sustainable-structures

RH Testing of Concrete Floors - The Harsh Truth

Sat, 31 Jan 2026 08:31:22 GMT

After endless debates and a constant request for data that apparently doesn't exist, I decided to expose a widespread fraud and call out the manufacturers who require RH testing in the mistaken belief that such testing will protect their interests with some believing RH testing is appropriate for existing concrete floors to ensure a safe condition in preventing moisture-related problems and failures.

RH Probes - What were these evaluated for?

Although most of the earlier exaggerated claims have been removed, false claims still exist with what the RH measurements actually measure and how the data is consistently misinterpreted and misrepresented. I will cite directly from the sources.

The Lund University/Hedenblad Study (1997)

Although now obscured (which I believe to be intentional due to the consistent pattern of bold claims then withdrawal then denial of the bold claims), the Lund University Study was the impetus in developing the ASTM F2170 method.

What Was the Purpose of the Lund/Hedenblad Study?

Irrespective of claims to the contrary, the study focused solely on the initial drying rate of concrete after placement. Here are excerpts taken directly from the study:

The title of the Study - "Drying of Construction Water in Concrete" "The publication discusses the length of time needed by concrete structures to dry out after construction in order that damage to adjoining constructions and finishes may be prevented."

Why the Study results (and subsequent studies and tests) are NOT applicable for concrete that has been in service - The drying times given cannot be used in drying out concrete after water damage. The reason for this is that old and mature concrete has different drying properties from those of younger concrete. The drying times given in this publication are typical values. Obviously, they are no substitute for moisture measurements but must be seen as a complement to these."

NOTE: Right in the very first page after the title/description the study clearly states this procedure is OBVIOUSLY "no substitute for moisture measurements."

How clear and obvious does a study language have to be to prevent misapplication and misinterpretation of intent and evaluation?

Study acknowledges high alkalinity but does NOT differentiate high pH from high alkalinity, so the message gets muddled.

"Damp concrete has very high alkali content. pH is never lower than 12.5 and may often be as high as 14. Cement of high alkali content produces a higher pH value in the concrete and thus entails a greater risk of degradation in e.g. adhesive and floor coverings."

The above statement from the study clearly refers to "new" concrete since older and mature concrete can have a pH lower than 12.5. High alkali content can also be lower in pH, depending upon the type of alkaline, particularly after carbonation.

Reaffirmation this Study was restricted to the mix water of concrete (NOTE: I added bold to "quantity of construction water which must dry")

"In making conventional concrete, often ca 180 litres of water is used per m' of concrete. Some of this water is chemically bound to the cement. Another portion is bound in the pore system of the concrete. The lower the water-cement ratio, the more moisture is bound chemically and physically, i.e. the smaller the quantity of construction water which must dry." Page 10.

The deadly word "assume" creeps in, where an assumption is made without verification and again indicates a misunderstanding of the difference between high pH and high alkalinity! I have highlighted assume

"This means, for instance, that the diagrams for drying to 90 %rh applies for drying to RH = 87.5 % in a concrete with Slite cement and w/c ratio of 0.37. It is thus assumed that water of higher alkali content in a concrete with w/c ratio = 0.37 has the same effect on the flooring material at RH = 87.5 % as a water of lower alkali content in a concrete with w/c ratio= 0.7 at 90 %rh. The effect of alkali in lowering RH is demonstrated. In the adjustment of RH in the above table it is assumed that it is the quantity of moisture in the liquid phase which is in contact with the floor covering that determines the critical moisture state." Page 15

This above section is wholly incorrect in its assumption since alkalinity and pH are used as interchangeable terms, yet represent completely different conditions. High pH WILL reduce measurable RH, but lost in this study is that increasing alkalinity will CONTINUE to reduce the measurable RH!.

The justification of results is based on a careful control of the ambient conditions, again based on freshly placed concrete, NOT concrete that has been in service!

"Case f: Continuous rain for 2 months. During the first two months after casting it rains. Drying then takes place at + 18°C and 60 %rh. 14 28 days Time 2 months.

Case g: Rain again after some drying. Normal conditions (Case a) during the first 2 months, followed by rain for 2 weeks. Drying then takes place at +18 °C and 60 %rh." Page 17"

"There is an American standard (ASTM E 104-85) for RH calibration which specifies the salts to be used, the required purity of the salt and water, the requirement regarding temperature stability, etc." Page 24

Calibration of RH sensors (ASTM E 104-5) Commercial calibration kits based on ASTM E104 commonly include LiCl (≈11% RH) and NaCl (≈75% RH).

WHY pointing out the calibration salts is important: The calibration salts, even though are mostly water are classified as "salt saturated solutions" where the salts used for calibration can no longer be dissolved into the water, hence achieving "saturation". The RH of these calibration salts is 11% and 75% respectively...it matters not if there is an ounce or a 100 gallons of a saturated salt solution, the RH is constant. Alkaline salts can vary in concentration and therefore vary in RH measurable by a RH Probe.

Different Errors

The Lund study points out critical errors that can be experienced, even when calibrating or recalibrating a RH Sensor.

"Examples of systematic errors are

a. Systematic error in the salt solution used for calibration.

b. Non-linearity of the RH instrument.

c. Temperature during measurement is different from that during calibration.

d. Drift in the RH meter, i.e. the reading for a certain RH changes in time.

e. Temperature difference between the RH sensor and the concrete.

f. Moisture is measured at a temperature different from that "in service" Page 16

NOTE: The most impactful and nom-disclosed to most who require or use these RH Probes are c, d and f.

c: I have yet to see ANYONE disclose if the temperatures during calibration and insertion into the concrete has been conducted. this alone can create a challenge since proper calibration without this data cannot prove the calibration was done correctly, undermining any and all results...has ANYONE been shown this data?

d: Even in field studies, it was noted that the were errors in the RH measurements as the sensors would "pin" at a higher RH and not adjust when RH levels would reduce during the testing. This required removal of the sensor, drying and recalibration before reinsertion, with differences being noted after this procedure....has ANYONE been warned of this possibility?

f: The gradient portion of the concrete, which averages a depth of 0.75-10 inches into the surface will actively change in both temperature and humidity in response to the ambient conditions. In depth, these changes are extremely slow and do not reflect surface absorption or desorption of moisture, where a concrete surface can be saturated or dried, even as the 1.5 inch depth remains constant. So moisture can readily penetrate a concrete surface as the depth section remains stable..what do YOU think will cause a flooring failure, a stable interior environment or a dynamic gradient where the concrete can be saturated and WILL begin to actively absorb moisture, possibly to critical levels if the temperature of the concrete is within 10oF of dew point.

The Influence of Alkali on RH in the Concrete

This is the title of appendix #4, page 49 of the Lund Study. It is acknowledged, but woefully understated just how dramatic alkalinity and the presence of other hygroscopic materials can have when measuring RH.

The quantity of alkali (sodium hydroxide NaOH and potassium hydroxide KOH) in the cement influences the RH measured in the concrete. The alkali in the cement is to some extent dissolved by water when the concrete is mixed. The more cement there is in the concrete, the more alkaline (basic) the concrete will be. Different cements contain substantially different contents of alkalis.

If the quantity of moisture in kg/m' is the same for two types of concrete which are identical apart from the alkali content, the measured RH will be lower in the concrete with the higher alkali content. Concrete with a low water-binder ratio can contain appreciably more alkali than ordinary concrete. This means that concrete with a low water-binder ratio can, at the same RH as conventional concrete, contain more moisture. This moisture which has a high alkali content - the pH value may be over 14 - can for instance cause saponification of the plasticiser in vinyl floor coverings, with bad odour as a result. As pointed out above, alkalinity depends on cement type and different mineral additives such as silica fume or slag.

One probable consequence of the fact that the same moisture content in concrete can produce different values of RH with different degrees of alkalinity is that there are no generally valid critical relative humidities RHCR1T' HCRITmay vary depending on the type of concrete and its alkalinity. This has not been generally known before.

NOTE: This fact ALONE is WHY neither F2170 nor F1869 can be considered "quantitative" and the F6 committee is in error for allowing such a title and even to the point to where neither can be even considered a qualification on a stand-alone basis.

Quantitative is based on known factors, with the most likely unknown factor being location and quantity of alkaline salts within the concrete. Even with known factors, to quantify also requires no significant deviation within a given context. Without context, quantification isn't possible.

Alkalinity in Concrete Even Affects the drying rate of Concrete and Errant Conclusions

The Lund Study makes an egregious assumptive error in the following statement from Page 50:

"For two types of concrete which are identical apart from the alkali content one consequence of different alkali content is different drying times to one given RH level (e.g. 85 %rh.). The concrete with the highest alkali content has shorter drying time to the level than the concrete with a lower alkali content. This is due to a larger quantity of construction water has to dry out from the concrete with the lower alkali content to reach the given RH."

The author assumes that removal or lowering of RH equates to removal or lowering of moisture content in the presence of alkalinity. In my view, this is an unacceptable misunderstanding of what alkalinity does as it concentrates:

As water is removed, alkalinity increases, along with a reciprocal decrease in measurable RH.

An alkaline/water solution at 20% NaOH has a measurable RH of 78% and as it continues to concentrate, the RH continues to reduce to where a 30% NaOH concentration has a measurable RH of 63%. This DOES NOT mean the concrete is dry, yet that is the assumption suggested by the authors.

Concrete with a higher alkalinity has a different "dry rate" than low alkaline concrete since its equilibrium moisture content is naturally greater.

A key issue is that any changes in the concrete chemistry also affects the RH of the concrete, which successfully supports the hypothesis that the continued changes in concrete need to be re-evaluated and ALL associated ASTM and other standards need to be updated to reflect these changes, yet most standards are based on concrete no longer used.

How can ANYONE require test methods for a material of any kind that is substantially different from what was previously evaluated? That is an indefensible, non-supportable position, particularly when it has damaged those who did not follow such inappropriate requirements.

Other RH Evaluations that need to be Questioned

The only published documentation for RH Probes are based around new concrete, with at least one of the studies conducted by a group with a vested interest (patent older).

To establish validity, methods and products need to be tested by accredited and disinterested third parties.

Worse, much of the non-facts circulated critical of moisture meters such as Tramex are by those with a vested interest in the RH Probes and NONE of them have any data to back up such critiques.

We NEED to Move Back to Reality in Moisture Testing

One of the most damaging, most disparaging and LEAST accurate claims by the RH Promoters is that Tramex moisture meters aren't accurate.

The reason behind this push to discredit Tramex is to guard the false assertion and insistence that all moisture testing MUST be in acclimated conditions...well guess what, that claim is pure BS and I used to buy into that until I realized just how dependent waterproofers, restoration contractors and roofing contractors were on Tramex.

What each of these professions have in common when the Tramex meters are used is that NONE of these professions require acclimation for accurate moisture measurement testing and in nearly all these conditions.

Profit is the motivation in blocking accurate testing...conflict creates opportunity and as Tramex continues to gain wide acceptance, the money train that runs on confusion and conflict will come to a dead stop.

Dear flooring manufacturers and installers, what do you think will happen when your required moisture testing no longer requires acclimation and the inevitable battles and conflicts with the construction managers, owners and general contractors end?

Likewise, if these same groups continue the path of inappropriate testing, requirements and easily provable methods where most moisture mitigation systems were unneeded, unnecessary and a burden on the flooring installer, project scheduling and damaged reputations and obligated penalties that should never have happened?

The potential legal battles could be endless and create a crisis within the flooring and coating industries.

Save your headaches and bottom line, make the change.

I will challenge any and all that take exception to the content of this article. Moving to accuracy will be a lot less stressful and a LOT less expensive than an endless line-up of lawsuits and settlements.

Remember the words of the RH promoters when they moved to successfully supplanted the CaCl test method; "If moisture testing was so accurate, why are we still having failures?"

Are the Industry Elites Failing Concrete?

Wed, 17 Sep 2025 06:06:20 GMT

Last week, I sat in on an event where a social media influencer—someone who’s built a sizable following in the concrete world—took the stage. His delivery was slick, and the crowd was split: some loved the energy, others saw right through it. As I listened, it became clear that what he was selling was more hype than substance—and worse, much of it was misleading to the very contractors he claimed to help.

Let’s talk about the elephant in the room. Over the past few years, the industry has been thrown into chaos by the sudden rollout of limestone and blended cements. These products arrived with little warning, and contractors had no choice but to adapt on the fly. The result? Mistakes, complications, and costly failures—costs that manufacturers didn’t have to bear. The people on the ground, the ones actually working with these materials, were left to figure it out, shoulder the expense, and clean up the mess.

Manufacturers fixed their formulas without taking responsibility for the fallout. They didn’t foot the bill for research, nor did they invest in training the workforce they blindsided. It’s a modern twist on an old story: push a new product, let others deal with the consequences, and treat real-world users as unpaid R&D.

That’s not where the rot stops. Watching that presentation, I realized how easily social media personalities, consultants, and even PhDs have turned industry committees and organizations into echo chambers. These platforms, which were intended to establish standards and protect the industry, have become platforms for self-promotion and corporate agendas. I’m not here to attack any one person or group. The truth is, most of these organizations started with the right intentions, but many have been corrupted by commercial interests and the relentless drive to push new products for profit.

We need experts, researchers, and standards—no argument there. But those standards must be objective and immune to company influence. When gatekeepers in the industry openly admit that certain admixtures will never be accepted as long as they’re around, despite proof they work, you know something’s gone wrong. The good news? Some of these old-guard power brokers are retiring. Maybe when they’re gone, real change can happen.

But we won’t get there if we keep ignoring reality. At that event, the “data” being presented wasn’t based on the new materials contractors are forced to use today. Instead, it was all about Type I/II cement—the old material, used for a century. As I watched the presentation, the data was all based on cement that’s no longer relevant. It’s misleading, and it’s precisely why contractors are struggling. We’re still relying on outdated data because, frankly, there’s no real history or experience with 1L cement here in the U.S. Manufacturers love to claim, “We’ve been using this for 30 years in Europe!” But they faced the same problems there, and many still do. If you want the truth, don’t ask the manufacturers—ask the contractors actually working with these products.

I’m all for innovation, but not when it comes at the expense of honesty. Over the last five years, I’ve watched this industry become more deceptive and self-serving. The stated commitment to “working together to solve problems” is little more than PR. Behind the scenes, the same influencers and researchers are protecting the old relationships between committees, manufacturers, and producers. Let’s not kid ourselves: researchers depend on industry funding, and they’ll do what it takes to keep the money flowing. That means Band-Aid solutions that guarantee recurring revenue, not permanent fixes that would put an end to the cash cow.

What’s worse, far too many in our field don’t know how to question the information thrown at them. We attended that event to learn how to work with new cement chemistries, but we received nothing but recycled lessons from the past. Challenge the status quo, and you’re treated like a heretic. But the truth is, the people we should be learning from are the ones in the field—those who’ve found ways to make these ever-changing materials work under real-world conditions.

Let me be blunt: the dogma around water-cement ratios and “strength equals durability” is outdated. Lowering the water-cement ratio and pouring in more chemical admixtures is like building the walls of a house before laying the foundation—completely backward. Lab results don’t reflect reality. Your lab might be a steady 70°, but out in the field, temperatures swing and humidity drops, and those perfect ratios stop meaning anything.

A final word: I love this industry. I’m not here to tear it down. But I am angry—angry at the corporations and individuals who profit while hardworking people pay for their mistakes. The men and women in this business just want to do their jobs, earn a living, and build a future for their families. They deserve honesty, transparency, and respect—not to be used as guinea pigs in someone else’s experiment.

It’s time we demand better.

The Chemistry Nobody Wants to Talk About: Why PLC (1L)Cement Is Forcing Us to Rethink Everything

Sat, 23 Aug 2025 05:16:14 GMT

Let’s cut through the corporate fluff for a minute. If you work with concrete—actually work with it, not just write specs from a desk—you know something’s off. The transition from classic OPC to One L cements hasn’t been smooth. It’s been a minefield. And the industry’s response so far? Mostly denial, hand-waving, and a lot of “Europe’s been doing it for years.” I’m done with that.

I’m a third-generation finisher who clawed my way through a real-world doctorate because I wanted answers. That’s why we partnered with a University on a study that isn’t just another lab exercise. We put five major PLCs head-to-head with old-school Type I/II, running every test that actually matters in the field: loss on ignition, real limestone content, heat of hydration, TGA for CH, set times, density, particle fineness. No shortcuts. No manufacturer-sponsored “happy path” results.

What We Actually Found

Loss on Ignition : PLCs are drifting by 2% compared to OPC.
Limestone Content : Limestone content inconsistent with what’s reported and what’s real.
Heat of Hydration : OPC clinkers run cool and steady. PLCs light up quickly, and after seven days, every PLC cement burns hotter than OPC. That’s not just a lab curiosity—that’s a real-world headache when you’re pouring in the summer.
Set Times : OPC’s initial set? Two hours. PLCs? 1.6 hours. Final set for PLCs drifted out to 4.5 hours, sometimes longer. If you’re scheduling crews or timing finishing, this matters more than anything on the datasheet.
Density & SSA : Lower density, higher specific surface area on PLCs. Water demand is very high if you’re still running old mix designs. Good luck.

The Admixture Roulette

Here’s where it gets ugly. We tested three major admixture lines—water reducers, air entrainers, accelerators, and self-sealing admixtures —with Minimum to maximum dosages. The results? All over the place.

Water Reducers : Either no workability change or a drop. The “neutral” claim doesn’t hold up in the field.
Air : Sometimes we gained, sometimes we lost. No pattern, no predictability.
Accelerators : went from “sometimes works” to “who knows?”
Self-Sealing Admixtures : a decrease in strength, decreased workability, and air instability.

For God’s Sake, Stop Worshipping Strength

And for God’s sake, quit depending on strength to be the end-all, be-all of great concrete. It’s absolutely madness to keep thinking in this mindset, and it’s dangerous to anyone who cares about actually producing quality concrete. Just because you pump up the strength numbers doesn’t mean your chemistry works. All you’re doing is gaming the system. You can hit higher breaks all day long and still end up with a mix that cracks, curls, or falls apart a year later. Strength is just one metric. If that’s all you’re chasing, you’re missing the real story—Finish-ability, durability, long-term performance, actual in-place results. We’ve got to break out of this mindset if we’re ever going to get real progress.

What’s Actually Going On

The chemistry changed. Less clinker, more limestone, plus whatever SCMs get tossed in. The old admixtures can’t keep up. And the worst part? Most of the committees and standards bodies are stuck in the past, more worried about politics and reputations than what’s happening at the truck chute.

Europe has been grappling with this issue for decades, but most of its problems have been swept under the rug. I’ve talked to contractors and producers over there—they’ve got the same issues, they just learned to live with them. That’s not good enough for me, and it shouldn’t be good enough for anyone who actually cares about performance.

Time to Blow Up the Old Rulebook

Let’s be real: The only way forward is to admit our old methods don’t work and start over. New cements need new chemistry, and that means new admixtures—real ones, built for the system we actually have. We’re already running nanotech admixtures in the field, and they’re outperforming traditional admixtures with PLC. But you can’t just bolt them onto old habits and expect miracles. You need to rethink everything: how you test, how you place, how you finish.

And yes, that means challenging a system that’s more focused on maintaining comfort zones than addressing issues. The resistance the industry shows indicates you’re on the right path. From smear campaigns to denial, they’re not new—they’re just the final effort of outdated thinking.

For the Next Generation

This isn’t just about me or my research. I remember what it was like to be out there with nobody looking out for my best interests. Now that I’m on the other side, I refuse to let the next generation get stuck with our mess. We owe them better than that.

Publishing of the Full work will be in 2026 with all the data—no spin, no sugarcoating. If you’re facing these challenges or want to talk through solutions, DM me. I’d rather have a challenging conversation now than watch another project fail quietly. It’s time to stop hiding from the chemistry and start building something that actually lasts.

Let’s get out of our own way and do this right.

Ask a Simple Question: The Key to Unraveling Confusion in Moisture Testing, Concrete Durability and Refocus on Context

Thu, 17 Jul 2025 11:33:14 GMT

I admit to being a bit of a curmudgeon; well-earned after decades of listening to and experiencing misdirection and false priorities.

I often ask simple questions with the intent to find out IF the subject matter is being dealt with objectively, or is being presented and used in the proper context.

Unfortunately more times than not, the information is not only lacking proper context, the information is intended to "prove" something that isn't within the realm of reasonableness, yet these STILL manage to get accepted if promoted by the right persons/entities.

Testing 1-2-3

Testing and what constitutes testing is one of THE most misunderstood areas in ALL disciplines. An incorrect test, standard or study promoted and/or interpreted out of context is currently a leading cause of why everything continues to become more expensive and when the different professions KNOW they are being pickpocketed, but can't or are technically incapable of protecting themselves, if a "test" or conclusion relieves them of these burdens, right or wrong, these approaches are the easiest to accept and questions are NOT asked for the appropriateness of these acceptances.

ANYONE Can Test ANYTHING

If I compare most current tests for concrete curing, there is little to no differentiation between tests conducted in the 1950's and tests being conducted as we speak.

Most of these tests arrive at similar if not the same conclusions, yet these conclusions do NOT match reality...this is where the simple questions should be asked to separate the chaff from the wheat;

What is the motive for the study/test?
What has been determined as "root-cause" to direct the study/test approach?
Is the test format based on isothermal or non-isothermal conditions? If the subject/material to be studied expected to exist in specific conditions, the base test/study should reflect these conditions.
What are the test/Study requirements?

These questions are very revealing by how they are answered.

The specifications for slab-on-grade concrete is based singularly on a single property, which is compressive strength at 28 days. As long as manufacturers of flooring and coating materials continue to accept this...nothing changes.

Likewise for specifiers and those who want durable concrete, a singular focus on compressive strength at 28 days, which does NOT directly correlate with any other property that can determine durable concrete, we end up in a hamster wheel of going round and round, doing the same thing over and over and expecting a different result.

IF YOU DO WHAT YOU'VE ALWAYS DONE, YOU WILL GET WHAT YOU ALWAYS GET!

F2170 - This Standard measures relative humidity, which is simply any moisture in its vapor/gaseous state. This standard is based on the INITIAL drying rate of concrete. The initial drying rate is the excess water used in concrete to be placeable (also called water of convenience). Once this initial drying is essentially completed, actual moisture testing can begin. This caveat is NOT indicated in the standard, yet should be since the premise is based SOLELY on the initial drying rate.
Relative humidity; this is water vapor present in open areas, irrespective of space volume...this critical point is consistently lost, ignored or unknown to those who WRONGLY require this as a standard to determine the "dryness" of concrete. The assumption, since these studies were not just based on the mix water, but also were tested under isothermic conditions, have NOT been qualified in ANY manner that duplicates field conditions
Capillary water and gel water; once the initial drying rate has concluded, the majority of moisture volume in concrete has been established to be capillary and gel water. The volume of water in capillaries and gel can be hundreds of time greater than concrete at 100% RH levels. This is easy to prove though gravimetric where a 100% RH will produce almost no weight change in the concrete, indicating the concrete for practical purposes is "dry". It was noted by Hedenblad and others in the Lund Study for capillary water, the volume of moisture is determinable most accurately when measuring the capillary water. The most important difference, even though, once again the study was based on isothermal conditions, this study was conducted to measure moisture content of set and cured concrete, whereas the study for RH Probes was based on the initial drying rate.
RH Probes in non-isothermal conditions. The promoters of RH probes, other than the companies such as Giatech and others who use embedded humidity measurement devices have NOT been effective or produced useful moisture content information when subjected to field conditions. In each and every situation, the RH probes could not accurately measure moisture content, with even the stated range/measurement limitation of 10%-90% RH. Four different RH sensors provided four different RH measurements, even in isothermal conditions....which is but one reason no one ever sees comparative "apples to apples" comparison of RH sensors, where instead the RH Promoters use "apples and oranges" attempting to justify their results versus other methodologies. In non-isothermal conditions, one constant WAS discovered when comparing shallow RH readings versus the deeper measurements within the F2170 standard; the surface RH was ]routinely lower than 80%, which produces a vastly different quality of concrete where the RH no longer permits cement development. The deeper measurements have a nearly full development of cement content whereas the surface experiences self-desiccation and essentially a concrete surface that is as different from the interior portion of the concrete as the bread crust is from the interior portion of the bread...technically it is still bread, but the characteristics are vastly different from the remainder of the bread. The surface of concrete is also distinctly different from the interior section. This isn't my opinion...it is proven through MANY third party studies.

Constants to Know When Asking the Simple Question

Are the Studies isothermal or non-isothermal? These test conditions rarely, if ever correlate, yet isothermic conditions are routinely used to determine suitability for non-isothermal conditions..THIS, more than ANYTHING else is responsible for the ongoing non-progress we have in solving most issues.
Are the studies representative of what the intended environment will be subject to? Unintentionally, the RH Promoters have shown us what happens with concrete, even in isothermal conditions where the concrete surface gradient can have an internal RH of less than 80%, which CLEARLY differentiates the surface from the remainder of the concrete. Even at 80% RH, cement development is estimated to be at a greatly reduced efficiency of 10%. Below 80%, cement formation ceases...so the RH promoters want all of us to believe that the full cement development 1.5 inches is somehow representative and predictive of the surface gradient that is shown BY THEIR OWN DATA to be significantly different.
ASTM and ALL accepted industry standards are VERY direct, if it isn't SPECIFICALLY stated as the intent, then ANYONE using a standard outside the intent is doing so in a misguided and VERY misapplied way.

Go on, show me where in the F2170 specifically states it measures the moisture content of concrete as is CONSTANTLY advertised by some of the RH Promoters.

And Finally

Two studies, many years apart conducted by The Army Corps of Engineers and the Solar Agency in Florida found that the center portion of the concrete can remain adiabatic.

Why this is important; Adiabatic means the temperature and moisture is unchanging/stationary, it ISN'T freely migrating THROUGH concrete as we are all taught to believe....when conditions were elevated concrete has higher moisture content than on-grade concrete with or without non-permeable steel pans...there is NO underlying moisture source for these concrete floors.

Where migration of moisture is misinterpreted by those with no experience in the waterproofing, roofing or restoration fields is that water can transport materials by diffusion, with those that do not understand the differences claim the reason the contaminants from another location PROVES the moisture migrated, even though the water has remained stationary. We conducted such experiments in high school where dyes and salts would "migrate" from one container to another or even within the same container by diffusion and even convection, but NOT by "moisture migration".

The other constant...although many have claimed otherwise, water is in its densest form as a liquid...therefore water vapor CANNOT migrate through liquid water, which is present in capillaries and gel water...so any moisture that enter from say the bottom, is blocked by capillary water and gel water..the capillary water remains non-moving for MANY years...but water WILL evaporate from the surface of the capillary and gel water. Here is where things get REALLY interesting; several researchers have expressed frustration that when cutting or breaking concrete, they cannot detect the migration of water and end up using gravimetric to determine moisture content. As is the case with so many others...because they can measure moisture going into the underside of a concrete specimen and measure moisture coming out of the top of the concrete, the ASSUMPTION is that this is moisture migration, even though it is much simpler than that...this is moisture moving in and out of the various external gradients of the concrete. NOT ONE SINGLE RESEARCHER HAS TRIED TO OR BOTHERED TO MEASURE NET GAIN AND LOSS....measuring ONLY the gain or loss.

Moisture moves in and out of a concrete surface, but this has been ignored..measuring ONLY in a single direction. THAT is why moisture content is measurable with gravimetric but not visible because the water ISN'T "flying" through the concrete.

Certification of Moisture Testing

Until the schools and agencies start teaching the basics of concrete and the chemical influences and the five forms of moisture within concrete, my criticism of what is taught about measuring concrete moisture remains unwavering. In my opinion, what is being taught is as much a negative as a positive...using circular logic to justify the respective curriculums.

NFCA has taken the first bold step into proper education.

From Logical Fallacy: "Circular logic, also known as circular reasoning, is a logical fallacy where the conclusion of an argument is assumed in the premises. In other words, it occurs when the reasoner begins with what they are trying to end with, creating a "circle" in reasoning. For example, saying "Everyone must obey the law because it’s illegal to break it" is circular reasoning, as it uses the conclusion as a premise. This type of reasoning is often seen as a pragmatic defect in an argument, as the premises require proof just as much as the conclusion does."

Now, let's apply this to the flooring industry: "we use this standard because everyone else uses it."

When I ask what is the reason you are using this standard as a warranty requirement. This straight forward and simple question rarely if ever gets a direct answer; instead, circular logic kicks in yet again, wash, rinse, repeat....

The Importance of testing the concrete Floor Surface - It's NOT my opinion, It's based in fact!

Thu, 22 May 2025 07:48:13 GMT

It still amazes me how there is even a discussion that the lowest volume of moisture, tested 1 1/2-2 inches into the concrete takes precedent over surface testing, where the floor actually fails, due to liquid moisture, the largest volume of moisture in concrete and the only way alkalinity or other compounds can damage a floor.

The Concrete Surface IS different from the rest of the concrete

I used the graphic where RH probes were trying to establish a narrative that uncoated concrete in this study had a low RH in the surface, with the RH being higher in the lower regions of the concrete, then later on it would "equalize". My question is, when hasn't this happened, and further, statistically nearly 100% of concrete foundations will re-equilibrate, but statistically less than 1% of them fail.

NEWSFLASH: This is EXACTLY why surface testing is critical!

When the RH of concrete drops below 80%, cement formation ceases; in the meantime, in this same graphic, it shows the cement formation inside the concrete (where the RH Probes are embedded) is in a desired RH threshold. Even at 80% RH, cement formation is very slow and inefficient. With ALL new concrete, to get a durable surface and in turn a durable concrete, the RH MUST be maintained at a very high RH.

Once the cement formation is interrupted, there is a permanent loss of available cement formation. I often saw this in petrographic analysis where I would request the petrographer estimate the percentage of unhydrated clinker. NOTE: "clinker" is the material designed to become dampened sufficiently to produce cement. "Cement" isn't cement until it hydrates, otherwise it is simply another form of "dirt", giving no beneficial functionality to the end product.

Claim Versus Fact

There is a terrible assumption that leads to claims of "properly cured concrete" producing a homogenous solid. Those claims are based on assumptions, NOT fact....I know because for many years I was also under that assumption, until more sophisticated testing and research revealed the fact that it is a rarity that concrete can be "properly cured" in the manner in which it is represented. Most curing protocol are over 100 years old...and the cement/concrete used 100 years ago (even 25 years ago) is MUCH different than the concrete we use today, yet adjustments to our procedures for curing concrete have NOT kept up with the constant changes cement AND concrete have undergone in the past 100 years.

Fact Versus Claim

One of THE most telling facts are those that undo the claims made about the importance of moisture in concrete and what that moisture does.

Those promoting RH Probes ignore the FACT that even a small amount of liquid water has much more volume than an area with a 100% RH - at ANY temperature. NOTE: In a cubic meter of air space, it would take more than 264 gallons of water to fill that space, yet it would take less than 2 ounces of water to produce 100% RH.

At 100% RH, the maximum volume of water in vapor/gas form is less than 200 grains per cubic foot of space, the maximum amount of vapor pressure (for an uncoated concrete surface) is 1.2 psi and is even lower once a floor covering is installed since one of the pressure influences (RH differences from the concrete surface to the ambient conditions) is removed. NOTE: The 1.2 psi is based on uncoated concrete where the differences in temperature AND humidity are involved, in reality is the pressure is substantially lower than the 1.2 psi maximum. A standard adhesive has 40 times more bond strength than can be exerted by the highest level of vapor pressure.

The narrative of RH measurements has altered, as questions have come up.

First the advertised claim was "RH Probes are the most accurate method to measure the moisture content of concrete", along with claiming to be a "predictor" of future moisture claims, neither of these claims are accurate. Most RH promoters now state what is described in ASTM F2170, which is the measurement of RH within the concrete, NOT moisture content.

There were statements made by some of the "technical experts" of RH Probes that claimed if a salt solution becomes saturated, the RH will return to 100%. Even worse, these "experts" claimed water vapor can transport alkaline salts.

The FACTS are readily available by three well-established examples: The hydrological cycle of the earth, the distillation process for purifying water and visible efflorescence on a concrete surface. ALL three examples prove that solids, alkalis, etc. are transported and carried by water in a liquid form, but as the water is vaporized, the solids are left behind. Yet these basic facts were ignored (or unknown) to these "experts".

Even worse, the building sciences have established a logical priority when dealing with excess moisture. The priorities are ALWAYS: 1. bulk water, 2. capillary water and 3. water vapor...in that order. Yet the flooring and coating industries are upside down in that priority.

With concrete, the initial bulk water is the water of convenience, where most of the bulk water is reduced by the very properties that make concrete such as useful building material; the bulk water begins to evaporate and much of it leaves of its own accord as "bleed water".

After the bleed water is no longer visible, the finishing operations can begin because the majority of the water in concrete at that time is "capillary water".

Capillary water is the highest moisture volume in concrete after the bulk water is lost. Capillary water is NOT measurable using a humidity measurement of ANY type. Capillary water IS measurable with an electric impedance meter. So the greatest volume of water, when relying on an RH Probe remains unmeasured.

As indicated in the above graphic used by the RH Promoters, the concrete surface can and usually will self-desiccate. Cement formation ceases when the RH falls below 80%. THIS changes the areas of the concrete that have prematurely "dried out" and are substantively different from the area(s) that will be measured by the ASTM F2170 procedure. NOTE: If you really think about it, here is what is being prioritized by using RH Probes: ignore the area of concrete that has higher permeability, porosity and great moisture volume and where the flooring/covering is actually applied to and has problems and let's instead measure the buried portion where none of the "bad stuff" is affecting the concrete!

This is the confusing part and why the assumptions exist that "properly cured" concrete will produce a consistency throughout the concrete matrix.

When the water is applied to cure the concrete, ideally it will hydrate ALL the cement.

Instead, as the water is consumed by the cement, the alkalinity present in the surface, greatly affected by elevated temperatures, lower humidity, air movement and sunlight will begin to concentrate.

When alkalinity concentrates, it reduces the measurable humidity. The most voluminous alkaline salt is typically sodium hydroxide. Sodium hydroxide suppresses the solubility of the newly formed calcium hydroxide, even as the NEEDED RH levels decrease. This reduces the "contactable" area normally available for moisture. This is exacerbated by rising temperatures.

This discovery of inadequate curing was discovered by accident rather than intent.

Many studies have shown that water ponding may not penetrate into the concrete where it is needed and as a result, the self-desiccation (autogenous desiccation) can manifest itself much earlier than anyone could have imagined.

In several studies, independent of each other and likely not aware of the other studies, it has been determined that the concrete surface develops a gradient, which coincides with the self-desiccation. This gradient was consistent with each study, determining the gradient to be 19-25 mm (0.75-1.0 inch) of the concrete surface. This self desiccation was noted to occur within the first 2-3 weeks after concrete placement.

The graphic used by the RH promoters even PROVES this gradient exists, even under laboratory conditions where cement formation ceases as the RH falls below the 80% threshold.

This was unintentionally confirmed in a study conducted by TTI (Texas Transportation Institute) where Dr. Zollinger took two concrete samples, one air cured for 7 days and the other water cured for 7 days.

The lower compressive strength of the air-cured as compared to the water cured sample surprised no one; but what WAS surprising is the 7 day water cure, where the top one inch of the concrete was evaluated independently from the remainder of the concrete, was a full 20% lower in compressive value as compared to the fully intact concrete.

This helps to explain the industry assumption of a uniform, homogenous concrete; even compressive strength tests helped to "hide" these differences since the compression strength tests are based on the breaking of the sample. With a slightly weaker surface, there may be some unnoticed crushing, but this crushing effect is outside the capacity of the standard compression test is measured ONLY at time of breakage.

I believe if all concrete samples were evaluated in the manner as devised by TTI, there would be a shockwave throughout multiple industries.

THIS is Why Electrical Impedance Meters (based on Independent, Third Party Study under field conditions) are critical, not only for the actual measurement of moisture content, but NEEDED immediately before and during installations. IT is the SURFACE that is distinctly different from the remainder of the concrete.

Testing At Time of Installation - The Missing Link

No testing hours or days prior to an installation is any indication of whether a coating/flooring installation will be successful. Too much can happen between the time of testing and what the concrete surface may be exposed to in the interim.

Older concrete in particular can present MANY challenges and way too often I've heard complaints where a former flooring/coating was removed after successfully performing for many years, only to have the subsequent floors fail multiple times. This is the genesis of more assumptions.

Concrete can be in dynamic equilibrium with the moisture content with an existing floor/coating, yet once the coating/floor is removed, the concrete surface is now exposed to a "new" moisture source, the ambient air.

The most profound example of this happened in 2023. I had given a presentation to a Northern California Installation Group where they asked me why older concrete was more of a problem than newer concrete even though the moisture readings were lower (lower according to RH Probes).

I explained that salts tend to collect at the surface and in extreme cases have caused ASR damage of led to "Slab Sweating Syndrome". If a flooring/coating is over a surface such as this, but not a particularly aggressive form of salt that will damage a coating or flooring, nothing will happen, until they removed the existing floor/covering. At that time, the salt laden surface will begin to adsorb moisture and the longer it sits, the more likely the moisture content will increase.

NOT 3 months later, David Daniels was giving a lesson on how to properly use a Tramex Concrete Meter. This was the exact same facility where I warned the installers about older concrete. The area was a 42 year old warehouse. The area they picked was measured, with what appeared to still be covered with a curing agent. They measured over the curing compound with a measurement indicating 1.9% moisture content, which should be expected with a healthy older concrete. They ground off the coating and measured again, with the moisture content of 1.9%.

After walking around discussing other aspects of testing the group returned, placed the meter on the same area and the moisture level had increased to 4.3%!

They tested again to see if there was something that caused this jump and the reading remained elevated...and this was only 10-15 minutes after the second test of 1.9%.

I have seen this happen many times before, but not to this extreme. THIS is where data gathering and the timing NEEDS to be established to determine root cause.

If the coating had been removed and not tested until the next day, the assumption would have been this moisture "rapidly migrated" up from inside the concrete, when in reality, this was 100% sourced by the ambient conditions.

This is why I am so pedantic about procedure and methodology. If you miss one thing, you can miss everything!

For Slab Sweating syndrome, older concrete, and self desiccated concrete surfaces what value would an RH Produce for a flooring or coating manufacturer?

Conclusion

Nearly every problem with concrete begins on the surface and within the gradient. In fact, it would be difficult to name deterioration of concrete that DIDN'T originate from the surface, which is why proper curing is critical, yet proper curing isn't being done and we need to give that the highest priority. It is entirely possible that through some modifications, even the problematic Type IL cement can be "corrected" to produce a satisfactorily durable concrete.

The Silent Revolution That Nobody Asked For: Type IL Cement and the Crisis in Concrete Finishing

Tue, 06 May 2025 09:45:49 GMT

The concrete industry is facing an unprecedented challenge, and it's time we talked about the elephant in the room: Type IL cement and its impact on finishing operations. While the cement industry quietly transitions to this "environmentally friendly" alternative, contractors across the nation are grappling with a material that's fundamentally different from what they've used for decades.

The Forced Transition

The cement industry is undergoing a major transition to lower its carbon footprint, but at what cost? Type IL cement, which contains up to 15% limestone compared to Type I's 5%, has been thrust upon contractors with minimal education or preparation. This isn't just a minor adjustment – it's a complete overhaul of how concrete behaves during finishing operations.

The Critical Timing Challenge

The finishing window with Type IL cement has become increasingly unpredictable. Contractors are reporting significant issues with project delays and unacceptable finishes. Here's why:

Modified Setting Behavior The greater limestone content significantly impacts set times , creating a less forgiving window for finishing operations. What worked with Type I cement now requires precise timing and enhanced attention to detail.
Surface Challenges Type IL concrete tends to have a softer, more porous surface , making it more susceptible to damage during finishing operations. This characteristic demands immediate adaptation in finishing techniques, yet contractors were given little guidance on these necessary changes.

The Industry's Failure

The cement industry's communication breakdown is evident. While some contractors have successfully finished concrete slabs with Type IL cement, others have struggled significantly . This disparity points to a critical lack of education and support during the transition.

Real-World Impacts

The consequences of this hasty transition are severe:

Increased likelihood of surface defects
Reduced workability
Decreased bleeding
Higher water demand
Less predictable finishing characteristics
The Admixture Complication

What makes the Type IL finishing crisis even more complex is its interaction with chemical admixtures. While the cement industry claims there's no significant difference in admixture dosage requirements , the reality on the ground tells a different story. The effectiveness window of admixtures has become notably shorter and less predictable with Type IL cement.

Critical Admixture Considerations:

Reduced Effectiveness Window The interaction between Portland limestone cement and admixtures requires careful dosage adjustments, with many contractors reporting that the traditional timing windows no longer apply. The effectiveness of water reducers and retarders, in particular, shows a shorter duration compared to their use with Type I cement.
Temperature Sensitivity Ready-mix producers have had to adjust their approach to retarding admixtures , as the temperature sensitivity of Type IL cement creates a narrower window for effective finishing. What worked with Type I cement now requires precise timing and enhanced attention to detail.
Modified Dosage Requirements While some producers report no adjustments are needed, others have had to tweak proportions to achieve the desired results. This inconsistency creates additional challenges for contractors who work with multiple suppliers.

The Compressed Timeline Effect

The combination of Type IL characteristics and admixture interactions has created what many contractors call a "compressed timeline effect." This means:

The window between initial set and final set is less forgiving
Admixture effectiveness peaks more quickly and diminishes faster
The traditional timing indicators for finishing operations have become less reliable

Contractors are reporting that the sawing window for some Type IL cement concrete slabs has become more critical and less predictable, leading to increased instances of slab blowouts and finishing challenges.

Real-World Adaptation Strategies

Field Testing and Quality Control The unpredictable nature of Type IL cement requires enhanced testing protocols. Contractors must now conduct more frequent field tests to monitor:

Initial set times
Surface water appearance
Bleed water characteristics
Early strength development
Surface hardness progression
surface durability

Environmental Considerations Temperature control has become more critical than ever. The cement's increased sensitivity to ecological conditions means contractors must:

Monitor ambient and concrete temperatures more closely
Adjust placement schedules based on weather forecasts
Implement more rigorous curing protocols
Consider night pours during hot weather
Provide additional surface protection during finishing

Mix Design Modifications With Type IL cement's different specific gravity (~3.09 vs 3.15) , contractors need to:

Adjust mix designs accordingly
Account for slight volume increases
Modify water-cement ratios
Re-evaluate supplementary cementitious material proportions

Economic Impact

The Hidden Costs The transition to Type IL cement has introduced several unexpected costs:

Increased labor due to more frequent testing and monitoring
Additional equipment for enhanced quality control
Higher risk of repairs and callbacks
Extended finishing time requirements
More sophisticated temperature control measures

Training Requirements The development of new admixtures and testing of different materials has created an urgent need for:

Updated finishing techniques training
New quality control procedures
Modified scheduling protocols
Enhanced environmental monitoring skills
Revised troubleshooting procedures

Future Considerations

Industry Evolution As the concrete industry continues to adapt to Type IL cement, several developments are expected:

New admixture formulations specifically designed for Type IL cement
Enhanced testing and monitoring equipment
Updated industry standards and specifications
Modified finishing tools and techniques
Improved education and training programs

Research and Development Needs The industry must focus on:

Understanding long-term performance characteristics
Developing more reliable timing indicators
Creating more effective admixture combinations
Establishing clearer finishing guidelines
Documenting regional variations in performance

Call to Action

For Contractors:

Document and share experiences with Type IL cement
Invest in updated training programs
Develop new quality control protocols
Build relationships with technical support resources
Maintain detailed records of successful approaches

For Manufacturers:

Provide more comprehensive technical support
Develop specific guidelines for different climate zones
Invest in admixture research and development
Create better educational resources
Establish clear communication channels for contractor feedback

For Industry Organizations:

Update specifications and guidelines
Provide enhanced training resources
Facilitate information sharing between stakeholders
Fund research into improved finishing techniques
Advocate for contractor concerns

Conclusion

The transition to Type IL cement represents one of the most significant changes in concrete finishing operations in recent history. While the environmental benefits are clear, the industry's failure to adequately prepare for this transition has created unnecessary hardships for contractors. The compressed effectiveness window of admixtures, combined with Type IL's unique characteristics, demands a complete reimagining of concrete finishing practices.

Success in this new era requires a combination of enhanced technical knowledge, modified procedures, and improved communication between all stakeholders. Until manufacturers provide better support and more effective solutions, contractors must remain vigilant in their approach to finishing operations, particularly regarding timing and environmental conditions.

The concrete industry stands at a crossroads. The path forward requires not just adaptation to Type IL cement, but a fundamental shift in how we approach concrete finishing. Only through collective effort and shared knowledge can we hope to overcome these challenges and establish new standards for successful concrete finishing in the Type IL era.

The time has come for the industry to acknowledge these challenges openly and work together toward practical solutions. The future of concrete finishing depends on how well we respond to this challenge today.

An Open Letter to the Concrete Industry

Fri, 04 Apr 2025 06:55:54 GMT

Unraveling Concrete's Hidden Surface Crisis

After 30+ years in concrete finishing, I'm witnessing unprecedented surface issues across our industry. The root cause? A perfect storm of changes that nobody's talking about.

Let me be direct: In the last three years, we've seen dramatic shifts in cement chemistry – driven by the green movement – that have fundamentally changed the game. But that's just the beginning. The increasing use of topical finishing aids has compounded these problems, creating a crisis of quality that can't be ignored.

Here's what's really happening:

Cement manufacturers focus solely on strength metrics. Ready-mix producers concentrate on meeting strength specifications. Admixture companies push more chemicals and less water – because water doesn't pad their bottom line. This obsession with water reduction has crippled our industry over the past 15 years.

Browse any concrete-focused social media, and you'll see an endless stream of problems. I've sat with PhDs and "industry experts" across the country, and despite all their supposed expertise, we're still facing the same issues. Why? It's simple: follow the money.

The harsh truth is that long-lasting concrete doesn't generate recurring revenue. But this short-sighted thinking is devastating our infrastructure. We're already trillions behind in repairs, and new infrastructure funding is going to fix existing problems instead of building for the future. Meanwhile, private sector investors are pouring billions into properties that require excessive maintenance due to subpar concrete quality.

The concrete finisher – the true craftsman – is caught in the middle of this mess. We're expected to work with mixes designed by people who've never finished concrete in their lives. Think about that: The people creating these mix designs have never had to finish what they're selling.

Shouldn't ready-mix producers consult with finishers about mix workability? When a mix isn't finishable, we're forced to take measures to get the job done. Yes, sometimes finishers are at fault – we get behind, cut corners, make mistakes. We own that. But we're operating in a system designed by lab technicians and PhDs who produce impressive white papers but can't create mixes that work in the real world.

The results are everywhere:

Increased delamination
Widespread scaling
Excessive shrinkage cracking
More plastic shrinkage
Severe curling and raising

We're not concrete finishers anymore – we've become chemical finishers. When did this happen? When did we decide that a simple mix of cement, aggregate, sand, and water – maybe with one or two admixtures – wasn't enough?

The cement manufacturers started this cascade by changing their formulations, adding grinding aids and cement additives to ease their production. They never disclosed how these changes would affect us in the field. Nobody stood up for the small business owners who bear the cost of fixing these issues – costs that should be borne by those who created the problems.

It's time for change. It's time for transparency. It's time for the industry to listen to the people who actually work with concrete every day.

Share your experiences – good or bad – about these new cement chemistry changes. Visit https://www.1lcementproblems.com and let your voice be heard. Only together can we push for the changes our industry desperately needs.

The future of concrete depends on it.

7 Day Water Curing of Concrete - It isn't WORKING!

Thu, 27 Mar 2025 08:00:04 GMT

Curing of Concrete

Robert Higgins

Trouble shooting/root-cause analysis with concrete, Consulting, teaching, product development

December 11, 2024

Again I read a series of studies that concentrate ONLY on concrete compressive value limited to the 28 day strength.

Interestingly, there are discrepancies that are noted but not investigated, even as the discrepancies threaten to undo the data that was apparently the original objective.

Texas Transportation Institute Study

It is interesting that many of the other studies concluded that air cure, water cure and curing agents were nearly interchangeable in their results to where a 7 day water cure sometimes had a negligible to minor beneficial effect on the compressive value of concrete at 28 days.

In the TTI Study, air cured and the 7 day water cured concrete samples were measured for internal RH at the concrete surface and various depths of 0.5 inches, 1 inch and 3 inches.

NOTE: Cement formation ceases when the internal RH is less than 80%.

The air cured concrete: the top 0.5 depth, the RH fell below 80% at 13 days, the top one inch reached 84% RH at 30 days and remained above 80% for the 30 test duration, at 3.0 depth there was a significant RH drop off on the first day where the RH was recorded at 83%, the RH gradually increased to approximately 93% at 5 days.

The 7 day water cured concrete: the top 0.5 depth fell below 80% at 14.5 days, the top one inch fell to 80% at 30 days and the three inch depth fell below 80% on the first day, but gradually increased to 93% and remained between 93 and 92% for the 30 day test duration.

Compressive strength calculations were also made at these depths, with the air cured concrete having a 0.70 at the surface, 0.85 at 0.5 depth and 1.00 past the one inch depth.

The 7 day water cured concrete having a 0.80 at the surface, 0.90 at 0.50 depth and 1.00 past the one inch depth.

What The?!?!?! Take-Aways

First off, 80% RH is the MINIMUM humidity needed for cement formation. Cement will form, but not very quickly. The higher the RH, the more robust the cement formation.

NOTE: If for any reason, the RH falls below 80% during the initial cure, cement formation will be lessened, permanently; how much depends on the chemistry of the concrete and environmental factors.

What appears as an anomaly, where concrete covered with a layer of water would STILL have a reduction in RH makes no sense, nor would it, in a open, unobstructed environment.

NOTE: This is an argument that I have to constantly educate people on since they do not understand the complexities of concrete; the straight forward air pressure differentials have little relevance when concrete chemistry complexities are introduced.

Concrete ISN'T an open, unobstructed environment. As cement is formed, the internal moisture is reduced, creating an increase in alkalinity. With the depth and surface activity, even covered with water, the water is blocked by the alkaline solution which can be saturated, but also lower in RH. This doesn't and won't happen in an open environment, which people mistakenly believe applies to concrete...it DOESN'T, yet we can't get researchers off center to start dealing with the reality rather than a disproven concept that water retention alone will maintain a RH suitable for cement formation.

A water covered concrete surface cannot experience surface evaporation, so water loss from the surface is now eliminated as a cause of "moisture loss".

With a reduction in RH, particularly after only 14 days, there is definitely something else going on!

The other significant take-away here is that the concrete surface IS weaker, whether air cured or water cured, yet when surface tests are conducted with rebound hammers (ASTM C 803 and ASTM C 805), these are dismissed as "inaccurate" since these consistently give lower compressive values than the standard concrete core compression test.

This is more of an indictment of the compression procedure unable to discern a weaker surface, since these weaker surfaces tends to crush rather than break, and it is only at break that the concrete compressive strength is determined.

I feel that rebound hammers are an invaluable tool and criminally underrated and undeservedly dismissed. If we could walk it backwards, I would wager that the rebound hammers have been extremely accurate, yet due to the industry believing the surface of concrete is as strong as the remainder of the concrete, another assumption has cost us valuable information over several decades.

This is essentially confirmed by this study where the top one inch of concrete was sliced off and exhibited a lower compressive value than the full depth would indicate.

This study and others from the field that correlate quite closely, other than field conditions have a much more severe issue since those studies indicate the RH within the top one inch of the concrete can fall to levels as low as 60%-70% within the first two weeks of placement, which ALSO correlates with the lab samples in the TTI Study where the drop offs are happening within the first two weeks, in a highly controlled environment!

Why hasn't anyone Taught This?

It was only by comparing the various studies where I got an "aha" moment where the dots began to connect and the information we have ASSUMED was accurate where a water cured concrete will be uniform and homogenous is a false legacy assumption rather than a fact.

Self Curing Concrete To The Rescue

I have been a party to and have observed different concrete types that are partially and some fully self/internally cured.

Even absorptive aggregate has been found to be very beneficial, though inadequate to fully compensate for autogenous self-desiccation. The irony is that absorptive aggregate was uniformly derided as damaging to the water-cement ratio and quality of the concrete; instead, absorptive aggregate has been shown to improve the quality of concrete, yet that assumption delayed beneficial discoveries for DECADES!

I used to buy into that hogwash as well, so I've been trying to "unlearn and then relearn" what is fact versus the fiction I've been brainwashed with. I now challenge anything and everything until I can find out first hand what is root cause.

Many I looked up to in my formative years were wrong, because the ones THEY learned from were also wrong...so we have to "un-wrong" a LOT of information to start dealing with facts rather than legacy myths.

RH Testing - Useful AND Misleading

I admittedly have been unrelentingly savage when dealing with some of the RH Probe peddlers who have been misusing and misrepresenting an extremely useful tool.

RH measuring devices of all types have been extremely helpful and even indispensable when analyzing root cause damage and gauging the initial curing rate of concrete. That is where these belong.

It is an unforgivable disservice that a cabal of influential people have managed to con several industries into believing the emperor has new clothes, claiming RH Probes or ANY RH measuring device for that matter can actually measure the moisture content of concrete.

They DON'T and they CAN'T. RH does not measure liquid water...period...only water in its gaseous form, which exists in open spaces, not the concrete itself.

There are MANY reasons that building science prioritizes moisture control and drying in a very specific order: 1. Bulk water: any other form of moisture is essentially irrelevant until bulk water is either removed or not present, 2. Capillary water: any interstitial moisture can be a challenge to correct/remove, depending upon the chemical make-up of the building material. Any mineral-based material that contains capillaries have competing forces where the attraction of the water to the solid may be close to or greater than the attraction of the water to itself...this can present a LOT of challenges, particularly with concrete, where removal of bulk water and then capillary water becomes increasingly difficult. Alkaline salts in concrete concentrate as bulk and then capillary water is removed/reduced. As alkalinity concentrates, the resistance to removal increases as the reciprocal internal RH is reduced. 3. Water vapor: water vapor is WAY down the pecking order and is by several orders of magnitude less important than bulk or capillary water.

NOTE: One of the ironies with the data used by RH Probes to "prove" their usefulness for moisture testing of concrete is that Lund University, released a study on RH Probes that was specific to mix water, and even though the study cautioned regarding alkalinity and concrete that has been rewetted, this study is the one the F2170 is largely based upon which is to ONLY measure relative humidity, NOT moisture content (it doesn't say that anywhere in the ASTM Standard, so why is it being promoted as such?) and is NOT qualified nor tested for concrete that has been in service....then the irony goes further, this same university produced a study, predating the RH Probe (Hedenblad study) that states in no uncertain terms: "measurement of capillary water is more accurate that the measurement of water vapor when testing for concrete moisture content". Didn't the RH promoters know of the capillary test?

How does RH Testing Tie Into Concrete Curing?

There is technology where embedded humidity devices have been used, which , coupled with thermocouples, have DISCOVERED that field concrete tends to self desiccate WAY earlier than ANY of us could have imagined. Until these devices proved otherwise, everyone ASSUMED that current curing techniques were sufficient, even considered optimized.

We can take this same technology, coupled with an electrical impedance concrete moisture meter, thermocouples and actually measure and monitor in real time, the quality of concrete being placed!

This process could also be used to validate products and/or mix designs that can reduce or even eliminate concrete self desiccation.

Such products DO exist, have been functioning incredibly well, but lost in the land of confusion and snake oil salesmen. Rather than simply accept a good line of bull...how about we instead, set out to prove this and in turn, improve concrete to where it should be, not as it is.

We have the tools and the technology and now we have methods that can validate rather than ASSUME.

Why We're Getting Concrete Curing All Wrong (And What It's Costing Us)

Thu, 27 Mar 2025 07:46:45 GMT

Why We're Getting Concrete Curing All Wrong (And What It's Costing Us)

Joe Shetterley

Principal CEO @ E5 | Construction Industry Solutions

March 6, 2025

Let me tell you something that keeps me up at night: we're completely dropping the ball on concrete curing. It's not just a small oversight - it's a massive failure that's costing us millions in repairs and replacements. And the worst part? Almost nobody's talking about it.

Here's the thing about concrete curing that most contractors won't tell you: it's not even making it into the bid anymore. Think about that for a second. The single most crucial step in concrete construction is being treated like an afterthought. It's like building a house and forgetting the foundation - it just doesn't make sense.

When we skip proper curing, we're basically setting ourselves up for disaster from day one. The concrete starts losing water immediately. Then come the cracks. The surface starts deteriorating. And before you know it - usually around the six-month mark - you've got an unhappy client wondering why their "perfectly good" concrete looks like it's been through a demolition derby.

I remember when we used to do things right. Back in the good old days - from 1900 to the 1980s - wet curing was standard practice. It wasn't some fancy optional extra; it was just how you did things. Quality wasn't just a buzzword - it was the expectation.

Then the 1980s hit, and suddenly everyone was pushing these miracle cures in a bottle. You know the ones I'm talking about - topical sealers, curing compounds, densifiers. The marketing was slick, and structural engineers bought into it hook, line, and sinker. Why? Because these products promised to solve their scheduling headaches. But here's what they missed: while we were racing to place and finish concrete faster than ever, we were literally starving it of the moisture it needed to develop properly.

Fast forward to today, and it's even worse. Most people aren't even pretending to cure properly anymore. Oh sure, they'll check the box saying they did it, but we all know that's just lip service. The problems have gotten worse, not better, since we abandoned wet curing.

But here's where things get interesting. In 2018, a company called E5 came out with something revolutionary: a genuine internal curing solution. Now, I know what you're thinking - "Here comes another miracle cure." But this is different. While traditional wet curing only dealt with the surface, this technology works from the inside out.

Think of it like this: when you eat healthy food, it shows on the outside, right? Same principle here. When concrete can develop properly from its core, the external problems practically solve themselves. This isn't just another band-aid solution - it's a fundamental shift in how we approach concrete curing.

And the timing couldn't be better. With the industry switching from Type I to 1L cement, we need this kind of technology more than ever. It's not just about meeting today's insane construction schedules - it's about maintaining quality while doing it.

But let me warn you about something: this industry loves its bandwagons. Suddenly everyone's claiming they do "internal curing." Don't fall for it. E5's nanotechnology is addressing both internal and external development - everything else is just playing catch-up.

The ACI (American Concrete Institute) can debate definitions all they want. Yes, concrete has always been somewhat self-curing. But until now, we've never had a way to properly support and extend that natural process. While the academics argue about terminology, real contractors are trying to solve real problems.

Here's the bottom line: we can either keep pretending everything's fine while watching our concrete deteriorate, or we can admit we've been doing it wrong and start fixing it. We have the technology. We have the knowledge. What we need now is the courage to change how we do things.

This isn't just about better concrete - it's about bringing integrity back to our industry. And if that doesn't matter to you, maybe the cost of repairs and replacements will.

What's your take on this? Have you seen the effects of poor curing in your projects? Let me know in the comments below - I'd love to hear your experiences and thoughts on this crucial issue.

Moisture migration through concrete floors; a persistent non-fact

Thu, 27 Mar 2025 07:19:26 GMT

Moisture migration through concrete floors; a persistent non-fact

Robert Higgins

Trouble shooting/root-cause analysis with concrete, Consulting, teaching, product development

August 8, 2023

For several decades, like many others, I was taught and led to believe that all flooring and coating failures were caused by moisture migration from the underside of concrete.

Even in the presence of anomalies such as higher moisture levels present in the upper levels of multi story buildings, these anomalies were addressed in non-scientific terms in order to dismiss how and why moisture "originating" from the underside or from the concrete itself could be higher when there was no soil contact. Even more so when concrete was placed over non-breathing steel pan construction, the moisture levels could be higher than at grade level.

No Mystery, just story-telling

With these "mysteries", once I began to apply the laws of physics and thermodynamics, there was nothing mysterious about these apparent anomalies.

The second law of thermodynamics dictates that moisture moves from warm to cool. This is a bit of over simplification, since higher pressure to low pressure is the prevailing reason for this movement. It is possible for a cooler wetter environment to have a slightly higher pressure than a warmer, drier environment, but those conditions are usually transitory and have little overall impact on the long-term conditions.

When I was first becoming involved with floor moisture failures in the early to mid 1980's, it was considered a "fact" that flooring failures were caused by "hydrostatic pressure". Virtually every manufacturer had this language in their warranty for on-grade concrete and hydrostatic pressure was conveyed as something akin to the "boogeyman" in that this tremendous force could cause failure, even with an epoxy.

There was a slight problem with this "scientific-sounding" and "proven" cause of flooring failures, unless a floor was substantially lower than the water table directly AGAINST the floor, hydrostatic pressure was IMPOSSIBLE. Hydrostatic pressure is caused by the downward pressure exerted by gravity onto the water surface. The amount of pressure is DIRECTLY related to the depth of the water against a structure since it is the weight of water that causes the pressure. The pressure itself, although relentless, is very underwhelming when considering most structures on or even below grade. NOTE: I spent many years waterproofing underground structures, including 60 miles of the London Underground tunnels, tanks for Sea World and Marine World, animal enclosures for the San Diego Zoo, the H3 Tunnel on Oahu, Hawaii etc.

To put this in perspective, for each foot of water DIRECTLY against a structure, the amount of hydrostatic pressure is less than 0.5 psi per column foot, so a floor that is 10 feet below the water table can conceivably be exposed to hydrostatic pressure of slightly less than 5.0 psi. That will NOT cause a flooring failure....however, even when I pointed out this boogeyman and concern was non-existent for ANY on grade flooring or coating material, it took nearly 30 years to rid this from "most" of the warranty exclusions for grade and even above grade level concrete floors. This always reminds me of the adage; "It is easier to fool someone than it is to convince someone they've been fooled.

Likewise, when I discovered the moisture migration as the primary cause of flooring failures was also a myth, I at first became very angry in that I trusted those I looked up to to give me factual information. I became less angry when I realized the people I looked up to also had their mentors who THEY looked up to, giving them the same "urban myth" information that ended up becoming a misinformation legacy, based on a good faith belief.

Moisture Migration Through Concrete

Does this happen? Yes, but in a very limited way and in very specific environments. For the most part, this moisture migration from the soil, through concrete to the concrete surface, causing a floor or coating failure is pure myth.

One of the lessons I DID learn that was at least semi-accurate was that the underside of concrete maintains an overall cooler environment than the concrete itself, and the body of the concrete maintains an overall cooler environment than the concrete surface, and the concrete surface maintains an overall cooler environment than the ambient conditions over the concrete. Since bottom to top needs the moisture movement to violate the second law of thermodynamics, HOW is this moisture somehow "proven" to be moving from bottom to top?

Answer: It isn't. Moisture movement follows the law of thermodynamics even as we are taught to suspend our belief in that law to now believe a "non-fact" that became a fact because the legacy myth says so!

If it isn't Moisture Migration, What is causing flooring failures?

Although there are exceptions with complex influences, what is perceived as moisture migration is actually diffusion, and in other instances, a combination of diffusion and convection (convection is not going to be explored in this article).

Diffusion answers many of the mysteries as to the how and why contaminants can migrate from the underside to the top side (which is why I have included this link to diffusion examples). NOTE: water acts as a transport medium for water suspendible solids and salts. The moisture is essentially a roadway..the more accessible the roadway, the more "traffic"..larger, connected pores and capillaries then allow the contained moisture to try and achieve equilibrium through diffusion..THIS is how a contaminant can manage to eventually make it to the concrete surface. In dense concrete with restricted, non-connecting capillaries, this would NOT be an issue.

Now think about what we DID learn that was reasonably accurate; the concrete exposed to the ambient conditions is generally cooler than the ambient conditions which would encourage the moisture to move from the warmer (ambient air) to the cooler (concrete surface), and as we keep going, the moisture will continue to migrate inward until it reaches equilibrium and/or saturation.

Saturation within concrete is nearly constant; which in turn dispels yet another myth - water vapor transmitting through concrete. Water vapor or any other form of water cannot move through water...water in a liquid form is in its densest form as a liquid and is effectively incompressible. As a result the only possible way for water vapor to move is when it leaves the surface of a body of water, usually through evaporation.

This in turn explains another "mystery" where a fully functioning floor is removed, replaced and the new floor fails, as does the next and the next.

In a recent demonstration (unintentional as it was), a coating was removed from a 40 year old concrete slab. Fortunately the concrete was tested for moisture immediately before and after the coating was removed. Each of these measurements were identical 1.9% Tramex measurement.

However, in less than 15 minutes after removal of the coating, this same exact area was measured, with a dramatic moisture content increase: 4.3%!

Now, think of what the industry-standard procedure encompasses; If an existing coating or flooring is removed, it is recommended to allow the concrete surface to "vent" before testing for moisture. Again, this procedure is based on the false premise that moisture is originating FROM the concrete. Think of what WOULD have happened if the concrete hadn't been pretested to prove the concrete was dry. The 4.3% moisture measurement would likely had been excessive, upwards of 6% or higher...the assumption? This moisture is "originating" from the concrete and needs to be mitigated. The concrete is shot blasted (likely removing most, if not all the hygroscopic material that collected in the surface that absorbed the moisture so rapidly), a moisture mitigation is applied and viola, we have a "successful" moisture mitigation, when in reality, all that was accomplished was a colossal waste of time and money. It is VERY likely the shot blast alone, along with site monitoring would have mitigated this issue without all that additional expense. Current standards do not allow for an effective establishment of a moisture baseline. Without a baseline, it becomes impossible to ascertain what may or may not have been effective...keeping the mysteries flowing with speculation and illusory correlations!

Even as the moisture claims have climbed (more like exploded) to an estimate 3 billion per year (and continue to get worse), most if not ALL of this expense was completely unnecessary. An associate (Larry Marvel) has been giving classes on the proper implementation of site monitoring with his track record speaking for itself. This who have learned this, not only do not have the repeating costs using testing of questionable value, there are essentially NO repeating costs with this site monitoring and (drum roll please)...in the three years of this site monitoring implementation, the installers have eliminated their moisture claims.

A drum I keep beating and won't stop until the nonsense/nonscience goes away; what value is ANY testing protocol if it isn't solving problems?

Diffusion demonstration: https://youtu.be/fN7b1aBunoM

The Concrete Industry's Forgotten Secret: It's Time To Look Within

Sat, 28 Sep 2024 05:54:41 GMT

THE CONCRETE INDUSTRY'S FORGOTTEN SECRET: IT'S TIME TO LOOK WITHIN

August 9, 2024

For decades, the concrete industry has been chasing a mirage. We've poured billions into developing fancy new coatings, sealants, and curing compounds, all promising to be the solution to concrete's perennial problems: cracking, spalling, and degradation. But in our pursuit of the latest quick fix, we've forgotten a fundamental truth about concrete. The real enemy isn't the elements – it's ourselves. And the solution lies not in some expensive add-on but in understanding and addressing the inherent flaws at the very heart of concrete itself.

Concrete is a paradox. It's one of the most ubiquitous and enduring materials in human history, yet it's also surprisingly fragile. The reason lies in its nature. Concrete is a matrix of cement paste binding aggregates like sand and gravel together. But this matrix is riddled with pores and capillaries, tiny channels that allow water to penetrate and wreak havoc. This is the root of all concrete problems. Water ingress leads to freeze-thaw damage, rebar corrosion, and alkali-silica reactions – the big three culprits behind concrete degradation.

Our industry's typical response is to slap a band-aid on the problem. We apply coatings and sealers to keep water out or use curing compounds to try to strengthen the surface. But this is a losing battle. Coatings fail, sealers degrade, and curing compounds only address the symptoms, not the cause. The real issue isn't the surface—it's the matrix itself.

That's where E5 comes in. E5 Internal Cure works by addressing concrete's inherent flaws, not just trying to protect it from the outside world. It's based on nanotechnology that binds to water molecules and optimizes the curing process, allowing for a stronger, denser matrix to form. It's more than a coating or a sealer—it's an integral part of the mix.

The science is complex, but the principle is simple. Water is both concrete's lifeblood and its nemesis. It's necessary for the curing process, but if it's not controlled, it leads to weakness and instability. E5 Internal Cure works by controlling that water, allowing it to facilitate the curing reaction without creating the pores and voids that lead to problems down the line. The result is concrete that's not just stronger but more durable and resilient.

But E5 is more than just an additive – it's the fifth element of concrete. We're all familiar with the traditional components of concrete: cement, water, sand, and gravel. But with E5, we have a new ingredient that transforms the entire equation. It's not just an addition but an integral part of the mix that changes how the other elements interact. It's like the discovery of a new primary color – it opens up a whole new palette of possibilities.

But the natural beauty of E5 lies in how it addresses the complete lifecycle of concrete, from the internal heart to the external surface. It's not just a quick fix but a long-term solution that creates concrete that's more durable and sustainable. And in today's fast-tracked construction schedules, that's more important than ever. We can't afford to go back to repair cracks and spalls and tear out of newly placed concrete a few years down the line. We need concrete that performs from day one and will keep performing for decades to come.

E5 Internal Cure delivers that. By optimizing the curing process and creating a denser matrix, it produces concrete that's more resistant to the elements and less prone to degradation. It reduces the need for costly repairs and maintenance and extends the lifespan of structures. And because it's integral to the mix, it provides protection from the inside out, not just slapping a thin layer of protection on the surface.

But perhaps the biggest benefit of E5 is one that's often overlooked: it's a true carbon-reducing technology. When you increase the durability and lifecycle of concrete, you decrease its carbon footprint. You're not ripping out and replacing structures as often, which means less cement being produced, less energy being used, and less waste being sent to landfills. It's a simple equation: more durable concrete = less carbon emissions.

This isn't just theory – it's been proven in the field. Specifiers and contractors who've adopted E5 technology are reporting dramatic improvements in concrete performance, with less cracking, spalling, and degradation. It's being used in everything from high-performance buildings to infrastructure projects, and the results are transformative.

So why has the industry yet to embrace this technology wholesale? The answer is a mix of inertia, misinformation, and a stubborn focus on quick fixes rather than real solutions. Many specifiers and contractors are still wedded to the old ways of doing things and are skeptical of new technology. Others may be aware of internal curing but think it's only for specialized, high-end projects.

But the truth is, E5 is for any project where you want better concrete. It's not a replacement for good mixing and placing practices, but it's a powerful tool to take your concrete to the next level. And in an era where our infrastructure is crumbling, and sustainability is paramount, we can't afford to ignore it.

For too long, we've been chasing strength at the expense of durability. We've been so focused on hitting those high psi numbers that we need to remember what really makes great concrete. It's not just about how much weight it can bear but how well it resists the elements, how little maintenance it requires, and how long it lasts. It's about creating structures that stand the test of time, not just structures that meet some arbitrary standard.

The concrete industry has lost its way. We've been so focused on treating the symptoms of our problems that we still need to address the cause. It's time to stop chasing the latest fad and look inward to the inherent flaws in our material and how we can address them. It's time to embrace E5 and the principles of internal curing, and create concrete that's not just stronger, but better. The future of our industry depends on it."

The Detrimental Impact Of High Compressive Strength And Safety Factors In Concrete Mix Design

Thu, 22 Aug 2024 06:04:12 GMT

THE DETRIMENTAL IMPACT OF HIGH COMPRESSIVE STRENGTH AND SAFETY FACTORS IN CONCRETE MIX DESIGN

In the pursuit of ever-stronger concrete, the industry has embraced mixes with high compressive strengths and safety factors. While these metrics may seem desirable, they actually promote detrimental practices that compromise concrete's durability, sustainability, and workability. It's time to reassess our priorities and get back to basics.

The industry relies on low water-to-cement ratios and high levels of chemical admixtures to gain safety factors that lead to excessive compression strength. These formulations may produce impressive lab test results, but they create real-world problems. The resulting concrete can be difficult to finish, making it challenging for skilled tradespeople to achieve the desired surface quality. This is more than just a matter of aesthetics; poor finishability can compromise the long-term performance of the concrete.

Moreover, the brittleness that accompanies these overdesigned mixes makes concrete more prone to cracking and degradation. Over-designed concrete mixes can lead to reduced service life, increased maintenance, and a larger environmental footprint over the long haul.

The focus on compressive strength also overlooks the importance of ductility in concrete. Ductile concrete can absorb energy and deform without failing, providing greater resilience in the face of stresses caused by settlement, thermal expansion, or loading.

So, how can we balance strength with the need for workability, finish ability, durability, and sustainability? One key is the use of nanotechnology, E5 nano-silica. E5 will enhance the packing density of the concrete, reducing porosity and improving durability. It also reacts with calcium hydroxide to form additional cementitious products, contributing to strength while reducing the cement content.

E5 Nano silica, in particular, has shown great promise. Its ultra-fine particles allow it to participate in hydration reactions more effectively than traditional SCMs, delivering improved strength, durability, and workability. Incorporating E5 nano silica into overdesigned concrete mixes will help mitigate the problems produced by overdesigned mixes and enhance their ductility.

However, we must also rethink our approach to mix design and construction scheduling. Unrealistic project timelines and quality expectations are driving the adoption of problematic mix designs. We need to return to more sensible schedules and specs that allow for the production and placement of high-quality, sustainable concrete.

The development of products like E5 nano silica reflects this shift. By enabling the creation of concretes that balance compressive strength with workability, finish ability, and durability, such materials allow us to get back to basics and make concrete more sustainable. They help reduce the cement content, and thus the carbon footprint, of our mixes.

Concrete is a beautiful material with immense potential for sustainability. However, to realize that potential, we need to focus on the right metrics and practices. It's time to move beyond the obsession with compressive strength and safety factors and create concretes that are strong, durable, workable, and kind to the planet. With the right mix of designs and technologies, we can do just that.

Why is polished concrete considered sustainable?

Thu, 08 Aug 2024 08:08:04 GMT

Why is polished concrete considered sustainable?

1. Durability:

Polished concrete is extremely durable and long-lasting, reducing the need for frequent repairs or replacements. This means fewer resources are consumed over time.

2. Energy efficiency

Polishing concrete requires less energy compared to other flooring options like tiles or vinyl. The process involves grinding and polishing the existing concrete surface, which eliminates the need for additional materials and energy-intensive manufacturing processes.

3. Reduced waste

Polishing concrete eliminates the need for additional flooring materials, such as carpets or tiles, reducing waste generation. It also minimizes the amount of construction and demolition waste sent to landfills during renovation or demolition projects.

4. Low maintenance

Polished concrete requires minimal maintenance compared to other flooring options. It is resistant to stains, easy to clean, and does not require regular waxing or coatings. This reduces the use of chemicals and water for cleaning and maintenance.

5. Thermal mass properties

Concrete has excellent thermal mass properties, meaning it can absorb and store heat or cold and slowly release it over time. This can help regulate indoor temperatures and reduce the need for heating or cooling, thus saving energy.

6. Reflective properties

Polished concrete has a high light reflectance value (LRV), which means it reflects more natural light. This reduces the need for artificial lighting during the day, leading to energy savings.

7. Recyclability

Concrete is a recyclable material, and polished concrete floors can be recycled at the end of their life cycle. The concrete can be crushed and reused as aggregate for new concrete or other construction applications, reducing the demand for virgin materials.

Overall, polished concrete's sustainability stems from its durability, energy efficiency, low maintenance requirements, waste reduction, thermal mass properties, reflectivity, and recyclability.