332, Performance-Graded Asphalt Binder Using the Multiple Stress Creep Recovery (MSCR) Test.

1.4. The values stated in SI units are to be regarded as the standard.

1.5. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. REFERENCED DOCUMENTS

2.1. AASHTO Standards:

T 350, Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a DynamicShear Rheometer (DSR)

T 315, Determining the Rheological Properties of Asphalt Binder Using a Dynamic ShearRheometer (DSR)

R 28, Accelerated Aging of Asphalt Binder Using Pressurized Aging Vessel (PAV)

T 240, Effect of Heat and Air on Moving Film of Asphalt (Rolling Thin-Film Oven Test)

M 320, Performance-Graded Asphalt Binder

M 332, Performance-Graded Asphalt Binder Using the Multiple Stress Creep Recovery(MSCR) Test

2.2. ASTM Standard:

D 8, Standard Terminology Relating to Materials for Roads and Pavements


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3. TERMINOLOGY

3.1. Definitions:

3.1.1. Definitions of terms used in this practice may be found in ASTM D 8, determined from common English usage, or combinations of both.

3.2. Definitions of Terms Specific to This Standard:

3.2.1. creep and recovery—a standard rheological test protocol whereby a specimen is subjected to a constant load for a fixed time period and then allowed to recover at a constant zero load for a fixed time period.

3.2.2. non-recoverable creep compliance (Jnr)—the residual strain in a specimen after a creep and recovery cycle divided by the stress applied.

3.2.3. percent recovery (Rec)—the ratio of the difference between the peak strain and the residual strain to the peak strain, expressed as a percentage. This is a measure of the elastic response of an asphalt binder at a given temperature and applied stress level.

4. SUMMARY OF PRACTICE

4.1. This practice is used to evaluate the elastic response of an asphalt binder under shear creep and recovery at a specified temperature. For most asphalt binders, this temperature will be the high temperature grade as determined only by environmental conditions (not as adjusted for traffic speed or loading).

4.2. Asphalt binder is first aged using T 240 (RTFOT). A sample of the RTFO-aged asphalt is tested using T 350 (MSCR). Unless otherwise specified, the 25-mm parallel plate geometry is used with a 1-mm gap setting. The sample is tested in creep and recovery at two stress levels. The stress levels used are 0.1 kPa and 3.2 kPa. The creep portion of the test lasts for one second which is followed by a nine-second recovery. Ten creep and recovery cycles are tested at each stress level. Two parameters are derived from the MSCR test – the non-recoverable creep compliance (Jnr) and percent recovery (Rec).

4.3. Using the Jnr and Rec values from testing conducted at 3.2 kPa shear stress (identified as Jnr-3.2 and Rec-3.2, respectively) data is compared to a curve of Rec as a function of Jnr. Values that plot on or above the curve are considered to represent an asphalt binder with a significant elastic response indicative of modification using elastomeric polymers.

4.3.1. As an alternative, the equation of the curve may be used and the Rec-3.2 value compared to the calculated minimum Rec-3.2 value determined using the measured Jnr-3.2 value.

5. SIGNIFICANCE AND USE

5.1. This practice is used to evaluate the elastic response of an asphalt binder under shear creep and recovery at a specified temperature. Like existing parameters which also attempt to evaluate elastic behavior in an asphalt binder – such as Elastic Recovery – the MSCR percent recovery, Rec-3.2, has no quantified relationship to performance. Nevertheless, some users may still want to ensure that an asphalt binder is modified using an elastomeric polymer due to a belief that polymers will increase cracking resistance and durability. In any case the exact nature of the effect of polymer modification of an asphalt binder should more appropriately be determined through asphalt mixture testing.


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6. APPARATUS

6.1. Use apparatus as specified in T 315 and T 350.

7. PROCEDURE

7.1. Conditioning – Unless otherwise specified, condition the asphalt binder to be tested in accordance with T 240 (RTFOT).

7.2. Sample preparation – The sample for the MSCR test is prepared the same as samples for T 315 using 25-mm plates. The temperature control will also follow the T 315 requirements.

7.3. Testing – Conduct testing on the asphalt binder sample at the desired temperature following the test procedure described in T 350. For most asphalt binders, the test temperature will be the high temperature grade as determined only by environmental conditions (not as adjusted for traffic speed or loading) using the LTPPBind 3.1 software or the principles behind the temperature determination in LTPPBind. In the absence of this information, use the temperature that corresponds to the high temperature grade of the standard unmodified grade of asphalt binder that would be used for the project location.

7.4. Analysis – After determining the Jnr-3.2 and Rec-3.2 values for the asphalt binder at the specified temperature, plot the data on either Figure 1a or 1b. Data that is plotted on or above the curve in Figure 1a or 1b is considered to have a significant elastic response for the associated value of non-recoverable creep compliance (indicating that the asphalt binder has been modified).

7.4.1. Alternatively, if the Jnr-3.2 value is between 0.10 and 2.00 kPa-1, inclusive, substitute the Jnr-3.2 value determined from testing the asphalt binder into the equation as shown below and solve for the minimum required Rec-3.2 value.

Rec-3.2min = 29.371*(Jnr-3.2)-0.2633

where:

Rec-3.2min = minimum required value of Rec-3.2 to indicate significant elastic behavior, %

Jnr-3.2 = measured value of Jnr-3.2 from T 350 testing, kPa-1

7.4.2. If the Jnr-3.2 value is less than 0.10 kPa-1 then the Rec-3.2min value is 55.0%.

7.4.3. If the Jnr-3.2 value is greater than 2.00 kPa-1 then the Rec-3.2min value is 0.0%.

7.4.4. Compare the measured value of Rec-3.2 from TP 70 testing to the Rec-3.2min value as determined in 7.4.1 to 7.4.3 or the curve shown in Figures 1a and 1b. If the measured Rec-3.2 value equals or exceeds the Rec-3.2min value (represented by the curve in Figures 1a and 1b), then the asphalt binder sample is considered to have shown a significant elastic response for the associated value of non-recoverable creep compliance – indicating that the asphalt binder has been modified.

Note 1 – the Rec-Jnr curve shown in Figures 1a and 1b, and Rec-3.2min values described in Sections 7.4.1 – 7.4.3, are intended to be used to evaluate the elastic response of modified asphalt binders when tested at the appropriate climatic temperature. It should not be used with asphalt binders that have Jnr-3.2 values greater than 2.00 kPa-1.


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8. REPORT

8.1. Report the following information:

8.1.1. Sample identification;

8.1.2. PG grade and test temperature, nearest 0.1°C;

8.1.3. Average percent recovery at 3.2 kPa, Rec-3.2, to nearest 0.1%;

8.1.4. Non-recoverable creep compliance at 3.2 kPa, Jnr-3.2, to nearest 0.01 kPa-1; and

8.1.5. Figure 1a or 1b with data point plotted representing the measured Jnr-3.2 and Rec-3.2 values or calculation showing the minimum required value of Rec-3.2 (Rec-3.2min) compared to the measured Rec-3.2 value to indicate significant elastic behavior.

9. PRECISION AND BIAS

9.1. Precision – The research required to develop precision estimates has not been conducted.

9.2. Bias – The research required to establish the bias has not been conducted.

10. KEYWORDS

10.1. Asphalt binders; creep and recovery; creep compliance; Dynamic Sheer Rheometer (DSR); elastomer identification; Multiple Stress Creep and Recovery (MSCR) Test; percent recovery; polymer modification; elastic behavior.


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0

10

20

30

40

50

60

70

80

90

100

0.00 0.50 1.00 1.50 2.00 2.50

Rec

-3.2

, %

Jnr-3.2, kPa-1

The curve stops at Jnr-3.2 = 2.00 kPa-1 and 0.1 kPa-1. Jnr-3.2 values greater than 2.00 kPa-1 are not required to have any minimum Rec-3.2 value. Jnr-3.2 values less than 0.10 kPa-1 are required to have a minimum Rec-3.2 value of 55%.

FIGURE 1a: Comparison of MSCR Jnr-3.2 and Rec-3.2 to Assess Elastic Response

0

10

20

30

40

50

60

70

80

90

100

0.01 0.10 1.00 10.00

Rec

-3.2

, %

Jnr-3.2, kPa-1

The curve stops at Jnr-3.2 = 2.00 kPa-1 and 0.1 kPa-1. Jnr-3.2 values greater than 2.00 kPa-1 are not required to have any minimum Rec-3.2 value. Jnr-3.2 values less than 0.10 kPa-1 are required to have a minimum Rec-3.2 value of 55%.

FIGURE 1b: Comparison of MSCR Jnr-3.2 and Rec-3.2 to Assess Elastic Response (Semi-Log)


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Appendix E

Asphalt Expert Task Group Items

Matthew Corrigan, P.E.U.S. DOT | Federal Highway Administration

Asset Management, Pavement, and Construction

February 2016

• Forum for Government, Industry, andAcademia

• Discussion of ongoing asphalt binderand mixture technology

• Provide technical input for current andfuture research, development,and specifications.

Asphalt Expert Task Groups


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Appendix E

• Asphalt Mixture & Construction ETG

• Last meeting in Oklahoma City on Sept 15‐16, 2015

• POC – John Bukowski

• Asphalt Binder ETG

• Last meeting in Oklahoma City on Sept 16‐18, 2015

• POC – Matthew Corrigan

• Sustainable Pavements TWG

• POC – Gina Ahlstrom

Asphalt Expert Task Groups

Open MeetingsAll are Welcome!

www.AsphaltETGs.org

Upcoming ETG MeetingsTo Be Announced (Next meeting plan ‐ week of April 25, 2016)

Past ETG MeetingsSeptember 2015 — Asphalt Mix ETG, Oklahoma City, OKSeptember 2015 — Binder ETG, Oklahoma City, OKApril 2015 — Asphalt Mix ETG, Fall River, MAApril 2015 — Binder ETG, Fall River, MASeptember 2014 — Asphalt Mix ETG, Baton Rouge, LASeptember 2014 — Binder ETG, Baton Rouge, LA


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Appendix E

“In some cases when the Jnr value is close to 4.5 a negative percent recovery may occur. With some rheometers when the load is cut off at the end of the creep cycle inertia of the movable plate causes it to continue to rotate and load the specimen. When the binder is Newtonian and has little to no recovery this can appear as a negative percent recovery. In these cases the strain at the end of the 1 second creep load shall be used to calculate the Jnr compliance value. The percent recovery shall be recorded as zero.”

MSCR – Note on Negative Recovery

Remove the Jnrdiff max 75% for Extremely Heavy Traffic “E” grades with Jnr3.2 ≤ 0.5 kPa

‐1 due to very low non‐recoverable creep compliance values for both Jnr3.2 and Jnr0.1 when “E” binders are evaluated at the specified environmental PG temperature (i.e. not the grade bumped temperature).

MSCR – Jnr diff for “E” traffic


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Appendix E

New REOB Task Force within ETG

Discussions:

• Which rheological parameter

– critical temperature change (ΔTc)

– Glover‐Rowe (GR)

– rheological index (R value)

– cross over frequency (ωc)

All of these parameters can be interrelated from understanding the relationship between loading time (or frequency) and temperature.

Re‐refined Engine Oil Bottoms (REOB)

ΔTc = BBR Stiffness critical temp (S) – the BBR

Relaxation critical temp (m‐value)

• Previous work by Mike Anderson and TomBennert indicates that when ΔTc “exceeds” 5°C(m‐S) there is a significant loss of crackingresistance.

• Note: As defined above, ΔTc must > ‐5°C (i.e.warmer than ‐5°C)

Re‐refined Engine Oil Bottoms (REOB)


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Appendix E

ETG Consensus Items• Concerns exists from the agency/DOT perspective

on the durability of asphalt pavements• ΔTc could be used to track performance and is

readily available in the existing data• The amount of REOB generally affects the ΔTc but

not all materials are created equal• High RAS and RAP/RAS binder replacement can

result in more negative values of ΔTc• PAV conditioning requirements (i.e. 40 hour PAV)

ETG REOB Task Force

LTTPBind Improvements

• Alpha Release: January 10, 2016 at TRB

• Beta Release: April 2016

• Go‐Live: July 2016 with the release ofLTPP Standard Data Release 30


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Appendix E

MERRA: MODERN‐ERA RETROSPECTIVE ANALYSIS FOR RESEARCH AND APPLICATIONS

• MERRA is a NASA reanalysis for the satellite era usinga major new version of the Goddard Earth ObservingSystem Data Assimilation System.

• Reanalysis is a scientific method for developing acomprehensive record of how weather and climateare changing over time.

MERRA Data

• Long‐term (1979‐present) synthesis of climate datafrom a suite of research satellite observations

• Continually updated with 4.2 million globalobservations every 6 hours (with 2 week delay)

• A native 1/2˚ latitude by 2/3˚ longitude data grid

• Conducted at the NASA Center for ClimateSimulations (NCCS)

MERRA Data


Page 27 of 30

Appendix E

• Alpha and Beta testers are needed!!

Please contact Larry Wiser at [email protected] for information on alpha and beta testing.

• Feedback and Comments.

Larry Wiser: [email protected] andRiaz Ahmad: [email protected]

Software Testing

New RAP/RAS Task Force within ETG

• Current main issue to be addressed:

– How much of the RAS binder becomeseffective asphalt binder? “Quantity”

– How to address the stiffness/brittleness ofthe RAS binder? “Quality”

– Binder grade adjustment guidelines

Recycled/Reclaimed Asphalt Pavement (RAP)Recycled/Reclaimed Asphalt Shingles (RAS)


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Appendix E

ETG RAP/RAS Task Force

Focus on the brittleness of the blended binder:

• Estimate brittleness of the blended binder withthe Bending Beam Rheometer (BBR)

ΔTc = BBR Stiffness critical temp (S) – the BBR

Relaxation critical temp (m‐value)

• Assumes “worse case” scenario (from abinder perspective)

– If blending is less than complete, theimpact of the aged binder on stiffening andrelaxation is less than the laboratory wouldpredict

– If blending is completely homogeneous,the impact on stiffening and relaxationwould be accounted for.

Assumptions


Page 29 of 30

Appendix E

Pros• Simple approach … easy for states to make an informed decision

on setting RAS limits based on available virgin binders andexisting RAS materials

Cons• Doesn’t address mixture issues (VMA) if the RAS binder does

not become fully blended– Binder volume would be less than calculated

– Could have a mix with better quality binder but not enough of it

• Some materials may not meet a ‐5°C criteria

• Standard PAV conditioning not effective to identify poor ageingcharacteristics

Pros and Cons

• To simplify the process further, the TaskTeam is looking at setting maximum RecycleBinder Ratio (RBR) for mixtures with RAS

• Possibly a RBR limit

• Corresponding to conservative RAS limitwith ΔTc = ‐5°C

• Agencies that want to exceed this limit wouldneed to test and evaluate ΔTc

• RAP further complicates things …

Draft Proposal


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