AASHTO re:source Q&A Podcast Transcript

Season 4, Episode 27: November PSP Insights - Unmodified Emulsified Asphalt and Paint

Recorded: November 20, 2023

Released: November 28, 2023

Host: Kim Swanson, Communications Manager, AASHTO re:source 

Guest: John Malusky, Proficiency Sample Program Director; Joe Williams, Senior Quality Analyst, AASHTO re:source

Note: Please reference AASHTO re:source and AASHTO Accreditation Program policies and procedures online for official guidance on this, and other topics. 

Transcription is auto-generated. 

[Theme music fades in.] 

00:00:02 ANNOUNCER: Welcome to AASHTO resource Q & A. We're taking time to discuss construction materials testing and inspection with people in the know.  From exploring testing problems and solutions to laboratory best practices and quality management, we're covering topics important to you. 

00:00:20 KIM: Welcome to AASHTO resource Q&A I'm Kim Swanson. Today we have another PSP Insights episode, and that means I'm joined by John Malusky, program director for the proficiency sample program.

00:00:35 JONH: Hey, good morning, Kim. Glad to be here.

00:00:37 KIM: And we're joined by Joe Williams, Senior Quality Analyst for the AASHTO Accreditation Program, or Heirloom quality analyst. Is that have an official title change there, Joe?

00:00:48 JOE: There's been no official title change as of this moment, but I am happy to be here and you can call me whatever you want. Whatever title position works for you.

00:00:58 KIM: All right. I do like heirloom. That was brought up a few PSP insight episodes ago, and I'm sticking with it. So welcome to both of you. Thanks for being back on the podcast. Today we are without Brian Johnson. If you've noticed and we're going to try to trudge along without him, so we're going to do our best here. But on this episode, we're talking about the unmodified, emulsified asphalt samples 79 and 80, as well as the paint samples. 71 and 72 so. John. What can you tell us about the unmodified, emulsified asphalt samples.

00:01:39 JONH: Well, this round was pretty typical for us. Sample was in good condition. We didn't receive really any complaints or comments about the stability of the material. Labs were able to get it back if it did slightly break or have any settlement, they were able to get it back into homogeneity and make it work and was viable. Round data looked very good. We didn't see anything surprising. No anomalies in the data. It was, you know, pretty typical solid round for us and lots of good data came. Out of it.

00:02:13 KIM: So how big is this sample around how many participants do we have in it? Just so I can have some context of what we're talking about here.

00:02:20 JONH: Yeah. For the emulsion around, it's actually pretty sizable. It's right around 200 participants. So once again, we get a really, really good pool of data spread out through the world. There's actually quite a bit of international participation in this one compared to some of the other rounds. Just I guess due to the nature of the material.

00:02:35 KIM: And I know. That unmodified, emulsified asphalt.  Is a new. Term, our new sample type, so we. I know we. Correct me if I'm wrong that we split it out because now we have modified emulsified asphalt as well, so there has been a split and we have added clarification that this sample is unmodified. Right.

00:02:57 JONH: It really wasn't a split Kim. It was an addition. So we had always had the emulsified asphalt program. But we were really limited in the emulsion that we could use because there are different specifications for polymer modified emulsion that we had requests from. The participants and the agencies to add the polymer modified material because it's being more heavily used in the industry. So it was more of an addition to add the polymer and just a continuation of what we renamed the unmodified emulsified asphalt.

00:03:30 KIM: That is definitely ringing some bells for me that I now remember that part of the conversation that this one was just a rebranding, so to speak, to clarify that it's unmodified. But it's the same type of sample that has been being sent for. I mean, I guess it's now 79 and 80 rounds.

00:03:48 JONH: Yep, yeah, decades.

00:03:50 KIM: Now Joe on.  The accreditation side for the unmodified emulsified.  Asphalt. Is there any new and exciting or interesting things that you can tell us from from that aspect?

00:04:02 JOE: There's a couple of things with this, one, we actually haven't gotten our suspension list for this sample yet, so I'm not sure how many labs will have accreditation impacts from low ratings or non participation in the sample. But what I can tell you is that usually those numbers are pretty low. With this sample, we don't do a whole lot of suspensions from this one. One interesting thing is that beginning with this sample, we will now begin enforcing accreditation policies for test D 8078, and that's ash content for emulsified asphalt residues. That one's been in this program for a little while.  Now so with this one, we're going to start taking a look at that and evaluating ratings on that. The other probably interesting thing with emulsified asphalts is unfortunately just with the emulsified asphalt and it's short shelf life and its tendency to to breakdown over time. Time. If a suspension for a laboratory does occur from this sample or from the PME sample. Unfortunately, laboratories just have to carry that suspension on their accreditation until the next sample round. We can't send out an XBS, an app XBS, or an extra proficiency sample in order for the lab to retest and attempt to get that.

00:05:16 JOE: Accreditation reinstated just because we can't keep the material. We're out it it breaks down. So not many accreditation suspensions from this sample, but the handful that we do get.  Unfortunately, they just have to carry that. Until the next round.

00:05:32 KIM: And this is one of the samples that is only sent once a year, correct? Because I know we have a few samples like performance graded, asphalt, binder and viscosity graded asphalt cement. I believe those are sent twice a year, but the emulsified asphalts are only just sent annually, correct?

00:05:50 JOE: They are now. They used to be sent twice annually, but now that it's EML and PME, it's now. It's one e-mail and one PME annually.

00:06:00 KIM: Alright, and you can't. Use your results for a different sample to resolve accreditation for the sample. OK I.

00:06:09 JOE: Correct, correct, correct.

00:06:10 KIM: Feel like I. Remember this conversation from earlier in the year?

00:06:12 JOE: Yeah, even. Yeah, even though those tests span different different samples. And this isn't just emulsified things, you can even look at that with some of the asphalt compaction samples, like bulk specific gravity. If if a suspension takes place in the Marshall sample, you can't be. Created through the gyratory sample. What's different? Different. There's slight. You know, there's differences in the material types and how those are tested. So it has to be from that same.

00:06:39 KIM: Sample type and you mentioned that you're the accreditation program is looking at some data and starting to make accreditation decisions about something new this year. But you which test was that I forgot already.

00:06:50 JOE: That was D 8078. That's ash content of asphalt and emulsified asphalt residues, so we'll be taking a look at that again. We haven't gotten any kind of suspension list. Obviously, if we get some kind of list and it shows that every lab should be suspended, we'll probably go back and.  Look at that. But I don't think it's gonna come out like.

00:07:08 KIM: All right. And so for that, if this is the first time laboratories are getting an accreditation decision based on the ratings, is that because you've had a couple years of data to already look at it or like if they have low ratings now because if you need 2 consecutive rounds of low ratings? That means it.  Technically you were looking at it last time. But no decisions were made because it's not enough data and then now you're looking at the. Last like clearing OK.

00:07:34 JOE: Correct. Correct. Yeah. So, so we we start.  Looking at it so so the previous rounds data for that will count toward an accreditation decision. This is the first round that we'll take any kind.  Of action.

00:07:46 KIM: OK Yeah, that's what I was trying to get at so.  Thank you for understanding. Thank you for.

00:07:49 JOE: Gotcha. That's a good question. That's a good question, yeah.

00:07:51 KIM: Thank you for understanding that that's what I was trying to get at because I was not asking that correctly. Now Speaking of new things, John, you mentioned before we started recording that there's some new methods that were added to this sample. Would you like to?  Talk about that.

00:08:06 JONH: Yeah, Kim, I I wouldn't want to say completely new methods. The first one that we added probably four to five year.  Ago was the rotational paddle viscosity, so we've got a quite a bit of data collected for that now and we're starting to see some nice trends in the data set and I believe it's eventually going to lead to some precision and bias estimates put into the standard standards. I guess I should say or even updated ones to make sure we're getting some coverage. But I ran a little bit of an analysis today. For the precision statistics and it looked very good, good strong correlation. So it it's. You know, we're getting good data from the participants and it's good to see that we can support. Standards development in. That way, that's awesome.

00:08:44 KIM: Yeah, new is relative, I guess so. Of new five years or not. So thank you for that clarification though.

00:08:50 JONH: Yeah. Then the other sample that the newer one that you're or new excuse me newer testament that that probably pinging your brain a little bit more is the residue by quick boil this test method was added to ASTM. I think it was about two years ago, or maybe even just a year ago. It came into the standard. I think it came out right around the time that the emulsion round was out and we put it in the round very quickly because we were asked by the technical contact of that standard to try to get. Some data for. Them. So we've got our second round for that. It's a method that, AASHTO. It's not offer accreditation for, so it's not part of the assessment and accreditation programs yet. We just did it as a data collection essentially to gather information for the ASTM committee and we're actually seeing some pretty good numbers from that as well. Very good relationship between our traditional. Methods to determine percent residue. So traditionally we would use the residue by distillation test or residue by evaporation. Those are the 2 standard methods that just about every specification is written around this new standard called quick boil. It's basically a residue by evaporation, but it's used with less material.

00:09:59 JONH: It's meant to be done very rapidly, hence the term quick boil. It's more of a a spot test for production facilities to just make sure that they're hitting their asphalt content in the percent residue.  And what I'm seeing with the two rounds that we've gotten data for, the values are actually very similar. I was expecting to see some additional variation believe if you look at this rounds, that was just out the residue by distillation and evaporation, those traditional methods we were seeing around 5858. .3% passing or excuse me percent residue.  And with the quick boil, we saw 52.9% so very, very similar data. The standard deviations are almost identical. So it's looking like a a viable method to be used in a short term period to provide good information for suppliers and producers to make sure that they're hitting their mark when they're doing their emulsion processing.

00:10:54 KIM: That's interesting. Not that I understood what you were talking about, but what? Was interesting to. Me, I'm sure. Was that what you just said was interesting to some people? I just don't know what you're talking about. But what was interesting to me was the idea. That we have a test method there that we're not accrediting for, and we're not. They're not assessing for and that we the proficiency sample program is being used to help improve the standard and to do that, that is actually really cool. Other other standards within other proficiency sample programs that are similar.

00:11:26 JONH: If there's actually kind of a progression, Kim, usually we get approached by. By whether it's AASHTO or ASTM, about a a newer test method, and if they can have some data collected. If it's being used in the industry, then the proficiency sample program is a pretty good venue to get some data and be able to have some information to analyze it from a number of participants, rather than trying to hunt for participants and to find a small, you know, find a study.  And do all the research and leg work if we just blast it out in the proficiency sample program. We usually get industry and agency reps who are already doing it. So we just go ahead and and piggyback it as I kind of mentioned before, there's a little bit of an evolution to it.  What is typically happened and this? This actually speaks to the rotational paddle test. That was a provisional standard in AASHTO. We started collecting data for it and providing it back to AASHTO and ASTM. I think actually that might be in a standalone AASHTO standard. I can't remember once that data was collected it was used to revise the standard and make some adjustments to it. It became a full standard in ash toe and then.

00:12:31 JONH: The assessment program picked it up as a as a test method to assess for and it became part of the accreditation prop. That actually also happened for the ash content test that Joe had mentioned before. And you know, I would imagine there will be an evolution to the quick boil that that will eventually become part of the assessment program and accreditation program. So there's a a little bit of a chain reaction there that takes place. It's usually a data collection and assessment. And accreditation.

00:13:01 KIM: Very cool. Anything to add to that?

00:13:02 JOE: When the standards are getting developed and they need that precision and bias statement, that's like John said that that's how they they'll approach us. If we have a PSP program to see if we can add a test. To kind of get that standard going and get it fully published with the PMB statement.

00:13:19 KIM: All right. Anything else that I should have asked? Or maybe a question that Brian would have asked about the unmodified and falsified asphalt before we move on to paint? Did I miss anything?

00:13:29 JONH: No, I think we're good, Kim.

00:13:30 JOE: Yeah, I think we're good with that one.

00:13:32 KIM: All right, now moving on to paint. I know you said that the unmodified, emulsified asphalt had a couple 100 participants, and I know paint has fewer. So let's start with that before we get into the nitty gritty with. That John about how many participants do we have in?  The paint sample rounds.

00:13:50 JONH: Paint usually runs around 70 participants per year, fluctuates a little bit here they're up or down. It's generally 70 participants and an overwhelming majority of the participants are actually agency. It's very, very limited industry wise. I think maybe 15 to 20 of those 70 participants. Our industry and there's actually, you know, kind of similar to the unmodified emulsion sample. Around we also see quite a bit of international participation in it and that international participation is also agency driven. It's not as industry driven as some of our. Other sample schemes 

00:14:28 KIM: when you say, Agency driven. Are you talking about? Like governments? Like in our case would be like state departments of transportation. Or like what are you specifically referring to?

00:14:38 JONH: Yeah, that's correct. Him State DOT's Department of Public Works City and County Laboratories, not specifically paint manufacturers and also private testing labs are very few private testing labs who. Are involved with the traffic paint testing.

00:14:54 KIM: That's what I thought you meant, and I just wanted that clarification on the record to make sure I was understanding it and for our listeners to. Understand it so. Thank you for that. So with paint, what are the participants actually testing for? Because if I recall from last year's PSC Insights episode regarding paint. I brought up that they should test for when it's wet, how slippery it is because I've almost fallen. And that was not one of the tests. That was it. So what are you actually, what are the participants actually testing for on these paint samples?

00:15:25 JONH: So we're really looking for viscosity, you know, ensuring that the paint is flowable and you could actually put it down with the sprayer and and make a good stripe. We're also looking at things like volatile content, you know, basically how quick the volatile material comes off of it and. What the amount of volatile material is in the?  I mean pigment content, we kind of joking around before like how yellow is the paint well, yeah kind of. We also look at no pickup time and I think this is where we have the confusion last year. Talking about whether. The paint was actually wet and slippery, like wet paint, wet paint, or whether there was water on top of the paint after it was put down and the striping. And that's where Kim talked about fall. So those are some of the methods that we that. We include in the round.

00:16:09 KIM: I still think there needs to be a test of how slippery it is when there's rain on it, because I feel like that is a hazard waiting to happen. I cannot be the only one that slips on crosswalk paint when it's raining. Can't be the only one.

00:16:23 JONH: I am sure there's some sort of skid resistance test. When it comes. To that

00:16:26 KIM:, well, maybe we can think about. Including it because I just want to. Know that data so I feel like. That's worth talking. About the process of how to add it just cause I want. I'm curious to so I think that's we should get the ball rolling on that. We'll see how far that goes. So with paint. You mentioned, I know or Joe mentioned earlier for with the unmodified emulsified asphalt that we don't have extra proficiency samples because they're not really shelf stable. Is there a similar problem with paint? I kind of feel like there might be, but. I don't know.

00:16:56 JONH: Yeah, Kim, that's correct. It's it's basically similar to the emulsion we have to deal with this.  It's like settlement for the the non volatile portion of the material changes the viscosity you know and also the volatile content. So right if if any anytime you lose volatile material, the pain's going to lose viscosity, it's going to lose that pickup time capability. So there are you know several issues that could occur with it. But we do see a a problem with the stability, so you know we generally back off on it and don't offer any XPS. We have had laboratories call and ask us if they could retest and we've done that you know, but obviously the sample is not blind, they know the round it came from and they're just trying to kind of do an an internal corrective action that's pretty much the that's our limited capacity as it relates to pain.

00:17:42 KIM: And Joe's actual accreditation program does not offer accreditation for paint, correct?

00:17:47 JOE: That is correct.

00:17:49 KIM: Why is that?

00:17:50 JONH: So we've sent out multiple surveys to the agencies and industry and it doesn't seem to be a super hot. Topic. Not sure why I don't know if it's because. The industry is. Moving away from just simple waterborne traffic paint to things like thermoplastics and other types of payment marking products that are a little bit different. So it it might be one of those things where we eventually just have to evolve to as a program and move away from your standard, you know waterborne.  Graphic paint and look into things like thermoplastic striping and other types of samples to test.

00:18:24 KIM: Yeah, I would imagine since we only have around 70 participants, it wouldn't be necessarily a worthwhile accreditation and especially if they're mostly. DOTs or other agencies like that. So I can imagine there's not necessarily a call for it. But John Speaking of some of the evolution of the pavement markings, is there any other progress or anything in the works that you know might be coming down the pipeline or down the road in the next couple of years or five years? With pavement markings besides paint.

00:18:54 JONH: Was the pun intended? [KIM: Yea]  I figured so right now we're we have been in discussion with the technical subcommittee with AASHTO to try to work on some different things to see what's out there. There has. Been a little bit. Of discussion about trying to figure out a way to incorporate glass feed testing for size retro reflectivity. Things of that nature. So there's things that are out there, we're just.  Not sure what we can do yet.

00:19:21 KIM: All right. And then as. Far as paint itself, I'm just imagining that the production process for that John and that is that just redistribute it like we don't actually do anything to produce it. We get that from a supplier and then just kind of repackage it. Or are we doing anything?  On our end to modify it.

00:19:38 JONH: Yeah, it's so it. It is similar to to what we would do for a liquid asphalt round or a multi asphalt round. We contact the supplier, get the material and then repackage it. But there are times where we do make slight modifications to the paint to change the samples between the even an odd sample. So yeah it's it's kind of a little bit of a. Mix of both. There are times where we do add some things to the paint to make a slight change and then other times where.

00:20:03 KIM: We do not. I have no other questions about any of these. Did I miss anything, though? Joe, do you have any questions for John about this sample? Maybe you have better questions than I do.

00:20:13 JOE: I have no questions about paint.  No, I don't. Don't get it on your clothes. I did help with the production. One time years ago and I still have paint on a pair of jeans that will. Just never come out there now, just.

00:20:28 JONH: Paint your pants.

00:20:29 JOE: They're, and they're they're painter pants. That's it. It does not come out.

00:20:33 KIM: I just now realized that there are two different colors we have. Most traffic paint is either white or yellow. Do we mix it up or do we send all white?  Or send all. Yellow. 

00:20:43 JONH: No, we. Try to rotate, we'll go white or. Yellow it just depends on what we. Do the one thing. That we have and still to try to help ensure that we're getting a high quality.  Product is we use the data from the ash toe product evaluation and audit solutions program to make sure that the paint has been tested by agencies and industries and it's of good quality. So we'll look at the data in there first before we make a decision on what paint to purchase.

00:21:10 KIM: And that program was formerly known as NTPEP. If our listeners are not familiar. With that title. Is there anything else, John that I didn't ask that Brian would? Have asked or that. You or Ryan, for that matter, would have answered. Is there anything? We want to contribute that we may.  Have missed in this episode.

00:21:27 JONH: No, I don't think so, Kim. I think we pretty much nailed as much as we can with these two rounds. Like I said, pretty simple, pretty standard, nothing too crazy. Usually the data analysis looks really good and we we generally see good homogeneity and good stability with the materials. So nice easy clean rounds typically.

00:21:43 KIM: All right, with that, thank you to our guests, John Malusky, Director of the AASHTO Proficiency Sample program. Thanks for being here today, John.

00:21:51 JONH: Anytime, Kim.

00:21:51 KIM: And and once again, thank you, Joe Williams, for your time today as heirloom quality analyst. Thank you.

00:21:57 JOE: You're welcome, Kim. It was a good time.

[Theme music fades in.]   

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