Why Roman Concrete Lasts for 1000 Years

[@thebookofclyde1822]

Bridges and other structures start falling apart when brittle modern concrete cracks and water seepage causes the rebar to rust . The Romans didn't even have rebar and apparently they didn't need it. 2000 year old aqueducts still carry water. Somebody needs to find out if hot-mixed slurry made with Mount St. Helens ash and US lime will substitute for the Roman ingredients. Heck - even a product that only lasts for 500 years would be a vast improvement over what the construction industry is using today.

[@chrimony]

I doubt Roman concrete without rebar would stand up to modern uses. Rebar adds tensile strength, which is critical in bridges and other structures.

[@hlessiavedon]

​@chrimony it may be a massonry bridge, but it still proves the point that roman contruction tecniques givevgreater longevity to most any structure. "The Pons Fabricius (Italian: Ponte Fabricio, "Fabrician Bridge") or Ponte dei Quattro Capi, is the oldest Roman bridge in Rome, Italy, still existing in its original state. Built in 62 BC, it spans half of the Tiber River, from the Campus Martius on the east side to Tiber Island in the middle (the Pons Cestius is west of the island)." The bridge has been in heavy daily use since 62 BC

[@einHaufen.]

Since the burn down of the library in Alexandria all ancient knowledge is burned to ashes... 🎉🎉🎉🎉🎉

[@nos9784]

​@@chrimonywell, romans used arches. Constructing without large tensile loads is one way to avoid cracks. We do this with pre-stressed concrete, but adding the crack- healing capabilities would propaply improve thing.

[@justinlowe2013]

😊😊😊😊😅😊😊😊 9:59 😊

[@Therealpicodogg]

Bravo. Construction Science Engineer here. I’ve poured it, I’ve managed the placing of it, and I’ve even tested it. Concrete is one of the most fascinating engineering developments that is often overlooked. You sir did a service for anyone that listened.

[@marcelotrejosievers5754]

Self reparing concrete?? Concrete Companies: Not in my watch.

[@PhysicalMath]

Who knows what other ancient technologies have been lost to time.

[@kittyhinkle3739]

Or surpressed.

[@JMSginoclave]

@@kittyhinkle3739 Ye probably mean either surpassed (exceeded, bested) or suppressed (ended by force), friend.

[@kittyhinkle3739]

@@JMSginoclave I misspelkkted. And definitely ended by force.

[@OriginalDonutposse]

Damascus steel is one of them. Also there was that insulating material called Starlite.

[@umutacar4133]

In this time of global idiocy, I find myself lucky to have stumbled upon your channel, Dr. Miles. I wanted to buy you a coffee. Cheers.

[@DrBenMiles]

Welcome aboard! Thanks so much! 🙏

[@johnebert2619]

This does raise an issue. If we can manage to get this kind of mixture into common use, we're going to need to be much more circumspect with construction. When our work can last millennia, we can't be so flippant with what we leave behind.

[@kathrynck]

Would increase the need for city planning, and likely more broad-purposed construction. If you build a pizzaria for example, just make sure that the structure is able to be easily repurposed. The bits which make it _particularly_ be a pizzaria need to be less permanent, while the basic structure should be more permanent. More than anything though, we would have to stop looking at the causes of 'urban decay' through rose tinted glasses.

[@nos9784]

The fact we aren't careful with planning is an obscenity in itself.

[@antonius.martinus]

So they pretty much found out how to calcificate concrete to make it harder after each repair, just like how our bones do it with micro fractures. They were damn geniuses.

[@chriswhite3692]

Almost surreal that they figured out to do that. Now you have to wonder how they found this out in order to incorporate it.

[@josephnebeker7976]

Either that, or damned lucky to come up with the procedure without understanding what was going on. I honestly wonder if they understood the existence of the self-healing clasts. Maybe they did, maybe they didn't. After all, don't fix what ain't broken, and they knew it worked.

[@creativeideas012]

@@chriswhite3692 or even this might be like the cancer cure that supposedly hasn't been found & will never be found even after many years of research & trillions of dollars of donations/funding

[@chriswhite3692]

@@creativeideas012 There are cures or cancers. Just depends on which ones.

[@Thomas-fn7vq]

You're telling me that in a thousand years not one person tried to just put the lime into the mix without hydrating it first? Seriously what are the chances of that?

[@Clayne151]

Probably a lot did, but when it takes decades to see the benefit it becomes easy to overlook.

[@francoisremise4267]

The addition of quicklime in the mix has certainly been made since Roman time. At least, it is often made now (without the knowledge of the MIT study).

[@DiegoMarquesBrazil]

Cool, hope concrete companies don't sabotage the solution

[@DrBenMiles]

🤞

[@AlanSanchez-ww9qb]

If Roman Concrete makes them less money... they will certainly try. Imagine if someone found the cure to all cancer? The person/team & findings would disappear.

[@DiegoMarquesBrazil]

@@AlanSanchez-ww9qb Veritassium channel just released a great video about concrete and they talk about this Roman issue. Worth watching!

[@charliehoy6336]

Just watched two of your videos back to back. Neither were topics I intended to delve into but the topics looked very interesting and your content and presentation made it informative and entertaining. Thank you! I liked and subscribed.

[@ObservingLibertarian]

Imagine, the solution to the question was to look at a sample under a microscope and - *instead of assuming ancient people were stupid* - simply postulate that maybe, just maybe, the methodology for the mixed materials was intentional rather than by mistake or due to inefficiency. This is the thought that crosses my mind every time I see something related to "ancient aliens" - the people involved are legitimately just operating under the assumption that people back in the day were too stupid to have accomplished some [thing/act]: because those people themselves naval gazing at the [thing/act] in question aren't themselves smart enough to figure out how that particular [thing/act] was accomplished.

[@eldritchedward]

It is an impressive feat for people who call themselves scientists to ignore that every human civilization we have ever found any evidence of were, biologically, the same beings as we are. So if they were stupid, we're as well. Biologically speaking. Of course you define intelligence based on education rather than basic intelligence, but then you'd have to provide evidence for the lack of education of people back then.

[@blue_beephang-glider5417]

We traveled through the UK and France marveling at thousand plus year old building that are still operational. Back in Australia a bulldozer was driving through our 30 year old school...

[@KennethDelavergne]

Amazing. Will help as long as the buildings are not demolished to construct newer, larger structures. Thanks for the new information on Roman concrete! 😎

[@andydiggle]

This stuff is super confusing to a layman dummy like me, and you are REALLY good at explaining it in a way I can understand. So... THANK YOU!

[@adrastoso9727]

I’ve mentioned this to a few people that have common knowledge about these things; this went over their head as they couldn’t comprehend a concrete mix for 2,000 years ago being superior to modern concrete 🤣 I wonder if it’s possible to make this ourselves for home use with out the need of volcanic ash…..

[@francoisremise4267]

Roman concrete is mechanically too weak. That's why it is no longer used.

[@adrastoso9727]

@ Roman concrete wants because the formula was lost for over 1,000 years after the Roman Empire fell! Concrete was only reinvented in 1824 I believe. The romula for Roman concrete was only recently rediscovered and why Roman concrete outlasts modern concrete by hundreds of years; eh oh is due to its self healing properties. The formula could be tweaked with how much water is added to make it stronger, plus rebar can be added to Roman concrete to give it the industrial strength that is what really makes modern concrete strong in the first place!

[@francoisremise4267]

@@adrastoso9727 The different recipes of Roman concrete have never been lost.

[@adrastoso9727]

@ oh yes they have, it took modern science closely studying Roman concrete to figure it out; mainly because they thought the big chicks of lime in the concrete was due to sloppiness when in fact it was done intentionally. People just can’t comprehend that the romans are still better at some things than modern society is! If structures like the colosseum and the pantheon were hypothetical made with modern concrete even with rebar, they would still not be standing today!

[@kaptainkraken]

Lime coated rebar and remesh would be a test i'd like to see. I hypothesize that the lime might help seal in the steel for even longer.

[@josephnebeker7976]

Maybe, and that would be an interesting test, but seeing as how our steel-reinforced concrete still usually doesn't last more than one or two hundred years, and that with constant repair of the encompassing concrete, yet the pantheon and other Roman constructions, such as their aqueducts, apparently have absolutely no steel reinforcement and are still standing after almost two thousand years, I wonder how necessary it is to continue putting rebar reinforcements into our concrete. If it's not necessary, save it for other uses.

[@rtificial8292]

@@koontroll3364 just cover it in lemon

[@JosePineda-cy6om]

you could coat the bars with a layer of something that doesn't react with lime, then cover the whole thing in lime before using it - sounds promising to me

[@DaveWave115]

​@@rtificial8292Funnily enough this would destroy the rebar. Concrete is a highly basic material (around pH 13 going from memory). Normally steel would be corroded in such an environment. But strangely enough at that high level of pH the surface of steel passivates and a thin layer of oxide forms that protects the rest of the material from further reactions. Things that increase the acidicity of concrete like citric acid or desolved carbon dioxide destroy and inhibit the reformation of this protective layer and greatly increase the rate of corrosion in the steel.

[@DaveWave115]

​@@josephnebeker7976Two thoughts on this topic - design flexibility and survivorship bias. 1) Most Roman construction exclusively used circular arches - which are very good in compression and well suited to concrete's material properties. However from a material efficiency perspective it's really bad. Let's say you want to build an interstate bridge over a 100' wide river, using a circular arch. A) You could design a single span but that means your bridge is now 50' in the air and has very steep or very long approaches. Something like a truck is only designed for going up a 1/10 slope (10% grade - I am using a very rough number) so you need a 500' long approach span on either side and all the material that requires or you have to accept maybe trucks can't use this bridge. B) Okay let's limit the height of the bridge to 10' tall to solve this problem - that means you need five 20' spans for this distance, and now you need to build four foundations in the middle of the river - pretty expensive and disastrous to boat traffic. C) Let's consider instead a circular arc; we can select a 100' long curve that runs between each side of the river and only 10' above the water. All the afformented issues are solved with this shape except that it is a very shallow arch, it is behaving much more like a beam and there are significant tensile forces in the section. Concrete is bad in tension, so let's use reinforced concrete instead. The only down side with this solution now is maintenance issues with the structure, it requires more attention and might not last as long. D) My question is how practical are solutions A and B? Can modern society accept the costs from those alternatives, or are we incompatible with them? Is the cost of a more disposable/vulnerable option like C worth it compared to the design flexibility it provides? 2) It is important to remember we only see the best examples of Roman construction, we don't see the buildings of Constantinople that were destroyed in earthquakes centuries ago. We don't see an old Roman bridge that was torn down because it wasn't capable of supporting the weight of modern car traffic. And stuff that we do see might be lying to us subtly - the Pantheon Dome was reinforced with steel chains in the Renaissance, and being culturally significant has been protected and maintained well for centuries.

[@pashaveres4629]

Dr Miles - Wow! Studied ancient Rome at the university and was fascinated by their concrete abilities, among others, lol. Am excited to learn this now. Appreciate your clear and thorough explanations. Second vid I've seen. Subbed. Aloha

[@MATLOCKE269]

This was the best explanation I’ve heard so far and that includes from the horses mouth Admir Masic. Thanks! I’ve recently mixed concrete for the first time in my life to patch around my pool and it sucked. Very frustrating .My house is 26 years old and already needs maintenance? I’m just looking to get that Pantheon look to feel like Augustus

[@justoldog]

good info! thanx!

[@_abdul]

Finally a concrete evidence.

[@alyti]

Booo

[@petrbohacek]

There is no money to be made in things that last forever!

[@dulio12385]

Congratulations. We have officially just ended the 2000 year Dark Ages. 🤣

[@michellejohnson9177]

Amazing information thanks for sharing in this great video!

[@marcfruchtman9473]

Thanks for the video on this topic.

[@manioso77]

Thank you for this info I want the same info but in my ancestor ruins in Belize

[@Houston123ABC]

Wow. Brilliant!

[@melaniemaec1]

Thank you for what you do.

[@MikePhilbin1966]

Can we now start to talk about the Builders of Puma Punku and Sacsayhuaman also using this kind of Concrete-making technique, just with different crystalline powders?

[@TheDocLamkin]

No. Cause you aint did no science yet to proves it

[@JosePineda-cy6om]

No, ancient Incas didn't use mortar nor cement in their buildings. Instead they polished each stone until it was a semi-regular polyhedron, put it in place so the gaps between it and the nearby stones were tenths of a millimeter (repolishing the stones if needed) then placed more stones. The advantage of this method is that when earthquakes hit all the stones move within the walls, thus a great chunk of energy is dissipated thru friction, and when the quake's over they fall back in place. As the structure is made of non repeating patterns of stone (no two stones are the same shape) there's no single resonant frequency for the whole structure, in worst scenario only a section of the walls would colapse if a powerful earthquake hits that sections' particular resonance frequency. Disadvantage, of course, is that building this way is really slow and requires *massive* amounts of labor

[@TheLunarAshley]

Thank you for covering this topic ive always been fascinated with roman architecture and its nice to finally see how they made it last, so again, Thank You!

[@rossmcleod7983]

I would urge anyone interested in hot mixed quicklime and it’s application in historic and contemporary building practice to look at the work of Nigel Copsey. Extraordinary stuff, has a host of positives from diy to broad construction projects. Many thanks for this vid too.

[@beorntwit711]

One of the problems for earthbag structures (hyperadobe or superadobe) has been rain on the walls causing cracks. A final coat of plaster with quicklime clasts could neatly solve this?

[@Tanktaco]

Where can I get a deeper dive?

[@Dragoon91786]

Disregarding variables cuz they don't fit your preexisting bias… 🤦🏽‍♂️💯 Like, were the people supposedly doing research seriously 😒 not replicating the recipe at first in as exacting a methodology as possible so as to limit introducing bias or undetected variables? 🤦🏽‍♂️💯 Thankfully, someone got the good sense to look closer.

[@mrbluemaui]

MIT working on research into "hot-mixed concrete"

[@nickllama5296]

So this would reduce the demand for concrete, meaning Big Concrete will never go for it, because that would mean less profit. The world today. Hurray...

[@OriginalDonutposse]

You watch too many movies. Why didn’t big lamplighter stop the production of electric lights, if what you say is true? Or even better, Big Knockers should have stopped the production of the modern alarm clock.

[@ad1103]

If I wanted to build a stone house to last a thousand years, what mortar should I use between the stones to last a thousand years?

[@nonnativenarnian]

FASCINATING stuff. Could you cite your sources so that I can learn more?

[@donquijote7463]

PORTLAND : HOLD MY BEER.

[@ObservingLibertarian]

9:55 Or just make use the Roman *method* with cheaper alternative substances, which may in fact accomplish the same goals (methodology), but better: and thus create both cheaper and even longer lasting concrete top-covers/layers for roads which last a lot longer than current types/methods. Which could *radically improve infrastructure* in a *multiplicity* of abstractions from road re-work rate to tire wear rates to vehicle shock replacement rates. To say nothing of how much faster it could lead to meaningful implementation of basic infrastructure for under-developed countries with an eye towards resource conservation and efficient/clean disposal of waste. Simply reducing the total need for concrete is only the barest and most meaningless factor in what this improved understanding of engineering materials can bring: when you extrapolate out to all of the other factors the potential gains in efficiency become almost logarithmic. Just having better road surfaces and the wear on tires for example - have a look at that, singular, aspect. Have you ever looked into how much energy and materials are used for tires? Let alone how much waste is *produced* as tires either get disposed of or have to be re-tread? If you reduce that *even by just a few percentage points* - the cost reductions in terms of money, energy, materials, green house gasses and carbon footprint are astonishing.

[@netizencapet]

It takes a special degree of naiveté to believe a vastly superior product would ever be voluntarily adopted by two industries whose livelihood it threatens.

[@iampiyushsingh7544]

I find Roman history most interesting after indian ancient history

[@foxglove65]

Wonderful

[@jessecamacho7685]

In today's world we don't need structures to last that long since we are always rebuilding and changing buildings...

[@squash9189]

We don’t really need roman concrete to be implemented in our everyday buildings and architecture. With the rate that we’re developing and growing, buildings and infrastructure are constantly being built, changed, and destroyed. We won’t be having buildings that need to last for centuries.

[@kelphiuspolluxeldanimus6426]

Wrong. The current colliseum that we see today is a restored version. Most of it looked like the other half standing ruins around it. It got rebuilt in the early 1900s.

[@hornetkeeperh]

for over 2 millenia...we were just reading the recipe wrong.....🤣🤣

[@davejoseph5615]

Our concrete is destroyed by the rust that forms on the steel rebar. How much better is galvanized rebar?

[@TasX]

That’s crazy I wonder how long it will take for the concrete producers to adapt this technique.

[@innerpeacesoundscape]

It would be nice to see, but I feel that a lot of our modern construction processes are intentionally substandard so that constructions companies can continue profits through repair and replacement. Quality is not a key tenet of late-stage capitalisms.

[@triton62674]

@@innerpeacesoundscape Regulation is a solution

[@antonius.martinus]

@@triton62674 What if regulators get paid off by big construction companies?

[@Steph.98114]

Companies are already looking at it

[@k.3004]

The quality of roman concrete compared to modern concrete allows it to be a one time thing. Maybe there's a reason the simplicity of roman concrete wasn't understood until now.

[@dev559]

'Constant Maintenance' Saved you 11 minutes.

[@aleenajohnson5335]

Does nanoparticles have role in it

[@thilakreddy1661]

WHAT I should do.... now to create it now

[@starkiller3583]

Love your videos Ben! Keep making great content!

[@DrBenMiles]

Thanks so much! 🙏

[@starkiller3583]

@@DrBenMiles no problem! You're videos are really interesting and entertaining!

[@donquixote3963]

Wait........ ..... ... .. . So nobody has ever thought of mixing quick lime directly into the concrete mix and then comparing the results until NOW? Nobody tried to replicate a "poor mix"?... A millennium old mystery solved by someone who Isnt a moron...

[@AaronC.]

Let me get it straight... The difference between a concrete that stands a hundred years, and another that stands for a thousand years... is on the order on which you place the ingredients of the mix? (quicklime and dry ingredientes before water?) So simple, yet so incredible.

[@sophbliss]

Coming soon: the Eternal Parking Lot

[@alanmalcheski8882]

ok but the romans took credit for building lots of things, so who really invented it?

[@shadeedmuhammad8107]

May you do a video over concrete made by the Egyptians maybe Southeast Asians also the Mayans and Incas

[@DrBenMiles]

I watched so many Roman construction vids to research this. Check out our sponsor and offset your carbon footprint with Wren: www.wren.co/start/drbenmiles1m The first 100 to sign up will get their first month of the subscription covered by Wren for free!

[@rebelusa6585]

Good, now make a house with roman concrete, it will last at least 2000 years. You can pass it down to your great, great..... Grand kids..... Everyone will be happy. Modern concrete can last a long time too. Hoover dam 87 years old and still going strong.

[@MyReviews_karkan]

But what about "mah quarterly profits"?

[@duchuyedisonvu]

Read it as roman cancel WE STRIVIN

[@eua4808]

Before brick lvl 100 now brick lvl so low that can't be a number

[@kdenyer1]

Every damaged concrete you showed had reinforcement which cracked it, 🤔🤔

[@saltyjo7514]

In the olden days, things are made to last. Nowadays, they are made to crumble, so you need to spend money to build again. This is capitalism. More new buildings, more money, which drives the economy. German cars used to last 3-4 decades. Then they learnt from the Americans. Now you will be lucky if they last half a decade.

[@timgibson3754]

You know what you can do with your carbon footprint

[@apidas]

it's either that romans technology are magical or that we're stupid we couldn't re-discover this in any other way for another 2k years

[@mystwolfe7791]

Climate change 🤦‍♂️ it was called global warming until things got colder Global cooling until things warmed up Now climate change. We called that seasons.

[@gnardogjay]

you sound very knowledgeable

[@wgebhard1]

They can't make up their minds, and it's always lovely when they're getting their message out they want your money. It's almost like behind every single green movement it's a transfer of wealth, isn't that strange?

[@wgebhard1]

​@@gnardogjayyou sound like you drink flavor aid while a certain "Mr. Jones" preaches to you over loudspeakers.

[@lucidmoses]

Ah.. Now they have Evidence. Concrete evidence. :p

[@gregsmith1719]

Good video, but bad advise on CO2 -- It's plant food and won't bother us much, in fact a little more will make life better.

[@Fivetimesthree]

Too much will shift ecosystems over time :)

[@Conrad75]

Greg, you are contradicting a whole sect of science. You’re also going against the most rigorously peer reviewed piece of scientific literature ever (the IPCC report) where scientific experts in all fields come together to create and critique research on modern climate problems and also predictions about climate change to then form an extremely comprehensive report on. Quit being an idiot and do 2 seconds of research

[@k.3004]

It's definitely plant food that's why majority of carbon dioxide is absorbed by our seas leading to the acidification of our oceans.

[@Nick-jf7ku]

volcanic ash

[@mystwolfe7791]

Tell me again how we have evolved and gotten smarter. 😂 Then explain Greek fire Ancient iron that doesn’t rust Pyramid construction that we can’t duplicate. Etc

[@rwall514]

We're smarter because now we know why a thing works, rather than simply knowing that it works. Also, we have no need to build gigantic solid pyramids anymore, especially not with earthen ramps and thousands of labourers.

[@TheDocLamkin]

Great video til the cult pitch at the end to enslave and monetize carbon based life

[@UristMcFarmer]

So...if the answer is to just to mix the lime in with the rest of the ingredients before adding the water, why do we need some sort of hullabaloo between scientists and business? So everyone can get their patents in and lock down their cut of the profit?

[@Zesmas]

now try to reinforce the roman concrete with Rebar and see how strong it is.

[@WTP_1776]

carbon footprint lmao. offset your existence....rigggghhttt.....

[@wgebhard1]

It's weird how any green initiative immediately displays itself as a transfer of wealth

[@firstname4337]

aliens DUH !

[@i_nvade8098]

You know Nazi concrete was also really strong.

[@kingmasterlord]

tldr calcium carbonate

[@nedisawegoyogya]

one thing they miss is to test the comprssive strength

[@Veetina]

There was no leonardo Davinci it was another advanced superior race another humanity that built all these wonders that last for thousands of years .

[@Reedasaurus]

Very interesting piece, right up until you started talking about climate change. Then you lost me...

[@wgebhard1]

Remember when it was global warming? Then it was global cooling? Now it's climate change? It's a transfer of wealth propaganda narrative, and a transfer of power propaganda narrative.

[@Nightscape_]

Who still uses AD and BC In 2023? We don't have to bend the knee to religious orgnizations anymore.

[@TasX]

Oh yeah let’s use BCE and CE because common era so no religious references. I wonder what marks the common era? Your criticism is meaningless, just shows the kind of person you are more than anything.

[@markuswinkler5625]

Educated people who can value the human history, tradition and culture. You don't have to like many things, but you can rate the story behind it.

[@wisdon]

idiots flocks together on Internet

[@curiodyssey3867]

Bro, relax. I know this is way out there but consider the fact that this man just maaayybeee has it engrained after it being the customary way of denoting time for 20 years of his life. Try and focus your energy on things that actually have real world impact, your comment makes you look as if you're out in the town square waggin your pecker about in the wind as you spout crack pot conspiracy theories. So, even if you're correct, nobody will pay attention.

[@Lukeor]

So worship government organizations instead? Just shut up. I hate being an atheist because of people like you.

[@jennyanydots2389]

They took r jobs!!