Latest / The Slump Monkeys Concrete Podcast / 006 - Jason Wimberly
Transcript
- paul: Welcome in to the Slump Monkeys Concrete Podcast, soon to be the world's number one concrete podcast. I am your host, Paul Finley. So happy to be here with you today and happy to announce that we have a new title sponsor for the month of August. Cannot believe August is already here. But with that said, very excited to introduce the new title sponsor. We are brought to you by XBE. The system of action for heavy materials, logistics, and construction on a path to autonomous operations. BCMI by XBE is built for ReadyMix producers, connecting dispatch, batch, fleet, ticketing, pricing, and financials all in one platform. They got a new guy or an agent. Agent XBE works alongside your team, schedules the loads, tracks deliveries, surfaces problems before they compound. So the operation runs. Doesn't just get managed. To learn more, visit their website, x-b-e.com. Meet Agent XBE, the super workforce. It's in the bottom right hand corner. You can ask it directly what it can do. Again, to learn more is visit their new capabilities with Agent XBE. Their website is X-B-E dot com. So excited to have them. As a sponsor, as many of our listeners would know, they made a fantastic hire recently. Sarah McGuire came over from Geotech over to XBE. If if I needed any endorsement of that company at all, it's when you make good hires. It's easy to want to be fans of that company. And we are happy to have them along. It's August, it's the beginning of August. very excited for this episode. Our guest is fantastic, by the way. Jason Wemberley, professional engineer, devoted his life to concrete. We're thankful he did. He is a phenomenal, phenomenal guest. If you haven't seen any of his talks or anything, definitely check those out where you can. hook up with him on LinkedIn. He's a great follow, very knowledgeable, he's like real down to earth, you know. So it's nice when you get guys that are you know are like way smarter than you, but they also talk to you like a normal human being. And Jason's one of those guys. Very funny. We have to forgive him though. in the middle of our interview, I almost almost ended the interview because he reminded me that he graduated from the University of Tennessee. for all the listeners here, I know we have several that are Vols fans. they're not welcome on this podcast. That is the worst offense, almost the worst offense you could make to me is to remind me that you either like the University of Tennessee football team or that you graduated from that university and still support that football team, that is a disgrace. We are huge Alabama Crimson Tide fans on this podcast. And I welcome you all to be Tide fans. I think, in fact, if I could convert those orange loving friends, am I even allowed to call them friends? Orange loving friends, if I could convert them to being fans of a real football program, I would do that. it has not been in the cards. And you know, I just you just gotta pray for them. You just gotta pray for them. That's all that's all we can do. with that said, you know, football season's less than a month away. when this podcast releases on August 5th, we are exactly one month away from the major teams kicking off on September 5th. There are some games like the week before that. Some of them are okay, but really like the real season starts. that's Saturday. September 5th. At that point, this podcast will start to halfway become a college football pack podcast. As you can see, concrete's the main focus, but we got sections on conspiracy theories. We got sections that are going to be about college football. We'll do that about once a month, probably. And then we've got a section on white paper of the month. And that is what we're gonna get into today. If you go back and listen to episode two, we talked about a white paper. Related to AI, Meta put out their paper. They they open sourced machine learning algorithm to design concrete mixes with AI. Really interesting. I think a lot of us in this industry hear concrete made with AI would just kind of roll our eyes. Like, my gosh, we don't need another piece of software. What are we doing? But some of it's actually pretty fascinating. And so that paper was a nice behind the curtain look at how they did it. And they were honest about the shortcomings, which I appreciated. And we hit some of the highlights and lowlights of that paper. Today we're gonna talk about a different paper. The white paper of the month this month is technically it's a bulletin, but it might be the most important and influential piece of writing in the history of modern concrete. we in fact we are going to talk about. The design of concrete mixtures by the one and only Duff Abrams. Duff Abrams may be a name some of you recognize. He's commonly known for the invention of the Abrams cone. We call that the slump cone today. this bulletin was published, it was finished in 1918. Some sources say it was published in 1920, but for all intents and purposes, it was released in 1918 through the Portland Cement Association. they sponsored the work. of Dr. Abrams. He was at the Lewis Institute in Chicago, researching concrete. It took him four years to research and write this bulletin. What I like about Duff is he had a little bit of real world experience before he came back and and actually did like the researching and and academic side of this. So that's good. Always appreciate it when our researchers have like a foot in the real world. It just really, really opens everything up for you. a little bit of background. Duff was born in 1880, lived to the ripe old age of 85 years old. That's right, 1965. Was his last year on Earth. He saw electricity go into your homes. He saw plumbing, indoor plumbing became a thing. He saw two world wars and the Great Depression. He did it all while transforming forever the way we design concrete mixtures. As a civil engineer, he graduated from the University of Illinois. Duff held a couple of real world jobs before going back full time into research at the Lewis Institute in Chicago. So this paper's super interesting because before Duff, there was no such thing as a mix design. How many of us listen to this podcast right now? We consider ourselves pretty good at concrete mix design. Well, that wasn't even a thing a little over a hundred years ago. the term actually comes from this paper. I'm gonna call it a paper, I'll call it a bulletin, just bear with me. It comes from this paper where he argued that the traditional one to four ratio proportioning was inadequate for the future of concrete building. What do I even mean about one to two to four? Well, you're talking about the way they used to make concrete mixtures. In fact, you there's still like stucco mixtures and other like basic concrete mixtures are still made with this one to two to four, one to two to three ratio. And it's one part water to two parts cement to three or four parts aggregate. Depending if you had four parts aggregate, then you're diluting the mixture and you make it a little bit weaker, three parts aggregate, you're concentrating the cement paste. And theoretically you should have a stronger concrete. Before Duff came along and wrote this bulletin, that's just how things were done, man. And they divide up the coarse aggregate and the fine aggregate in that aggregate chunk. And people would play with water, but there were no like real hard rules for concrete mix designs. And he he first keyed on. That the one to two to four doesn't factor aggregate sizing or grading. It was just here's your rock and here's your sand. Have at it. And this bulletin that he created would give us a new term. He defined what we call today the finest modulus. So he also then saw that water content was not regulated. People were just adding water so that it became workable. Nobody Nobody really took the time to say what is an appropriate water content. It's just one to two to four. And he said, okay, well, we're gonna define how sizing and grading affects concrete mixed design. And then we're also gonna define exactly what water contents mean to concrete. And he coined the term the water to cement ratio. So a lot of big things going on in a single bulletin. To where we now get concrete mixed design as a formality. So Duff saw the future that concrete would go on to be used in a wide variety of building applications. He's like, we're gonna build sidewalks plus slabs on grade, plus footers, plus columns, more. And understanding that these mixes serve different purposes, demanded different strengths and workabilities, Duff set out to define a framework that could allow engineers to answer four things. Thing number one. What mix is necessary to produce concrete of proper strength for a given work? Thing number two, with given materials, what proportions will give the best concrete at a minimum cost? Point three, with different lots of materials of different characteristics, which is best suited for the purpose at hand? And point four, what is the effect on strength of concrete from changes in mix design? Consistency and size or grading of the aggregates. So this all important bulletin released in nineteen eighteen sought out to provide answers to those four things that engineers could use to then specify concrete mixtures and future building products. So while went into it. What did he do? For four years, he performed fifty thousand tests. Test mortar, concrete, did it all, man. He laid out 14 key principles from that word. Now, I read you the four things he was trying to, you know, prove here. But I think if I read all 14 of the key principles, you'd turn this off or go to sleep or whatever. So I'm not trying to kill you with boredom. So I'm gonna I'm gonna summarize these for a second. principle one, eleven, twelve, and thirteen, they kind of go together. says with given concrete materials and conditions, the quantity of mixing water Determines the strength of the concrete so long as the mix is workable. He was really clear to highlight mixing water, saying like you have to have enough water. Again, this this is all everything I'm saying right here is revolutionary from this paper that was not considered before. He was defining that you have to factor in the absorption of the aggregates. Or, I mean, they could be saturated. So whatever the water content of the aggregates is or isn't was absolutely key. Along with the sizing and grading, but beyond that, how much water did you need to hydrate hydrate the cement? And then beyond that, you have water for mixing. And so the quantity of mixing water determines the strength of the concrete, so long as that mix is actually workable. He goes on to define the relationship of water contents to achieve workability. Create cement placed, absorption aggregates, water contained in those aggregates. And the biggest revelation of all is we should start considering water content based on the volume of water to cement ratio. Boom. That's huge. Water cement ratio. Every one of us listening to this right now that have even tangentially worked in concrete know that the water cement ratio is one of the key determining factors when you're talking about you know. concrete and people started relating it to concrete durability. the specs there's so many specifications out there that limit your water smit ratio. You can't go above a a certain point. And none of that would ever happen if Duff Abrams hadn't locked himself away between 1914 and 1918 and done the work to define it here in this bulletin. Second key factor from the from the paper is Sort of summed up in principles two through nine. They kind of all go together. And they drive home how important the sieve analysis should be. Duff argues in 1918 that the sieve analysis furnishes the only correct basis for proportioning aggregate and concrete mixtures. Again, remember, proportioning before was just, we just need one to two to four. So in that mixture, it's four parts aggregate. But he's saying, no, no, no, no, no. That's not how we should be proportioning aggregate. We need to do it based on sizing. And grading. And this seems obvious to us today in 2026, but remember, Duff's trying to move people away from that proportionate thing into a much more really complicated at the time, mixed design process. To define a method of measuring the effective size and grading of the aggregate, Duff elevated a function known as the finest modulus of the aggregate. Commonly known to us as an FM, geez, I still get freaking goosebumps when I think I there was a plant in Alabama we were working with back in the day. And they received a man sand that had a 3.8 FM. Jesus Christ. Let me tell you, wasn't a whole lot of good concrete coming out of that plant that day. But you know, one way they could have had even better concrete is if they were using our friends over at Command Alcon. That's right. Command Alcon's got systems today that help you track your inventories, your batching, communication. And work together have the smoothest operation in the industry. I love that we have two different sponsors on this show today that are kind of working in the same space, but they're going at it in two completely different ways. typically I wouldn't have two sponsors on the show that are in the same industry, but I love that these guys are approaching everything in a different fashion, XBE they're they're out there Trying to create a super workforce with their agent XP. Commands out here telling you we've been here fifty years. We're doing the basics and we do it really well. And then beyond the basics, we're moving to the cloud. And they want you to come be a part of it. So I invite you to celebrate 50 years with Command Alcon. Please visit them at commandalcon dot com. We thank them for being a part of this show. So why was the water cement ratio considered by Duff to be the most important revelation in this new design of concrete mixtures? Well, Duff went through and he plotted the relationship between strength and water content to produce one of the most beautiful curves I've ever seen in concrete research. it's interesting to know, by the way. His water to cement ratio chart, it begins at zero point four five. That's the that's the upper bound in ACI three hundred eighteen three hundred one for the exposure class F two where you have exterior concrete exposed to three freeze thaw with Yeah, de icing chemicals. So I mean if it's an outside slab with freaking salt on it, man. 0.45 is as high as you can go. That's where he freaking started. Like that was the low end of his water semi ratio. interesting to see how things have changed in some respects. But a lot of what Duff Abrams published in nineteen eighteen still holds true today. another interesting note, going back to that strength as a function of water content, Picture the graph in your head, right? So strengths are plotted from zero going up to like seven thousand psi on the y axis, and the water smint ratio runs along the x-axis starting at zero in the corner. And we see the curve like starts really high. So starting points up in the top left where you've got six thousand psi at zero point five water cement ratio, and then it steeply drops. It's a nice sharp slope down, and then it Gently curves off and to the left. And this line asymptotes along the x-axis, that is, it reaches near zero, stretching to an assumed affinity, around 3.50 water cement ratio. Yeah, yeah, you heard that right. There's a 3.50 water cement ratio. If you're listening to this and concrete's not your main job, or mixed designs are not your main job, that's absolute insanity. to even have a water cement ratio above one point zero, it's water divided by cement on a mass by mass basis. To even have it above a one would be farcical. And to have it above point eight, I think is farcical. I don't know that I've I don't know that I've seen a mix trying to think. So been in some form or fashion been looking at concrete mixed designs for 20 years. I don't think I've ever seen one like legitimately used that was Higher than 0.64. Now there's probably like, you know, other people out there other than me. And I'm not talking about like playing in a lab and just seeing what you can do. I'm talking about like actually like somebody used a concrete and not a flow fill mix. I don't want to hear any crap. Not a grout mix, like an actual concrete. 0.64 watersmith ratio. I think that's the highest I've ever seen. But you know, look, Duff's doing research. So he just ran it all the way out as far as he could. He ran it to like four or four and a half water smith ratio. but to be fair to him, most of his tests were per performed below zero point seven zero water smart ratio. And he didn't factor in admixtures to these tests. He he does comment later in the paper that like, hey, admixtures exist and they're gonna get better. So we should, you know, add into our water content equation that the when when we're using these things. But for the per purposes of this paper, he really kept it simple, and he pushed it past the limits of the day. It was revolutionary in his day to discover at the same time this is a quote from Duff. Quote The size and grating of the aggregate and the quantity of cement are no longer of any importance except insofar as these factors influence the quantity of water required to produce a workable mix. I think there's been a lot of conversations I've had over the years with guys that are into mixed designs and we kinda all like understand this implicitly. Like it doesn't it doesn't inherently mean that large aggregate, small aggregate, lots of aggregate, little aggregate, ten sacks of cement versus five sacks of cement are the factors by themselves that are gonna give you strength in your concrete. In fact, most guys that make a lot of mix designs, they'll tell you that you could have double the cement, the most rich cement mix ever, but that joker could fall apart. It could fall apart. It could shrink. How many different types of shrinkage are there, by the way? it could shrink and crack. It could be brittle. There's a lot of ways that it could fail. And, you know, Duff said it without beating around the bush. The size and grading of the aggregate and the quantity of cement are no longer of any importance, except insofar as these factors influence the quantity of water required to produce a workable mix. When I was reading through Abram's revelations and definitions on finest modulus, I couldn't help but be amused at how clearly our modern mixed designs are based on Duff's work. By the way, I love calling him Duff. I don't I hope he doesn't mind that I'm using him on a first name basis. I went and looked it up. According to Social Security Administration, there are less than five people born in eighteen eighty, the year he was born, that were given the name Duff. How do I know that? Because they don't track names where there's less than five of them, they don't get listed. So less than five people in 1880 were given the name Duff. In fact, he could have been in the only one. But at age seventy-four, the US experienced peak duffness when thirty-four males were born with the given name Duff. You know, you gotta wonder if there were thirty-four concrete nerds out there who wanted to honor Mr. Abrams and name their sons after one of the greatest pioneers of modern concrete. Anyway, back to finest modulus. For all of us mixed design folks, we certainly have grown to know what FM means. just in case it's not like regular in your world, let me let me define it real quick, how it's calculated and why it matters. Also why it was revolutionary. finest modulus is calculated by measuring the size and grading of the aggregates over like a stack of sieves or nest of sieves. the resulting sum of the percentages in each sieve analysis is then divided by 100. And that just gives you an a numerical score. We call that fineness modulus. The sieve stack is something I learned. I didn't how do I not know this? 20 years in this and didn't understand this part of it. I'm I'll tell you what I didn't understand. You can laugh at me. the sieves in the stack, they range from one point five inches for the course aggregate all the way down to 0.0058 inch. So 1.5 inch square down to 0.0058 inch square opening on the smallest sieve. We call that smallest sieve the number 100 mesh sieve for the sands. But did you know that each sieve in the stack, the clear square opening is exactly double of the previously placed sieve. So an eight mesh sieve going up to the larger four mesh sieve, which would be the next one in the stack, the size of the opening doubles from the eight to the four. So the four is a point one eight four square inch hole. The next sieve above that is 0.37 square inch opening. The next sieve above that 0.75 square inch opening and the next one doubles above that. So did not know that. That was awesome to see. and by calculating the FM We're gaining an understanding of the coarseness of that aggregate gradation. A lower FM means finer aggregates. he gave an example in his bulletin. So, like a 1.54 FM would be a fine sand, 2.41 would be a medium sand, and 3.10 FM would be a coarse sand. Those numbers hold up today. In fact, I'd argue 1.5 is extremely fine. I did not, I personally didn't like making concrete with. sand that was finer than two, finer than one point eight. I really didn't even want to deal with it. There are I know people are listening to this well, I've made it with a one point four. Yeah. Great. Well go have fun in Florida. Keep making concrete. We're all proud of you. We love ya. but I didn't like doing it. It wouldn't it wasn't very fun to me. it I I would love to just have like normally graded sands. That that would be great. Thanks. one thing to mention though. There is a factor of his research that wasn't explored that I think today we would not take for granted at all. he did so he talked a lot about sizing and grading, right? But he didn't talk anything about particle morphology. He did not mention shape at all. He understood empirically that a rounded aggregate versus an angular aggregate could give you a different workability. But there was no point in this where he says, you know, because we're using an angular particle, we need to adjust our mix X, Y, Z. I think we understand that better today. I don't know that our equations and how we're doing mix designs always take that into account, but we certainly understand it. And it can really be a pain in the rear end for a bunch of us when we're out there making mixes. But When they published this bulletin, Duff spent many, many pages outlining why aggregate Civ analysis is so important. He summed it up with the FM calculation, but to be clear, before Duff, people were not standardizing Civ analysis or gradations for aggregate that's used in concrete. That wouldn't come after until after the release of this work when ASDM C thirty three gets published in nineteen twenty one. And although Duff spends a lot of pages of this bulletin devoted to the aggregates, it was secondary to water content. Duff creates a complicated algebraic formulation that he says takes into account all the factors which affect the water content required in a concrete mixture. Factor one was workability. Duff defined workability as the relative consistency of the concrete. Now I gotta take a pause here. I love Mr. Duff and we're celebrating him and his paper here, but today we clearly delineate the terms workability and consistency. For consistency, we're actually talking about Abram's own invention, the slump cone, to quantify the fluidity of a specific concrete batch at a specific moment in time. Workability, however, is a broader term related to how easy the concrete is to work. For example, Two concretes can have the same consistency, a three inch slump. But concrete number two could be made with coarse angular man sand. And we'd likely agree that concrete two is less workable than concrete one, despite their equal slumps and consistency. And another fun note, the slump cone Invention itself was created in 1918. It was part of this work. He had to find some way to have a constant among these mixes. 50,000 tests. He had to have a constant somewhere. And that's what he chose. And we still do that today. There's a another point of contention, right? Bunch of us out there banging our heads against the wall, like Somp is not the end all be all. Slump is not the end all be all. But but Name me another test that can be run by anybody speaking any language with any education level, can be performed in under a minute, and provide you some tangible result in the field to let you know how your concrete's doing. Go ahead. I'll wait. No, didn't hear anything, didn't think so. so as much as like some of us want to deride the slump cone and the slump test and say, gosh, man, like that shouldn't be failing concrete mixes. I agree. But until we find something else that's going to give us a measure of consistency. from batch to batch that we can not just see what happened in the lab, what happened to the batch plant, but now we're seeing what happens to the concrete on the field that anybody can run in a very short amount of time, then that's what we're gonna be using. also it's cheap. So there's a couple other pieces of equipment out there that are trying to do some things like to clearly define water smint ratio fairly quickly. But if the sh machine's really expensive and You know, can't have one on every job site. Slump cone, you just throw it in the back of every truck. It's really, really, really simple. So I'm gonna leave it to the the next generation of of concrete thinkers to come up with anything better than that. But in 1918, Duff came up with it during during this work. the second factor Duff accounted for in his water content calculation is a cement factor. So back in nineteen eighteen, he had to be super clear that quality And quantity both play a part in his equation. Thank God in 2026, we most mostly just focus on quantity. Probably got some Smit buddies out there listening right now or laughing out loud saying, Paul, I promise we we got quality issues with some of these poor sources. Hey, Paul, they ain't played nobody, Paul. Yeah. we're not gonna point fingers at Smit quality. Between sources on this show, when they're they're all our friends. And so thankfully, when we're designing mixed designs and we're thinking about water content, cement quantity is what we're thinking of. And Duff goes on to say there is a third factor affecting water content, and that's the aggregates. So the equation, this big complicated algebraic equation he wrote to define water content, necessary water content, accounts for sizing and grading absorption in the water contained in the aggregates. these are things we do naturally today, but they were revolutionary to Duff. How many of us have cooked off moisture in our sands on a hot plate at 6 a.m.? Yeah, a bunch of us. Probably everybody almost everybody listen to this. I wonder if Duff imagined that would be our lives a hundred years later. We're doing that. man. I can imagine the technology people listen to this show too and they're screaming that we need to have moisture probes and mag bins and you know need to be constantly checking all yeah, we'd we'd all love that, man. We all love that. But not every plant is high tech and outfitted. But you know what we all got? We all got a freaking twenty dollar hot plate from Walmart that's been used for the last decade and we cook up handfuls sand. And we can calculate our moistures right there. So it's been very useful for us in the concrete world. And we we thank Duff for outlining all these things back in 1918 to give us what we consider today the foundations of concrete mixed design. So to finish off this segment, I kindly ask that you allow me to read the closing paragraphs of Abram's bulletin. He concludes The importance of the water to cement ratio on the strength of concrete will be shown in the following considerations. One pint more water than necessary to produce a plastic concrete reduces the strength to the same extent as if we should omit two to three pounds of cement. Our studies give us an entirely new conception of the function performed by the various constituent materials. The use of a coarse, well-graded aggregate results in no gain in strength unless we take advantage of the fact that a small amount of water necessary to produce a plastic mix can thus be reduced. In a similar way, we may say that the use of more cement in a batch does not produce any beneficial effect, except from the fact that a plastic workable mix can be produced with a lower water ratio. The reason a mix a rich mixture gives a higher strength than a lean one is not that more cement is used. But because the concrete can be mixed and is usually mixed with a water ratio which is relatively lower for the richer mixtures than for the lean ones. If advantage is not taken of the fact that in a rich mix, relatively less water can be used, no benefit will be gained as compared with a leaner mix. The mere use of richer mixes has encouraged a feeling of security, whereas in many instances nothing more has been accomplished than wasting a large quantity of cement due to the use of an excess of mixing water. The universal acceptance of this false theory of concrete has exerted a most pernicious influence on the proper use of concrete materials and has proven to be an almost insurmountable barrier in the way of progress and development of sound principles of concrete proportioning and construction. Rich mixes and well-graded aggregates are just as essential as ever, but we now have a proper appreciation of the true function of the constituent materials and concrete and a more thorough understanding of the injurious effect of too much water. Rich mixes and well-graded aggregates, after all, are only a means to an end. That is, to produce a plastic, workable concrete with a minimum quantity of water as compared with the cement used. Workability Of concrete mixes is of foundational significance. This factor is the only limitation which prevents the reduction of cement and water in the batch to much lower limits than are now practicable. The above considerations show that the water content is the most important element of a concrete mix and that small variations in the water cause a much wider change in the strength than similar variations of cement content or size or grading of aggregate. This shows the absurdity of our present practice. And specifying definite gradings for aggregates and carefully proportioning cement, then guessing at the water. It would be much more correct to carefully measure the water first and then guess at the cement in the batch. Without regard to the actual quantity of mixing water, the following rule is a safe one to follow. Use the smallest quantity of mixing water that will produce a plastic or workable car. The importance of any method of mixing, handling, placing, and finishing concrete, which will enable the builder to reduce the water content of the concrete to a minimum is at once apparent. Guys, that is the maximum that we've learned for the last hundred plus years of how to design and proportion concrete mixtures. There have been new technologies, there have been new materials and constituents in the batch that sort of aim to shift that paradigm slightly, but overall, from an engineering standpoint, Duff was correct and he continues to still be correct today, more than a hundred years later. I want to thank you guys for listening to White Paper of the Month. I also want to thank our third and final sponsor of this episode, Rocket Start. you heard Manny on the last episode, episode number five. He came on with some friends of his and we had a great discussion. his company is doing phenomenal things. They are leading the way on building culture. looking at driver retention, truck driver retention and rewarding folks through public gratification and recognition for a job well done. Some of that's just like your regular job, like you show up to work every day. Some of it's like, hey, I took an extra load, guy needed help. I helped him. different different things. Just going above and beyond. And if they're gonna go above and beyond then, you know, we as company owners should go above and beyond and recognize them. It mainly's company facilitates that. I love what he's doing over there. So if you would please go check him out at gorocketstart.com. They're gonna be doing more stuff in the future, bigger stuff in the future, you probably wanna be in on the ground floor today and be talking to Manny today before things get like super awesome and wild. You want to be in right now. that is gorrocketstart.com. Ask for Manny, tell him you heard him here on the Slump Monkeys Concrete podcast. And with that. We will lead in to the interview portion of our podcast. Please welcome Jason Wimberly of AM Concrete. Welcome into the interview portion of the Slump Monkeys Concrete Podcast. Welcome into the show, the great and powerful Jason Wimberly. Thank you for joining us, sir. Jason Wimberly: Thank you very much, Paul. I appreciate the invite. I I laugh when you say that because Kevin Cox once made the mistake with my wife sitting in the car with me of of I can't remember even the word that he used now. And and it's just and it's just always stuck and my wife now uses that word all the time to describe me w and just to kind of get under my goat. And And I'm just kinda like, Dad Gummit, will you stop that? paul: Shout out Kevin Cox. Jason here for those I mean I'm guessing a lot of the people that are listening right now probably know Jason already. In case you don't, professional engineer got a bunch of other acronyms after his name that nobody knows what they mean. But he is the VP of Technical Solutions and Innovation for AM Concrete. We're happy to have him here. I knew Jason previously, when he was at Lithco, We connected briefly back in the day, but it's really nice to have you here. We have like full conversations, man. Jason Wimberly: thank you. and that word, by the way, it it just hit me. It's what happens when you get old, man. Like I hit fifty and my brain's like started to disappear. I'll write everything down now because I won't remember it. I'll text you in the middle of this interview probably just to text you and remind you about something we've talked about 'cause that's just the way life goes. But the word was brilliant. But yes, yes. So now I paul: There you go. Jason Wimberly: I always have to hear that your brilliant see and I'm like, Will you please stop? Like you're driving me and like paul: Well, it's you know, it's my job as the podcast host. When I see those gears spinning but nothing's coming out, I jump in. We keep this thing rolling. Nobody's nobody's gonna have any clue. But since you outed yourself, I'll out some people in my company. there are people in our organization that have that same problem of not being able to remember everything. And there are more post it notes around some of these offices than you would ever imagine. They got color coded post it note systems, brother. Jason Wimberly: that's a hoot. You know, years ago when I first started in this industry, I was a little peon project engineer straight out of college, working for a self-performed GC. And I was working for our it's really where I started out, our our concrete side. That's how I got into concrete construction. We were buying all of our steel from Godow and Mary Steel at the time up in Charlotte. And I would I would have to go over to Godal's office to meet with their detailers. They had a rule back then that you were not allowed to use post-it notes. It was illegal and against company policy to even have a post-it note in the facility. paul: What what for? What was that? Why? Jason Wimberly: I because I guess post-it notes will disappear. Like, man, look look at my whole stack. My whole stack of different colored post-it notes that I use to put all over the place to help remind me of things, man. paul: For the audio only listeners, Jason just turned around on his very neatly organized desk. I'm I'm wondering if he did that just for this podcast because he knew he was gonna on camera. But there is an unbelievably large stack of post-it notes. You know. Jason Wimberly: Of all different colors. paul: Yes, yes, all different colors. And another I have another post-it note story for you. My own mother got fired from ATT back in the day for having a post-it note. There was right when the rules for like credit cards, you couldn't write down anybody's credit card information. you you couldn't have it or store it or anything. It was like a new law that came into place and they were yelling at everybody. And she had somebody who was buying like eleven devices, but for every device she had to re input their credit card numbers. Having to ask them what's credit card number, which credit card number, which credit card number. But she was like, I'm just writing this one down so that I can just enter this on all of these line items. And then she crumpled it up and threw it away. And somebody saw it and reported it, said, sorry, it's no tol a zero tolerance policy. Cannot write that down. And that sticky note cost my mother a job. How about that? Jason Wimberly: Wow. paul: Yeah. So the sticky n the the moral of that story is sticky notes can be both good and evil. Be careful how you wield the power of the sticky note. So appreciate Jason coming on here. And what had me I actually reached kind of sort of reached out to him, if I'm being truthful here, because I noticed a talk that you had given recently. And you know, the title of it was like super catchy. And I initially wanted to talk about one factor of it, but then you you mentioned how the talk actually d evolved into a talk about how The durability factors are being inappropriately packed into specifications. And because of that, they're actually doing the opposite of what they're intended to do. Could you unpack that for me, please? Jason Wimberly: Yeah, so you know, first of all I think it's it's most appropriate to give a shout out to Full Force, because it was Full Force by ABC Polymers who actually brought me out to Oregon to come and speak at Knife River. And they had a room I mean there was probably over eighty people in that room, a bunch of Knife River folks, but then they had invited a number of their contractors and local design community into the room and it was really talking about you know durability myth busters right and and and the real concept was we were focusing primarily on pavements and slabs interior slabs and as you mentioned these these durability requirements that somehow find their way from ACI 318 and then many cases often get misapplied to slabs and pavements. And it's a funny thing and and I like talking with engineers about this, right? Because when when you open up three eighteen And then, you know, the the specification is 301s. It's the sister document to 318. You know, 318 says, hey, engineers, design like this and tell your contractors to build it in accordance with 301 because we marry the documents together and everybody that's familiar with ACI knows how their document cycles work and the one-year delay on 301. this good stuff. Not a lot of practicing engineers quite understand that, but that's that's what happens, right? paul: Mm-hmm. Jason Wimberly: And it's funny because like 318 explicitly states this design methodology and the associated constraints do not apply unless whatever it is that you're designing is carrying building loads, right? So it doesn't apply to slabs on ground unless building loads are tran being transmitted through that slab to the ground. And it explicitly does not apply to pavements. Right? and and it's funny because we get into so many of these conversations, and and I've got one right now. We're we're jumping into we we say at AM, we're we're a regional contractor, right? And then we take a job in Wisconsin and I'm like, really? Like, really? We're gonna go take a job in Wisconsin. But I've even got the same thing up there where I have the slab, it's an ASRS slab, completely isolated from the building, right? paul: Mm-hmm. Jason Wimberly: And yet I I have a spec that says 0.45 max water dismiss ratio on the slab concrete. Yet paul: Mm-hmm. Jason Wimberly: you want me to go pound 60 pounds of fiber into this concrete and maintain a four-five slide, we do know that we are transitioning our mindset from water to cement ratio that when we talk about slabs, it's more about water quantity. Right? and and and and that's a really kind of easy conversation to transmit it it through a presentation to a designer in that it it's important that we understand that when we're doing flat work, water quantity is probably more important than water to cement ratio because I mean unless we're doing something really crazy, I've yet to see many slabs on ground that are fully supported slabs spec'd at over 5,000 psi. And and when you ask why you're at five thousand, they're really what they're trying to do is they're going back to the ACI correlation to modulus of rupture and they're wanting to get paul: Mm. Jason Wimberly: a little bit better than the seven and a half square root f prime c. They're wanting to try to push it to what really would probably be an eight and a half, eight, eight and a half, so they'll increase the compressive strength. Instead of specifying hey I only need four thousand psi compressive strength when I run those numbers, but I need seven hundred flex or something like that, right? And paul: Okay. Mm-hmm. Jason Wimberly: and so it it's kind of interesting when you start to take a look at all of these things. in in understanding that an engineer in most cases is specing a water to cement ratio because when you really boil it down and can kind of pull them away from everybody else to where they they're not feeling embarrassed or on the spot or in a position where they're gonna have to otherwise defend themselves, they're like, Really we're just trying to control the shrinkage of the mix. paul: Mm. Jason Wimberly: Hey, that my friend That's the best thing I've heard all day because I agree with you. We need to control the shrinkage in these mixes. But how about instead of you possibly not having an understanding of the materials in the market and just arbitrarily starting to bolt on all of these prescriptive limitations, thinking that we're actually going to get to what we're really trying to get to? How about we just specify what the performance criteria is in the first place? paul: So when you're having these water to cement versus total water conversations, these are with the engineer of record for these projects. That's who you're having that conversation with. Jason Wimberly: I try to get there. I try to get directly there. paul: Okay. Who hold on, hold on. Who's who's standing in your way? Jason Wimberly: Well, you have to realize my contract is not ever with an engineer, right? I I may have a contract with an owner paul: Okay, wait, wait, wait, wait. Gotta cut you off. I just dealt with this like a month ago. So we're trying to put our calcy clay that we make. It's you know, new plant, new company, new product. we're putting in some projects to reduce the GWP value of the concrete. But we've been doing this testing for like most of the year. And when I was talking to like the ready mix producer, and I was like, Okay, like when this all goes goes well, like how do I how do I get the person to say yes? And they're like, no, we don't we don't say yes. You gotta talk to the contractor. So I talked to the contractor and I was like, hey, like they said like as long as you're okay with it, like we could use it. Who how do how do we get to yes? And they're we don't say yes. Okay. There's like, no, you gotta go see the G C. Okay, so I talked to the G C. Well, how do we get to yes? no, no, no, no. We don't say yes. You gotta talk to the client. Well, a client just happened to be there that day. And I said, Hello, client, how do we get to yes? They're like, no, no, no. We don't say yes. Jesus Christ. What do you mean you don't say somebody's gotta say yes? Like somebody has to say yes. We're all in this together. We all have the same goal. How do we say yes? And they all like sort of like together, sort of pointed at an invisible figure that wasn't in the room. He said, The engineer Jason Wimberly: Yeah. paul: of record. They whispered his name like it was Voldemort or something. So now I'm like super concerned that I've got to go find whoever the EOR is and get them. to to bless this mix design. And you're saying that that's easier or I was I'm not I'm not picking up what you're putting down. Is that is that difficult? Is it fun? Is it hard? What's it like trying to convince the ER to this new mix design? It's okay that it's got a point five eight water smell ratio. It was seven thousand PSI on a forty five hundred mix. Who cares? Let's go. Jason Wimberly: So Funny enough, I may or may not know a little bit about the story you're talking about, but I shall not speak of that. paul: Ha ha. Jason Wimberly: but I I will say this, it's it's always an interesting pathway. what what I have found in and I and I'm probably gonna get my hands slapped for saying this, is oftentimes GCs are the gatekeeper it's hard to get by because they don't really understand what it is that we're trying to do from from a concrete perspective. And and and and and the reasons as to why they won't push it further up the ladder can be one of many. But in most cases that's really the hardest obstacle to overcome. And so, you know, it's interesting, you know, here being at AM Concrete, we we do very thankfully have very close relationships with Overwhelming majority of the GCs that we work for, and they really trust that when we bring something to their attention, it's going to be for their benefit too. We're not paul: Mm-hmm. Jason Wimberly: just trying to herky-jerky them around somewhere, you know. but we also have really close relationships with the designers, the the structural engineers of record. I would say so far in my four months of being here, and and looking at who the EORs are, at the overwhelming majority of work, there's probably four firms that account for around 70 to 80 percent of the projects that we're on. And paul: Mm. Jason Wimberly: so we we developed really tight relationships with those engineers and ironically I've known people at two of those four firms for years. and so for us to get to the EOR is is a little easier because sometimes quite honestly I'm just backdooring it. I'm just picking up the phone and saying hey word What the world were you thinking, man? And we all have a good laugh and you know we all, you know, just just have a great conversation and everything's fine and twenty-four hours later we get a revised document coming out, right? sometimes it may not be quite that simple. You know, I go back to this project in Wisconsin that we for some crazy reason decided to take. again, just so happens to know that we know the slab EOR in this case. that's the only thing we took out of this whole package was the slab. paul: Mm. Jason Wimberly: and I knew the Slavio R and I got some details that I'm are really kind of squirrely and quite honestly I don't like. and so matter of fact just this morning I called him, I said, Hey, I know we talked about this last week. but I got a few other things I need to ask you about. Like this is a constructibility issue. What w w what do you think we can do? And you know, and we start working through some things and and we start revising details. And then he's like, but listen, I need you to get this actually up the the structural engineer of record through a formal RFI so that I can really answer it for you. And hey, no problem, right? At the end of the day, the owner is getting what they need from from a performance standpoint. The GC is not being negatively impacted. If anything, they're being positively impacted because it's gonna help us on time, which is one of the biggest things that they can't control is time, right? And and and and we're benefiting because it's something that well we can actually build now instead of something paul: Yeah, right. Jason Wimberly: that came out of the mind of somebody. But we have the same conversations with with concrete. And even on this project, there was a specified shrinkage in and I the project is so fast, it's moving so fast. Like from the time that they said go, they're wanting foundations in in a week. slab starting out in two possibly three weeks, and that's good except for paul: You don't have time to do the shrinkage test. Jason Wimberly: Amen, brother. So what do I do? Well, thankfully I've got a couple really good producers in the market. and I will say, and I will make a plug again, the same type of strong relationships that that we within AM have with Full Force, who brought us all the way out to Oregon to have the conversation that drove this podcast. thankfully, when I worked for Grace, I was able to develop a lot of those same type of relationships with ReadyMix producers all across the US. And because of that, we know a couple producers in the market. And I was able to have some really quick conversations with them that may possibly have taken a lot longer to get to and say, this is really what we need. What what do you got? What do you got you can feed me right now that I can get across the bowel? Because we don't have enough time to run the tests. And so, you know, in this case we had everything else that we needed, but we're at 380 microstrain instead of three hundred and fifty microstrain and I was able to get that passed across the bow of the slab engineer. So A lot of a lot of what we drive and talk to in so many cases though is this conflict and water to cement ratio and water demand. And especially if you're using performance-based concrete, and what I mean by that is not just your cheapest 4,000 mix that you can buy from a ready mix producer. paul: Mm-hmm. Jason Wimberly: that's a really key concept because you're trying to meet other performance requirements than just Compressive restraint, if that makes sense. paul: Yeah, it does. Let's let's jump into that. Let's talk about the relationship between durability testing and water smit ratio. And look, I I've I've been taught the twenty years that I've been putting concrete into cylinders that there is a direct correlation between a lower water smint ratio and a more durable concrete. And it hasn't been until the last twelve months where I've been almost second guessing what I've been taught. I've been playing with mixed designs that do not hold true to that maxim. And I don't know if it's because we're entering a world of new materials and new mix designs, things have gotten better, or if we all just sort of pigeonholed ourselves into trying to come up with the most simple way forward that everyone could understand. Low water cement ratio, more durable concrete. That looks really good on a bumper sticker. I'm gonna tell you, bumper stickers start movements. So it's really possible that there was a lot of truth to that, but it wasn't the whole story. So what is it that when you want to talk about the relationship between durability and water cement ratio, is that kind of what you've seen as well or or is there something different? Jason Wimberly: Yeah, so and I'm gonna I'm gonna run some numbers, you know. years ago they taught us in engineering school never never to do numbers in your head. So I I try I try really hard not to. But let's just let's just take this example. So this is two hundred and ninety one paul: He's got his calculator. For the audio only folks, he's got his calculator out. So you're you're hearing him rattle off these numbers, it's 'cause he's punching them in one Jason Wimberly: Yeah. paul: set at a time here. Jason Wimberly: So thirty-five gallons of water is two hundred and ninety-two pounds, right? Thirty-five gallons paul: He shot it. Jason Wimberly: of water is two hundred and ninety two pounds of water, right? So paul: Yeah. Jason Wimberly: let's just say that my aggregate water demand is is like thirty-eight or so, thirty-seven gallons, and and pull it back with a type A, I can get down to thirty four, thirty-five gallons, right? So we'll use we'll use thirty five gallons 'cause I don't know, sounds like a decent number. It's probably a paul: Sounds like a nice round number to me, Jason. Jason Wimberly: nice round number. It's 292 pounds. So 35 gallons is what that combined aggregate gradation is going to require to produce about a one to two inch slump with just water. Okay. And you know, generally speaking, a a a well-proportioned slab mix. is gonna have a water to cement ratio around 5052 with with most aggregates and materials and yada yada yada across the US that's gonna still outperform a four thousand psi mix right it's gonna get us into the verge of a forty five hundred and in some markets maybe even a five thousand mix but paul: In Georgia right now, that's gonna get you five thousand all day long for sure. Jason Wimberly: exactly so we already know that we're kind of Suppressing the water to cement ratio beyond what we need for a 4,000. But the other side of that picture for a for a slab mix or even a paving mix is the fact that we need to get a certain amount of heat generation started early enough. We need to hold back enough of the water so it's not going to bleed too much. And what we have just learned over the years is that number for a water to cement ratio seems to work pretty well, right? so we already know that we're artificially suppressing our water to cement ratio for a slab or a pavement mix, right? We're already improving if water to cement ratio is is your driving factor for improving durability. We're already doing that over what we need in most cases just for a 4,000 mix. And proper proportioning of concrete mixtures really Goes back to that kind of key concept of what we call aggregate water demand, right? And so if we're already determining what volume of water we need to get a one to two inch slump, and then you know, an engineer wants to arbitrarily put in a 0.45 water to cement ratio. Well, there's only two things that can happen. either either your water goes down, which means now we're starting in a negative water situation, negative slump situation, which means you're gonna have to push everything with high range. Everything is going to become horribly temperamental. This is when you know finishers talk about mixes getting sticky and things like that, tearing underneath your trial blades, or You're going to arbitrarily increase your powder. neither of which really provide a more durable solution to what you're trying to get to, right? Because you know, the argument I like to have a lot of times is if your goal is a.45, if I could do it with 35 gallons and how many ever pounds of powder we had just talked about, 584. So 292 pounds of water and 584 pounds of cement. If if if we going back to your conversation, if durability is simply a function of water to cement ratio, why don't I put 45 gallons of water in there in the associated powder and just have a whole ton of paste in this concrete? But by golly gosh, I still got a 4 or 5 water to cement ratio, so I still got a durable mix. I'm gonna argue you're gonna have a substantially less durable. Durability, durability, the tables within 318 for structural concrete, concrete bearing the load of the building to need resistance to either freeze thaw or sulfates or chlorides based upon a water to cement ratio. The water to cement ratio is kind of the easy way to get there. There are always ways to specify performance criteria that are an alternative. It's just it's easier and and it meets the standard of care for a licensed design professional to rely back upon the durability tables. But I I love too having the conversations, how many times do we see tilt panels being specified with air and 0.45 max water to cement ratio? I mean that's another paul: Yeah, for Jason Wimberly: conversation we have with engineers all the time. paul: It's it's cra well, I mean I've seen interior slabs that have air specs. I mean it's basically this you're the same route you're about to go down with that conversation. you know, when I talked to engineers in the past, I wasn't talking about to the EORs of these massive projects. I was talking to like, you know, guys that were on my level at the time, you know, lower level guys. What I noticed about a lot of these engineers, whether they were civil guys or structural guys, concrete was not. a part of their education. It was like one chapter inside of one course during their engineering degree. And I wonder sometimes when you're having these conversations with the EORs, how much of it is education? How much how many to the time are you educating folks not on here's why we should buck the trend, but even even just the basics? Jason Wimberly: Yeah, and you bring up another good point because you know, I I am a licensed engineer, right? And and I remember what my undergraduate education was like. I'm a graduate of the University of Tennessee, Go Falls, and paul: this podcast is over. Ladies and gentlemen, thank you for Jason. I didn't realize he graduated from Knoxville. We can't have that on the show. Just kidding. Just kidding. It's a big it's a big role, Todd. Jason Wimberly: That's okay. You can roll tide all you want. I mean everybody paul: It's Jason Wimberly: needs to wipe their hineys and then clean their uniforms after they do it, so that's okay. paul: this podcast will turn into a college football podcast here shortly. We got like thirty days till kickoff. Jason Wimberly: j yeah, yeah, that's exactly right. paul: So the the beginning of this show always has before the interview, you know, always has like its first portion. cause we're doing weekly shows. So once a month. It'll be a conspiracy corner. We go over a non political conspiracy theory. the last one was how JP Morgan sank the Titanic, because he made sure that the rich people that went down were the people who opposed the creation of the Federal Reserve. And then one year later he created the the Fed. And then the one before that was about Nikola Tesla and the strange ongoings right after He passed away. So that was super interesting. The next one coming up is gonna be I don't know if I should give it away. You know what? I'm not gonna give it away. It's really great reading a book about it now. It's gonna be phenomenal. So that's one, that's one segment. Then other segments are white paper of the month. I was inspired. I thought someone said something really clever, said, wish more people in this business were reading white papers. now we're all so busy, like who has time to read that? But as someone like myself who I thought was always like up to date on things, I was like, yeah, I do that. And I kind of like informally tracked myself over a year and I was like, I am not reading one a month. So as a way to sort of force myself to live by an ethos that I thought was pretty, pretty neat. Like we should all be doing this. I'm gonna just make it part of the show. So the last one we went over is like Meta published a paper on AI, machine learning algorithm that was helping them develop. low carbon concrete. It was pretty neat, has its flaws. And but I thought it was great that they open sourced it. So we went through that one in detail. The one that is released, and you don't know this, Jason, because you're in the interview of the show, so you didn't hear the part that went right before this. But we're actually digging into white paper of the month today. And it is looking back at arguably the most influential white paper of all time. The design of concrete mixtures by Duff Abrams. So a lot of us know of the Abrams Cone, he named after him, but why was he so significant? Why was that bulletin so significant? And it was the change, like just like we're talking today about changing people's mindsets on water smith ratio or water contents or performance versus prescription specifications. Well, back then, just designing a concrete mix was as simple as four buckets of sand. two buckets of cement, one bucket of water. And that four two one or three two one, depending on if you needed it stronger or weaker, that was how you make concrete. And he came along and said, you know what? There's probably a better way to do this. Took him four years to develop their first like concrete mixed design, was great that he did that. You wanna know what fascinated me the most about that story, Jason? He was 34 Jason Wimberly: What's that? paul: years old. Thirty-four years old changed the world. How about that? Jason Wimberly: That is wild. That's that's crazy to think about somebody that young and the impact that they're having a hundred plus years later. paul: That's right. Look at us. We're just farting around on a podcast. Jesus. Changing the Yeah, I totally Jason Wimberly: That's exactly right. Talking about football on the concrete podcast. paul: I actually don't even remember what you were talking about. You you sent me into like a a bit of a rage for like a second when you mentioned the vols. Jason Wimberly: Well, that's okay. I'll give you your next conspiracy theorist is is is the conspiracy theory on on why Saban quit when he did. paul: What what do you mean? How's that a conspiracy theory? It was NIL and he could no longer pay the players under the table and keep his advantage. What do you what's the conspiracy? Jason Wimberly: Okay, well as a Bama fan, you admitting it, that's great. We can move on to the more technical part of this podcast now. paul: I should have just bleeped out the Go Valls. We didn't have to have this 10 minute tangent. Jason Wimberly: Ha! That's okay. And y you paul: Mm. Jason Wimberly: know, you can choose whether or not you want to put parts of it back in there. So but no, where were paul: No. Jason Wimberly: we? yes. So yes, I was an engineering student at one time. And I remember the number of courses that we took on construction materials. It's one. Like when you're a civil engineering student, they are teaching you structures, transportation. construction, materials, hydraulics, hydrology, water treatment, wastewater treatment, and then good civil engineering curriculum, at least back then from ABED accreditation, you also had to have understanding of basic fundamentals of electricity and electrical design. You had to understand thermodynamics and all of these things, right? So you you were taking all classes even within civil engineering you had one class on materials one and in that materials class you had concrete and aggregates and steel and I mean all kinds of other I mean soil and dirt paul: Mm. Jason Wimberly: yeah don't forget the geotechnical and soil mechanics and all that stuff classes right but then all of this kind of stuff that you were learning in a in a materials class so I remember and then even in graduate school You know, I went to NC State for grad school, so that one'll be okay, right? you know, I remember teaching, you know, undergraduate courses as a graduate student in materials. And and I'd always ask our professors, I'm like, Can I spend more time on concrete? Like, can I really? Like we're gonna use con like they have soils lab for the soils side of it. And that you know, it's paul: Mm-hmm. Jason Wimberly: like, can I focus you know, by the way, we had wood, timber, asphalt, and all that stuff. And I was like, you know, these guys going into asphalt, what are they gonna do? Build roads with it. Concrete goes to everything. Concrete builds roads and buildings and walls and all kinds of stuff. We need spend more time on concrete. It was not seen that way. So you know, I think about this. You did not take a concrete specific class at most any engineering university unless you were taking a Graduate level materials course. And that whole course would get into concrete and really delve into what I'll call the material science side of concrete per se. But think about the number of students that go on to graduate school. So most of our students are coming out of an undergraduate. They're going in, they're going into the work segment. Who are they really learning from? The people before them who learned from The people before them who learned from Duff Abrams. and right, paul: Yeah. Jason Wimberly: probably didn't even learn from Duff Abrams back then, but you know, probably back in that day, engineers were not as and this is the other part too, that that I try to remain a focus as I interact with these engineers, is so many times their services have been commoditized. paul: Mm. Jason Wimberly: And it's so sad. That's why the cut and paste is so prevalent. That's why paul: Mm-hmm. Jason Wimberly: the standardized details are so prevalent. They're not digging in. I mean, they're kind of leaving it to the contractor to help show them really what's what they need to some clarification on on how we actually build this thing. And then they'll just issue revisions. and so I I really do try to be aware of that because, you know, most of the time it's structural engineers that we're w that I'm working with, right? and I couldn't do their job. You know, I've I've 25 plus years of experience, but not as a structural engineer, and I respect that. and so I think that when we start having conversations with each other, there's a mutual level of respect from one engineer to the other that I respect what they're trying to achieve. And want to make sure that we are not putting that at all in jeopardy because it's not beneficial to our joint client. I'm I'm hoping though that they will acknowledge and respect the knowledge and the experience that I'm bringing to the table and help us help them through a challenge, right? paul: Yeah, that's interesting. So when when I'm involved in these projects, it's because the client's trying to achieve a certain goal. And in order to achieve that goal, they sometimes need new materials and that's where I come in. And if a mixed design strays from the typical, then, you know, how is that ER going to respond? Understanding that the clients made a request. And then do we have enough data to support that request? And then we see where the decision lands. you know, it's an it's a new world, man. I just I can't even like I c it's hard, it's hard to admit to myself some of these mixes that I've seen recently. The water contents are through the roof, but set times aren't delayed, finishing looks great, strengths are really good. In fact, there's I've I've actually Been on more mixes where I was like, man, thing's water starved. I need more water in this thing. And then we have a less than perfect result. Things are sticky, thing, you know, things aren't going as well for the finisher. Last thing I ever want is a finisher complaining about anything. That's the fastest way to get a mix turned out, is for that finisher to say, I'm having a tough time. So when AM concrete is is helping provide, you know, these technical services are Where do you f where does AM Concrete typically fit in in the in these projects? And who all are you communicating with to make sure that they're okay with whatever changes are being made? Jason Wimberly: Yeah, so you know, if if a what we'll call a novel material is being specified by the engineer of record, and we are simply responding to the specification, our hope is that the EOR has also done their due diligence and their homework in speaking with the manufacturer of this novel material to understand what the impacts are. are going to be and not start putting in a bunch of these bolt-on prescriptive requirements that really inhibit the use of the material that they've otherwise specified. With with exception to that, I would say, you know, where do we fit in? I would say that we probably fit in from the standpoint that, you know, our contract is held with typically through the GC. And that they then have a contract with the owner in most cases. The owner are then also contracts with their designers. Oftentimes it's with an architect who then chooses the structural engineer. and so we have this really kind of unique relationship in place where Where we really don't have that direct line of communication back to the EOR. And so using novel materials is always interesting because a lot of our work in that arena has to paul: Mm-hmm. Jason Wimberly: do with educating ourselves. and then once we get a good enough hand because we're purchasing the concrete, we're ultimately responsible for its performance, right? Well, I mean, I guess you could argue the ready mix producer and their material vendors are responsible, but you know, GCs don't point the finger at a Ready Mix guy, they come back to who they have a contract with, who is as us, right? And we're always kinda paul: Mm. Jason Wimberly: you can call it in the middle, which is why we're so keen on making sure that everybody is following the appropriate rules, because we want to help everybody out. So we're really taking a consultative approach, like you're saying, and which is why I think your choice of a of a concrete contractor is so key. you know, if if especially if you're looking to use a novel material or a novel construction process, why your choice of concrete contractor is so important. there's a lot of really large concrete contractors out there that have a lot of internal expertise that they have developed over decades, right? and and and very good contractors. There's a lot of smaller contractors, though, that just because of their size, it doesn't mean that they don't have the technical capacity to do what you need to do. And in a lot of cases, sometimes their capacities may be not as large, but their competencies maybe being more acute are can yield a benefit to a general contractor and an owner that they may not otherwise. be able to find in another contractor. And really in the process of determining who that concrete contractor is going to be, it's it's it just as important as the numbers, because we all know numbers are important. Let's just not bury our heads in the sand and say they aren't. but should be the interview process of understanding who the people are that that contractor is bringing to the table, what competencies do they have. because that's one of the unique things about you know, AM concrete in particular is, you know, we're developing our own slab system or already have developed our own slab system. And now we're actually going through further processes of refining that. We are actually evaluating and picking materials that we use in our own slab system to compete in an ever increasingly complex construction environment where owners are demanding more And they're wanting it to be done at the same price or at least within some realm of of you know competitive value. And that's why, you know, one of the things that we're doing right now in particular, you know, we've been able to secure a project that, you know, some people may argue and we kind of looked at each other internally, said, Man, we we should not have been awarded this project. Like, you know. A small regional concrete contractor should not have been awarded this expansive of a project where it's like, don't really know what we're gonna do with the slab, we're just gonna leave it out there for the contractor to design. but we were, you know, and it's a 1.2 million square foot project. and we're just now, you know, probably about two to three months in on the slab design process. We're using our own internal proprietary design for the slab. We've we've picked an EOR, we have our design methodologies that we use. we have our materials. We were we were very, very, very intentional during our concrete buyout. We went down and and spent two days interviewing five ReadyMix producers, giving them this whole kind of barrage of information that we needed them to bring to the table that we were wanted to discuss. And understanding what their capacities were, what their competencies were, what they thought they could do with their materials, and awarded the project not off a price, which is where most concrete contractors would award off of, but award off of what we knew was going to be some like core performance requirements for our mixtures that we employ, but then ultimately knowing what the owner specifically was wanting on this project. paul: Mm-hmm. Jason Wimberly: Who we thought brought the best possibility to the table of helping us meet or exceed that. this owner wanted the reduction of GWP as as far as they could get it. And this owner in particular has kind of set these multi-level goals, the highest goal of which they have never been able to achieve in the United States, at least not to date, which is a 40% reduction in GWP in their concrete mixture alone. Regardless of thickness, you know, when we talk about volume and reducing paul: Mm-hmm. Jason Wimberly: net GWP on the basis of volume, we're talking just on the mixture alone. and we're expecting our last little bit of data to come in later this week. But if everything tracks as as we're looking to track right now, we're gonna be looking at an excess of 40% reduction in GWP on this concrete just by how we approached and thinking about We're not just offering this system that only approaches design this way, or this system that only approaches design this way. We have taken the intellectual capacity within ourselves and our Amcret system to say we look at all potential available materials, all potential available design methodologies. We use some very high level FEM modeling in our slabs, in in in partnership with our EOR that we choose to be our slab EOR and we really get down into understanding like all the details of how we're going to construct the slabs and everything to where we can drive as much performance out of the concrete as we can. And that's a really important picture. and and it's and it goes back to understanding that you know so so what do we do as AM concrete? We sell the ability to bridge the gap between the engineer's lack of knowledge of local concrete materials, which is not a bad thing. That's not a negative statement. Again, they're really good at engineering and structural engineering and all of that. But again, the same conversation we had about materials, go back and ask paul: Mm-hmm. Jason Wimberly: that same engineer how much education they had on slab design. That same engineer is probably going to tell you that they may have had one lecture on non-structural slab design. paul: Mm. Jason Wimberly: So we then go back to that is again a graduate level class that will focus in on so many different types of non-structural slab designs and this, that, and the other. What percentage of our students are going to grad school? And then what percentage of those are really actually being able to take what they may have learned and put it into practice because the Firm already has another way to approach this. Or we don't have paul: Yeah. Jason Wimberly: the time to do this because there's only X amount of fee associated with the project, right? So we like to really look at ourselves as being the company that can bridge constructability to design by understanding how it needs to get built, the materials it's getting built with, the entire intrinsic requirements for durability, both structural durability that's defined by 318 and and getting beyond the myth busters reality, as well as other forms of durability that I would argue are just as if not more important to slabs and pavements, which has to do with abrasion resistance and you know crack control and understanding how we begin to really understand how we can delay the initiation of cracks or the propagation of cracks within the concrete itself, right? And so that's kind of the knowledge that we bring. That's that's the role that we like to live in. And the beautiful thing is is we're not really making any more fee, right? Like I it's not like we're we're being allowed to charge all this much extra for what we're doing. It's just that It's how we're winning work. It's how we're choosing to position our business in today's competitive marketplace against our competition. Because it's something that we can bring to the table, that we may not have something else. paul: When I hear you talk about that process and then having to convey all that to the engineer, like the level of trust that engineer must have with you has got to be insanely high to be able to present these new topics. know, like one example of what we kind of got into on an email conversation you and I had was engineers are using durability excuses. And it's not to be negative to them. It's they have a lot of other things they're having to consider on these projects. Concrete and material science may have only been a small portion of not just their formal education, but maybe even a small portion of what they've been trained on in the real world. And it's much easier. And I try to put myself in their shoes and I say, well, if there's a spec and the spec has existed and the spec has worked, I'm just going to copy and paste that spec and you should just go meet that. And we can all just live a happy life. But sometimes that's really just causes more problems than solutions, even though their heart was in the right place, their mind was in the right place. Like one is like concrete cover over rebar. It's like, you have to have a minimal thickness. It's like, well, why? Why? well, we just don't want to ruin the, we don't want to rust that rebar. It's like, okay, well. Have we considered the porosity of the concrete at all? we considered, what if you had concrete that had no joints? If we had joints, spacing, what if they had no joints? There's other ways to skin these cats. And not that that's anything I'm advocating for, because that's not my business. But it's just a way of discussing that what you might call a durability excuse is not the engineer being lazy. It's not the engineer even being incompetent. It's, hey, this is how it's always been done and it's worked and we're going to keep going. But we're in a different age. It's 2026. It's August 2026 right now. And there are just different materials and different designs and different ways to do anything, to do things. And the fact that you're even trying, Jason, is incredible. Hats off to you, Jason Wimberly: I appreciate it. It's it's a lot of fun. it's I think that there is a massive amount of trust that has to take place and has to be present between all of the parties. At the end of the day, the general contractor also is the one who has the contract with the owner and is ultimately responsible for the totality of the building being turned. So there even has to be a level of trust there. And I think that you'll find it, especially with the contractors that we work for, a lot of our mutual success has been based on and built on that trust. and and it's a trust that you know our founder and CEO, Alfonso Garcia, President and COO Kevin Cox have spent decades building through their relationships, that when the two of them ended up deciding to come together five years ago and really build AM into you know one of the Southeast's leading concrete contractors, turnkey contractors, it's evident. in in the growth in the growth pattern that has taken place over the last five years to allow somebody like myself to even be employed by the company. And you know it it's something that you know every day I seem to be further amazed at at this level of trust that that all of these parties have with each other. And I think it speaks to a lot to a lot of the organizations that are So I'm I'm I'm truly blessed to be here. Happy that I'm here. We're having fun. like I told you earlier, you know, it was kind of funny that Justin, who I think was your episode one interviewee, had reached out to us and said, Hey, I wanna I wanna try this new material with you guys and you know, it's yours. You know Yeah, yeah. paul: Turns out, yeah, turns out it's higher material. I mean, it's full circle, full circle, man. Hey, it's been a great having you on here. Really enjoyed this conversation minus, you you say Go Vols on my podcast, but you know, I, you know, forgiven, forgiven. Water under the bridge. I, you know, it's funny. Jason Wimberly: Is is go big orange better? paul: No, no, GBO is not any better. Jason Wimberly: Sorry. paul: But we can just throw acronyms at each other all day. RTR. But I wanted to say is We got we only got about half of what I wanted to talk to today, which is that that's the best conversations when we only get through half of it, which means you get to come back another time. I hope you'll join us again in the future. Maybe maybe at the end of the year or the start of 27 when the Vols are unranked, the Tide are going to the college ball playoff. We can have another discussion. How about it? Jason Wimberly: Okay, I I think that I think that's great. somebody asked me the other day, they said what what what's your prediction for the season? And I'm sitting there looking, I was like, Hmm Alabama, LSU, Texas, Georgia. I was like, Hm man, things ain't looking too good, dog, but I mean I'm I'm a faithful over here. I I th I think I think we're gonna go eight and four. I'd like I'd like to be ten and two, but I don't think it's gonna happen, so paul: Man, 10 and 2 would be, I think 10 and 2 for almost anybody in the SEC right now is going to be a great season. There's some tough schedules out there this year. Jason Wimberly: Well, thank you for having me. I really appreciate it, Paul. look forward to seeing you again. paul: absolutely man. Thank you again. It's another episode of the slump monkeys concrete podcast. We'd like to thank our new title sponsor of the month XB. Thank you so much for joining us this month. If you would like to be a sponsor on the show, please email me directly at admin at slump monkeys.com that's O N K E Y S slump monkeys.com come join the community. on LinkedIn and download the episode rate and review wherever you listen to your podcast. Again, it's Jason Wimberley of AM Concrete. Thank you so much for coming. We're going to see him again in a future episode, I bet, and hopefully out in the wild. Thank you, brother.