2013 TS 2a Minutes - Transportation

AASHTO SUBCOMMITTEE ON MATERIALS (SOM)

TECHNICAL SECTION (TS) 2a EMULSIFIED ASPHALTS

Stateline, Nevada

Thursday, August 8, 2013 8:00 a.m. - 10:00 a.m.

MEETING MINUTES

1. Call to Order/Opening Remarks/General Business – TS 2a, Emulsified Asphalts, met on Thursday, August 8, 2013, in Stateline, Nevada, with ten members, one proxy, and 23 visitors in attendance. Chairman Ron Horner of North Dakota called the meeting to order at 8:04 a.m. and welcomed all members and guests. He introduced himself and Vice-Chairman Allen Myers of Kentucky. Vice-Chairman Myers announced the circulation of the TS 2a sign-in sheet; members should register on the first page and visitors on the following pages. He also noted that another sign-in sheet, developed by AMRL personnel, was circulating throughout the group.

2. Roster – As recorded on the sign-in sheet, the TS 2a members and proxies present at

the meeting were as follows:

Georgia Peter Wu Idaho Mike Santi Kentucky Allen Myers, Vice-Chairman Louisiana Chris Abadie Mississippi James Williams North Carolina Chris Peoples North Dakota Ron Horner, Chairman Oklahoma Reynolds Toney (proxy for Scott Seiter) Pennsylvania Tim Ramirez Rhode Island Colin Franco Virginia Bill Bailey

As indicated on the sign-in sheet, Lyndi Blackburn of Alabama and Darren Hazlett of Texas expressed an interest in joining TS 2a.

3. Approval of 2012/2013 TS 2a Minutes – Chairman Horner reported that the TS 2a

minutes from the 2012 meeting in Biloxi, Mississippi, were approved during the TS 2a conference call/webinar on April 10, 2013. He accepted a motion from Bill Bailey of Virginia, seconded by Peter Wu of Georgia, to approve the minutes developed by Maria Knake of AMRL for the TS 2a webinar as written. The motion passed unanimously.

TS 2a 2013 Minutes of 71

4. Old Business

4.1 Review of 2012 SOM Ballot (October-December 2012) – Chairman Horner noted that the TS 2a ballot items on the 2012 SOM ballot were discussed at the conference call/webinar earlier this year. TS 2a reported four SOM ballot items for 2012 (AASHTO M 82, M 316, T 59, and T 301). Chairman Horner briefly described the nature of these revisions and reported that all changes to these standards passed the ballot without any negative votes.

4.2 AASHTO T 40 – This method was also discussed during the TS 2a

webinar in April of 2013. AASHTO T 40-02 (2012) is a “C” standard, equivalent to ASTM D 140-01 with numerous exceptions. This standard was previously provided to Cecil Jones of Diversified Engineering Services for modification to a solely owned standard. Chairman Horner commented that the sampling methods and equipment found in T 40 appear to be dated. A survey concerning this method was distributed in July to evaluate the use of the standard and the relevance of the sampling techniques and equipment therein. The results from this survey should provide helpful information to Mr. Jones concerning his revisions to T 40. Chairman Horner reported that 25 of 30 respondents use AASHTO T 40, so the effort to modify this method is still justified. He recommended that Mr. Jones continue his work to modify T 40 to be a solely owned standard. Chairman Horner will contact other states to identify better figures and pictures for inclusion in this method.

4.3 Review of 2013 TS 2a Ballot (July 2013) – The 2013 TS 2a ballot

involved five standards: AASHTO M 208, T 50, T 59, T 78, and T 302.

4.3.1 AASHTO M 208 – AASHTO M 208-01 (2009) is a jointly

owned standard, similar to ASTM D 2397-02. This specification for cationic emulsified asphalt was due for reconfirmation in 2013. Recent changes to the ASTM version added references for the new emulsion standards created by dividing ASTM D 244. These revisions do not affect M 208 because it references AASHTO T 59 rather than the ASTM standards. This specification received 12 affirmative votes, with three ballots not returned. Therefore, M 208 received the “2/3 majority” of votes necessary for reconfirmation. Kentucky suggested deleting Section 5.1.1 of M 208 in light of the recent changes to the sieve test in AASHTO T 59. After a brief discussion, Kentucky decided to withdraw this comment.


4.3.2 AASHTO T 50 – AASHTO T 50-09 is a “C” standard, equivalent to ASTM D 139-07 with two exceptions. This method involving the float test was also due for reconfirmation this year. ASTM D 139 was revised in 2012 to remove Section 7.3.1. This portion of the standard prohibited float testing on samples for which the minimum temperature was not attained. AASHTO T 50 received 12 affirmative votes, with three ballots not returned. Therefore, T 50 received the “2/3 majority” of votes necessary for reconfirmation.

4.3.3 AASHTO T 59 – AASHTO T 59-13 is a solely owned

standard. The TS 2a ballot proposed many revisions recommended by AMRL and the Rocky Mountain Asphalt User/Producer Group (RMAUPG). Major changes included provisions to allow alternatives to mercury thermometers. Also, the pertinent sections of AASHTO T 72 regarding Saybolt viscosity were incorporated. The ballot item received 12 affirmative votes, with three ballots not returned.

Chairman Horner considered the comments returned for AASHTO T 59. Kentucky noted several issues. The first comment suggested adding AASHTO R 18 and R 61 to Section 2.1 as referenced standards. Chairman Horner agreed to this idea. Next, Kentucky questioned the redundancy of some of the notes in this method. Identical verbiage is found in different notes throughout T 59. Chairman Horner remarked that although several notes are repeated, the wording involved is brief. He expressed his preference to leave the notes as currently written.

Kentucky questioned the metric dimension in Section 6.3.4; the equivalent to 6.25 in. is “159 mm” rather than “165 mm” as given in T 59. Chairman Horner asked if the “6.25 in.” dimension is correct. If so, then the metric equivalent is “159 mm.” James Williams of Mississippi offered a motion, seconded by Chris Peoples of North Carolina, to ballot this change. In the discussion following, Mr. Williams questioned the need to measure this distance to the nearest millimeter. Brian Johnson of AMRL agreed to check all the units in AASHTO T 59 prior to the ballot to ensure accuracy and consistency. Mr. Peoples asked how the distance to the bottoms of the thermometers should be properly measured. Ms. Knake explained the normal procedure. Mr. Johnson remarked that these thermometers are normally positioned correctly and then left undisturbed. Next, TS 2a approved the


motion unanimously. The modified version of AASHTO T 59 will be included on a concurrent SOM ballot this fall.

Another comment from Kentucky concerned the thermometer verification at the “ice point” in Note 8. The ice-point verification involves one temperature point, and this reading is not the test temperature. During a recent AMRL on-site assessment in Kentucky, the inspector required a two-point thermometer calibration. Would Note 8 in AASHTO T 59 contradict AASHTO R 18 with respect to thermometer calibration? Ms. Knake explained that modified wording was recommended by AMRL throughout T 59 to improve the thermometer descriptions. She clarified the difference between “verifying at the ice point” and “recalibrating.” The thermometer should be recalibrated if the ice-point check is unsuccessful. A true calibration requires two temperature points.

Next, Chairman Horner addressed Kentucky’s remark about Note 10. This note recommends immersing the bottom of the still in cold water if excess foaming occurs. Kentucky questioned the wisdom of placing a very hot still in water. Ms. Knake stated that newer emulsion formulations may foam and possibly damage the distillation equipment. She noted that AMRL inspectors have not reported any steam or other danger when placing a hot still in cold water. Mr. Johnson remarked that this change was recommended by RMAUPG technicians, and they did not mention any safety concerns.

Also, Kentucky challenged the container specified in Section 9.3.11.1 because the state materials laboratory has traditionally utilized a 125-mL flask with a cork stopper. This type of container would no longer be suitable under the proposed wording. Kentucky recommended revising this section to require a bottle with “a minimum capacity of 118 mL.” Chairman Horner expressed his agreement with this idea. Bill Bailey of Virginia presented a motion to propose this change on the upcoming SOM ballot. Tim Ramirez of Pennsylvania seconded the motion, and it passed without opposition. This revision will be incorporated into the ballot item described previously for AASHTO T 59.

Following this discussion, Chairman Horner considered a question from Kentucky regarding Section 9.3.11.2. Does the container specified in this section not require a lid as the bottle described in Section 9.3.11.1? Mr. Johnson replied that a lid is


not required for the container specified in Section 9.3.11.2. Finally, Kentucky suggested adding a more specific description for “an appropriate solvent of low toxicity” in Section 9.4.1. Chairman Horner asked the group for recommendations in this regard, but the participants could not offer any insight. Additional editorial comments were suggested by Kentucky; these remarks will be incorporated as appropriate.

Next, Chairman Horner introduced a comment on AASHTO T 59 from Georgia. In 2011, the National Institute of Standards and Technology (NIST) stopped providing calibration services for mercury thermometers. Since state agencies cannot obtain NIST calibrations now, will AMRL inspectors report nonconformity for mercury thermometers that are not NIST-traceable during the on-site assessment? Ms. Knake replied that although NIST is no longer offering this service, other agencies are still calibrating mercury thermometers. These calibrations are traceable to NIST. Mr. Wu requested a list of secondary agencies acceptable to AMRL that offer this service. Alternately, Mr. Peoples suggested that Georgia propose a list of selected calibration agencies for consideration by AMRL. Ms. Knake agreed to review this information if provided by Georgia.

Pennsylvania provided the final comments on AASHTO T 59 as presented to TS 2a. In Note 11, Pennsylvania suggested adding a reference to the alternate distillation temperatures and mass correction factors in the new Table 2. Chairman Horner agreed to adopt this idea editorially. Additionally, concerning Note 20, Pennsylvania agreed that filtering the sample before pouring it into the container is preferable to filtering while pouring it into the viscometer. Therefore, Pennsylvania recommended deleting Note 20. Mr. Johnson reported that RMAUPG technicians were divided on this issue and preferred to offer an option in the method. Chairman Horner decided to leave Note 20 as currently written.

4.3.4 AASHTO T 78 – AASHTO T 78-10 is a solely owned

standard. The proposed changes to this method involved deleting references to various British standards. These revisions were discussed and recommended at the 2012 TS 2a meeting. The ballot item received 12 affirmative votes, with three ballots not returned.

4.3.5 AASHTO T 302 – AASHTO T 302-05 (2009) is a solely

owned standard due for reconfirmation in 2013. Section 1.2


addressing operation of the equipment by experienced personnel was deleted. The ballot item received 12 affirmative votes, with three ballots not returned. Therefore, T 302 received the “2/3 majority” of votes necessary for reconfirmation.

4.4 Task Force Reports

4.4.1 Task Force 2a-2010-01 – This group was created to remove

Section 8 (Saybolt Furol viscosity) from AASHTO T 59 and incorporate that information into AASHTO T 72 as appropriate. Also, this group is considering the practicality of the sample temperature tolerance of ± 0.05°C (± 0.09°F) in Section 8.7 of AASHTO T 72. Chairman Horner leads this group with assistance from Vice-Chairman Myers and Mr. Bailey. Chairman Horner recalled the decision to retain the Saybolt Furol viscosity test in AASHTO T 59. He noted that the other proposed changes to T 72 could be considered when this method is next due for reconfirmation. Given this updated information, Chairman Horner declared the work of Task Force 2a-2010-01 to be complete.

4.4.2 Task Force 2a-2011-01 – This task force is charged with

revising AASHTO PP 71 in response to the negative vote from Minnesota and other comments received on the 2010 SOM ballot. The responsibilities of this group were expanded to include resolution of the negative votes and comments submitted for AASHTO PP 72 and TP 91. The group is comprised of Chairman Horner, Mr. Peoples, Mr. Bailey, a representative from Minnesota, and Colin Franco of Rhode Island [representing the Emulsion Task Force (ETF) of the Pavement Preservation Expert Task Group (ETG)]. The ETF originally submitted these provisional standards for TS 2a review. Chairman Horner reported that the ballot comments for PP 71 were distributed to the ETF for recommendation. Mr. Bailey volunteered to consider the responses from the ETF and modify AASHTO PP 71 as appropriate.

4.4.3 Task Force 2a-2012-01 – This group was created to determine

the proper specification values for polymer-modified cationic slow-setting emulsions for inclusion in AASHTO M 316. The task force is comprised of Mr. Ramirez, Mr. Hazlett, and Aaron Gillispie of West Virginia. Mr. Ramirez updated TS 2a on the activities of the task force. He remarked that Texas had provided suggestions for inclusion in the specification. Mr.


Ramirez hopes to offer the proposed revisions to M 316 at the TS 2a mid-year conference call/webinar.

4.5 Provisional Standards – Chairman Horner turned his attention to the

provisional standards sponsored by TS 2a. He reported that the following standards are due for extension in 2013:

AASHTO PP 71, Certifying Suppliers of Emulsified Asphalt AASHTO PP 72, Recovering Residue from Emulsified Asphalt

Using Low-Temperature Evaporative Techniques AASHTO TP 91, Determining Asphalt Binder Bond Strength

by Means of the Asphalt Bond Strength (ABS) Test

Significant changes to these provisional standards are planned pending recommendations from the ETF.

Chairman Horner asked Mr. Franco for an update from the recent ETF meeting in July. Mr. Franco briefly discussed his presentation on Monday (August 5, 2013) at the plenary session. He reiterated the goal of the ETF: elevate the specifications for asphalt emulsion to the same level as asphalt binder. Ultimately, a Superpave-type specification is desired for emulsions as well. Mr. Franco reminded TS 2a that research projects on chip seals, microsurfacing, and tack coats have produced provisional standards developed by the principal investigators in recent times. A few years ago, the first four standards were submitted to TS 2a. Two years ago, the following six standards were presented for consideration by the technical section. These tests originated from NCHRP 14-17, Manual for Emulsion-Based Chip Seals for Pavement Preservation (NCHRP Report 680):

Standard Method of Test for Determining the Strain Sensitivity

of Asphalt Emulsion Residue Using Strain Sweeps Performed on a Dynamic Shear Rheometer (DSR)

Standard Method of Test for Embedment Depth of Chip Seal Aggregates in the Lab and the Field

Standard Method of Test for Laboratory Chip Loss from Emulsified Asphalt Chip Seal Samples

Standard Method of Test for Measuring Moisture Loss from Chip Seals

Standard Method of Test for Recovery of Asphalt from Emulsion by Stirred-Can Method

Standard Method of Test for Field Emulsion Viscosity

These proposed standards were tabled and not distributed to TS 2a pending updates and recommendations from the ETF.


Mr. Franco remarked that the recent Pavement Preservation ETG meeting in July resuscitated the overall effort and renewed hopes for additional FHWA funding for the ETF. The six standards listed above are being evaluated by the committee chairs within the ETF. Mr. Franco noted that few comments had been generated to date, but any information from the ETF will be provided to Chairman Horner for consideration. Next, Mr. Franco reported that a standard for microsurfacing will be submitted to TS 2a soon. He repeated his request for support from the technical section. Emulsions are the “orphan” of the asphalt area, but many preservation techniques are in use across the nation. Finally, Mr. Franco acknowledged that Mr. Hazlett is also a member of the ETF. Texas research concerning chip seals has been very helpful to the group.

Chairman Horner reminded the technical section that AASHTO PP 71, PP 72, and TP 91 were balloted previously and produced many comments. These issues were provided to the ETF for review and recommended action. The University of Wisconsin returned comments for TP 91, and this test method is ready for a TS 2a ballot in 2014. Chairman Horner has requested ETF guidance and rationale for the six proposed provisional standards listed above. He will distribute the ETF responses with any upcoming ballots. Chairman Horner reiterated that AASHTO PP 71, PP 72, and TP 91 are due for extension in 2013. Mr. Peoples introduced a motion, seconded by Mr. Bailey, to extend the three provisional standards by “voice vote” for two years. The motion passed TS 2a unanimously.

5. New Business

5.1 Presentation – Delmar Salomon of Pavement Preservation Systems, LLC provided a presentation to the 2013 TS 2a meeting attendees regarding new emulsion test procedures for viscosity and residue recovery. He briefly discussed the different versions of viscometers available, including the Brookfield, Saybolt Furol, and rotational paddle-type. Next, Mr. Salomon described test results from the digital paddle viscometer (DPV) for a CRS-2 emulsion as determined at 50, 100, and 200 r/min. He noted that the Saybolt test in AASHTO T 59 can be completed quickly, but the sample preparation is difficult. Then, he explained the DPV procedure. The preparation of the emulsion sample is the same as that required for the Saybolt viscosity test. The paddle viscometer “pushes” the emulsion sample during the test. ASTM has approved this test method; it is designated as ASTM D 7226. Mr. Salomon noted that an interlaboratory study was completed within ASTM. He described the different emulsions and laboratories involved with this effort. Precision statements for both the Saybolt Furol viscometer and DPV were developed. Mr. Salomon


explained that the precision statements for the two devices were similar.

Next, Mr. Salomon discussed the moisture analyzer balance (MAB) test. This procedure is specified in ASTM D 7404 and used for asphalt residue recovery from emulsions for further rheological testing. He reported good correlation between this test and the “residue by evaporation” method. In the MAB test, the residue may be recovered in the unit directly or recovered in a silicone mold and analyzed in the DSR. Testing is performed at 163°C for unmodified emulsions and 100°C for modified materials. A sample of 4 ± 0.1 g is conditioned until the mass changes less than 1 mg in 140 s. Mr. Salomon noted that the high-temperature performance grade of the asphalt residue can be determined from the MAB/DSR procedure.

Considering the moisture evaporation that occurs, Mr. Bailey questioned the proper thickness of the material sample in the DSR. Mr. Salomon responded that the DSR plate smoothes the heated asphalt sample to the correct thickness. Next, Mr. Bailey requested a cost estimate for the device, and Mr. Salomon reported an expense between $1500 and $3000 depending on the degree of sophistication. Mr. Bailey remarked that the MAB test could be advantageous for polymerized emulsions that cannot be distilled. Then, he asked about the time needed to perform the test. Mr. Salomon replied that 15 to 25 minutes are required. More time is necessary for high-float emulsions. Chris Abadie of Louisiana questioned the orientation of the paddle in the cup for the DPV test. Is it a “tight fit?” Mr. Salomon responded that shearing the emulsion damages the material. The paddle viscometer attempts to push the material similar to a pumping operation. A smaller size of paddle is acceptable. To summarize, Mr. Salomon noted that the emulsion sample preparation is similar to existing methods, but the paddle viscosity test is faster. The viscosity value from the DPV is roughly twice that from the Saybolt viscometer. Mr. Bailey remarked that the MAB test may be attractive for state departments of transportation.

5.2 Standards Requiring Reconfirmation – Chairman Horner reported that

only AASHTO T 72 is scheduled for reconfirmation next year. This standard will be distributed on a TS 2a ballot in 2014.

5.3 TS 2a Mid-Year Conference Call/Webinar – Mr. Peoples asked for a

date for the TS 2a mid-year meeting. Chairman Horner stated his preference for the last week of February 2014. The actual date and time will be provided to the technical section when determined.


5.4 TS 2a Research Liaison – Ms. Knake inquired about a research liaison for TS 2a. Mr. Bailey suggested that Mr. Franco would be a good candidate due to his involvement on the ETF. The group generally agreed with this idea. Chairman Horner will contact Mr. Franco about this assignment.

5.5 SOM Ballot Items – As noted earlier in the minutes, TS 2a will submit

one concurrent SOM ballot item for 2013 as follows: (Attachment 2)

AASHTO T 59 [concurrent SOM ballot item – correct the dimensions between the bottom of the thermometers and the bottom of the still in Section 6.3.4 and revise the capacity of the flask in Section 9.3.11.1 (see Section 4.3.3 of these minutes)].

The 2013 SOM ballot item for TS 2a is summarized in the following table:

Num. Ballot Item SOM Concurrent

1 Concurrent ballot item to correct the dimensions in Section 6.3.4 and revise the capacity of the flask in Section 9.3.11.1. See pp. 3-5 and pp. 19-71 of the minutes.

X

5.6 TS 2a Ballot Items – The following standards will be presented on a

TS 2a ballot in 2014.

5.6.1 AASHTO T 72 – As documented in Section 5.2 of these minutes, AASHTO T 72 will require reconfirmation in 2014.

5.6.2 AASHTO TP 91 – As documented in Section 4.5 of these

minutes, AASHTO TP 91 will be balloted next year to include the recommendations of the ETF.

6. Adjourn – With no further business identified, Chairman Horner accepted a motion

from Mr. Peoples, seconded by Mr. Williams, to adjourn the meeting. The motion passed unanimously at 9:23 a.m.


2013 TS 2a Minutes - Transportation

Documents

Transcript of 2013 TS 2a Minutes - Transportation