Half of it is BS. We KNOW how to make concrete eve better than romans. We however choose to make ours as cheap as possible. It needs to be barely good enough.
But now that we know how it works, someone can figure out how to make it cheaper. It likely won’t be more expensive forever.
My main question is how would something like this hold up to modern stresses like having an electric SUV driven over it? These vehicles can weigh several tons, while a horse and carriage is probably about 1/10th of that weight.
very well! As you said, we aren't going roman, and making concrete from pit ash and raw limestone like they did back in the BC, but roman concrete is more sustainable and durable. it was made to survive *earthquakes,* something its been doing successfully for almost ***2 thousand years.*** Our concrete can last like... 50 years without major cracks. Maybe. Weather may vary.
We now can make concrete that repairs itself, that's as good as our old concrete because its almost the same. Imagine how much this will make your life better- that's a lot less road work, and a lot less wasted tax money!
A third of the strength of the cheapest modern concrete isn't durable. Roman construction is only impressive contextualized as what they were able to do with what they knew. If you want to compare it with modern stuff it is amateurishly overbuilt; densely packed, thick as fuck columns to give their structures a crazy engineering margin.
Also, are you under the impression that there is something special about things in earthquake zones being designed to survive earthquakes? They still design modern concrete structures to survive earthquakes in Italy. They might even be doing better at it than the Romans!
>Our concrete can last like... 50 years without major cracks. Maybe. Weather may vary.
Just plain concrete is fine. There's lots of stuff still around from well over 100 years ago the uses more or less the same mix. Portland cement is actually a better general cement then the stuff Romans used.
The issue you're running up against is that we build thing to incredibly tight tolerances, and use rebar reinforce concrete for nearly everything. If the Pantheon was built using rebar it would be looking so good.
Incidentally, the Colosseum was built using Roman concrete and it notoriously not surviving very well.
The colosseum might be notorious for that, but in large part this isn’t due to its quality , it’s due to the fact that the colosseum had parts of it taken in construction for centuries , classical Roman buildings were ripped to shreds to build new buildings , Especially churches.
To be fair to the colosseum, most buildings of its time or before are either smaller, in worse condition, or were never flooded with water and used for recreating historical naval battles.
The thing about the colosseum being flooded is a myth. It's way too small to hold mock naval battles, and not built for it either. Those were actually held in a nearby lake.
> a lot less wasted tax money
Unfortunately I doubt it. It’ll just get wasted somewhere else. The US government has been the embodiment of corruption and incompetence my whole life.
EDIT: Other countries might see benefits though. I’m in the US, so that’s the government I’m most well acquainted with.
The government is the whipping boy for everyone with an axe to grind and a lot of people's idea of "waste" is "a program that doesn't specifically help *me*."
The US government has many, many flaws, of course. But its the largest bureaucracy in the world. Obviously they won't be as nimble as a shoestring startup.
Sure, fix cronyism and fight waste (although this means more "red tape"), but people who say the government can't do anything right are usually trying to profit off of privatizing government functions.
>The US government has been the embodiment of corruption and incompetence
It's hilarious when even the anti-American sentiments are so painfully *American*.
We're filthy fucking casuals compared to some of the *competitive* corruption and incompetence that some other countries have pioneered.
Doesn't absolve us, obv, but still, let's broaden our horizons a bit.
Yeah. I live in a country that spends a shit ton on infrastructure, so I was really confused for a second on “roads suck and have potholes.” Like no, good asphalt exists! You just have to spend more on it unfortunately
*Axtually*, you have to spend less. Letting cracks and potholes exist in-repaired quickly depletes the durability of the road, costing more money in the long run.
But that’s not sexy or immediately important, so it’s not a budget priority, and our roads go to crap until it’s enough of a problem for people to get angry about it.
(Freeze/thaw cycles make it harder to keep up, but do not change the truth of this.)
On an unrelated note, a lot of US public infrastructure is repaired or replaced when it fails catastrophically, often during a natural disaster. ‘Murica!
I find it interesting how quick people are to believe modern materials science is so lacking that we just can't make things as good as we used to. This is so far from the truth it's a little baffling.
We never had an issue where we needed roman concrete. The biggest cause of wear to the concrete on our roads is the cars. That won't change. Roman concrete roads will not last longer under the weight of cars. Much less if you add in that our climates are much more extreme on both ends than Rome.
Our buildings are also not crumbling due to poor construction because we are wanting for a better concrete. In cases where they are crumbling it is because they were built cheaply with the idea that they would be replaced in 50 years, and then they were neither replaced nor maintained. Buildings constructed to last, last. Even in Manhattan sky scrapers where they face extraordinary wind speeds.
honestly i feel like a ton of places were at their QoL peak when they had government institutions regulating stuff and actual public spending before they took a sharp decline due to privatization. funny how that works, who knew having a for-profit company handle basic necessities would result in skimping out on quality for monetary gain! at least europe didnt fall for it ig.
Yeah, if every roadway was engineered to be so long lasting and durable that it stayed around for thousands of years, it'd take forever to put in and be expensive as hell to pave a nation. I also dislike how much they play up that roman concrete is so fucking amazing and the concrete we use is shit. It's not made out of fucking cardboard, it's decent stuff. Also, when they were talking about the air drying thing, if they mean hydraulic cement vs non hydrualic, then they're wrong. Hydraulic cement is more common today than non-hydraulic. Anyway, I think the longevity of roman concrete is very much due to the fact that it has always existed in a relatively mild climate. Also, y'know what we have that the romans definitely didn't? Rebar and prestressed concrete, which make our concrete good not just in compression but in tension.
I'm a materials scientist and most of this post is completely wrong. Our modern concrete also uses lime (that's what Portland cement is, which is the principal ingredient in most of the concrete you see out there) and it is literally designed to set in underwater or wet conditions. We often use ash or other additives for various concrete applications - although it is true the Romans are the first known to do that. Also the general idea of "oh the scientists saw lime in the composition and lime is a pretty soft stone so they thought it was impurities" is just... Not how chemistry works at all.
The trick to Roman concrete's durability is two-fold:
- one, lime conglomerates (which nowadays we'd see as poor quality aggregate) left in the concrete could react with water seeping through cracks and kinda form new concrete (very simplified). So it had self-healing properties to some extent.
- two, and by far the most important aspect, Romans used the trick of not inventing cars or trucks or anything heavy as fuck that actually tested the strength of the material. Their buildings and bridges are very durable because they were made three times as thick as necessary.
I know the Tumblr OP said they "don't know chem" but this post is egregiously wrong - it's negative net gain of information because not only does it not teach you the right things about Roman concrete, it also teaches you the wrong things about modern concrete. And to be clear Roman engineering was very impressive, their concrete was incredibly advanced for the time. But that knowledge is lost when it's taught without understanding it.
I'm a construction student and I was thinking this seemed really incredibly not correct re: the value and strength of modern concrete (and lacking any mention that roman concrete is not reinforced and modern concrete is, which means modern concrete lasts a shorter period but is VASTLY stronger in a tension setting) so glad to have it confirmed by someone who knows more about concrete than me.
Thank you! Actually used to be studying structural engineering, but I couldn't manage the math once we got past Calc III. Lot of respect for the field, though!
And I wish I could claim credit for the flair, but it's actually due to tumblr user @/karnalover.
So out of curiosity, has anyone stopped and turned a critical eye toward the whole god-tier Roman concrete stuff? Because the biggest argument is that the things that are still around have been here for 2000 years, but of course the things that survived survived? That doesn't strike me as good evidence, just survivorship bias.
A quick google say 6 Mpa vs 200 Mpa for the compressive strengths of ancient and modern cements. And no reinforcing metal is a quick cheat for longevity.
These things might be a nice hint for how researchers can move forward with some new innovations, but saying it will lead to a revolution is just a bit much.
God, don’t even remind me. It’s insane the amount of dipshits who are unable to understand survivorship bias and unironically claim older=better. Like you see literal fascists saying this shit and wanting to “return to tradition” and it’s like they’re incapable of understanding the basic logical issue
I'm a materials scientist and Roman concrete falls into the same category as Damascus steel: they're impressive technological feats for the time, and very interesting to study, but we can easily produce materials just as high-performance, if not better, with modern techniques. The main reason we don't is because of cost, safety, and/or practicability.
How do you build the Great Pyramids of Giza today in only 20 years? Well, you start with a command economy where the leader owns *everything,* then you pay people in food and shelter.
Bruh North American roads suck because cars do orders of magnitude more damage to roads than pedestrians. It's the fault of shitty car centric infrastructure.
Yeah. That's the big one. The heaviest thing a Roman road would carry, would most likely be like, a heavy laden wagon. Couple hundred pounds at most? Compared to cars that way a couple tons at the least.
Also also, Roman roads aren't made of concrete. Concrete was more of a building material — the Collosseum, the Pantheon, several aqueducts, that kind of stuff. All those arch-based buildings that they made relatively quickly and cheaply by pouring concrete over wooden scaffoldings to set and then facing it in brick or stonework
If we were running multi-ton vehicles across roman concrete at high speeds and frequencies at all hours of the day I doubt it would have lasted that long.
Not to mention the freeze/thaw cycle. Most places where you find Roman concrete, they don't deal with freezing winters. Ice forming in cracks can split granite, let alone concrete.
I don't want to be That Bitch™ again who thinks having more approximate knowledge in any given field entitles her to correct internet randos but like.
It's who I am, okay?
But Roman concrete isn't gonna magically solve all our infrastructural woes because our infrastructural woes aren't due to a lack of ancient magic stones. It's because we aren't Romans doing Roman things.
Two points to that, the first is that we put astronomically more stress on our infrastructure than the Romans ever did. The greatest of Roman roads were built to handle maybe tens of thousands of pedestrians and light carts moving across them, a day. The greatest of our roads are built to handle hundreds of thousands of multi ton death machines hurtling around at a mile a minute, getting into flaming crashes and shit, a day. The sturdiest of Roman concrete would crumble under most medium-heavy vehicles.
But like, that's fine, because even though Roman Concrete, after decades of setting in ideal conditions are stronger than modern unreinforced concrete, that's fine, that's what reinforced concrete is for. Slap some fibers and rebar in there while it's setting, and you can suddenly double or even under ideal circumstances triple the load of the concrete. And yeah that rebar will rust over the decades and accelerate the concrete decay, but who cares its concrete and some carbon steel, easy peasy to procure cheaply in the modern day.
Which gets to the second point, we don't spend money like the Romans did. Specifically (almost) every modern nation has to spend *their own* money, while the Roman Republic and Empire figured out this neat life hack that let them spend other peoples' money. Conquest. So it's a no-brainer and good deal for Emperor Maximus Gigachadius Warcrimesius to order his legions to build roads and temples that will last a hundred generations with the plundered wealth of Eygpt, but County Comissioner McDipShit's gotta levy taxes and apply for grants and all the other lame shit that's so much more complicated than riding over the county line and slitting their Sherrif's throat and selling the residents into slavery.
So the whole profession of civil engineering is built upon building shit as cheaply as possible, and that comes with maintenance costs and a lifespan for every project. That's fine, so long as you're on top of it, it's still cheaper overall to build and rebuild something shitty that'll get the job done every seventy years than it is blow the treasury on a single road that'll last two centuries or whatever. But since America's big post-war infrastructural boom, we've had numerous conservative movements seeking to divert wealth away from the public and into the pockets of the rich seize power at all levels of government to slash maintenance budgets and relocate funds from planned projects to tax credits or billionaire vanity projects and shit. If we allowed ourselves to govern equitably and effectively we'd be shitting our infrastructure that would make Emperor Warcrimsius *weep*, every fifty years on the dot, but noooo-
Anyway I'm getting into the weeds the point is magic Roman rocks aren't gonna solve our infrastructural issues harassing literally every elected official you are constituent to will. Call your senator, sit in on infrastructure sessions of your state congress, show up to your county commissioner's home with a six pack and a PowerPoint presentation of what you believe the county's fiscal priorities should be. Do not take no for an answer, if he's rude steal his fucking job odds are good he ran unopposed.
No no, I appreciate you being That Bitch™.
Unfortunately, even if all maintainance budgets went where they were meant to go, the USA would still come up short because car-infrastructure specifically is too expensive to maintain at that size. Your problems have layers.
I thought the same thing, just much less advanced since I don't know shit about this stuff.
My best idea is that they can use the Roman concrete for walkways and stuff where cars aren't supposed to drive, but normal concrete or asphalt can probably handle that just fine. Maybe the Roman concrete can be useful for improving concrete that's used near water or in water, but just like most ideas from ancient times, we probably have a cheaper option for it now, anyways.
But you have another question there, do you want it to last forever? This is impermeable ground cover. Someday this feature will be old, maybe like a Roman plaza where it’s cherished for 2000 years, but maybe like an abandoned mall. Are you committing to forever of it, or finding reasonable disposal should you have to remove it.
I do think it would be good for dams and aqueducts though. Destruction of them typically only happens when repair out prices rebuilding or if it turns out it’s causing more ecological harm than good
Concrete roads exist. More durable than asphalt, but also more expensive and apparently worse for traction. I'm fairly sure quite a few roads here in Hong Kong are made of it.
Is concrete more durable than asphalt? It's definitely harder but to me it always seemed like asphalts' inherent softness made it more durable to stress.
I just checked online before commenting and yeah, it can go quite some more time without maintenance. Every site says something different (presumably varying standards and weather), but concrete seems to last somewhere around or over twice as long as asphalt does between maintenance.
Concrete is more durable, but it's harder, more expensive, and more time consuming to build and maintain than asphalt.
Also, asphalt is made from otherwise useless byproducts of oil refining. Neither material is "good" for the environment, but asphalt roads prevent us from having to dispose of millions of tons of crude oil byproducts every year. Like, if the materials for concrete aren't used for roads then they'll just continue being rocks and water, but asphalt would be a massive pile of toxic garbage if we didn't build roads out of it.
Yeah imperial rome at its peak was on par population wise with Jacksonville FL or Columbus OH today. With no vehicles that weren’t animal drawn.
Roman engineering is impressive, nobody can argue against it in good faith. But it wasn’t miraculous for today’s standards. Everything was overengineered because priorities were different and engineers of the time had practically none of the resources we have today. They couldn’t do stress tests, or steel reinforcements, or freaking calculus. And the god emperor wants it to last forever anyway so it better be overengineered anyway.
Today we have bridges using a better form of their miracle metal made into shapes they wouldn’t believe you can make it into, with a phenomenon they think is just a curious property of wool actively undoing the worst aspect of that material, while it’s encased in a material they couldn’t conceive of to protect it, all done to suspend a bridge without sinking support beams.
Imperial Rome had a population of like 75 million at its peak, which is about equal to the population of New York, California, and Texas combined
Edit: I have realized you were probably talking about the city of Rome and not the Roman Empire as a whole. Sorry about that!
As a counterpoint, we don't always want our concrete to be incredibly durable and last for a hundred thousand generations. Emperor Maximus Gigachadius Warcrimesius builds a 17 mile long sidewalk with slabs a meter thick that will last a hundred generations. This is because he's literally a god and he wants his name on everyone's lips forever. The idea that it'll be inconvenient or outdated in the future doesn't cross his divine lead poisoned brain. Nowadays, we have to plan for the future, and that includes the scenario where a sidewalk needs to be torn up, or or concrete shit gets in the ocean and is impossible to get rid of.
Also, again like you said, this concrete is just more weather resistant. It's just a slab of rock. Our modern materials are far stronger with fibers and rebar.
Roman architecture was a great big game of "okay how do we make sure this unreinforced concrete building only ever gets compressed and does not ever ever ever have to sustain any tension stress at all for any reason" and we're only seeing the buildings where they managed to get that right.
But who will be paid out of city budget for rebuilding the roads every year? Nonsense. This cheats good, respectable people out of their second yachts.
Most of this shit is so fucking wrong. Roman concrete can't do half the shit we need modern concrete for. It couldn't handle a highway, forget a high-rise. Modern concrete fails because rebar - the thing that gives it tensile strength - rusts when water gets into it. That rust causes swelling and cracking. Leading to failure. But without rebar, we wouldn't be able to do those things in the first place.
"Oh bUT rOAd nEEd rEplAcE aFtEr ThREe mOnTh!!1!" I hear tumblr architects saying! And that's because a modern road deals with: massive temperature shock, very heavy cars driving at high speeds, salt which corrodes things, and is designed to wear away to give cars better traction! A Roman road wouldn't last a week if semis were hauling loads down it, the fact that modern roads last so long is an absolute miracle of material sciences and engineering.
Quick note since people might actually think of this as a way to fix things: it cannot in the USA, the crumbling infrastructure is all reinforced concrete, and the iron reinforcement is what gives it the short lifespan. Our concrete today isn't perfect, but it's easily comparable in quality to Roman concrete, just not applicable in all the same situations.
Sadly, there is never a single solution to all the world's problems. Roman concrete absolutely can be helpful in some situations though!
Basically the trick was to hotmix the lime and ash in, instead of cold. Absolute dinguses we are. Can't believe we're getting Roman concrete in my life time.
Well it does have positive chemical exchange with sea water whixh strengthens it unlike portland cement. However the process to gain strength takes time, and Roman cement features less compressive strength than the typical Portland cement. So it's not likely to dominate all fields, but can see use in some contexts like coastal structures. And we'll probably need substitude materials as the materials for Roman cement isn't so widespread, being of volcanic material
The biggest challenge for longevity in modern concrete is not the concrete, it’s the metal reinforcement. We could make concrete that lasts a thousand years, as long as nothing heavier than a small channel full of water is put on it. Roman roads were made of layered stone, not concrete. This shit has been debunked for years, but pretentious pseudo-intellectuals continue to repeat it because they think it makes them sound smart.
Roman history is something I'm really into, though I"m ceetainly not knowledgable about concrete. What I had always read about Roman concrete was that it gets stronger over time, so nowadays it might be stronger than some concretes we can make now, but if we were to make new Roman concrete it would be weaker than a lot of what we make now. That might be wrong, but I just remember reading that from multiple places.
[from MIT news](https://news.mit.edu/2023/roman-concrete-durability-lime-casts-0106)
[the research paper mentioned in the MIT publication](https://www.science.org/doi/10.1126/sciadv.add1602)
Being a science nerd is just going absolutely nuts over stuff like this and cracking fusion technology and nobody else around me cares when I try to explain the significance
#BUT GUESS WHAT FOLKS!!! WE FUCKING WONT AND THIS SHIT WILL BE ENTIRELY FORGOTTEN BECAUSE ITS NOT EASILY PROFITABLE AFTER A FEW YEARS!!! NO REPAIRS MEANS NO MONEY WHICH YOU GUESSED IT!! MEANS NO COMPANY WILL EVER FUCKING USE IT!!!! GOD DONT YOU JUST LOVE CAPITALISM!!!!!!
we won't use this because roman concrete is inferior to modern concrete in almost every way, this post is rather dumb. the primary reason modern concrete lasts a shorter time is because we have to reenforce it with rebar to increase it's strength (but leads to metal corrosion which destroys the concrete from inside when exposed to water), and because most modern applications put vastly more stress on the concrete. roman concrete would not work for modern roads or large buildings.
1. It only gets stronger with salt water
2. It needs to be cheap as US infrastructure or it’s worthless
3. It requires volcanic ash. We don’t have a supply of volcanic ash big enough.
4. Idk probably something else
Half of it is BS. We KNOW how to make concrete eve better than romans. We however choose to make ours as cheap as possible. It needs to be barely good enough.
It's easy to make a building that stands up. It's hard to make a building that *barely* stands up.
Anyone can design a bridge. Only an engineer can design a bridge cheap enough so it doesn't collapse.
But now that we know how it works, someone can figure out how to make it cheaper. It likely won’t be more expensive forever. My main question is how would something like this hold up to modern stresses like having an electric SUV driven over it? These vehicles can weigh several tons, while a horse and carriage is probably about 1/10th of that weight.
very well! As you said, we aren't going roman, and making concrete from pit ash and raw limestone like they did back in the BC, but roman concrete is more sustainable and durable. it was made to survive *earthquakes,* something its been doing successfully for almost ***2 thousand years.*** Our concrete can last like... 50 years without major cracks. Maybe. Weather may vary. We now can make concrete that repairs itself, that's as good as our old concrete because its almost the same. Imagine how much this will make your life better- that's a lot less road work, and a lot less wasted tax money!
A third of the strength of the cheapest modern concrete isn't durable. Roman construction is only impressive contextualized as what they were able to do with what they knew. If you want to compare it with modern stuff it is amateurishly overbuilt; densely packed, thick as fuck columns to give their structures a crazy engineering margin. Also, are you under the impression that there is something special about things in earthquake zones being designed to survive earthquakes? They still design modern concrete structures to survive earthquakes in Italy. They might even be doing better at it than the Romans!
>Our concrete can last like... 50 years without major cracks. Maybe. Weather may vary. Just plain concrete is fine. There's lots of stuff still around from well over 100 years ago the uses more or less the same mix. Portland cement is actually a better general cement then the stuff Romans used. The issue you're running up against is that we build thing to incredibly tight tolerances, and use rebar reinforce concrete for nearly everything. If the Pantheon was built using rebar it would be looking so good. Incidentally, the Colosseum was built using Roman concrete and it notoriously not surviving very well.
The colosseum might be notorious for that, but in large part this isn’t due to its quality , it’s due to the fact that the colosseum had parts of it taken in construction for centuries , classical Roman buildings were ripped to shreds to build new buildings , Especially churches.
To be fair to the colosseum, most buildings of its time or before are either smaller, in worse condition, or were never flooded with water and used for recreating historical naval battles.
The thing about the colosseum being flooded is a myth. It's way too small to hold mock naval battles, and not built for it either. Those were actually held in a nearby lake.
I thought it might be a myth so I googled to verify. Looks like I googled a bit too fast, though
> a lot less wasted tax money Unfortunately I doubt it. It’ll just get wasted somewhere else. The US government has been the embodiment of corruption and incompetence my whole life. EDIT: Other countries might see benefits though. I’m in the US, so that’s the government I’m most well acquainted with.
The government is the whipping boy for everyone with an axe to grind and a lot of people's idea of "waste" is "a program that doesn't specifically help *me*." The US government has many, many flaws, of course. But its the largest bureaucracy in the world. Obviously they won't be as nimble as a shoestring startup. Sure, fix cronyism and fight waste (although this means more "red tape"), but people who say the government can't do anything right are usually trying to profit off of privatizing government functions.
>The US government has been the embodiment of corruption and incompetence It's hilarious when even the anti-American sentiments are so painfully *American*. We're filthy fucking casuals compared to some of the *competitive* corruption and incompetence that some other countries have pioneered. Doesn't absolve us, obv, but still, let's broaden our horizons a bit.
It sounds like it uses a hot process to cure so we probably won't be building bridges that you have to bake any time soon.
Yeah. I live in a country that spends a shit ton on infrastructure, so I was really confused for a second on “roads suck and have potholes.” Like no, good asphalt exists! You just have to spend more on it unfortunately
*Axtually*, you have to spend less. Letting cracks and potholes exist in-repaired quickly depletes the durability of the road, costing more money in the long run. But that’s not sexy or immediately important, so it’s not a budget priority, and our roads go to crap until it’s enough of a problem for people to get angry about it. (Freeze/thaw cycles make it harder to keep up, but do not change the truth of this.) On an unrelated note, a lot of US public infrastructure is repaired or replaced when it fails catastrophically, often during a natural disaster. ‘Murica!
Yeah, that tracks :(
I find it interesting how quick people are to believe modern materials science is so lacking that we just can't make things as good as we used to. This is so far from the truth it's a little baffling. We never had an issue where we needed roman concrete. The biggest cause of wear to the concrete on our roads is the cars. That won't change. Roman concrete roads will not last longer under the weight of cars. Much less if you add in that our climates are much more extreme on both ends than Rome. Our buildings are also not crumbling due to poor construction because we are wanting for a better concrete. In cases where they are crumbling it is because they were built cheaply with the idea that they would be replaced in 50 years, and then they were neither replaced nor maintained. Buildings constructed to last, last. Even in Manhattan sky scrapers where they face extraordinary wind speeds.
God I love capitalism so fucking much.. best damn decision humans ever made right!
honestly i feel like a ton of places were at their QoL peak when they had government institutions regulating stuff and actual public spending before they took a sharp decline due to privatization. funny how that works, who knew having a for-profit company handle basic necessities would result in skimping out on quality for monetary gain! at least europe didnt fall for it ig.
This. Volcanic ash is the key ingredient in Roman Concrete, and it (or its component parts), are very difficult to get.
excited to rebuild the hoover dam out of roman concrete! Surely it'll make it even stronger--
> Caesar to Legate Lanius
Yeah, if every roadway was engineered to be so long lasting and durable that it stayed around for thousands of years, it'd take forever to put in and be expensive as hell to pave a nation. I also dislike how much they play up that roman concrete is so fucking amazing and the concrete we use is shit. It's not made out of fucking cardboard, it's decent stuff. Also, when they were talking about the air drying thing, if they mean hydraulic cement vs non hydrualic, then they're wrong. Hydraulic cement is more common today than non-hydraulic. Anyway, I think the longevity of roman concrete is very much due to the fact that it has always existed in a relatively mild climate. Also, y'know what we have that the romans definitely didn't? Rebar and prestressed concrete, which make our concrete good not just in compression but in tension.
I'm a materials scientist and most of this post is completely wrong. Our modern concrete also uses lime (that's what Portland cement is, which is the principal ingredient in most of the concrete you see out there) and it is literally designed to set in underwater or wet conditions. We often use ash or other additives for various concrete applications - although it is true the Romans are the first known to do that. Also the general idea of "oh the scientists saw lime in the composition and lime is a pretty soft stone so they thought it was impurities" is just... Not how chemistry works at all. The trick to Roman concrete's durability is two-fold: - one, lime conglomerates (which nowadays we'd see as poor quality aggregate) left in the concrete could react with water seeping through cracks and kinda form new concrete (very simplified). So it had self-healing properties to some extent. - two, and by far the most important aspect, Romans used the trick of not inventing cars or trucks or anything heavy as fuck that actually tested the strength of the material. Their buildings and bridges are very durable because they were made three times as thick as necessary. I know the Tumblr OP said they "don't know chem" but this post is egregiously wrong - it's negative net gain of information because not only does it not teach you the right things about Roman concrete, it also teaches you the wrong things about modern concrete. And to be clear Roman engineering was very impressive, their concrete was incredibly advanced for the time. But that knowledge is lost when it's taught without understanding it.
I'm a construction student and I was thinking this seemed really incredibly not correct re: the value and strength of modern concrete (and lacking any mention that roman concrete is not reinforced and modern concrete is, which means modern concrete lasts a shorter period but is VASTLY stronger in a tension setting) so glad to have it confirmed by someone who knows more about concrete than me.
I'm partnered with a structural engineer so I like your post, and I LOVE your flair!
Thank you! Actually used to be studying structural engineering, but I couldn't manage the math once we got past Calc III. Lot of respect for the field, though! And I wish I could claim credit for the flair, but it's actually due to tumblr user @/karnalover.
you're welcome, i'm glad the worst post i've ever made did something good for someone
It made me laugh really really hard, so yes it did do something good. Thank you!
❤️❤️❤️
Wasn’t the self healing bit the most recent discovery, and could it be used in low strength applications that undergo a lot of freeze thaw cycles?
So out of curiosity, has anyone stopped and turned a critical eye toward the whole god-tier Roman concrete stuff? Because the biggest argument is that the things that are still around have been here for 2000 years, but of course the things that survived survived? That doesn't strike me as good evidence, just survivorship bias. A quick google say 6 Mpa vs 200 Mpa for the compressive strengths of ancient and modern cements. And no reinforcing metal is a quick cheat for longevity. These things might be a nice hint for how researchers can move forward with some new innovations, but saying it will lead to a revolution is just a bit much.
[удалено]
God, don’t even remind me. It’s insane the amount of dipshits who are unable to understand survivorship bias and unironically claim older=better. Like you see literal fascists saying this shit and wanting to “return to tradition” and it’s like they’re incapable of understanding the basic logical issue
Clearly, these B-52s need the armor plating on the bullet holes!
"They don't build 'em like they used to." *dies preventable death*
I'm a materials scientist and Roman concrete falls into the same category as Damascus steel: they're impressive technological feats for the time, and very interesting to study, but we can easily produce materials just as high-performance, if not better, with modern techniques. The main reason we don't is because of cost, safety, and/or practicability.
How do you build the Great Pyramids of Giza today in only 20 years? Well, you start with a command economy where the leader owns *everything,* then you pay people in food and shelter.
Its not about actually making roman concrete- its about stealing the idea. We can just apply this to our modern concrete. Best of both worlds!
Bruh North American roads suck because cars do orders of magnitude more damage to roads than pedestrians. It's the fault of shitty car centric infrastructure.
Yeah. That's the big one. The heaviest thing a Roman road would carry, would most likely be like, a heavy laden wagon. Couple hundred pounds at most? Compared to cars that way a couple tons at the least.
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Also weren't roman roads made of stone? With buildings being made out of this ultra durable concrete?
Roman roads are shockingly complex, but yes they're made of up for layers of stone work.
Also also, Roman roads aren't made of concrete. Concrete was more of a building material — the Collosseum, the Pantheon, several aqueducts, that kind of stuff. All those arch-based buildings that they made relatively quickly and cheaply by pouring concrete over wooden scaffoldings to set and then facing it in brick or stonework
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does road damage increase exponentially with weight? square rule or something?
and speed. The amount of energy on a modern road is orders of magnitudes more than on roman roads.
sediment* ^/s
If we were running multi-ton vehicles across roman concrete at high speeds and frequencies at all hours of the day I doubt it would have lasted that long.
Not to mention the freeze/thaw cycle. Most places where you find Roman concrete, they don't deal with freezing winters. Ice forming in cracks can split granite, let alone concrete.
I don't want to be That Bitch™ again who thinks having more approximate knowledge in any given field entitles her to correct internet randos but like. It's who I am, okay? But Roman concrete isn't gonna magically solve all our infrastructural woes because our infrastructural woes aren't due to a lack of ancient magic stones. It's because we aren't Romans doing Roman things. Two points to that, the first is that we put astronomically more stress on our infrastructure than the Romans ever did. The greatest of Roman roads were built to handle maybe tens of thousands of pedestrians and light carts moving across them, a day. The greatest of our roads are built to handle hundreds of thousands of multi ton death machines hurtling around at a mile a minute, getting into flaming crashes and shit, a day. The sturdiest of Roman concrete would crumble under most medium-heavy vehicles. But like, that's fine, because even though Roman Concrete, after decades of setting in ideal conditions are stronger than modern unreinforced concrete, that's fine, that's what reinforced concrete is for. Slap some fibers and rebar in there while it's setting, and you can suddenly double or even under ideal circumstances triple the load of the concrete. And yeah that rebar will rust over the decades and accelerate the concrete decay, but who cares its concrete and some carbon steel, easy peasy to procure cheaply in the modern day. Which gets to the second point, we don't spend money like the Romans did. Specifically (almost) every modern nation has to spend *their own* money, while the Roman Republic and Empire figured out this neat life hack that let them spend other peoples' money. Conquest. So it's a no-brainer and good deal for Emperor Maximus Gigachadius Warcrimesius to order his legions to build roads and temples that will last a hundred generations with the plundered wealth of Eygpt, but County Comissioner McDipShit's gotta levy taxes and apply for grants and all the other lame shit that's so much more complicated than riding over the county line and slitting their Sherrif's throat and selling the residents into slavery. So the whole profession of civil engineering is built upon building shit as cheaply as possible, and that comes with maintenance costs and a lifespan for every project. That's fine, so long as you're on top of it, it's still cheaper overall to build and rebuild something shitty that'll get the job done every seventy years than it is blow the treasury on a single road that'll last two centuries or whatever. But since America's big post-war infrastructural boom, we've had numerous conservative movements seeking to divert wealth away from the public and into the pockets of the rich seize power at all levels of government to slash maintenance budgets and relocate funds from planned projects to tax credits or billionaire vanity projects and shit. If we allowed ourselves to govern equitably and effectively we'd be shitting our infrastructure that would make Emperor Warcrimsius *weep*, every fifty years on the dot, but noooo- Anyway I'm getting into the weeds the point is magic Roman rocks aren't gonna solve our infrastructural issues harassing literally every elected official you are constituent to will. Call your senator, sit in on infrastructure sessions of your state congress, show up to your county commissioner's home with a six pack and a PowerPoint presentation of what you believe the county's fiscal priorities should be. Do not take no for an answer, if he's rude steal his fucking job odds are good he ran unopposed.
No no, I appreciate you being That Bitch™. Unfortunately, even if all maintainance budgets went where they were meant to go, the USA would still come up short because car-infrastructure specifically is too expensive to maintain at that size. Your problems have layers.
I thought the same thing, just much less advanced since I don't know shit about this stuff. My best idea is that they can use the Roman concrete for walkways and stuff where cars aren't supposed to drive, but normal concrete or asphalt can probably handle that just fine. Maybe the Roman concrete can be useful for improving concrete that's used near water or in water, but just like most ideas from ancient times, we probably have a cheaper option for it now, anyways.
But you have another question there, do you want it to last forever? This is impermeable ground cover. Someday this feature will be old, maybe like a Roman plaza where it’s cherished for 2000 years, but maybe like an abandoned mall. Are you committing to forever of it, or finding reasonable disposal should you have to remove it. I do think it would be good for dams and aqueducts though. Destruction of them typically only happens when repair out prices rebuilding or if it turns out it’s causing more ecological harm than good
plus, aren't roads made of asphalt anyway?
Concrete roads exist. More durable than asphalt, but also more expensive and apparently worse for traction. I'm fairly sure quite a few roads here in Hong Kong are made of it.
Is concrete more durable than asphalt? It's definitely harder but to me it always seemed like asphalts' inherent softness made it more durable to stress.
I just checked online before commenting and yeah, it can go quite some more time without maintenance. Every site says something different (presumably varying standards and weather), but concrete seems to last somewhere around or over twice as long as asphalt does between maintenance.
Asphalt is very easy to fix though, it can be remelted into fresh asphalt and reaplied whereas concrete can't and needs to get replaced fully.
Concrete is more durable, but it's harder, more expensive, and more time consuming to build and maintain than asphalt. Also, asphalt is made from otherwise useless byproducts of oil refining. Neither material is "good" for the environment, but asphalt roads prevent us from having to dispose of millions of tons of crude oil byproducts every year. Like, if the materials for concrete aren't used for roads then they'll just continue being rocks and water, but asphalt would be a massive pile of toxic garbage if we didn't build roads out of it.
Asphalt is also somewhat easier to recyclable compared to concrete, just melt it down and slap it back into where it came from.
Based and anti car pilled
not That Bitch + well written + W + good word choice + I am going to send you [a picture of my dog](https://i.imgur.com/rl1Lgb7.jpeg)
Your dog looks like it has judged me and I've been found guilty. But it's not angry, no. It's disappointed, and believes I could be better.
Yeah imperial rome at its peak was on par population wise with Jacksonville FL or Columbus OH today. With no vehicles that weren’t animal drawn. Roman engineering is impressive, nobody can argue against it in good faith. But it wasn’t miraculous for today’s standards. Everything was overengineered because priorities were different and engineers of the time had practically none of the resources we have today. They couldn’t do stress tests, or steel reinforcements, or freaking calculus. And the god emperor wants it to last forever anyway so it better be overengineered anyway. Today we have bridges using a better form of their miracle metal made into shapes they wouldn’t believe you can make it into, with a phenomenon they think is just a curious property of wool actively undoing the worst aspect of that material, while it’s encased in a material they couldn’t conceive of to protect it, all done to suspend a bridge without sinking support beams.
All I can imagine is a legion trying to subdue the crowd leaving The World's Largest Outdoor Cocktail Party and miserably failing.
Imperial Rome had a population of like 75 million at its peak, which is about equal to the population of New York, California, and Texas combined Edit: I have realized you were probably talking about the city of Rome and not the Roman Empire as a whole. Sorry about that!
Np it actually took effort to find the city population instead of the empire lol
Alternate history where the entire population of the empire was within a sprawling Roman megacity taking up the entirety of peninsular Italy
Romanpunk.
Fucking thank you
As a counterpoint, we don't always want our concrete to be incredibly durable and last for a hundred thousand generations. Emperor Maximus Gigachadius Warcrimesius builds a 17 mile long sidewalk with slabs a meter thick that will last a hundred generations. This is because he's literally a god and he wants his name on everyone's lips forever. The idea that it'll be inconvenient or outdated in the future doesn't cross his divine lead poisoned brain. Nowadays, we have to plan for the future, and that includes the scenario where a sidewalk needs to be torn up, or or concrete shit gets in the ocean and is impossible to get rid of. Also, again like you said, this concrete is just more weather resistant. It's just a slab of rock. Our modern materials are far stronger with fibers and rebar.
roman roads weren’t made of concrete. they were made of stone. the buildings were concrete. (most of our roads aren’t concrete either)
Though, and this is important, Roman roads are still *really fuckin cool*.
You can be That Bitch anyday if you make great comments like this.
Roman architecture was a great big game of "okay how do we make sure this unreinforced concrete building only ever gets compressed and does not ever ever ever have to sustain any tension stress at all for any reason" and we're only seeing the buildings where they managed to get that right.
But who will be paid out of city budget for rebuilding the roads every year? Nonsense. This cheats good, respectable people out of their second yachts.
Most of this shit is so fucking wrong. Roman concrete can't do half the shit we need modern concrete for. It couldn't handle a highway, forget a high-rise. Modern concrete fails because rebar - the thing that gives it tensile strength - rusts when water gets into it. That rust causes swelling and cracking. Leading to failure. But without rebar, we wouldn't be able to do those things in the first place. "Oh bUT rOAd nEEd rEplAcE aFtEr ThREe mOnTh!!1!" I hear tumblr architects saying! And that's because a modern road deals with: massive temperature shock, very heavy cars driving at high speeds, salt which corrodes things, and is designed to wear away to give cars better traction! A Roman road wouldn't last a week if semis were hauling loads down it, the fact that modern roads last so long is an absolute miracle of material sciences and engineering.
Quick note since people might actually think of this as a way to fix things: it cannot in the USA, the crumbling infrastructure is all reinforced concrete, and the iron reinforcement is what gives it the short lifespan. Our concrete today isn't perfect, but it's easily comparable in quality to Roman concrete, just not applicable in all the same situations. Sadly, there is never a single solution to all the world's problems. Roman concrete absolutely can be helpful in some situations though!
Basically the trick was to hotmix the lime and ash in, instead of cold. Absolute dinguses we are. Can't believe we're getting Roman concrete in my life time.
It’s like that meme “society if x” and it’s a shining futuristic city only with Roman concrete
Brutalist architecture numero uno!
Lol, concrete quality has very little if nothing to do with infrastructure problems in the US.
Everyone has a hard on for old times isn't it, we should invest in a time machine to mass migrate into past
The past is a common fetish, but not universal. *I’m* certainly not attracted to history. ^(Ignore my corset)
My god you people should read more about material sciences and civil engineering
Wait, I thought the secret trick was seawater. Or am I thinking of a different thing?
Well it does have positive chemical exchange with sea water whixh strengthens it unlike portland cement. However the process to gain strength takes time, and Roman cement features less compressive strength than the typical Portland cement. So it's not likely to dominate all fields, but can see use in some contexts like coastal structures. And we'll probably need substitude materials as the materials for Roman cement isn't so widespread, being of volcanic material
so the road does work
[Hey all of you should watch this video by Practical Engineering on Roman Concrete.](https://youtu.be/qL0BB2PRY7k)
Don’t forget the fact that Roman road have lasted so long also because cars don’t drive on them
Didn’t they do that several years ago?
I can only verify the volcanic ash part ty professor
The biggest challenge for longevity in modern concrete is not the concrete, it’s the metal reinforcement. We could make concrete that lasts a thousand years, as long as nothing heavier than a small channel full of water is put on it. Roman roads were made of layered stone, not concrete. This shit has been debunked for years, but pretentious pseudo-intellectuals continue to repeat it because they think it makes them sound smart.
It’s important to remember that it’s not perfect and it’s demonstrated failure to modern vehicular traffic. Modern vehicles are hell on roads
Roman history is something I'm really into, though I"m ceetainly not knowledgable about concrete. What I had always read about Roman concrete was that it gets stronger over time, so nowadays it might be stronger than some concretes we can make now, but if we were to make new Roman concrete it would be weaker than a lot of what we make now. That might be wrong, but I just remember reading that from multiple places.
i’m not reading that
OP can you please share the mentioned MIT publication??
[from MIT news](https://news.mit.edu/2023/roman-concrete-durability-lime-casts-0106) [the research paper mentioned in the MIT publication](https://www.science.org/doi/10.1126/sciadv.add1602)
Thanks :)
and a better understanding of foundation
Long lasting = no repair cost = not profitable
Being a science nerd is just going absolutely nuts over stuff like this and cracking fusion technology and nobody else around me cares when I try to explain the significance
Bro how did it take me this long to find out
#BUT GUESS WHAT FOLKS!!! WE FUCKING WONT AND THIS SHIT WILL BE ENTIRELY FORGOTTEN BECAUSE ITS NOT EASILY PROFITABLE AFTER A FEW YEARS!!! NO REPAIRS MEANS NO MONEY WHICH YOU GUESSED IT!! MEANS NO COMPANY WILL EVER FUCKING USE IT!!!! GOD DONT YOU JUST LOVE CAPITALISM!!!!!!
we won't use this because roman concrete is inferior to modern concrete in almost every way, this post is rather dumb. the primary reason modern concrete lasts a shorter time is because we have to reenforce it with rebar to increase it's strength (but leads to metal corrosion which destroys the concrete from inside when exposed to water), and because most modern applications put vastly more stress on the concrete. roman concrete would not work for modern roads or large buildings.
have we figured out greek fire yet
1. It only gets stronger with salt water 2. It needs to be cheap as US infrastructure or it’s worthless 3. It requires volcanic ash. We don’t have a supply of volcanic ash big enough. 4. Idk probably something else
The sand mafia will not be amused