Guest Contributor – Jason M – 10JAN2023 – Ancient Roman Concrete – Continued

Ancient Roman Concrete’s Durability Finally Explained

 

I actually work for a cement and concrete manufacturer. I was thinking more along the lines of roads and large buildings in my comments above.

For individuals, I completely agree with you that stronger foundations and floors in homes would be a good thing. The problems of energy to generate heat and cost of transporting the materials are still there. But because it is on a much smaller scale it MIGHT be easier to overcome.

Availability of quick lime might be an issue, as well. At least in some locations.

For pouring a driveway or a garage floor though…I’m still not sold on it.

“Strength” for concrete is a measure of compressive force. It’s measured in PSI. Unfortunately, even a very high PSI concrete can break if its support is somehow undermined. The biggest thing for homeowners is making sure that the foundation is done properly with the correct support around the concrete and diverting water away so that it is not washing or damaging the support in some way.

That being said, there are several methods to avoid the kind of cracks you’re talking about. For anyone reading this… make sure your builders include rebar in your foundations. This goes for driveways, too, although it doesn’t have to be rebar in this case… a simple wire mesh or wire fence laid in the concrete (especially if you’re DYIing it) is probably enough. There is also a fiber that can be added to decrease the likelihood of cracks in driveways, etc. but that’s more for if you’re paying someone to do it. I don’t know that you can buy that kind of concrete unless you’re dealing directly with a seller with the mixer trucks and stuff.

You can also increase the thickness of the concrete. This adds significant cost, but a 9 inch thick driveway would be better than a 6 inch thick driveway. There is a diminishing return here though. Once you get to a certain point, the additional cost is not worth the additional “protection.”

For a foundation, especially, make sure they dig deeply enough to get good ground underneath the concrete. This is one thing I had to be careful of when we built our home. We have horrible dirt. I know it sounds funny, but the kind of dirt we have in this area is really bad for settling. It simply compresses too easily so the weight of a house is going to cause it to settle quickly. I had to make sure that the contractor building my foundation dug deeply enough to get past more of the bad stuff before putting in gravel and pouring concrete. I was fortunate in that the contractor was already doing this which made me feel good about using him for some other projects I had associated with the house.

Finally, do anything you can to ensure proper drainage. Water will erode soil even under your home or driveway or cause the soil to settle.

One thing I learned when I joined my current company is that there are hundreds of “recipes” for cement and that many more “recipes” for concrete. (Cement is essentially the “binder” that holds everything together in concrete.) I don’t know that anyone realized exactly how the Romans did it, but I do know that the manufacturers have MANY “levers” they can pull in order to achieve varying strengths and curing times. They are also constantly testing and experimenting with different additives and other cementitious (It’s a real word… honestly) materials in an effort to lower costs without sacrificing strength, etc.

It was more interesting than I thought it would be, honestly.

Ancient Roman Concrete’s Durability Finally Explained

If you’ve ever seen the concrete in your house’s foundation or on your sidewalks start to crack and crumble after a few years then you might be interested to know that the answer to this sad situation exists in the 2,000 year old Roman Pantheon.  Apparently the Romans were better engineers than we are, at least as far as concrete goes.

Researchers at MIT have been studying the phenomenal longevity of Roman concrete edifices and they’ve discovered that using quick lime instead of slaked lime provides for the more reactive inclusions in the material to actually “self-heal” incipient cracks.

“The benefits of hot mixing are twofold,” Masic says. “First, when the overall concrete is heated to high temperatures, it allows chemistries that are not possible if you only used slaked lime, producing high-temperature-associated compounds that would not otherwise form. Second, this increased temperature significantly reduces curing and setting times since all the reactions are accelerated, allowing for much faster construction.”

Near the end of the article it’s stated that the researchers plan to commercialize the ancient technique.  Well, as a descendant of the Romans, I declare this cultural (or technical) appropriation.  And I demand reparations.  I’ve estimated my cut as approximately one billion denarii (silver of course).  If enough denarii can’t be found I will settle for gold doubloons.

16MAY2019 – American Greatness Post of the Day – Our Modern Satyricon – VDH

Victor Davis Hanson is a classicist by training so it is perhaps unsurprising that he finds the analogies between Petronius’s Satyricon and the cultural rot of our own age.

https://amgreatness.com/2019/05/15/our-modern-satyricon/

But I still praise him for the accuracy of his point by point comparison.  Comparing the present age to post-republican Rome has become a common trope but Hanson points out just how accurate it is.  Nothing new here, just the scholarly expertise of the author pointing out the exactness of the analogy.

25AUG2018 – Quote of the Day

“The first rule is to keep an untroubled spirit. The second is to look things in the face and know them for what they are.”

Marcus Aurelius

 

Reading the Stoic quotes you could be tempted to think it all sounds too inhuman, too sterile.  But what I remember then is that Aurelius lived his creed and selflessly struggled to hold back the forces of entropy that were inexorably waiting for his death to pummel the seemingly invulnerable Roman Empire with the first of an endless series of blows that would eventually grind it dust.  A lesser man, like his son Commodus would abandon the grinding drudgery of defending the imperial frontier and devote himself to decadent pleasure while the world dissolved.