EP #151: Most Concrete Durability Problems Start Here (Alkalinity Explained)

Seth Tandett (00:00)And welcome to another episode of the Concrete Logic Podcast. And we have Bob Higgins back with us. Bob's been in the concrete industry for decades. He's worked across the cement chemistry, admixtures, durability, and performance. If you've been listening to the podcast for any length of time, I'm sure you've ran across Concrete Bob's episodes. There's quite a few.Today he's joining us. We're going to talk about alkalinity, the pH environment inside concrete, the lever or levers that controls durability for concrete. So if you don't understand alkalinity, stick with us. You will by the end of this episode. But before we get into the topic at hand, I just want remind you guys how to support thepodcast. So if you go to www.concrete logic podcast.com on the home page, there is a link at the top that says ask Seth. If you click on it, ask Seth link. That's a way to get ahold of me. 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And it's if you enjoythe format of the podcast. do the same thing on the Academy, but we give you quizzes and some other extra things within the Academy that helps you absorb the content that we're talking about. Okay, Bob, we're back. just behind the scenes, this is take two. We lost internet, so we're back. We're going to try this again.Bob Higgins (02:21)Okay.Seth Tandett (02:27)Bob, just to get you warmed up on the subject to hand, when we say alkalinity and concrete, what are we actually talking about?Bob Higgins (02:38)Alkalinity is actually the concentration of a salt. It's an alkaline salt. There's a lot of different salts that are out there. And I'm going to give a background on what salts do and how they affect moisture, not only moisture that's available to concrete for hydration, but just moisture in general, how it affects it. And once people understand what they're dealing with, a lot of the mysterious problems are running across.be able to figure it out.Seth Tandett (03:07)So is this the root cause of all the problems? And when we say problems, what kind of problems are we talking about?Bob Higgins (03:14)It is one of the root causes because alkalinity, unfortunately, people get high pH and high alkalinity mixed together. And I keep reading study after study and they keep doing that. So no wonder people are confused. They say, we have this, we have a lower pH concrete. No, it's a lower alkalinity concrete. The pH is the same. But if you notice when you read studies like that, they won't give you the pH because it's the same, but they don't know why.So they just use the term pH. But the biggest issue that we have with alkaline salts is its ability to grab and hold on to moisture. And that is really, really critical during the curing phase of concrete. So I'm going to just go back and just give some basics on salts. All salts will reduce relative humidity, some more than others.And the ones that are consistent are the ones that are used as calibration salts, where they have basically four different salts that they use in these little containers that are full of water. Because no matter how much water is in there, if it's saturated, it will maintain a consistent relative humidity through a very broad range of temperatures. Because temperature will also affect the alkalinity and the ability of these different salts to hang on to water.because a lot of mistaken belief is the water once it's hung onto, well, it's chemically bound. Well, no, it's not, because it can be taken on and released in normal, everyday climate. So that is not bound water. They keep mixing and matching these terms to where even the experts get confused. So I'm going to get into the most critical alkaline salts that are in concrete.Your two most critical alkaline salts in concrete are calcium hydroxide and sodium hydroxide. I've heard people say potassium hydroxide, but that's kind of interchangeable with sodium hydroxide because their response to moisture is almost identical. There's very little to separate them. So I'm just going to focus in on sodium hydroxide so it doesn't get overly complicated. Because one of the things iswhen they started adding cement kiln dust to cement between 2002 and 2018, that didn't change the pH as much as it changed the alkalinity. And that's where that kind of slid in under the radar. And that's one of the problems that we're seeing, because as the alkalinity increased, it also increased the setting of the cement. It also made.moisture less available to creation of cement. So I'm going to go into the background of salts. Again, all salts will reduce relative humidity, even if the moisture hasn't changed at all. It can remain the same. It's like sodium chloride, table salt. Table salt is available anywhere. And one of the examples I give people is it can create a condition where it will take water and hang onto it, even thoughit's not at dew point, it can actually create condensation. So that's called ionic dew point. So that condensation can be captured and can cause issues in the concrete because now with it capturing the water, that's no longer available for the cement. So in that little tabletop example I gave is I'll take just table salt and I put it in a little container.and it's dry and it's 70 % relative humidity, then I put a cap on it and I raise the humidity to 80%. And even though it's not even close to 100 % relative humidity, which normal atmospheric condensation will occur at dew point, it will begin to liquefy and it turns into a liquid at 80 % relative humidity. So that water is now captured. That's not available to be measured.because as you put something down on there, like a relative humidity probe or anything like that, it will measure 75 % relative humidity, according to some experts that's supposedly dry. Well, it can be saturated, but it's measuring dry because they misinterpreted what the salts do. Now here's where the alkaline salts were.Seth Tandett (07:45)Well, hold up, hold up.I'm going to pause you. So is the, so the moisture is in the salt.Bob Higgins (07:52)Yeah, it's captured to a certain extent.Seth Tandett (07:53)captured in thesalt so it's holding on to the salt and that's why you're saying if you use a RH meter it's not capturing what's going on in the salt just what's going on in the airspace right?Bob Higgins (08:05)And the airspace, yes.That's all it's measuring is the airspace. So there can be a whole bunch of water in there and the RH will not see it. It can't see liquid water. None of them can. Let's be honest, capability. Now when you have a lower RH, that also equates to a slower evaporation rate. So things like the calcium chloride test, because it's fixed at 60 to 72 hours, there's only so much moisture it can capture.Seth Tandett (08:19)Okay.Bob Higgins (08:35)in that kind of a climate versus an open system where it can readily capture moisture and will give you an accurate reading. Especially now with the cement kiln dust in there and now with the changes in concrete, that's no longer a viable way of measuring moisture content. RH and calcium chloride are not viable. And here's why. Because there was one famous consultant said, well,The reason why calcium chloride isn't accurate is because it overdrives the concrete. Well, that's nonsense. Because it has what's called a higher critical humidity threshold.The alkaline salts have a higher, excuse me, the calcium chloride has a higher humidity threshold than either the alkaline salts. The calcium chloride in these test devices, it will try to get the relative humidity down to 18%. That's its critical humidity threshold. It's 18%, it'll start attracting water and will hold on to water 18%. So if the moisture is up,relative communities higher in these air spaces is trying to get it back down to 18 percent. That's how calc and chloride is used in closets. They put a bag of calc and chloride in a closet and it's trying to dry everything out. That's why keeps things from getting mildewed. There's no difference. That's exactly what it's doing. That's a passive effect. So when people hear, well it's vapor emission, they think it's water vapor freely coming out of the concrete. That's not true. All it's doing is trying tobalance the environment within that lid.Seth Tandett (10:15)It's pulling themoisture from the air and it's collecting on the surface of the concrete because of the salt that's inside the concrete.Bob Higgins (10:23)Exactly.And that's one of the cheap causes of slab sweating syndrome. When you get older concrete, because older concrete tends to collect a lot of the salts at the surface, so when the relative humidity gets around 75-80%, it looks like somebody took a shower. The concrete's wet. And they dry it out.Seth Tandett (10:41)Sothat's a sign that your concrete has a high alkalinity.Bob Higgins (10:46)Yeah, towards the surface, correct. And here's the thing. Calcium hydroxide, which is a byproduct of cement formation, has a critical humidity threshold of 12%. It can get soaking wet and will not release water to the calcium chloride until it hits a past saturation point where it has excess water, where it's enough to produce a relative humidity above 18%.Seth Tandett (10:48)Okay.Bob Higgins (11:13)Then and only then will the calcium chloride begin to capture that. So that's what it measures. And you can't measure what is actually captured in the calcium hydroxide, but it will capture anything that's in excess that isn't captured within those ranges. What will happen, you'll get a different reading because calcium hydroxide gets more soluble and gets colder, so it grabs onto the water more readily.But as it warms up, it starts releasing the water because it becomes insoluble. So it starts losing the water. So if you were in a calcium chloride test on the same exact concrete, if it's 80 degrees, you're going to get a different reading than you would at 60 degrees. Well, there's no more or less water in there. It's just the ability of that salt under that condition to capture the water.That's where we're getting it to the sodium hydroxide. That's the bad guy. That will start capturing water at 9 % relative humidity. Even if it's desert dry, it can get wet and stay wet in really, really low humidity environments. And that's what's in the concrete. And that's what's interfering with the top surface of the concrete. it is my, I'm absolutely positive.That's what's causing the self-desiccation that we're seeing now. Because there's not enough moisture available for the cement formation. And the reason why that happens, when the cement is initially initiated, it uses up some of the water. Well, now that they have limestone, all these other little particles in there, to properly dampen those, those are actually competing against the clinker to form cement.it wants water and wants to get wet. The clinker wants to get wet, but there's only so much water to go around. So what happens when it starts, the clinker absorbs some moisture and forms cement, it drops the moisture level. When you drop the moisture level, that raises the alkalinity. And when the alkalinity gets raised, it lowers the relative humidity in the surface of the concrete, because that's most susceptible area. So if you haveFor example, if gets to 20%, the relative humidity in that area where the sodium hydroxide is 20 % concentration, the relative humidity will drop to 78%. Well, people say, well, that's no big deal. Yeah, it is a big deal because at 80 % and under, cement formation stops. That water is no longer available to the cement. If it's not available to the cement, you get a more porous permeable surface.And that's what we keep doing. even if you put water on top, it will not allow the water to penetrate because it's now in an equilibrium. as it keeps going, as things keep going south, because what puzzled me at first when I saw some of these global studies, there's one in Portugal where it was showing that in the first two to three weeks after the concrete was placed on a roadway and also a bridge deck, the relative humidity was dropping betweenSeth Tandett (14:06)All right.Bob Higgins (14:28)50 and 70 percent. And they were trying to blame that on the cement hydration. So there's not enough cement in there to create that kind of a condition. It won't use up that much water to drop the humidity. So there's got to be something else. So then when I started looking at calibration salts and everything that salts do, that gave the answer. And if you look at where they have sodium hydroxide in bulk, where they ship it at 40 percent, that's typical.40 % concentration in water, they have to keep it heated at 70 degrees because here's another strange property. Sodium hydroxide, as it gets concentrated, and here's the problem. The state of the art study on concrete in NIST in 1999 said that sodium hydroxide is an antifreeze. And they showed a truncated graphic.and showed up to 20%, it would drop the freezing point of water to negative 14 degrees Fahrenheit. Well, that's true. However, it doesn't stay at that. As it gets concentrated from 20%, when it goes to 40 % concentration, the freeze point of water is now 59 degrees Fahrenheit. And as it goes towards 60%, the freeze point of that water in the concrete is now over 100 degrees Fahrenheit.It doesn't want to move. It's behaving like ice. It's not freely evaporating moisture. So not only is the RH dropping, but the water now thinks it's freezing, and the water is now getting more viscous. If you get sodium hydroxide moisture combination, it gets up towards 60%. It's now got the viscosity of like molasses. It won't move. You can't dry it out.That will damage the concrete surface because now it's dehydrated, but it looks wet. You go, well, it's wet. Why is it cracking? Well, because that is not available to the cement. So that's why the top surface of the concrete, the first inch, tends to self-desiccate. And that will even happen in a laboratory. When Texas Transportation Institute did this study, I believe it was back in 2005, where thewater cured the concrete for seven days. When he isolated the top one inch of the concrete, it was a full 20 % lower in compressive value than the remainder of the concrete. That shows there's a lack of strength gain. The lack of strength gain means that the cement is not properly hydrating. But we're being told that's okay. That's always been an assumption. And that assumption began way back in the day when they had a coarser grind of cement.So we've not modernized our techniques to study the concrete properly. Because now, with concrete, it's changed dramatically since 2002 to the present day, where we don't have a track record of any particular concrete or cement mix design that makes any sense. Because the type one is what everything was based on, but as they started grinding it finer, concrete began to crack and warp and curl, so they started adding type two.and the reasoning for it was it makes it more sulfate resistant. yeah, it does, but that's kind of like hiding something out in the open. It's my opinion. That's the excuse they gave, not the reason. It's an excuse. So what?Seth Tandett (17:59)Right. Whereare all the salts coming from?Bob Higgins (18:04)That occursnaturally in the aggregate in the concrete. And it's also coming from the cement now with the cement kiln dust. Because cement kiln dust, and unfortunately I didn't screenshot it, but there was one recorded example where the alkalinity was 400 % higher with the cement kiln dust than it was in the concrete without the cement, without the kiln dust. So it's pretty dramatic.So with that concentration of alkalinity coupled with the initial hydration of the cement, now it makes sense why the concrete is self-desiccating towards the surface. Now, it doesn't do that in the center of the concrete, but it does that in the top surface. And that's where it's receiving all the damage. So.Seth Tandett (18:48)Why does that? Whyis that?Bob Higgins (18:50)That's because you've got evaporation, and it's exposed to radiant heat and the environment. Because there's a lot of contributing factors, which I'm not going to get into because it's a real deep dive. But with evaporation alone and exposure to sunlight or even light, there's an acceleration of evaporation. So the acceleration of evaporation, even with a water cure, it's notcooling the concrete properly. here's the other contributing factor is when the concrete heats up, even with water on it, it heats up, the calcium hydroxide loses solubility. Because it's one of the few alkaline salts that gets more soluble as it gets colder. It becomes less soluble as it gets warmer. The sodium hydroxide on the other side loves to get warm, loves elevated temperature, but then as soon as it starts capturing that water,make an unavailable for the cement. If it's not available for the then it'sSeth Tandett (19:48)And the cementkiln that dust that's causing the high alkalinity, that was because of the EPA restrictions on the, right? So it's not releasing that dust anymore and that's dropping down into the cement. Is that right? Do I have that right?Bob Higgins (20:00)Correct. That was a requirement,Well, basicallywith the more alkaline cement, gets to that point very quickly. the cement hydration isn't as complete as it used to be. So we've got a, we've got a really a cascade effect on what's causing the damage in the surface of the concrete. It's temperature along with the insoluble of the calcium hydroxide and the increased concentration of sodium hydroxide. That's why alkalinity is so important here. Now,They keep mixing up high pH with high alkalinity. High pH is a concentration, it's not concentration, but it's the strength of a salt. Now, sodium hydroxide is, the other curve that gives us is that it's really buffered. If you can have a difference of 20 %, excuse me, 20 times higher alkalinity and virtually won't change with a pH strip.or any other pH device for that matter. So I experimented with this on a case I was brought in where I suspicion there was an alkaline salt, sodium alkaline salt in the concrete. And where it was severely damaged, I did what I call a relative alkalinity test. Where I did the normal pH test, but what I did is I put a ring of plumber's putty down, a half a milliliter of water, of deionized water. Then I put the...pH strip in and the area were of no damage a moderate damage is severe damage all measured around 11, but the severe damage was up around 12 So I added more water to the area that wasn't damaged as I added water to it quickly dropped down to a pH of 9 the moderately damaged area when I added the Additional water to it another half milliliter water the pH didn't changeThen I did it again. It started to lower. I did it again. Between five and six times of adding water, it finally went down to nine, because that's basically concrete when it's neutral. When it's fully carbonated, it should be around nine. But the severely damaged ones, there were areas I added where it started to overflow and it couldn't add anymore, and the pH is still 11. Well, that's alkaline. The other one is a high pH, but it is an alkaline.the alkalinity and the damage corresponded with each other very, very closely. But just plain concrete, it will dry it out and will crack it. It will cause warping because it responds now more to heat than it did if it stays wet. Because if it stays wet, at least it's swollen, but it won't stay wet. It captures that. And so we keep going around and around this technical hamster wheel.where people keep doing the same thing over and over again. And what really is annoying to me is I read these lab tests. It is assumed that, and then they come to a conclusion. You can't come to a conclusion if you're making assumptions. Because what if any of those assumptions are incorrect, which most of them are? Well, your conclusion is wrong. Most concrete studies are not correct. At least 90 % of the ones I've readand I'm being generous here, are incorrect. so I... Go ahead.Seth Tandett (23:30)Yeah. Sowhat's a sign of high alkalinity? the sign of what happens to the concrete itself? Other than that the salts draw the moisture from the air and you can see it on the surface of the concrete. What are other things that is a telltale sign?Bob Higgins (23:53)Well, I'm going to be stepping into a landmine here, but here we go. A good example is any precast concrete, because they heat cure the concrete. Now, the center portion of the precast is really, really dense and durable, because what water does, it wants to move from warm to cold. So as you're heating up the skin of the concrete and heating up the concrete, it's pushing towards the cold center. But the poor skin of the concrete is now dehydrating. Now, the way you can look at it,is I've taken just plain standardized concrete, poured in place, and I've taken precast side by side. I'll put water on the standardized concrete. It'll absorb a little bit, but it takes a while. But if I put it on the precast, it disappears. Put some more on the precast, it disappears. Put some more on the precast, it disappears. I've typically seen five time greater initial absorption with precast than I do with standard concrete.That's because they heated it up. The calcium hydroxide and the cement formation got retarded. So when I looked at the study conducted by ACI with all these different inputs from the 1940s through around 2005, it showed that the higher the temperature, the better the compressive value was at 28 days.but the weaker the concrete was at 365 days. That correlated with what we're seeing with alkalinity. Because if you add everything else in, the only thing that makes sense is alkalinity. So at 120 degrees, they were showing that the concrete at 28 days had 200 % of its targeted 28-day strength. But then when they put it in a chamber at 73 degrees,Seth Tandett (25:21)Right.Bob Higgins (25:45)100 % relative humidity for the remainder of the full year when they got to 365 days, the concrete was 73 % weaker than the targeted value.Seth Tandett (25:55)Yeah, that's a compressive strength, right? Which we've preached on this show many times that shouldn't be your measure of durable concrete. So what you're saying is the precast concrete has a more porous surface than a cast in place.Bob Higgins (25:57)Yeah.More permeable. There's a there's a difference. Yeah, andSeth Tandett (26:12)Permanable. Permanable.See, I'm using the wrong term. Permanable, which is...Bob Higgins (26:17)And see that,and the labs do that too. I'm so glad, I'm going to jump in here. I'm so glad you brought that up because I saw a professor giving a presentation where he showed this curve for the water cement ratio and reciprocal curve for what he was saying is permeability. Well, I didn't want to embarrass him. So I waited until after class was over. I said, what you're actually showing is a porosity curve, not permeability. He thought they were the same thing. said, no, porosity is absence of mass permeability.Seth Tandett (26:20)Okay. huh.Bob Higgins (26:46)is the ability to absorb something like a gas or a liquid. And what I use as a desktop, I'll get this vitrified pumice stone, which really pours, looks like a big sponge. You pour water on it, but it's somewhat hydrophobic, so the water sits on it. It doesn't want to penetrate. Then I'll take a saltier tile where there's no apparent porosity at all. You pour water and it disappears. That's permeability. That's porosity. That's permeability. There's a difference.And they keep mixing the two up. So they mix porosity and permeability, alkaline, IPH. We keep mixing these terms. And when we keep mixing these terms, no wonder people are confused.Seth Tandett (27:27)Yeah, so this is good. So porosity versus permeability, which you define the difference is porosity.Bob Higgins (27:37)Absence of mass.Seth Tandett (27:38)Yeah, is that worse or same or different as permeability? If you were like, if I have to have concrete that has high porosity, I'm struggling just saying that, or high permeability, which one do you, are you following what I'm asking?Bob Higgins (27:42)But if there's if there's.Yeah,I would prefer the hyper-hossy unless it's in area where there's water pressure. Then water will push in and get much greater volume. But under normal circumstances like a roadway surface, a bridge structure, a floor, you do not want a permeable surface because it absorbs water and it transports things in and out of the concrete. water is fine as long as it doesn't move. If you could keep concrete under water permanently,Seth Tandett (28:00)huh.Okay.Right.Okay.Bob Higgins (28:24)For example, if you take a 3,000 psi concrete, leave it underwater and test it 50 years later, it'll probably be up around 12 to 13,000 psi. But if you put, move it to the tide line and you look at piers, where's all the damage? At the tide line, where the water goes in and out. The more movement of moisture you have and the more allowable moisture over time, that will damage the concrete. So porosity and permeability are both bad news.We can produce concrete that doesn't have either, but we're not being allowed to because all we have to do is hit the compressive value standard. That doesn't tell you anything because I better not say which, it was a military base and I went up to this military base and they had this road waste. My God, look at how durable that is. Well, they couldn't use it. The reason being is they had all these shredded tires and everything else in there.Seth Tandett (29:00)AllBob Higgins (29:17)And he said, well, it didn't match our minimum. It didn't meet our minimum compressive value. Yeah, but the roadway is holding up. The other ones are falling apart. But we don't have a choice. Our hands are tied.Seriously.Seth Tandett (29:28)So they could see it, like actually see it. There's a roadway that had hit the compressive strength that was specified. And then the one that didn't was actually performing better. Yeah. Well, if they weren't allowed to use it, how did they know that the one that didn't hit the compressive strength was doing better than the other? Is it the other one was just falling apart and the other one was?Bob Higgins (29:28)And I worked together with...Yeah, I mean it's-We're durable. Yeah. Yeah.Well, everything around it was falling apart. They didn't experiment with the rest section, but it didn't meet their minimum compressive value, so they rejected it. But there it is, holding up year after year. That pavement was about 20 years old when I saw it. And there was roadways around it that were less than five years old that had extensive damage from free-thaw. Yes, and exceeded compressive values.Seth Tandett (29:58)Okay.that met compressive strength.Mm-hmm. Okay. I'm trying to piece this together. So high alkalinity can cause high permeability, which is... and high porosity. Okay.Bob Higgins (30:31)and high porosity. It will do both. Yeah, becausethe cement formation doesn't occur. So what replaces it? Water. Because the alkalines capture that water and it's sitting there in place. And if you do a cross section where this has happened, it's really obvious because you see the first inch is full of these little holes and pores and it gradually dissipates as it gets deeper into the concrete. now if it was properly cured,Seth Tandett (30:40)⁓ huh.Right. Yeah.Bob Higgins (31:01)and we control the water, such as with with an internal curing, it should be the same all the way through. Because the goal is if the water gets in, we're going to have problems. If the water doesn't get into the surface, we can get rid of the problems. It is really that simple. But we're not being allowed to do that because the only requirement is how much load will this bear.Seth Tandett (31:23)All right. Well, they're putting, I mean, can you just solve the problem by putting a sealer on it?Bob Higgins (31:28)No, because sealers will wear out. also, don't have, for the most part, they actually can create more problems because with the free porosity and permeability of the concrete, you can get an alkaline buildup behind them. that salts come in, and the salts have considerable hydraulic pressure. For example, if you have an ettringite or like a potassium sulfate orSeth Tandett (31:30)What is that?Bob Higgins (31:52)something like that, if it goes through wet dry cycles, it'll just break the concrete underneath the sealer. The sealer is a real strong sealer. If it's a water repellent, you may end up getting what's called self-fluorescent spalling damage. And so those never work in the long run because they always wear out because they're organic in nature. Concrete should not be treated with an organic material. It should remain completely inorganic.But again, they don't think outside the box. look at it. Well, look at that. It's protected. Well, yeah, for the time being, but at what cost? Because if you look at ASR for floors, ASR can get triggered by the application of an epoxy resin. Whereas if you left it alone, the ASR wouldn't trigger. Because the ASR needs alkaline and moisture and a medium.which is your amorphous aggregate to create ASR. But if you don't trap the water in there, there's generally not enough to trigger the reaction unless it's like a polished surface. We get a dense surface.Seth Tandett (33:00)Can you remind everyonewhat ASRS or.Bob Higgins (33:03)That'salkali-silica reaction. It's actually alkali-agric reaction because there's other aggregates that can react as well. they're now seeing, apparently, seeing an uptick in ACR alkali-carbon reaction with the limestone. So we're jumping into new territory and creating some more problems.Seth Tandett (33:18)Yeah.Gotcha. All right. So I think we've defined alkalinity. Do you want to talk about how to prevent high alkalinity today? Or is that not something we can talk about in a short amount of time?Bob Higgins (33:32)No,that's no, that would probably take a series to do that because it depends because it really these are regional and and I have offered to the different cement producers look I'll sign an NDA but let me know what kind of alkalinity you have and also the other wild card in this because we don't know what it's doing are the cement grinding aids. We don't know what happens to those when they're exposed to the high alkalinity.Seth Tandett (33:34)Okay.Bob Higgins (34:00)because it still meets the compressive value. And these grinding aids are amine-based and glycol-based. Now, they're not supposed to migrate, but they do, because that information got out in this one study, and they've been scrambling around trying to cover it up, saying, no, that didn't really happen. That was something else. No, these things migrate. the moisture migrates to the surface of the concrete because of the heat.Well, no, it doesn't work that way. If it's migrating towards the surface, that means it's containing a chemical that's activated by heat. That's not the water moving. It's something else that's moving. Because he said, it's moist. Well, the moisture is moving through. I said, no, it's not. That's called diffusion. So if something's dirty and there's a place that's clean, it wants to go from dirty to clean. That's the way it works. It's really that simple. So when salts get more active,when they're warm, it wants to move towards the warm side. And it brings the water with it. It's not the water bringing that. It's bringing the water with it. So it's kind of a dual whammy here. And again, it is not being studied. And if it's not being studied, we're not going to figure out how to fix it. And I keep asking these laboratories, would you please start looking at alkalinity? And they're not doing it.That will fix so many issues if we start addressing that. If we can consume alkalinity, but here's the other one too.Seth Tandett (35:25)Yeah. Is there, is there,wait, is it, think they're not doing it because there's no money in it?Bob Higgins (35:32)I think, I think what I honestly don't know. Cause some of, I believe is intentional and some of it I believe is just because this is the way they've always done it. Cause I was, I was caught in that trap for a long time. And then when I realized almost everything I learned about concrete was wrong at first, I was upset. Then I got intrigued. Then I realized why I was part of the problem too. Cause I was telling everybody the same bullshit that everybody else was.Seth Tandett (35:36)Okay.Right.Right.Bob Higgins (35:59)That's not the way it is. The real world, this is what happens. Because we're dealing with kinetics here. We're dealing with influences that you can't capture in a laboratory. it's like I was helping this one company where I was doing some consulting for. They literally had a waterproof concrete. Water did not move through it. It had no connecting capillaries. But it was being flunked by the architects because the RH was too high.I said the RH has nothing to do with water volume. Because he said, what do you mean it has nothing to with water volume? I said, if you take a cubic meter of space and you want to fill it up with water, it takes a little over 264 gallons of water to fill it. But if you want it to get to 100 % relative humidity, you need less than two ounces of water. So don't tell me this 100 % relative humidity is a big deal, because it's not. It gives no.indication as to water volume, but they couldn't do that. So what I did is I took my knowledge of salts and I had them add a salt, a very inert salt to their concrete mix design. And we were able to engineer it to hit between 80 and 85%, which is what the architect wanted. The water content was exactly the same. We just add a little bit of salt to it. I mean, how stupid is that? We have to modify the concrete.to meet a standard that doesn't make any sense. But that's because everybody told you it does make sense. The humidity is really deadly and all that, blah, blah, blah. said, okay, then explain this to me. The National Association of Homebuyers builders in the United States have stated there's over 148 million residences in the United States. Over 70 million of those are built over slab on grade and the slab on grade will try to.reach equilibrium and they're making that the big scary issue with RH. Once it goes into equilibrium after you put the floor down, this disaster's gonna happen. really? Then there should be some correlation. There should be like 50, 60 million failures. There's a few thousand, but not millions. There's a few thousand. And so that means it's something else. So we're being, again, we're herded into this fenced area.Seth Tandett (38:07)Right.Bob Higgins (38:16)were of non-science, and I call it nonsense non-science, that doesn't make any sense. But everybody's trapped there because they're afraid to ask questions because they don't want look stupid. Well, I've never been afraid of looking stupid. I've done that all my entire life. And I will ask questions.Seth Tandett (38:32)Ido it multiple times a day. All right. Well, I think we defined alkalinity. And yeah, we'll bring you back. I know we got a lot to talk about. Is there something that you have coming up that you want to plug? I know you just did a talk a couple of weeks ago with the moisture mob. Is there anything else coming up?Bob Higgins (38:35)Yeah!Well,I'd like to do a follow-up on this and the four different common properties of water. Because everybody is familiar with water is a vapor, water is a liquid, water is a solid. But there's two more forms of water that are in concrete that are not being addressed. And that will tie in with what we've just covered here with alkalinity. And once that tie-in is given,people understand why moisture moves the way it does. And then once you understand why moisture moves the way it does, now you've got the tools to start controlling it. That's why I didn't want to a dive into that area because that needs its own coverage, its own podcast.Seth Tandett (39:22)Okay.Perfect.All right. We'll do hold another episode on that. That's perfect. I appreciate it. Thank you, Bob, for coming on the show today. Yes, sir. It's always a pleasure. And folks, until next time, let's keep it concrete.Bob Higgins (39:42)Well, thank you for having me.