EP #091: Rethinking Time Limits on Concrete

Seth (00:01.33)
Welcome to another episode of the concrete logic podcast. And today I have rich say Z say Chi. I missed it. Did I get it that time? Nice. He's a executive in the concrete supply, arena. he's been on the podcast, twice before episode way back episode 20, where we talked about there was, there's nothing more sustainable than concrete. That was the first one.

Rich (00:08.84)
There you go. You got it.

Seth (00:31.186)
And then the second one, we talked about concrete and type one L cement, no turning back. That's when we were making the transition. So, I'm sorry. The first episode was episode 20. that was back in 2020, 2022, and then, episode 44, that was, early. What was that? So 44 seems sounds like a long time ago. last April, April 23.

So Rich, thank you for coming back on the show.

Rich (01:02.632)
Well, good, I'm pacing about every once a year now, so.

Seth (01:05.874)
Yeah, there you go. But we'll, we'll have to get you on more, more frequently. You're, you're, you're a popular guy, as far as getting, people always looking out to you for your, for your opinions on things. So I appreciate you coming here, before we get started with Rich today, just remind folks how you can support the podcast. there's three things you can do. if you enjoy the, the episode today with Rich, please share it with a colleague or a coworker and then in the industry.

Rich (01:09.192)
Yeah.

Seth (01:34.674)
the second thing you can do is if you go to the website, concrete logic podcast .com, there's two ways you can get ahold of me. one is you click on the, there's a contact link on there. If you click on that contact link, it'll shoot me a email message or you at the bottom right -hand corner of the website. there's a little microphone. If you click on that, you can actually leave me a voicemail and I'm looking for a couple of things from you all.

One is a topic suggestions, things you want to hear on the podcast. And, another is a guest suggestion. So, rich, was a, he was a suggestion from someone, originally, way back when, I think actually rich's story is unique because someone heard him speak at the world of concrete and told me, Hey, you need to get this guy on your podcast. He's a great speaker.

and then the last thing is, on the same, homepage is, on the upper hand, right hand corner. there's a donate button. You click on donate button and you can give any, amount and any amount is truly appreciated. And then you, if you donate, you will be listed on the next episode, that's released. You'll be listed as a producer of the show. So you're.

Showing that you're contributing to the show. You enjoy the show all that good stuff. So That is it. That's my that's my little spiel If I said that right dr. Belkowitz will correct me on that Anyhow rich thank you for coming back on rich is for folks That

maybe haven't heard you speak before, World of Concrete or ACI conventions or anything. Can you just give a background? You were talking about you're on some committees with ASTM. Just real quick.

Rich (03:37.128)
Sure. Yeah. You bet, Seth. And again, thank you so much. It's always an honor to come speak to you on this podcast with the amount of people that you reach with this podcast. Truly a privilege to be able to ask for my opinion, be able to speak. So again, thank you very much, Seth, to you and the podcast for having me on. In terms of just quick backgrounds and kind of things we might be talking about today, we were talking about ASTM. So I'm currently the C09 chair.

09 is the standard subcommittee that controls concrete and aggregate specifications, testing methods, those kind of things. And just a little tidbit that'll win you a bar bet, the number one most used ASTM document in the world is ASTM C94, which is the standard specification for ready -mix concrete. Again, should come as no shock to anybody, concrete being the second most consumed product in the world.

the standard that governs it probably should be the most popular and it truly is. And then the other thing I was just sharing with you was I got a very humbling and great news from ASTM is that they'd like me to consider being put on their international board of directors starting in January.

which truly is another honor and privilege to serve in that capacity. So the other members there probably like it, but probably won't like it, but it's a collection of the nerd Illuminati when it comes to concrete and aggregates. And it's an honor and privilege to be part of it. So.

Seth (05:05.49)
Yeah. Congratulations. so Rich, wanted to bring you on the show. Cause again, someone that listens to the shows, wanted to hear your opinion on, the change for the batch time, from 90 minutes to 120 minutes. So if we could talk a little bit about that, and if we have time to, I like to, we were talking before we hit record.

Rich (05:07.592)
Thanks.

Rich (05:24.296)
yeah.

Seth (05:34.482)
a little bit about the temperature specs as well if we have time. We'll see how much time we spend on this monumental change in how we view the time on concrete. So.

Rich (05:38.408)
Sure.

Rich (05:43.72)
So...

Rich (05:50.312)
Sure, so a great segue because I was just talking about ASTMC 94 as the governing specification for ready -mix concrete. And in that, going back to the 1930s, there was a phrase in there that talked about concrete and a rejection point at 90 minutes after batching. Once batch time started, you had 90 minutes to discharge the concrete.

There was a second part of that sentence that also talked about 300 drum revolutions as well, but we're going to talk about the time right now. So that had existed in that document since the 1930s. And the analogy I always give people about making changes like this, fundamental changes, is if you are a person of faith, and let's say that that faith happens to be a Christian faith,

I want you to, in the next time you attend service, stand up in the middle of it. Just pick a time right in the middle. Stand up, raise your hand, and say, I don't like the way the book of John is written in the Bible, and I'd like to suggest a change, and see how that goes. I said, that was kind of the equivalent of trying to change 90 minutes in ASTM. Now, the interesting thing about that is people ask, where did that come from?

Why is it 90? Why is it not 91? Why is it not 89? Where is 90 minutes from? And so you had to do a little bit of history. And I enjoy that when it comes to technical things, because what we find out is we're kind of shocked and amazed how the technology at one point in time dictates what we do today.

70, 80, 90 years later. And what happened was the number one market in the United States in the 1930s for ready -mixed concrete was New York City. It was the biggest place where they produced it. And

Rich (07:34.184)
They had the trucks there, they were smaller than they are today, but they didn't have a variable speed drum. They had a one speed drum. And the speed of the drum was six RPMs, period. Didn't go to seven, didn't go to five, four. When you turned it on, it went right to six RPMs. No, no, no, it was just a one speed motor. Now.

Seth (07:51.89)
Was that a hand crank?

Seth (07:56.562)
Yeah.

Rich (07:57.544)
So then what they did is they said, what's the average delivery time from New York where it was, where we'd make it to where we deliver it. And the city wasn't that big. The average delivery time was 50 minutes. You want to know where the, that's it. So that's how we got the drum revolutions was six times 50 was 300. So that was it. And then the other one was why 90 minutes, what it was magical about 90 minutes. So then somebody used an aggregate at the time that was developed.

Seth (08:14.674)
50. Yeah.

Rich (08:26.632)
And they said, how long does it take for the aggregates, not with concrete, just the aggregates? They put them in a drum and they kept turning the drum and then they would discharge it. And then they looked at it and they said, these aggregates have pulverized themselves in 90 minutes. Therefore, the concrete must be no good. That's it.

Seth (08:44.178)
What?

Rich (08:45.448)
That was the entire sum of how that technology was used to then become part of the standards in the 1930s and progressed all the way to today. And we used that as a point of rejection on job sites. People would look at their watch and go, it's 91 minutes. The concrete is supposed to be bad. Get rid of it.

It didn't matter what the temperature outside was. It didn't matter what the mix design was. It didn't matter what its purpose or use was. We just had people who go, it's 91 minutes. Now, I'm not a smart guy, but I think the concrete is a little bit less smart than me. And I'm telling you, concrete is not smart enough to know that it has gone bad at 91 minutes. And here's the other thing that just practical capper I'll give you that started this was.

I asked, has anyone ever experienced, and we did a survey, we did a poll, we were checking on this at societies and other meetings, has anybody aware of an engineer or an owner that has taken something out of service that made its strength and was performing, but was placed past the time limit specified?

Did anybody rip something out like, hey, concrete's supposed to be, it's a deck. It's supposed to be 3000 PSI, let's say. And let's say the cylinders broke at 4 ,200. Yay. Meets its strength. And about seven months later, somebody finds out, hey, I'm looking through the tickets and this was delivered at 105 minutes, but was as a 90 minute spec. Should we tear that deck out? Are we concerned about the safety of people using that in service? And the answer is no.

Seth (10:24.69)
No, I don't think, I don't think anyone would, I don't think anyone would do that, but I, I guarantee an owner or general contractor would threaten your payment. You put old, you put, you put old concrete in there. I don't care how well it's performing. That's out of spec. I'm going to hold money on you.

Rich (10:27.176)
No!

Rich (10:35.752)
Yeah, yes, retainage. Yeah. So.

So interestingly, what we had to do was we had to bifurcate those two issues, even though they were in the same sentence. Then there was 300 drum revolutions, and so that got fixed. And then we got to the 90 minutes. Now the interesting part about it is, then we had to go to the science of it. They're like, okay, let's understand what's actually happening.

And somebody brings up things like, well, they didn't have retarders then. You know the retarders and admixtures in the 30s were actual fluids from a livestock? Were commonly used. Now we have tremendous chemistry. We have polymers. We have polycarboxylates. We have all of these things that can change the properties of concrete. But the 90 minute limitation didn't recognize any of that.

Seth (11:16.306)
Yeah.

Rich (11:33.896)
And then the other thing too was we asked scientific community, the nerd elite, we said, can you actually develop a data set big enough to justify 90 minutes should exist? How many tests would you have to run under how many different conditions would you have to go to go, yes, it should be 90 minutes? Well, why not 88? Why not 95?

So this is almost unexplainable from a data standpoint. Now you can give me an anecdotal example you have. For every anecdotal example you're like, that concrete was no good at 100 minutes. Okay, I'll accept your anecdotal example. If you'll accept mine that, hey, I had concrete that I placed at 200 minutes and it was just fine. And so we actually did some tests about...

You know, we did these tests and my guys hated me. God, Seth, they hated me. We took a ready mix truck and we batched 10 yards.

And then we discharged it at 45 minutes, at 50, at 60, at 70, 80, 90, 100, 110, 120. And we kept going. And we measured slump, and we measured all of the properties. And then we took cylinders. The problem was these guys that were making cylinders so fast, because every 10 minutes, we're making another cylinder set, another cylinder set. And when I say cylinder set, I wasn't talking three. We made 20.

Because somebody would go well three is not enough. Well, we had enough debt So we produced this data set and then it was like somebody tell me why this data set is wrong produce the contrary And so that's one of the things that kind of started this So now so i'll come back and fill in a little bit Fast forward to well, what does the document say today? What does it truly say? And seth when you introduce the concept the the topic originally you're like 90 minutes

Rich (13:28.296)
There is still a time limit in ASTM C90 Thor. And let's just take, for example, you and I here. You're a contractor, I'm a producer. And what happens in the spec is it says you, Seth, get to specify what the time limit is. And you can pick anything you want. You could pick 45 minutes. You could pick two hours. I, as the supplier to that,

get to bid that appropriately just like any other thing you specify to me. It's no different than you Seth if you said to me, hey Rich, I want you to put in two pounds of ground up unicorn for every yard of concrete. Okay Seth, my answer's gonna be sure. Let me quote that for you. And that quote may or may not be acceptable for you. If you say, hey Rich, I'm gonna hold you to a 45 minute temperature, I'm sorry 45 minute time limit to discharge.

Okay, Seth, let me quote that for you. And you may or may not accept that quote. Now, the other part of the specification is, Seth, you may say to me and say, Rich, I don't know what time limit to specify on that. And I could say, you know what, Seth? Okay, I understand that. I will specify that. It's a closed loop spec. If you don't pick it, I get to pick it. And that is so that, hey, when it shows up on the job site, I'll give you an example.

This may happen. I show up on a job site and a contractor's not ready or they decide we're going to discharge that concrete 10 yards via one quart buckets. Right. And all of a sudden that truck is out there for four hours. Gee, never heard of that before. Four hours it's out there and all of a sudden at the end of that truck, they're like, man, this concrete's no good. But you didn't have a time limit. So the time limit also protects.

both the owner, the producer, and the contractor buy this closed loop system. But it allows for a purchaser. And this is the interesting distinction that always has to get made with specifications and standards. I, as a producer, have an obligation to one person only as part of this process. It is the purchaser, which is what that document exists for.

Rich (15:50.76)
A lot of people think, hey, you've got to answer to the engineer. You've got to answer to the owner. You've got to answer to the specifier. The truth of the matter is that completely incorrect. I have one responsibility and one responsibility only. It's to the person who purchased this concrete from me. And you as a contractor know that. And if you're buying concrete, you don't want to hear from anybody else. You want to hear from who you're paying, who you're contracting to, which is me.

So that's always the other interesting part about this is that the responsibility exists between the two people that are engaged in that contract. And that is me as a producer and two, that is you as the purchaser, which is clearly stated in that document. And so that's the other part about why that specification needed to be changed. It gets to the root or the core of the relationship. I can quote you based on the specification you give me.

And I will tell you, you and I have both been on projects for far too long where somebody had literally their watch out and they were looking at the concrete going 91 minutes, get these trucks out of here. Meanwhile, you're like, I'm at 250 yards. I've got a 350 yard pour. You're going to reject these next four trucks.

Meanwhile in the and I've got I'm gonna have a cold joint, you know All this stuff goes on and the concrete wasn't smart enough to know it was supposed to be bad So that that change that we're talking about Took 10 years To get done in ASTM 10 years and again, the process is a very good process. It's a very open process It's a very well established. What's process?

Seth (17:14.45)
huh.

Rich (17:36.008)
and it's a consensus -based process. Now the interest, and by consensus -based means that, this is the other interesting part about how science works. Everybody thinks that there's one guy in a lab who comes up with something and he says, the new color is blue, and the world says, okay, the color should be blue. Well, the way science really works is somebody develops something in a lab and they bring it to a technical association, a society, a governing body like ASTM, and they say, here's my data.

And the people in the room, 100 of them, let's say, if 51 of them say, we think the color should be blue, guess what? That's the new scientific color is blue. And a year later, if somebody comes up and says, you know, we have new results with new technology that says the color should be red, comes back to that same group. And 51 of the people say the new technology says the color should be red. Guess what? Science works again and the color's red. So in the 1930s, when somebody said we should establish these time limits,

based on how aggregates degrade coming out of the back of a drum, everybody said, congratulations, science. And that's why we're going to set the limit. Science changes, and that's how it does. And that's exactly how we got to it. It took us about 10 years to get that change made. And then to your point, how long does it take till it's adopted? That's the other big thing. Just because the document changed yesterday or was published that way,

There are hundreds of thousands, tens of thousands of specifications that still have it at 90 minutes. And that's okay too. There's nothing wrong with that. It just means we get to bid that accordingly. You know, shockingly in a competitive bidding environment, that's the way it's supposed to work. And I'll give you one final capper on this that was probably one of the most interesting arguments that got made was,

15 years ago, nobody would have made this argument. But 10 years ago, somebody, it was a good argument to make, which was, aren't we supposed to be focusing on more sustainable construction methods? Aren't we supposed to be focused on greener building processes? Aren't we supposed to be focused on lowering carbon footprints? All good things to do, right?

Rich (19:52.584)
What is the impact of 91 minutes on a concrete rejection that we know is not bad? How does that affect the green footprint of that project? I use that term loosely to just go we're gonna reject that load of concrete at 91 minutes knowing it's good, but because the spec said that What's the impact to the carbon footprint of that project by doing that? It's like brilliant argument to use brilliant

Seth (20:17.746)
Yeah.

Rich (20:21.32)
So again, it's one of these fascinating things that when you start to dig into it, you're like, why does that exist? Good Lord, we have, not only do we not understand why it exists, but if we do find out, we're like, it has nothing to do with how we build things today. And the interesting, one of the more interesting part was the people who oppose this, who said, we have to have this, we have to have a time limit. 90 minutes has to exist. Okay, pick 90 minutes. You can still do it if you want.

Seth, if you're a contractor who's been doing this 30 years, and you say to me, son, I've done this for 35 years, and I've read, done more than read a few books, and I know that 90 minutes is supposed to be there. Okay, then yes, you old man, Seth, I'm gonna get off your lawn, and you can pick 90 minutes. Right? There's nothing that prevents you from doing that. And I get to quote it accordingly. So.

Seth (21:14.642)
Right. So, so does see the ASTM C94, the newest edition, does it say 120 minutes or is it open? It's, it's open ended like you're. Okay.

Rich (21:22.28)
No, there isn't. It is open -ended. You could pick 400 minutes if you would like, and I could bid that accordingly. I could tell you, Seth, I can't do that. Or I can do that, but here's how I'm going to have to quote it. There's no minimum. There's no maximum.

Seth (21:37.842)
Okay. Yeah. Okay. Yeah. For some reason I thought I saw someone post on LinkedIn that it was 120 minutes now. And I think I might've been guilty of sending it out to everybody who said, Hey, look at this. So, so it's up to, so is there any like, I guess in your, in your, we'll call that experiment where you had your guys.

Rich (21:52.424)
No.

Rich (22:05.384)
Sure.

Seth (22:06.098)
do the every 10 minutes batching. What did you find? What was your discovery?

Rich (22:13.)
So if somebody asked me now at that mix design under the conditions we tested it, so this would have been out of North Texas, this would have been you know and what we tried to pick was a mild temperature month for mild for us is anywhere between 75 and about 85 degrees ambient temperature. We did this at 10 in the morning so under those conditions with that mix design and those materials.

Seth (22:17.106)
Yeah.

Rich (22:38.888)
What we found out was, yeah, the material does begin to perform less than designed at a certain time period. For us, that was approaching 300 plus minutes. Now, but here's the other thing most people forget. They're like, well, I would never let concrete be out there for 300 minutes. As a producer, neither would I, but it's not for the reason you think.

I have a commercially vested interest in getting concrete to you as quickly as possible, discharging it as quickly as possible, and getting that asset off your job as quickly as possible. I have a commercial interest in that. Just because I can do it for past a certain time period doesn't mean I have a disincentive financially to keep it there longer unless I've quoted you appropriately.

Now again, if you tell me, hey, Rich, I've got this job. We're going to be wheelbarrowing the concrete. OK, understand. Maybe there's a condition that says that. And we have one wheelbarrow and we have two people. And they have to take the wheelbarrow 100 yards to discharge it out of the back of the truck. OK, Seth, I'm going to tell you that truck may need to be there for about four hours. So let's do what we need to do with our technology and our admixtures and the mix design to make that happen for you.

Excuse me. I would quote that accordingly Right to take an into account for that time Because otherwise I want to get there if it if all of the fresh properties check out slump air temperature these kind of things I want that material out of my truck as fast and as safely as possible and I want that truck back as fast and safely as possible at my plant

Seth (24:02.706)
Bless you.

Rich (24:28.072)
I have a financial incentive to have that truck there the least amount of time possible. And this is what everybody kind of missed as part of that spec was, you know, I don't want it there a minute longer than it's supposed to be. So that's why to me, it's an open ended thing. It's if you, you know, and the irony is in some markets.

Seth (24:34.066)
Yeah.

Rich (24:53.448)
You could go very rural or you could go very urban if you wanted to. And again, let's go back to Dallas, Fort Worth. You're really not going to go a whole lot of places in about 50 minutes there. You know, I got, if you're traveling, depending on unless it's between midnight and 6 a It's going to be a 45 minute one way hall.

So I've got batch time, I gotta get off the yard, I got this. By the time I get to you, concrete could be anywhere between 45 to 60 minutes old, almost all the time, unless the plant's geographically convenient to the job. And that doesn't include traffic, right? So some of these things are almost impractical when somebody, you know, cause I'll see specs like that. They're like, if the ambient temperature exceeds 80 degrees, the discharge time must be 75 minutes.

Congratulations, you're not pouring in Dallas, Fort Worth between April and October. Please inform your owner that the specification prevents them from constructing anything for six months out of the year. Well, what do we need to do? Well, let's look at some things practically. And I think that's how we approached that 90 minute limit was what is this really doing? What does this prevent it?

And for anybody who still wants to have a 90 minute limit, there is no prohibition in the specification that limits that choice. You can still do it every time, all the time, in your jobs, on your specs, whatever you'd like to do. But for purchasers who choose not to have that in place, they also get that option.

And that was the most that was again as we're talking to people and everything else We're not limiting people from continuing to keep it. In fact, there's a footnote in there that says This historically had been 90 minutes You know for a variety of reasons and there's nothing that prevents you from continuing to pick it And for those people that want to do that they can and I can quote it accordingly And I think that was the other part was there were no other options really I

Seth (26:59.538)
Yeah.

Rich (27:04.828)
Anyway, that is literally changing a sentence in the book of John. It just was so dramatic because it had been there for 90 years.

Seth (27:19.826)
Yeah.

Rich (27:20.84)
And it became almost part of the lexicon when it came to specifications and job site things and everything else and colloquial conversations at contracting meetings or technical associations or societies. They're like, 90 minutes. Well, why? What was the purpose of it? Well, it's just there for 90 minutes. Well, why? And then you start to dig in and all of a sudden people's arguments fall away pretty quickly.

You know, because they were like, well, it protects, protects the, okay, you can still pick it, but why does everybody have to pick it? And the other part about that was go back to the first point I was making regarding the performance, the concrete. What if the concrete performs past 90 minutes? What was the value of the time limit then? It didn't serve one.

It actually rejected, and I think of the, over the multiple decades you and I have been working, how many yards of concrete were rejected because of a 91 minute limit that should have gone in place, that should have been used, that could have built something. And I think this is not tens of thousands, this is millions of yards of concrete that have been summarily rejected.

Seth (28:38.194)
yeah, most definitely.

Rich (28:43.56)
for no other reason than that sentence existed in that document for 90 years. And so to me, this is a huge step forward from an industry standpoint, from a logic standpoint, and from a practical standpoint on how we build things.

Seth (28:50.13)
Yeah.

Rich (29:02.952)
Because at the end of the day, that's where I always get to, every time I'm in a meeting with people, let's say it gets a little contentious, the sentence I always come back to is, hey man, I just want to build something. Do you want to build something? You guys want to build this building? Do you want to build this structure? Do you want to build this project? Because I do. What do we need to do to figure out how we build this? And that, to me, was one of these fundamental things of like, how does this help us build anything? It didn't.

So I'm sorry to wax a little philosophy there on you, but you know, as an engineer who's got obligations, as a person who's been in this business and like the mafia can't seem to get out. It's important to me that we make an impact on our communities and these kinds of things, people don't think about it, but it truly did. Where does that concrete go? Those millions of yards that got rejected. Yeah, some of it gets resold. Maybe some of it gets repurposed. Maybe some of it gets recycled.

But I bet you a lot of it got dumped in places that had to, you know, and just dumped and dumped and dumped. We can do better than that, Seth. We can. And to me, that was one of my true motivations on this was, man, we can just do better. We can. And I think the standard and I think the science and I think the people who helped this all recognize and realize that.

Seth (30:07.474)
Yeah.

Seth (30:23.922)
Yeah. So is, is temperature next?

Rich (30:27.464)
you really want to poke the bear today, don't you? Yeah, if we can chat about it for a little bit, I'll be happy to. OK. So I'm sure I don't know if you're going to link to it or not, but somebody had posted something on LinkedIn. And it was almost in a.

Seth (30:32.498)
Yeah.

Dr. Justin Marchegiani Yeah. We got– we got– got about 5 minutes. We could–

Rich (30:52.264)
I'm going to use the wrong terms here, but they were almost promoting the fact that they could cool concrete temperature to 75 degrees using liquid nitrogen. There was a video and everything else on it. And to me, it was one of those things of like, what are you promoting here? And for what purpose? Because there is no reason concrete has to be cooled to those temperatures for delivery.

Seth (31:01.522)
Yes.

Rich (31:16.2)
Now, yes, I will put a caveat on there. Under specific conditions, under certain circumstances, under these kind of things, yes, that may be important, but not for all concrete. And mass concrete, absolutely, under those kind of specific conditions. But if I'm doing a pavement on a roadway,

Seth (31:31.89)
No. You're referring to like mass concrete, right? Yep.

Rich (31:44.936)
On a bridge deck, do I need to be at 80 degrees and 85 degree temperature? No, go back to my earlier point about concrete not remembering what it used to be once it gained strength. Again, I've been on projects where like, hey, Rich, that concrete was placed at 105 degrees and the temperature spec was 90. Do you think we should tear it out? Well, what were the cylinder brakes? Well, they were at 160 % of the design requirement.

Okay, what do you want to do? You want to tear it out because it wasn't placed at the right temperature? Well, no, it'll be okay, but I'm just letting you know. Then what was the purpose of it? And I can't, and again, if I put on my material scientist hat, and this would be a great nerd debate for you. I think concrete, much like other materials, should not be thermally shocked. I think, now here's the analogy I always use. Have you ever looked at an ice cube?

that you could see through. And it was almost like a glass cube and it was ice. And it was just perfect. You could see through it. The reason glass gets that way, or I'm sorry, ice gets that way, it looks like almost glass, is because it is cooled at a very slow rate. The crystals are allowed to grow to their maximum potential and it is a very constant rate and it is not shocked.

Now have you ever seen that same ice cube that has cracks in it? And all of a sudden it went from, say, room temperature to freezing temperature very, very rapidly. It gets shocked. The crystals grow poorly. There's flaws in them. The same thing I believe is true in concrete. I want it to go through the least amount of temperature gradient as possible.

In fact, I think concrete delivered at 100 degrees that reaches a temperature of say 140 is a good thing versus delivering concrete at 80 degrees. And it's still going to get to 140 because of its mixed design and all these other things. So now it's moved through a temperature gradient, double that of the other in the same time period. From a material science standpoint, that's worse. But yet we cling to this thing that temperature is a control.

Rich (34:02.376)
Because, well, if you don't have the, if you don't control the temperature, guess what's going to happen, Seth? The concrete is going to lose its slump. It's going to lose slump life because the temperature gets, is too high. And if you lose slump, you're going to have to add water. And if you add water, you're going to get to low strength. If I do that math right, that's three different assumptions. So, and it says, so you want me to quote you liquid nitrogen based on three different assumptions that completely ignore the concept of.

Seth (34:21.202)
Yup.

Rich (34:31.88)
Mix optimization, add mixture chemistry, and our ability and what are the ambient conditions during that? I've had people say I have to have an 80 degree temperature spec in November when the ambient temperature is 55 degrees. So you want me to warm the concrete up? You know, it's just this, this ludicrous nature of it. And somebody posted and was promoting that.

And again, if you drive people to that where it was, I'll highlight one particular example here in the couple of minutes we have left was the only time I see that is either A, because somebody has an outdated or antiquated spec or two, the owner of the project is dealing with public funds where costs aren't an issue. Because if I was building that myself with my own money, I sure as hell wouldn't be spending that kind of money on that thing. But if you're dealing with public funds that are...

Seth (35:23.058)
Mm -hmm.

Rich (35:26.536)
You know, largely unlimited. Sure. Let's use liquid nitrogen. Sure. Let's let's use brand new hammers. Sure. Let's let's replace concrete truck drums. Everyone, every third truck. All ridiculous things to think about and consider. And so, yeah, go ahead.

Seth (35:41.746)
Well, what about, what about all the, the, the cold water and hot water for seasonal concrete pours? What about that? I know you love doing it. Cause you charge us for it.

Rich (35:48.04)
I love doing that. I've got two kids and I've got, I've got two kids in college. I've got a lake house. I got to buy jet skis this summer, Seth. Please specify that more.

Seth (36:00.53)
Yeah, no, I mean, the first thing we do when we see that 90 degree, requirement in the spec is write an RFI and say, can we do 95?

Rich (36:10.152)
So, and what I'll wind up doing, Seth, when you send that to me, is I send you a letter that says, look, I'll guarantee concrete temperature strength or performance requirements up to 105, 100 degrees, 95 degrees with the following conditions, right? Let me use a retarder. Let me use a polycarboxylate mid -range or super plasticizer. Let me do these things that allow us to go to those temperatures. And then all of a sudden, and the other one is,

If somebody says, well, you know, if you can get an engineer to sign that, congratulations. I'm an engineer and to be happy to, I'd be happy to sign that for you. But.

Seth (36:48.21)
Well, you're more, you're more of a concrete engineer than the guy that stamps the drawing.

Rich (36:52.808)
Well, and that's the other thing too, is that, you know, we can talk about this anytime in the future, but they're over the last 20 years, there's a huge shift. You know, the guy who stamps that drawing when I submit a mix design, they don't approve mix designs anymore. They review them. Yes. And there is a very subtle shift there in liability. So, and my thing is what an awesome thing to do because I'm happy, because my position in risk profile hasn't changed no matter what they do.

Seth (37:07.378)
review. So they're turning into architects. Yeah.

Rich (37:22.92)
I'm still responsible and you, Seth, as the purchaser is my number one and primary obligation. And so it's just to me always funny when we see these things get recycled like this, where somebody's like, see, we could cool concrete to this temperature. Why? For what purpose? And when you begin to ask those questions, you wind up that there's a triple assumption or a quadruple assumption somewhere. And when you ask the what I would call the closing question,

Are you going to advocate for concrete to be torn out when it gets placed above temperature but makes strength? Well, no. Then what was the purpose of the spec?

You know, it's like, you know, some I've been on job, very good jobs where they're saying, look, contractor says, here's what the slump needs to be to go into the, into the pump. So it can be a place because of their placing technique or whatever they're doing. Concrete goes, slump is above that purchaser. Seth, what do you want to do? You want to keep going or do you want to, you want to reject this truck? What do you want to do?

Well, hey, pull a couple of cylinders just in case we got a problem we can note it here, but let's keep this job going. Fantastic. Let's build something, Seth. Let's go. You betcha.

Seth (38:33.73)
Yeah. Yeah. Yeah. I think that's a perfect way to end today. Keep building. All right, Rich. I love our conversations. We got to do it more frequently. I know you're, you're, you're in the middle of switching, switching jobs. When you get your feet underneath, you will get you, we'll get you back on. Cause I think we're just, yeah. So, yeah, that I think, that the,

Rich (38:47.784)
You bet.

Rich (38:54.504)
nice teaser Seth, nice teaser.

Seth (39:03.026)
your efforts to change that time limit. I mean, I think we're opening it up some other opportunities there that we can refine the requirements on concrete that will help us out, all of us out. Rich, thank you for coming back on the show. And folks, let's keep it concrete.