It stood empty for many decades until the fashion brand Fendi took residence there . Until today, you can ready the proud fascist inscription there: All the neighbourhood was erected by Mussolini to the world exhibition of 1940 which had to be canceled because of the war.
Modern concrete does NOT need air or CO2 to “harden”. The water chemically reacts with the cement (hydrating). This is an exothermic chemical reaction (it produces heat). Modern concrete can indeed be poured and set under seawater (it’s a challenge but possible). The exact properties of modern concrete are adjusted according to specific needs by the addition of admixtures (additives to control various properties). Extremely strong and durable concrete can be produced if desired.
Modern concrete is mostly fly ash because it was historically cheap due being a byproduct of coal plants. With less and less reliance on coal in facor of oil, alternates will need to be used going forward. Maybe something better can emerge?
I'm using this type of concrete for waterproofing jobs and know they're used annually by underwater bridge pylons maintenance filling up cracks. They're super hard when set but a bit expensive
What a well rounded and succinct explanation to this topic, your final words even more so. The methods were amazing for there time, but methods change and adapted to the project at hand. I’d love to see Roman concrete utilized to build structures again, and people finally finding out how it was made had me excited.
That building in Chicago is indeed a hulk of a space. Solid hallways, but not claustrophobic when one walks it. Open to the public as well. First floor has small shops.
how did finance system in rome work? how did they pay rent? where loans with intrest a thing back then. How did companies work in that time? And how did the companies get financing for growth and new projects?
Diversification, innovation, and growth weren’t really priorities among Roman businesspeople. It was really just a series of pyramid schemes until mercantilism really took off.
Companies did not exist at the time; it was about aristocratic members with lots of money from their land ownership. The concept of a company as an economic institution is recent and started in the Middle Ages. Loans were a thing, and so was interest; loans have existed since the Mesopotamian era. I don't know much about rents, but I remember that people did not rent apartments in the big insulae; they usually rented rooms for the entire family of commoners.
I believe he has answered at least your second question in a video. People paid rent annually and usually in the early days of July. That's what I recall at least.
Concrete is certainly a pretty amazing material, but on its own, it can be pretty ugly, especially in places with gloomier climates. I like the Roman idea of hiding it away behind a nice layer of masonry. I used to live in Warsaw, a city shaped by a post-war love of modernism and brutalism. Perhaps it's just a style that's too old to be modern and not old enough to be valued yet... but I don't like it!
The Romans didn't hide the concrete with masonery because they thought the concrete was ugly, the masonary was a technical necessity. If you pour Roman concrete just like in the cuppola ceiling of the Pantheon, you have to wait several years for the concrete to harden enough before you are able to take down the formwork and scaffolding otherwise your wall would collapse. By pouring the concrete between two thin brick walls you need much less sheeting and the wall is much sooner stable enough to build higher, therefore you can build much faster. And even if you would encase the Roman concrete and wait long enough until it settled, it would look mostly much better as the most of the time very grey brutalist buildings. Roman conrete is through all the rubble used in it, much more colorful and less grey. If you smooth the surface it is more or less like terrazzo. You can have this with the right modern concrete too, but that is very expensive.
The Hoover Dam uses unreinforced concrete, so its similar in that sense. Pozzolana, as mentioned in the video, is also how the we get the term for pozzolanic materials which are a set of common additives in concrete that react similarly to the original roman clay, but are more common around the world. Commonly, they're industrial by-products like fly ash and blast furnace slag but can also include volcanic ash even today!
@@andrewjensen7454 do you work with concrete? Roman concrete would basically heal itself on the piers and water breaks, maybe the Hoover Dam actually did use a form of Roman concrete, but at the same time there's damn failures everywhere nowadays which if they had used the Roman concrete would not happening, I live in the Eastern US it's kind of a big deal right now. Modern concrete hits his strongest point in 50 years, and then, from that moment on, it degrades, and yes, I have worked with concrete before in my life.
@@kalrandom7387 I'm a structural engineer and have taken several courses in concrete materials science and concrete design (at the undergraduate and graduate levels), but haven't trowelled anything myself beyond a fence post anchorage of ready mix. Did work for a contractor for a bit though while in undergrad and we installed a fair bit of concrete. I've also done a fair bit of research work with dams (specifically focusing on dam monitoring), and they aren't a monolith, there are a lot of different types from concrete and arch supported to earthen embankment to clay core. Most dams are earthen embankment dams as they're much cheaper per linear foot of dam to construct. Typically failure modes for them are either abutment failures, overtopping events, or seepage failures leading to piping (water is constantly flowing out from under the dam througbt he ground, if it moves too quickly it causes internal erosion which is typically a runaway problem and can be disastrous). The thing is, none of these issues are solved by using a mix with higher pozzolanic material content. Many of them don't even use appreciable quanties of concrete in their construction! For long term durability, adding more pozzolanic materials does help resist chemical attack, which is helpful but not sufficient to ensure safe operation under extreme conditions. As for what's going on on the East Coast, it is a big issue right now and really tragic. I have family in Asheville and they've been couch surfing because their house doesn't have road access or running water at the moment. However, and this is gonna be an odd statement, overtopping of dams isn't even nessicarily a design failure. They often are, and will always be considered a performance failure by the regulators and public, but there's more to it than that from a design perspective. Dams, like all structures, are designed to meet certain service criteria which are probabilistically likely to be observed and are established by the given the owner/regulator's risk tolerance. It could be designed for a 1 in 475 year flood or a 1 in 2475 year flood, but there is always the chance that a 1 in 9975 year event comes along and the dam gets sees a service environment beyone what it was reasonably designed to withstand (Side note: those numbers seem random and kind of odd, but they correspond to a likelihood of occurrence of 10%, 2%, and 0.5% in 50 years using the standard Poission Model for hazard modelling). Same goes for earthquakes. After initial design and construction, it's down to maintenence and monitoring, but these are again primarily informed by operator budgets and willpower rather than construction material. As another note (sorry for going long), sure, concrete can degrade decades after it's placed, but that reduced strength (from peak strength) is still generally substantially higher than the 28-day cured strength. Some research papers I found indicate that it's still over 50% above 28-day strength, but I will acknowledge that how you cure the concrete matters a lot so that number will vary greatly. "Strength is essential, but otherwise unimportant." - Hardy Cross
I feel like we often get carried away with ideas of what could have been if we stretch things to the limit that we forget that they did things that were actually practical. it's really amazing when you look at how much we have advanced in the last century-and-change of building tall stuff and how we sometimes forget that when we assess how impressive things were.
Love this one. Keep rewatching to catch details I missed the first time or two. One thing about the “insulae” or apartment buildings. I’ve read about how in Rome, they would extend upper stories using wood construction. Unlike today, the poorer you were, the higher you went.
As an architect I would like to propose iron reinforced travertine on corners and load bearing exterior columns, paired with Roman concrete vaults between those columns to stablize them laterally, and one additional medial layer of concrete columns and vaults to sablize them in depth. Then, all flooring will be wood over wood truss. This is somewhat similiar to the sections of many roman basilicas. I'm sure there would be ways to optimize the structure, lean on the strengths of the selection of materials to create larger windows and less ristricted living spaces.
Roman concrete is an example of just one type of ancient "geopolymer." Other cultures, like the Egyptians and Incans, had their own recipies. Geopolymers are quite different from modern "portland concrete." If we simply focus on the chemistry, we will find geopolymers an excellent material for modern applications including skyscrapers! There are many companies working on modern geopolymers for industrial and commercial uses. Perhaps a video should focus on how the Romans discovered how to combine the ingredients in the correct order to create a type of carbon-neutral concrete that has lasted 2000+ years?
Garrett, I should speak up more, but please understand I love everything you do here on UA-cam. Remember when History Channel was cool? I do. You're part of the modern version of History Channel. Thanks for regurgitating the knowledge that led you to a PhD right here in public where we can lap it all up. It means a lot to me. Plz hook up with all the other history UA-camrs and get the planet back on track. Stay happy and thanks for all the videos!
If they built it properly you could probably go.... 6-10 stories? It'd have to be done with arches and what not though. Like most their structures. They also used concrete for the floors and foundations but block for walls. And they didn't really "pour" concrete like we do. It was troweled on. Unless they figured out reinforced concrete they would likely do blocks.
The problem with regular modern concrete is that it's porous, so water can seep into it over time. This eventually corrodes the reinforcing, leeches soluble components out of the concrete, and causes damage when the water expands during freezing. Fortunately we now have many additives that can solve all these problems. Obviously these additives cost more than regular concrete, but we can now make concrete that is far superior to anything the Romans had.
The interesting thing about Roman concrete is that it continues to cure as long as it is in situ. and it will cure under water. It is also self-healing.
Given how most pyramids have almost no open space inside, and they are always, well, pyramid shaped, I would say until it becomes so tall the builders suffer from hypoxia, or you run out of flat land to build on.
@@LucyKosaki Maybe, I'm no structural engineer, but I imagine that effect is minimized by everything being pressured equally on all sides, like how eggs work when sat on.
@@ackchyually9461 Assuming a constant density of 2500 kg/m3 (it needn't be constant) and a compressive strength of 8,5 MPa, a ( constant cross-section) column of concrete would collapse under its own weight at a height of 346m.
When I was visiting Indonesia I noticed that the modern methods used in masonry construction differed from those in the USA. When I asked around apparently their concrete was particularly strong and cheap compared to elsewhere in the world. Turns out they too like the ancient romans would add volcanic ash to their cement.
Some modern concretes start to crumble after 20 or 30 years. The Roman stuff lasts millenniums. I know which one I'd use speaking a construction worker who works with modern concrete all the time.
The Tower of Hercules in Galicia, Spain isn't technically a skyscraper, but it has similar dimensions and form and it was built in Roman times, and it is still standing.
I’m curious as to how they would have mixed so much concrete back then. Any project today that requires anything more than a small amount will need several trucks worth and any DIYers know how much effort the wheelbarrow and shovel method of mixing takes after just a couple bags, so surely they had a better method than that for mixing the stuff, but I also doubt they had trucks that would pull up on the worksite and automatically mix and pour directly where it’s needed
I imagine most of it would be mixed by hand by labourers, there would have been tens of thousands of idle hands in the Roman countryside in between harvests looking for work
I've seen a team of 2 mix up a pallet of concrete by hand on the ground in a day if that's their only job which it probably is since masons are very skilled and cost alot a small team could mix up enough for a building
@@furrycircuitry2378 I loaded and unloaded from the pickup then mixed 19 of the 80lb bags one afternoon, and the internet says there’s 42 of them to a pallet, so a pallet per day is definitely reasonable for two people, but I was extremely sore for a couple days after that and could barely move my arms and my hands were nothing but open wounds from having so many blisters form and tear. Obviously if it were something I did often I would adjust to it, but there’s still a limit to how much you can expect a person to do, and those 19 bags came out to a surprisingly small amount of concrete. It would take an enormous labor force to get that work done, especially when you consider the materials had to be gathered by hand, transported, then mixed by hand, then water brought by hand, then mixing the water and concrete together by hand, then pouring. It’s just an incredible amount of effort and the labor that would be needed to get it done in a reasonable time frame would be incredible
@BobbyHill26 hmm yes I forgot to account for the shear weight of the raw material as there was no prepackaged bag to mix back then! But still never underestimate laborers, especially when their next meal is on the line! I say this as I've been there and done that personally I've moved about 2 tons of gravel for the mix in half a day but I was younger than so that's gotta factor for something
Me, sitting in my concrete vault, first floor dungeon, looking through my slit windows at those fools in their modern skyscrapers: “At last, I can begin to live like a human being.”
You can still make armed cement with the Roman recipe, and although it would be less durable than the historic material, on account of the iron framework's eventual rusting, it would last longer than the modern version since Roman cement would let much less water reach said framework.
They didn't have concrete mixing trucks, and it was easier to shovel and pack down solid concrete than trying to mix watery concrete in a barrel and tip it over. Roman concrete was strong because it was trowled, as said, rather than poured. We can still make it. We don't because pouring and reinforcing is easier and better in modern applications. No thick concrete walls for us. Oh, and modern concrete heats when it sets and can do so underwater if you plop it down thick.
I did enjoy this thought exercise. My question is, would differing weather conditions affect the structure? I know Roman concrete was used outside of Italy, but were there downsides to building with it in less temperate climates?
I really want to know if the Romans ever encountered snow? Idk of they even had the chance but is think it would be interesting what they said about it if they did
I always wondered why didn't the Romans build walls of solid brick but instead prefered brick facing and mortar/concrete interior? Medieval brick buildings almost excusively use solid brick technique as do more modern brick structures. Roman technique seems unnecesarily complex in comparison.
I think I asked this question before, but I forgot the answer.. Why have the iron 'clamps' in the wall of the colosseum not been replaced? ..Would they not help to preserve the integrity of what is left of the structure in the event of an earthquake?
How about combine our building materials with theirs? Use modern reinforcing at a minimum (I've heard they did use some reinforcing using bronze bars).
Acfually can you expand on that their were no companies in ancient rome...i had never considered. Did they have a legal system to seperate the busniess from the person like a corporatión. When someone invested in a company was it always a loan or profit sharing basically or did they have something similiar to shares
Would it be possible to make building blocks out of Roman concrete, then, use Roman concrete (or some such derivative) for the mortar, and as such make a building out of Roman concrete that wasnt terrible inside?
If salt water actually strengthens roman concrete, would it help to submerge a portion of the skyscraper with salt water?. Either totally or partially submerged or even just spraying the setting concrete while setting.
Slow curing time makes Roman Concrete less practical. It also keeps curing as it ages after decades, but modern concrete buildings are slim and light, while the Roman buildings were massive and thick. You can solve some of the limits with addictives, but still, portland concrete is more convenient if less durable.
Maybe they built skyscrapers and then had one of those famous earthquakes italy has about every 4 to 7 weeks and they all came tumbling down? I joke but this was a interesting video.
@@kirkvoelcker5272 are we talking about living or business space? i was actually talking about apartment buildings around the 1900´s, up to 10 story buildings without elevators there is a famous picture of a poor guy living in the attic having to carry up the coal bars from the cellar for heating and everything else several stories every day issn´t for the better off a time before elevators became common u know... not so many yoga and martial arts dojos back then....
@@kirkvoelcker5272 if my mind serves me correctly even the insulae in ancient rome from toldinstone were structured the same way with the most luxurious apartments in the first floor and getting cheaper the higher u go
I assume that the amounts of available pozzolana are low, so has anyone figure out how to make artificial pozzolana so it could be used in modern building in some way?
People get so h***y over roman concrete as if it's this wonderous, unknown, lost-to-time building material that we have never been able to replicate. Nah, we have significantly better shit for building now and we're not building the same thing they were. Our buildings are DESIGNED to last 100-200 years max, with a 50 year accuracy. Theirs were designed to last 50 years with a 2000 year accuracy. They simply did not have the tools nor the knowledge to refine that accuracy number down as we have, and thus, the material and effort cost along with it. The colosseum would cost about $1 billion to build today, as noted in a video on this same channel from about 2 years ago (though it assumes building with modern machinery and has quite a margin of error). The empire state building only cost ~$650 million in todays money and the Lucas Oil Stadium by contrast cost about $1 billion.
I do wonder how well prepared we are to tear down and rebuild our construction works before they crumble. We are already seeing that many countries, including the US and Germany, are unable to prevent bridges from collapsing. (Edit: I am not advocating for adopting Roman construction techniques, just wondering how things will develop in our modern age.)
I am going to watch this a bit later but I have always wondered and I do have an idea why but given the tech we have these days surely we can find a better environmental solution.
The Building of the thumbnail was built in 1936, it is called "Palazzo della civiltà italiana", also known as "Colosseo quadrato" (square Colosseum)
aka the Cheesecake building; I lived a block from there in 1962 in EUR
I visited that place about 20 years ago. It was a hot summer in Rome.
It stood empty for many decades until the fashion brand Fendi took residence there .
Until today, you can ready the proud fascist inscription there: All the neighbourhood was erected by Mussolini to the world exhibition of 1940 which had to be canceled because of the war.
That ‘answer, not a solution’ sounds like it came straight from Garret’s teaching days
There are no solutions, only compromises
@@XDarkGreyXthats a dillema, not a problem.
Modern concrete does NOT need air or CO2 to “harden”. The water chemically reacts with the cement (hydrating). This is an exothermic chemical reaction (it produces heat). Modern concrete can indeed be poured and set under seawater (it’s a challenge but possible). The exact properties of modern concrete are adjusted according to specific needs by the addition of admixtures (additives to control various properties). Extremely strong and durable concrete can be produced if desired.
Modern concrete is mostly fly ash because it was historically cheap due being a byproduct of coal plants. With less and less reliance on coal in facor of oil, alternates will need to be used going forward. Maybe something better can emerge?
I'm using this type of concrete for waterproofing jobs and know they're used annually by underwater bridge pylons maintenance filling up cracks. They're super hard when set but a bit expensive
What a well rounded and succinct explanation to this topic, your final words even more so. The methods were amazing for there time, but methods change and adapted to the project at hand. I’d love to see Roman concrete utilized to build structures again, and people finally finding out how it was made had me excited.
That building in Chicago is indeed a hulk of a space. Solid hallways, but not claustrophobic when one walks it. Open to the public as well. First floor has small shops.
how did finance system in rome work? how did they pay rent? where loans with intrest a thing back then. How did companies work in that time? And how did the companies get financing for growth and new projects?
I’m sure there is a book for that.
Diversification, innovation, and growth weren’t really priorities among Roman businesspeople. It was really just a series of pyramid schemes until mercantilism really took off.
Slave labor made a lot possible, as well as looting whatever you need from someone else. Why pay, when you can just take?
Companies did not exist at the time; it was about aristocratic members with lots of money from their land ownership. The concept of a company as an economic institution is recent and started in the Middle Ages. Loans were a thing, and so was interest; loans have existed since the Mesopotamian era.
I don't know much about rents, but I remember that people did not rent apartments in the big insulae; they usually rented rooms for the entire family of commoners.
I believe he has answered at least your second question in a video. People paid rent annually and usually in the early days of July. That's what I recall at least.
The last time i was so early pompei still had the go to red light district
Concrete is certainly a pretty amazing material, but on its own, it can be pretty ugly, especially in places with gloomier climates. I like the Roman idea of hiding it away behind a nice layer of masonry. I used to live in Warsaw, a city shaped by a post-war love of modernism and brutalism. Perhaps it's just a style that's too old to be modern and not old enough to be valued yet... but I don't like it!
The Romans didn't hide the concrete with masonery because they thought the concrete was ugly, the masonary was a technical necessity. If you pour Roman concrete just like in the cuppola ceiling of the Pantheon, you have to wait several years for the concrete to harden enough before you are able to take down the formwork and scaffolding otherwise your wall would collapse. By pouring the concrete between two thin brick walls you need much less sheeting and the wall is much sooner stable enough to build higher, therefore you can build much faster.
And even if you would encase the Roman concrete and wait long enough until it settled, it would look mostly much better as the most of the time very grey brutalist buildings. Roman conrete is through all the rubble used in it, much more colorful and less grey. If you smooth the surface it is more or less like terrazzo.
You can have this with the right modern concrete too, but that is very expensive.
Was brutalism just a bunch of architects trying to make the most insane concrete bunkers.
@@red.aries1444 they did however use marble to hide the concrete and masonry, for fancy buildings at least
It supports this channel which is a monument in its own right
At the end you stated piers and breakwaters, I wonder about building a dam with it.
The Hoover Dam uses unreinforced concrete, so its similar in that sense. Pozzolana, as mentioned in the video, is also how the we get the term for pozzolanic materials which are a set of common additives in concrete that react similarly to the original roman clay, but are more common around the world. Commonly, they're industrial by-products like fly ash and blast furnace slag but can also include volcanic ash even today!
@@andrewjensen7454 do you work with concrete? Roman concrete would basically heal itself on the piers and water breaks, maybe the Hoover Dam actually did use a form of Roman concrete, but at the same time there's damn failures everywhere nowadays which if they had used the Roman concrete would not happening, I live in the Eastern US it's kind of a big deal right now. Modern concrete hits his strongest point in 50 years, and then, from that moment on, it degrades, and yes, I have worked with concrete before in my life.
@@kalrandom7387 I'm a structural engineer and have taken several courses in concrete materials science and concrete design (at the undergraduate and graduate levels), but haven't trowelled anything myself beyond a fence post anchorage of ready mix. Did work for a contractor for a bit though while in undergrad and we installed a fair bit of concrete.
I've also done a fair bit of research work with dams (specifically focusing on dam monitoring), and they aren't a monolith, there are a lot of different types from concrete and arch supported to earthen embankment to clay core. Most dams are earthen embankment dams as they're much cheaper per linear foot of dam to construct. Typically failure modes for them are either abutment failures, overtopping events, or seepage failures leading to piping (water is constantly flowing out from under the dam througbt he ground, if it moves too quickly it causes internal erosion which is typically a runaway problem and can be disastrous). The thing is, none of these issues are solved by using a mix with higher pozzolanic material content. Many of them don't even use appreciable quanties of concrete in their construction! For long term durability, adding more pozzolanic materials does help resist chemical attack, which is helpful but not sufficient to ensure safe operation under extreme conditions.
As for what's going on on the East Coast, it is a big issue right now and really tragic. I have family in Asheville and they've been couch surfing because their house doesn't have road access or running water at the moment. However, and this is gonna be an odd statement, overtopping of dams isn't even nessicarily a design failure. They often are, and will always be considered a performance failure by the regulators and public, but there's more to it than that from a design perspective. Dams, like all structures, are designed to meet certain service criteria which are probabilistically likely to be observed and are established by the given the owner/regulator's risk tolerance. It could be designed for a 1 in 475 year flood or a 1 in 2475 year flood, but there is always the chance that a 1 in 9975 year event comes along and the dam gets sees a service environment beyone what it was reasonably designed to withstand (Side note: those numbers seem random and kind of odd, but they correspond to a likelihood of occurrence of 10%, 2%, and 0.5% in 50 years using the standard Poission Model for hazard modelling). Same goes for earthquakes. After initial design and construction, it's down to maintenence and monitoring, but these are again primarily informed by operator budgets and willpower rather than construction material.
As another note (sorry for going long), sure, concrete can degrade decades after it's placed, but that reduced strength (from peak strength) is still generally substantially higher than the 28-day cured strength. Some research papers I found indicate that it's still over 50% above 28-day strength, but I will acknowledge that how you cure the concrete matters a lot so that number will vary greatly.
"Strength is essential, but otherwise unimportant." - Hardy Cross
Such a great video and channel. Clear and concise.
I feel like we often get carried away with ideas of what could have been if we stretch things to the limit that we forget that they did things that were actually practical.
it's really amazing when you look at how much we have advanced in the last century-and-change of building tall stuff and how we sometimes forget that when we assess how impressive things were.
Didn't know this was a question I needed answering, but when I read the title... ❤
this is terrifying, i LITERALLY asked myself this question 30 minutes ago, man you're good
Woo! Told in stone! One of my fav channels.
Ooh, what a fascinating question!
Love this one. Keep rewatching to catch details I missed the first time or two. One thing about the “insulae” or apartment buildings. I’ve read about how in Rome, they would extend upper stories using wood construction. Unlike today, the poorer you were, the higher you went.
I had always wondered! Thank you for the video!
As an architect I would like to propose iron reinforced travertine on corners and load bearing exterior columns, paired with Roman concrete vaults between those columns to stablize them laterally, and one additional medial layer of concrete columns and vaults to sablize them in depth. Then, all flooring will be wood over wood truss. This is somewhat similiar to the sections of many roman basilicas. I'm sure there would be ways to optimize the structure, lean on the strengths of the selection of materials to create larger windows and less ristricted living spaces.
Fascinating! Thanks, Dr. Ryan.
Roman concrete is an example of just one type of ancient "geopolymer." Other cultures, like the Egyptians and Incans, had their own recipies. Geopolymers are quite different from modern "portland concrete." If we simply focus on the chemistry, we will find geopolymers an excellent material for modern applications including skyscrapers! There are many companies working on modern geopolymers for industrial and commercial uses. Perhaps a video should focus on how the Romans discovered how to combine the ingredients in the correct order to create a type of carbon-neutral concrete that has lasted 2000+ years?
Garrett, I should speak up more, but please understand I love everything you do here on UA-cam. Remember when History Channel was cool? I do. You're part of the modern version of History Channel. Thanks for regurgitating the knowledge that led you to a PhD right here in public where we can lap it all up. It means a lot to me. Plz hook up with all the other history UA-camrs and get the planet back on track. Stay happy and thanks for all the videos!
This is the content I'm looking for👍
After all those videos by geologyhub, now I wonder how earthquake resistant ancient roman buildings were.
Beautiful video essay
If they built it properly you could probably go.... 6-10 stories? It'd have to be done with arches and what not though. Like most their structures. They also used concrete for the floors and foundations but block for walls. And they didn't really "pour" concrete like we do. It was troweled on. Unless they figured out reinforced concrete they would likely do blocks.
The problem with regular modern concrete is that it's porous, so water can seep into it over time. This eventually corrodes the reinforcing, leeches soluble components out of the concrete, and causes damage when the water expands during freezing. Fortunately we now have many additives that can solve all these problems. Obviously these additives cost more than regular concrete, but we can now make concrete that is far superior to anything the Romans had.
The interesting thing about Roman concrete is that it continues to cure as long as it is in situ. and it will cure under water. It is also self-healing.
Engineering meets History. This video was made for me!
What would be the largest pyramid you could build with roman concrete?
Given how most pyramids have almost no open space inside, and they are always, well, pyramid shaped, I would say until it becomes so tall the builders suffer from hypoxia, or you run out of flat land to build on.
@@-caesarian-6078 i imagine there comes a point where the pressure would be so great, the blocks get crushed into dust
@@LucyKosaki Maybe, I'm no structural engineer, but I imagine that effect is minimized by everything being pressured equally on all sides, like how eggs work when sat on.
assuming σ=8,5 MPa it would be around 1250 meters
@@ackchyually9461 Assuming a constant density of 2500 kg/m3 (it needn't be constant) and a compressive strength of 8,5 MPa, a ( constant cross-section) column of concrete would collapse under its own weight at a height of 346m.
huh, very useful information as a geophysics student. Was not expecting that.
"An answer, but not a solution." goes hard
When I was visiting Indonesia I noticed that the modern methods used in masonry construction differed from those in the USA. When I asked around apparently their concrete was particularly strong and cheap compared to elsewhere in the world. Turns out they too like the ancient romans would add volcanic ash to their cement.
Very informative!
Romans could have built some epic castles.
Great channel!
Some modern concretes start to crumble after 20 or 30 years. The Roman stuff lasts millenniums. I know which one I'd use speaking a construction worker who works with modern concrete all the time.
For job security you'd work with modern concrete :)
The Tower of Hercules in Galicia, Spain isn't technically a skyscraper, but it has similar dimensions and form and it was built in Roman times, and it is still standing.
I’m curious as to how they would have mixed so much concrete back then. Any project today that requires anything more than a small amount will need several trucks worth and any DIYers know how much effort the wheelbarrow and shovel method of mixing takes after just a couple bags, so surely they had a better method than that for mixing the stuff, but I also doubt they had trucks that would pull up on the worksite and automatically mix and pour directly where it’s needed
I imagine most of it would be mixed by hand by labourers, there would have been tens of thousands of idle hands in the Roman countryside in between harvests looking for work
Slaves.
I've seen a team of 2 mix up a pallet of concrete by hand on the ground in a day if that's their only job which it probably is since masons are very skilled and cost alot a small team could mix up enough for a building
@@furrycircuitry2378 I loaded and unloaded from the pickup then mixed 19 of the 80lb bags one afternoon, and the internet says there’s 42 of them to a pallet, so a pallet per day is definitely reasonable for two people, but I was extremely sore for a couple days after that and could barely move my arms and my hands were nothing but open wounds from having so many blisters form and tear. Obviously if it were something I did often I would adjust to it, but there’s still a limit to how much you can expect a person to do, and those 19 bags came out to a surprisingly small amount of concrete. It would take an enormous labor force to get that work done, especially when you consider the materials had to be gathered by hand, transported, then mixed by hand, then water brought by hand, then mixing the water and concrete together by hand, then pouring. It’s just an incredible amount of effort and the labor that would be needed to get it done in a reasonable time frame would be incredible
@BobbyHill26 hmm yes I forgot to account for the shear weight of the raw material as there was no prepackaged bag to mix back then! But still never underestimate laborers, especially when their next meal is on the line! I say this as I've been there and done that personally I've moved about 2 tons of gravel for the mix in half a day but I was younger than so that's gotta factor for something
babe wake up toldinstone just posted!
Babe wake up new TIS just dropped!
Me, sitting in my concrete vault, first floor dungeon, looking through my slit windows at those fools in their modern skyscrapers: “At last, I can begin to live like a human being.”
You can still make armed cement with the Roman recipe, and although it would be less durable than the historic material, on account of the iron framework's eventual rusting, it would last longer than the modern version since Roman cement would let much less water reach said framework.
Do you have any books on these recipes for concrete? That would most helpful
They didn't have concrete mixing trucks, and it was easier to shovel and pack down solid concrete than trying to mix watery concrete in a barrel and tip it over.
Roman concrete was strong because it was trowled, as said, rather than poured. We can still make it. We don't because pouring and reinforcing is easier and better in modern applications. No thick concrete walls for us.
Oh, and modern concrete heats when it sets and can do so underwater if you plop it down thick.
I did enjoy this thought exercise. My question is, would differing weather conditions affect the structure? I know Roman concrete was used outside of Italy, but were there downsides to building with it in less temperate climates?
I really want to know if the Romans ever encountered snow? Idk of they even had the chance but is think it would be interesting what they said about it if they did
They crossed the Alps, so yes they encountered snow.
Every year.... in winter 😂
I always wondered why didn't the Romans build walls of solid brick but instead prefered brick facing and mortar/concrete interior? Medieval brick buildings almost excusively use solid brick technique as do more modern brick structures. Roman technique seems unnecesarily complex in comparison.
Concrete-faced brick was quicker, cheaper, and (if done right) ultimately more durable than a solid brick wall.
I think I asked this question before, but I forgot the answer.. Why have the iron 'clamps' in the wall of the colosseum not been replaced? ..Would they not help to preserve the integrity of what is left of the structure in the event of an earthquake?
Pretty sure I know the answer but more information is always a blessing:)
How about combine our building materials with theirs? Use modern reinforcing at a minimum (I've heard they did use some reinforcing using bronze bars).
There is much interest these days in Roman concrete, it does have some advantages over the concrete used today.
Acfually can you expand on that their were no companies in ancient rome...i had never considered. Did they have a legal system to seperate the busniess from the person like a corporatión. When someone invested in a company was it always a loan or profit sharing basically or did they have something similiar to shares
Big up to darmon antonini ...
Very Interesting as are all details pertaining to ancient Rome. :)
Would it be possible to make building blocks out of Roman concrete, then, use Roman concrete (or some such derivative) for the mortar, and as such make a building out of Roman concrete that wasnt terrible inside?
we need to find a developer willing to start building a roman concrete based skyscraper UNDER water!
Very cool
If salt water actually strengthens roman concrete, would it help to submerge a portion of the skyscraper with salt water?. Either totally or partially submerged or even just spraying the setting concrete while setting.
Now what happens if we dope Roman concrete w/ graphene?
Slow curing time makes Roman Concrete less practical. It also keeps curing as it ages after decades, but modern concrete buildings are slim and light, while the Roman buildings were massive and thick.
You can solve some of the limits with addictives, but still, portland concrete is more convenient if less durable.
The fact that it uses sea water is genius. No need to waste fresh drinking water.
Maybe they built skyscrapers and then had one of those famous earthquakes italy has about every 4 to 7 weeks and they all came tumbling down? I joke but this was a interesting video.
without elevators, skyscapers dont make any sense...
in high rise buildings without a lift the upper floors become cheaper each level
It's why dance companies, yoga schools and martial arts dojos are usually upstairs.
@@kirkvoelcker5272 are we talking about living or business space?
i was actually talking about apartment buildings around the 1900´s, up to 10 story buildings without elevators
there is a famous picture of a poor guy living in the attic
having to carry up the coal bars from the cellar for heating and everything else several stories every day issn´t for the better off
a time before elevators became common u know...
not so many yoga and martial arts dojos back then....
@@kirkvoelcker5272 if my mind serves me correctly even the insulae in ancient rome from toldinstone were structured the same way with the most luxurious apartments in the first floor and getting cheaper the higher u go
I'm thinking why not for things like sidewalks?
Are rebar and Roman concrete compatible?
MIT is apparently patenting a version of Roman concrete.
Let's hope the patent office will cite an old latin text as prior art.
What if it was reinforced with modern steel rebar?
The answer is simple...if there's a skyscraper built of masonry today than the romans could do it better
That 'skyscraper' sure looks like a midrise to me.
I assume that the amounts of available pozzolana are low, so has anyone figure out how to make artificial pozzolana so it could be used in modern building in some way?
You could use crushed terracotta instead of pozzolana
Invented by Fred Flintstone 👏🏾
What about steel reinforced roman concrete?
ryans calming voice....love it
Well if you reinforced it with steel beams, why not?
Seeing your mouth actually moving while you're talking made me realize how little you actually move your jaw and now i can hear it in your voice
People get so h***y over roman concrete as if it's this wonderous, unknown, lost-to-time building material that we have never been able to replicate. Nah, we have significantly better shit for building now and we're not building the same thing they were.
Our buildings are DESIGNED to last 100-200 years max, with a 50 year accuracy. Theirs were designed to last 50 years with a 2000 year accuracy. They simply did not have the tools nor the knowledge to refine that accuracy number down as we have, and thus, the material and effort cost along with it.
The colosseum would cost about $1 billion to build today, as noted in a video on this same channel from about 2 years ago (though it assumes building with modern machinery and has quite a margin of error). The empire state building only cost ~$650 million in todays money and the Lucas Oil Stadium by contrast cost about $1 billion.
I do wonder how well prepared we are to tear down and rebuild our construction works before they crumble. We are already seeing that many countries, including the US and Germany, are unable to prevent bridges from collapsing. (Edit: I am not advocating for adopting Roman construction techniques, just wondering how things will develop in our modern age.)
Roman engineering!
Skyscrapers are a solution to space. If Romans would have had that need, they could have invented steam frames?
good luck? we have plenty of volcanic places and still don't know how to make Roman concrete..
tuff luck
Didn't know what you looked like, you look like a Roman sculpture, without trying to be mean
Yeah bwuoooiy!
Easy, no because modern concrete doesnt aupport concrete steel does
🏛🏛🏛🧙♂
cause capitalism and profit 🤑🤑🤑🤑
Garrett, you need to back off on the drugs.
you look so sad... OMG
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I am going to watch this a bit later but I have always wondered and I do have an idea why but given the tech we have these days surely we can find a better environmental solution.