If you think that is impressive, you should see what a team of archaeological students from Texas dug up. It may revolutionise how we build everything from sewers to skyscrapers. Google "Waco Compound" for details.
It's the volcanic ash. That's the secret for why their concrete is superior to ours today. Back in ancient times, there were some active volcanoes of the era.
"right well apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the ROMANS done for US?" "well, they brought peace." "SHUT UP"
I grew up in the coal mining heart Carbon County, Utah. In our rural double wide trailer on 2 acres of clay ground. We had a coal stove that heated the house, a standard truck bed of coal went for $50-$100 in the 90's and was enough to heat the house all winter. We used to pile the coal ash on the side of the property, but I noticed the pile of ash was surprisingly sturdy compared to the sloppy messy wet clay surrounding dirt when wet from the snow and rain. So from that point on I spread the ash over the dirt driveway. Over the years the driveway became harder and less sloppy muddy when wet, almost like concrete.
I would stop spreading the coal ash, especially since you've been doing it for years. Coal ash contains at least 17 toxic heavy metals and pollutants including lead, mercury, cadmium, chromium, and selenium, all of which can endanger human health, and at least six neurotoxins and five known or suspected carcinogens. Short-term exposure can bring irritation of the nose and throat, dizziness, nausea, vomiting, and shortness of breath. Long-term exposure can lead to liver damage, kidney damage, cardiac arrhythmia, and a variety of cancers.
Have a charcoal grill. If you pour the ash onto the ground, it starts turning into concrete over time. Not great for mulch but an interesting observation.
I was so excited when I saw a few years ago that they finally figured out the secret to Roman concrete-mainly just because I kind of assumed that it would be a mystery forever, and then to find out that it was actually really simple and easy to replicate. There's an argument to be made that these structures that have long outlasted their purpose are overengineered, but I think that attitude is dismissive to the potential applications that figuring this out may have in modern construction that's exposed to water. Yes it's not as physically strong, but if it's strong enough and much lower maintenance, we should use it.
Roman projects are considered over-engineered only through a modern lens. We build everything to be as cheap as possible, using as little material as possible. So in that regard, everything they made is over-engineered. Engineers put rebar in all their projects not because it's necessary for strength, but because it's significantly cheaper to achieve the desired strength. It is absolutely possible to design concrete structures without rebar, we just don't do it. Rebar compromises concrete from within.
What about making the core of the structure out of modern concrete for its strength, then covering it with a layer of corrosion resistant Roman concrete.
Another issue of duration is that (modern) concrete slowly dissolves Steel! Hence you got rusty rebar in every thing more than a few years old!! Lifetime, depending on the environment and various other factors is 150 years maximum and often less than 100 years for Modern Concrete!!
The thing is, while easy to replicate once the composition is known, the tools to find out and analyse that exact composition from solid chunk samples was not availiable until the mid 1980ies...
Fly ash is a fairly common additive to concrete today depending on exactly what it’s being used for. Modern concrete can be a very sophisticated mixture of chemicals, including things like plasticizers that reduce the amount of water needed to mix, pour, and smooth the concrete. As noted in the video, additional water beyond the minimum tends to reduce the strength of concrete. But as noted in the video, we are still learning things from the Romans. They were brilliant in many areas and idiots in others. We serve ourselves well to study both.
I've seen a lot of guys who request the concrete mixed very loose. They like a lot of water in it for the sole purpose of making it easier to work with and increase the work time. Obviously more water is not good for the integrity of the concrete. The Hoover dam was made with a very dry mix of concrete and it is still getting stronger after over 100 years.
Romans mostly copied the greeks and other european cultures. Made some improvements here and there. I would say the greatest feat of the romans was capitalization through the temple of saturn.
In northern Italy, in the mountains, the olive garden walls are still built and repaired using the old ways - they still add rough stones, caulk stone, hot ash to portland premix, and pour it almost dry. The old men say it takes a month for the terraces to harden, and millennia for them to crumble. Roman cement was never really forgotten by the old, there was just this cheap alternative.
interestingly east Germans working on private projects also use bigger aggregate, like rocks found on the fields (or from the dirt they excavated before making the foundation), smashed bricks, and other things. this mainly started as a way to keep cost down, by subtly getting rid of garbage which would have been expensive to get rid off and reducing the amount of cement needed, but the benefits have not been lost on us.
Short answer: they didn't have to deal with modern priorities and the resulting budget constraints. If you want to build stuff that will last for thousands of years, like the Romans did, you theoretically can, in the sense that we know the underlying physics of how to do it. But it changes the nature of the project, considerably. Among other things, you can't use steel reinforcing wire in your concrete if you want it to last that long, because steel encased in concrete corrodes over time. Without reinforcing wire to bear tension, you have to build compression-supported structures (like classical arches), and you can't build tension-supported structures (like a flat rectangular bridge held up by a few small pillars spaced far apart). This greatly increases the total amount of concrete you need, which increases your costs for materials and labor, as well as the timetable for the project. On top of that, it places a lot more load on the ground underneath, which greatly increases the amount of soil and subsoil that you have to dig out and replace with something less compressible (like concrete or stone). Now your foundation is also ten times as heavy-duty as it would have been, so add up more materials, labor, and time for all of that. Perhaps you can see where this is going. When all is said and done, you've taken an two-year project and turned it into a multi-decade project, and the cost has ballooned correspondingly. If you want to do that sort of thing in the public sector, you need thirty-year terms of office, which are (for very good reasons) not common in the developed world. And if you want to do it in the private sector, all your funding has to come from sources that share your build-for-the-ages vision, which instantly rules out shareholders and venture capital. We don't build like that these days, because leaders with a god complex who want a monument to their administration that will last for thousands of years, tend to get voted out or overthrown.
Pay a lot now, pay next to nothing for decades. I think it's time we reevaluate our math. It looks good at first when we can build a bridge for "just" 10 million dollars. But they we have to spend 200,000 every year to maintain it, and have to replace it in 20-50 years. Or, we could spend 50 million to build, which okay, ouch, but then we pay like 10,000 a year to maintain it, if not less, and never have to replace it.
@@forestwells5820 Your figures are a bit off. Building in the Roman fashion, you can't build that $10 million bridge for $50 million. You can't build it for $100 million either. $500 million, maybe. Also it will take about twenty times as long to build as the $10 million version, which is probably the larger problem. Modern people get impatient waiting two minutes for a microwave oven to warm up a plate of food. They don't want to hear "This bridge will end up being better, so just be patient while we take twenty times as long building it. Sure, you'll be retired by then and won't need to drive to work over the bridge any more, but you can just suffer through going the long way around for your whole life so that your grandchildren can inherit a masterwork bridge. It'll be great." There's going to be an election at some point, and the geniuses who pushed for the build-for-the-ages project will likely be out of office, and their successors will scrap it and build the $10 million bridge that can be done in three years.
Imagine all the knowledge lost over time. Not just ancient technologies like roman concrete and greek fire but all the literature, poetry and philosophical teachings that burned in the library of Alexandria. How far were we set back by that? Centuries? Millenia? We'll never know.
Eh, the Library of Alexandria is a bit overrated, especially with how it was at the time it finally shut down. By that time it had long been in decline thanks to the rise of other large insitutions of learning in the region, as it was no longer The Place to go to learn
The library of Alexandria being some long lost fountain of knowledge and wisdom is just as bad of a modern myth as that of Nikola Tesla's exploits vs the reality of his life. The truth is that the LoA would have been vastly more oriented towards TRADE records than any other source of written material. Alexandria was a trade city - a harbour for ships and a place where land caravans would pass through on a circuit around the north coast of Africa, up the coast of Canaan and west along the south coast of Europe. Because of this they would have mostly got shipping and caravan manifests. That's not to say that such information does not have power all by itself, but it's not the secrets of the ancients in any way that you want it to be either.
*In colder region, imagine an asphalt that is self-healing and instead of creating bigger and bigger pothhole, the cracks just never happen. Every non-greedy city/companies would start using this mixture.
Asphalt is not concrete. It's very nature as a traction material for automobiles makes it more prone to erosion over time. The best you can do is slow it down by mandating lighter vehicles - given EVs are going to make cars significantly heavier (in the short term) that isn't likely to happen soon.
They used an ash from a volcano that set it quickly. It even set quickly under sea water. The salt water even made harder. They broke the code of the concrete a few years ago. As to the done, they made it lighter and lighter as it went toward the center by tossing in clay pottery and straw.
Bingo ^ For those wondering that volcano is called Campi Flegrei, in the Bay of Naples. A Volcano with a highly active hydrothermal system that provides the conditions to almost instantly mix the ash with needed materials. I'll give them credit in the sense they managed to find a solution that not only worked but has held out very well for them. However, to say it didn't require an insane amount of luck and however many bodies the roman's were willing to throw at, would be a complete lie.
@@deathninja16 They probably didn't watch the video. For years, many just assumed that using volcanic ash instead of coal ash was the key. I don't understand why people leave comments like this - assuming they know better, throw out their two cents and just leave without actually paying attention to what they're commenting on.
@@shopshop144I'm quite certain he has a hand in picking topics to present, at least some of the time, he's said he's asked writers to produce scripts based on his own ideas
During the late 19040's thru 1960's the US build Nuclear Bomb shelters in government building , hospitals, and the like. That concrete is the strongest , hardest , and virtually undamageable material ever made from a mix. I would like to see a video/documentary on the making of that concrete . And I wonder why all structures are not made from it?
@@atodaso1668No, that’s because the old silos weren’t water tight and ground water seeped in over time. The walls themselves are virtually unbreakable.
Pumicecrete is by far the best building material on the planet Pumicecrete is a mixture of pumice cement and water mixed and poured into a set of reusable forms walls are poured from 12"to 24" thick pumicecrete is fireproof termite proof rust rot and mold proof non toxic and has a high R value and good sound attenuation solid poured walls means no critters can live in your walls Pumicecrete can be built for a fraction of the cost and time and pumice is one of the few building materials that can go directly from the mine to the job site ready to use without any additional possessing and zero waste My goal is to build a pumicecrete home for Community First in Austin Texas Can you help? Take care Ray
Architecture seems like a lost art today. Just about all I see being built today is plain concrete boxes for commercial buildings and residential areas with the same stucco house repeated over and over again.
Probably because they actually cared what their buildings and cities looked like, instead of today when all that the powers that be care about is the bottom line. Who cares if it looks like shit, it's cheap.
I don't fully disagree, but there's still some very beautiful architecture around today that's not necessarily what you'd call ancient. European castles and palaces, American art deco skyscrapers like the Empire State and Chrysler Buildings and Old South plantation houses, the Sidney Opera House, Asian temples and pagodas, Scandinavian stave churches, more bridges than I can name, etc.
Because of its unusual durability, longevity and lessened environmental footprint, corporations and municipalities are starting to explore use of Roman-style concrete North America.
Well that and biology. Nature is an unending source of inspiration for advancement in many fields of science and engineering. Chacnes are high in more than half a billion years of evolution can wild that natural selection has provided a solution to most problems. Case in point the coming optics revolution of metalenses based on a new field of research stemming from discoveries about the way light interacts with the wings of a buttefly.
@@AveCaesar2025 I actually do study Ancient Egypt daily and yes, in the light of the evidence it seems it was less cruel. Not uncruel (authoritarian government, social inequality, malnutrition etc), but way less cruel than Romans, who on top of having those things fought endless wars, had huge arenas dedicated to torture and killing for entertainment, whose whole economy relied on slaves (for example pyramids were not built by slaves and it seems that slaves were a relatively rare commodity in pre Roman times), and whose females could only dream of the kind of rights the ancient Egyptian women had. Actually it seems that Egyptian women had it quite good compared to the rest of the antiquity (that we know of), especially compared to their sisters in Greece (excluding Sparta maybe) or in the kingdoms of the middle east. Simon has made a video about the exceptional cruelty of the Romans, check it out if you have not.
There's a huge misunderstanding about Roman concrete. The kind that survived millennia was their _best_ variety. You can have that today and better if you're willing to pay for it. But then, as now, the vast majority of projects wouldn't or couldn't buy that quality.
IIncredible, well done. All the knowledge, the technology just zipped in 12 minutes video!... Also I think the .75 play speed just invented for us to understand you :) Thanks alot.
That's not the way it works at all. If a city council realised it could save a ton of money on infrastructure maintenance due to longer lasting concrete they would do it in a heart beat. Just look at how much US infrastructure was falling apart and in desperate need of repair or replacement before the big infrastructure bills was passed by the current administration. That shows just how little they want to spend money on these vital things, even to the point of waiting until people are literally dying from it.
@@mnomadvfxalso the truth of how Roman concrete functions was only discovered recently. Back in those days, the 30s and 40s, the US government actually cared about building things to last but were limited by the construction techniques and technology of the time. Now a days there's so much special interest, legalized bribery, and lowest bidder nonsense that building to last is literally the last thing in their minds.
The use of steel in modern concrete is the number 1 reason for it’s short lived usefulness. The moment the chloride crystals reach the steel, it starts rusting which expands and causes cracking and spalling.
Before the coming of steel spanning bridges and other structures was very limited and challenging. How the Romans could achieve these things is amazing.
The Romans still couldn't do what we can today with bridges. Like the guy said - modern concrete IS stronger, can span greater distances and take more weight. Roman concrete is just more durable long term and better without steel reinforcement than modern concrete without reinforcement (the chemical processes that make Roman concrete so attractivee do not work so well with current reinforcing materials like steel rebar). The trick will be to try and meet somewhere in the middle to get the best of both worlds in one material with reinforcing materials that can stand the higher temperatures of the quick lime reaction.
I agree, but I've also got to point out the only reason that style of building was even remotely viable is because the Roman Empire clearly didn't mind throwing as many bodies as they needed for such a grand scale projects. Nowadays, I seriously doubt that would be easy to do.
@@Akechi_The_Phantom_Detective Thanks for the reply. Yes indeed, workers were expendable. Even later in Medieval times, many lives were lost building Castles and those beautiful churches.
It is important to recognize that Roman concrete is much, much weaker than modern concrete rendering it unusable for any applications that requires high strength. Roads, bridges, and buildings cannot use it in any efficient manner. Dams, retaining walls, piers, foundations, etc could potentially benefit.
Fair enough - unless we allow the Roman concrete to "age" for a year or 2 after the end of the construction to obtain the physical strength it needs. Remember: Italy is a country prone to earthquakes, so the great problem in certain structures would be vibration, not weight
Lived in Rome on a student visa for 6 1/2 years attending AUR ( The American University of Rome) after serving active duty USN in Naples Italy for 4 1/2 years. Had they figured out that there was lead in their drinking water pipes and not reacted so very harshly to monotheism we might've well had the industrial revolution almost a full millennia earlier , via avoiding the "dark ages". We also might all be speaking a modern form of latin and learning "rhetoric" in schools instead of English loL who knows
Why do you consider the harsh reaction to monotheism something which held the Romans back? After all Christianity coming in force was one of the reasons the Roman empire in the west fell.
Hmmm, lead pipes were commonly in use until around the end of last century, and according to others they are still commonly found in many parts of THE DEVELOPED world even today. Largely because the cost and inconvenience of replacing them means they are left until they HAVE to be replaced. And the amount of lead you imbibe from said lead pipes is also amazingly small according to a programme I was watching on the subject recently. However it is also accumulative and came from more sources than just water pipes.
@@northumbriabushcraft1208 My view would be, because of the internal turmoil caused by religious conflict. Of course they also had economic turmoil, succession & political turmoil, & perennial barbarian problems.
Sounds great except that "1/10th the compressive strength of modern concrete" might be a bit of an issue unless we can find ways to maintain the new benefits while still achieving modern strength standards. Or maybe it will simply have niche uses.
I'm assuming it's a combination of the brittle lime clasts and the lack of steel/etc rebar. I'm sure that with additives like small CMC rods and larger scale bars that they could increase it's strength a lot. It wouldn't be cheap though.
I like all your videos, but this one was the best !! Both historical and greatly educational. I will be sharing this and discussing it with my brother in law, who builds dams and just built the biggest in Laos which broke the world record for the most concrete poured in a day 6 times in just a few weeks ! He will love this as he is just about to start a new dam in the Philippines. Thanks !
This is a fascinating episode. The only thing I knew about concrete is how much damage it can do to you both externally and internally if you fall on it or crash into it. Most concrete, primarily outdoor structures, has deliberate inclusions from little pebbles to large stones as big as 2" long. I have always wondered what reason is behind this and what the optimum mix is for any given structure. We constantly conceive of the "ancients" as being more primitive than we are with all our machines and sophisticated chemistry, but I loved your vid on 5 Chinese inventions from ~2,000 years ago without which Western civilization would never have advanced; written pages (invention of paper), seafaring (the compass), irrigation and flood control, (pumps, making rivers navigable) and of course gunpowder.
Do you even realize, that as you talk about the Pantheon in Rome, at 0:19 you showed images of The Panthéon in the Latin Quarter of Paris ... built in the 1750's? ... ya ... you actually did that.
Thank you for pointing out that in old Latin, C is hard, like K. I remember that from parochial school and seminary. And the secret ingredients for Roman concreta!
I think the biggest reason the Romans developed concrete that would cure underwater and last so long was that they only wanted to build it once. Modern contractors want to insure they have a future so they don't want concrete that last forever, because they would put themselves out of work after about 10 years. Not entirely true but the demand would basically be limited to solely new construction and they would loose all the work they get tearing out old concrete and pouring new concrete.
Pozzolana being what it is, I reckon there is some opportunity for nations with a lot of volcanoes, as that silica is generally found there. If I lived in Japan or on Hawaii for example, I would be looking into that.
Interesting review. Two points. Concrete cures, rather than dries. This is a chemical reaction which also creates heat. Roller Compacted Concrete, or RCC is used in dam construction worldwide. Nothing new there. The ancient Romans were indeed, fine engineers. 👍
Seen a nether video saying they add hey to it as well. Also that sound a lot like aircrete or styrofoamcrete it's got a lot of names but it's concrete mix with foam.
One thing that's been found though is that even our modern concrete, over time, pulls about all the CO2 output by its creation into it (especially in buildings that we're leaving for decades longer than roads) and this property of concrete makes it stronger over time and is something that makes concrete far more environmentally friendly than we ever imagined.
While everyone needs as revenue, more ads and discussion about ads and ads and ads and discussion of ads than USA network TV. That reaches greedy level
You smart folks probably will not care about this but I am going to post anyway. I lived in New Brunswick on the Atlantic Coast. It was where my Dad’s BFF poured CEMENT for a living. He did this all year round! In that cold & snowy climate. He gave the secret recipe to my Sister who had her contractors license in Massachusetts. She was able to get a basement poured in November by sharing the recipe with her concrete guy. Unfortunately all 3 have passed away and I have no clue what they did to the concrete. FYI Going to Pompeii is on my bucket list!
Urggg....the real answer is 'by accident' and 'trial and error' -they had little 'chemistry' theory knowledge, they tried stuff and if it worked or was noticeable better than what they had; they kept doing it. Also 'Survivorship bias' (wiki)-"Just as new buildings are being built every day and older structures are constantly torn down, the story of most civil and urban architecture involves a process of constant renewal, renovation, and revolution. Only the most (subjectively, but popularly determined) beautiful, most useful, and most structurally sound buildings survive from one generation to the next. This creates another selection effect where the ugliest and weakest buildings of history have long been eradicated from existence and thus the public view, and so it leaves the visible impression, seemingly correct but factually flawed, that all buildings in the past were both more beautiful and better built." Another thing, though it was a bit vague -they seem to have compared modern reinforced concrete with non reinforced; which are very different animals and have different properties.
This is honestly kind of true. I'll give them credit in the sense they found a formula that worked and kept on using it but I can't honestly say it was a feat of intelligence as it was pure luck. The fact they managed to source Ash not only from a volcano but a super volcano with a hydrothermal system that would've allowed them to mix and heat that is kind of insane. It also didn't hurt in their case that they were willing throw as many bodies as they needed to get these projects done. Can't help but imagine trying to do this with Ash from any other volcano would take a lot more prep and A LOT more bodies. That said, Volcanic Ash actually seems like a really good material abeit not a practical one.
If you are willing to make your walls 20 feet thick, like the Pantheon and the Colosseum, it's easy to skip reinforcing your concrete structures. That's okay for a couple huge public buildings but isn't a practical strategy for homes, businesses and roads
@@Matt-yg8ub sure, but if you are laying slabs 10 feet thick you are going to have to first construct a roadbed strong enough to keep thousands of tons from sinking into the earth. That's gonna cost you, durability and economics are always an engineering compromise. Fast, cheap, good...best case you get 2
@@Adiscretefirm considering that I design roads, most of the problem is the federal requirements that makes us have to make them cheap and brittle….. and the water department, demanding that everything be less than 18 inches thick so that they can dig through it and patch pipes a month or two after we resurface a road. If they had designed the road to be a road, and not a poorly paved surface covering all the utility pipes…. They would last longer.
@@Adiscretefirm you are missing the point, instead of running the pipes under the road where the water department has to cut through the road on a regular basis, run them alongside the road in the right of way. You end up with bigger trees in the right of way, more forestation, lower temperatures, less urban heat island effect, less global warming, and you don’t damage the road repairing pipes. The Romans built a sturdy road base that could sustain a road for 2000 years because they didn’t bury their pipes under the road
The fact that fly ash (which my laboratory regularly tests and just from the amount we receive is very abundant in the industry) could be used to help make better concrete is astounding… my only question would be if Roman concrete could stand up to Minnesota winters. If the answer is that they can… I’m going to be severely disappointed in the concrete industry, cuz we obviously need more durable roads but that wouldn’t negatively impact them financially because roadwork is a never ending process.
i’ll sum it up, roman concrete is not strong, but it lasts longer, modern concrete is built to handle the weight of skyscrapers and modern vehicles. also the sea salt in rome helps harden it
They truly made things to last forever where as modern inventions are built to break and be rebought because money is the primary focus. Imagine how advanced the world could be if we werent selfish were community based
The reason why our concrete is different has to do with water. Our 'wet' concrete is necessary to pour huge foundations for modern buildings. As well as bridges and dams. We can build big things fast but our concrete has weakness like expanding and contracting do to temperature. It doesn't do well in humid environments & needs more maintenance. On the other hand the romans could never make a colossal structure like the hoover dam.
So in essence, the volcanic ash solution simply isn't as adaptable unless you're willing to throw a shit ton of bodies at it. It's good for it's insulative properties just not practical for any grand scale projects.
while we're on the subject of concrete, there is another type which is a mystery to this day: german WW-II flack towers. these were apparently so sturdily built that they not only survived allied bombing raids, but even after the war, with full access, allied attempts to demolish them failed, with most of them having simply been covered under a hill of dirt after they just gave up.
I love this channel and constantly think I'm leaning by watching it, today was the first time you've ever covered anything I know about: the properties and differences between lime and cement used in construction, and frankly I'm horrified, this is historical story telling interspersed with half truths and misleading information.
People don't understand that the way we build things today is not only to be the most cost effective way but is designed to be knocked down and replaced within a few decades. We can make all these things to much higher qualities but that's just not how we build things.
Does that mean this would be good for a garden based on collecting rain water from your roof and funneling it into your garden spaces over time? Would this be hard to make at home?
It always baffles me when you hear of a new bridge or similair project and they say "This has a lifespan of 100 years", when roman bridges and other projects last 2000 years.
Pronunciation tip: hyperbole is pronounced like hyper-bowl. The word you said, sounding like hy-PER-bolee, is the plural of hyperbola, which is a geometric shape, one of the conic sections.
Sorry but you’re incorrect here. No one pronounces it like that. It comes from Greek, and uses Greek pronunciation. The "le" at the end isn't a silent letter, it's meant to be pronounced. It's like how the name Hercules is pronounced Herk-u-lees, not Herk-yewls.
Ye but no. There are simply too many current uses for concrete where the Roman recipe would be inadequate to purpose. For somethings it would work fine, but for others you would make even worse problems from concrete that just can't take the same weight over it from 10x lower compressive strength. Those lime clasts are brittle and decrease the overall strength of it vs modern portland cement based concrete.
OMG…this storyline was just on the Billions episode on Showtime on America on September 22, 2023. The episode dealt with a modern inventor replicating the bacteria to creating self-healing concrete and the lead character of the show then went in and started “patent sharing” all of the subsidiary and tangential patents when the main inventor rejected the buy out offer. They explained the science behind the concrete really well and now you have an episode about it just two days later. Small world of coincidences.
That stuff pops up in the media every other year. It's not like it hasn't been investigated, it is just not economically viable. And as long as this is the priority, nothing will change.
I’ve always wondered why people say broom and concrete was so much better. I love working with concrete. I love the pressure. I love that you cannot screw up if you do well, nobody likes chipping concrete.
honestly with all the alleged advancements in material science since then i find it hard to believe how they haven’t come up with something in our time that would mimic this behavior.
That dam in Utah will last millennia waiting for the recipe to hit the mainstream market. I'll be building an elevated small house near the ocean and want to use this material for the piers holding up the house, as well as footers for the dock. I need durable and as cheap as possible.
Interesting video, but some weaknesses. - It's not true to say that Roman concrete used materials fired at much lower temperatures. After all, a key component came from a volcano! - Your description of mixing modern concrete was wrong. Lime is not involved and all the ingredients (typically cement, sand and gravel) are mixed together with water at the same time. - The construction industry has been using fly ash as a partial replacement for cement for decades. However, that material will become increasingly scarce as coal fired power stations are phased out. - Low water content giving increased durability is well recognised. The additional water is largely to be able to pour the concrete into the formwork (mould). It is then vibrated to try to eliminate voids. The way the Romans placed their concrete would be immensely labour intensive and quite unsuitable for many of the ways that concrete is used in buildings today. - The main cause of modern concrete failing is because it has rebar inside it. Ultimately this will corrode and expand within the concrete mass, causing damage. As a final thought: Would we really want modern concrete buildings to last 2,000 years?
You know I will give the Roman's credit for the innovation especially so long ago but I feel like it's fair to point out them even figuring out how viable volcanic ash even is took a fair amount of pure luck. Not just to experiment with Volcanic, but to do so at a volcano that would just so happened to have a hydrothermal system where it would be so readily available in such a state, that Volcano being Campi Flegrei. Kind of feels they used whatever mass material they could use as a cement mixture and ended with a very fortunate result. Of course, I may not be giving them enough credit but I can't help but think if you tried this with Ash from any other volcano it would take WAY longer and probably require more man power.
3:52 Thousands of Tons of Concrete was transported. How did they do that? If we look at Modern Populations and look at back then. I mean. This is as almost mind blowing looking at the White House and see how they got all that Lime Stone to that location and man Penn Station. That place is Massive. Who did they get it to there location with horse and buggy. Just food for thought. Namaste Dave Ross
Fly ash was used here as a cheap, lightweight & easy to work self compacting material for building pads. In the decades to follow, this material has grown crystalline structures within it that has been lifting the structures built on top of it. Used incorrectly, flyash is a very bad long term solution.
when I grow up ... I'm want to be just like this genius ... UTube channels like this better get compensated fair ... it's a ton of work and better than anything on streaming other things
Go to www.drinktrade.com/brainfood and get a free bag of coffee with any subscription.
Perhaps You could do a follow up about RAAC 🤔
If you think that is impressive, you should see what a team of archaeological students from Texas dug up. It may revolutionise how we build everything from sewers to skyscrapers. Google "Waco Compound" for details.
It's the volcanic ash. That's the secret for why their concrete is superior to ours today. Back in ancient times, there were some active volcanoes of the era.
“What have the Romans ever done for us?” LOVE that last line and Monty Python nod!
He’s not the messiah, he’s a very very naughty boy
Same here! Replace “Romans” with “Europeans” and you have what the Native Americans, Africans, and Asians would be asking today.
@@Labyrinth6000 Wow! Yes, you absolutely nailed it.
"right well apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the ROMANS done for US?"
"well, they brought peace."
"SHUT UP"
@@frogs_under_your_bedGreat scene! 🤣
Yet another example of why we think about the Roman Empire regularly!
ha, multiple times per week apparently
I am trying my urge to stop myself searching "Rome" in my phone.
Wondering if the History of Rome podcast is going to get a resurgence.
Lib
I need more concrete evidence that Romans built the best and longest lasting concrete
I grew up in the coal mining heart Carbon County, Utah. In our rural double wide trailer on 2 acres of clay ground. We had a coal stove that heated the house, a standard truck bed of coal went for $50-$100 in the 90's and was enough to heat the house all winter.
We used to pile the coal ash on the side of the property, but I noticed the pile of ash was surprisingly sturdy compared to the sloppy messy wet clay surrounding dirt when wet from the snow and rain. So from that point on I spread the ash over the dirt driveway. Over the years the driveway became harder and less sloppy muddy when wet, almost like concrete.
Thats incredibly cool
I would stop spreading the coal ash, especially since you've been doing it for years. Coal ash contains at least 17 toxic heavy metals and pollutants including lead, mercury, cadmium, chromium, and selenium, all of which can endanger human health, and at least six neurotoxins and five known or suspected carcinogens. Short-term exposure can bring irritation of the nose and throat, dizziness, nausea, vomiting, and shortness of breath. Long-term exposure can lead to liver damage, kidney damage, cardiac arrhythmia, and a variety of cancers.
That sounds like it would work but I worry about the health costs of living with coal ash.
Well done.
Have a charcoal grill. If you pour the ash onto the ground, it starts turning into concrete over time. Not great for mulch but an interesting observation.
I was so excited when I saw a few years ago that they finally figured out the secret to Roman concrete-mainly just because I kind of assumed that it would be a mystery forever, and then to find out that it was actually really simple and easy to replicate. There's an argument to be made that these structures that have long outlasted their purpose are overengineered, but I think that attitude is dismissive to the potential applications that figuring this out may have in modern construction that's exposed to water. Yes it's not as physically strong, but if it's strong enough and much lower maintenance, we should use it.
Roman projects are considered over-engineered only through a modern lens. We build everything to be as cheap as possible, using as little material as possible.
So in that regard, everything they made is over-engineered. Engineers put rebar in all their projects not because it's necessary for strength, but because it's significantly cheaper to achieve the desired strength. It is absolutely possible to design concrete structures without rebar, we just don't do it. Rebar compromises concrete from within.
What about making the core of the structure out of modern concrete for its strength, then covering it with a layer of corrosion resistant Roman concrete.
If it took thousands of years to figure out.
It wasn’t simple stfu
Another issue of duration is that (modern) concrete slowly dissolves Steel! Hence you got rusty rebar in every thing more than a few years old!! Lifetime, depending on the environment and various other factors is 150 years maximum and often less than 100 years for Modern Concrete!!
The thing is, while easy to replicate once the composition is known, the tools to find out and analyse that exact composition from solid chunk samples was not availiable until the mid 1980ies...
Fly ash is a fairly common additive to concrete today depending on exactly what it’s being used for. Modern concrete can be a very sophisticated mixture of chemicals, including things like plasticizers that reduce the amount of water needed to mix, pour, and smooth the concrete. As noted in the video, additional water beyond the minimum tends to reduce the strength of concrete. But as noted in the video, we are still learning things from the Romans. They were brilliant in many areas and idiots in others. We serve ourselves well to study both.
I've seen a lot of guys who request the concrete mixed very loose. They like a lot of water in it for the sole purpose of making it easier to work with and increase the work time. Obviously more water is not good for the integrity of the concrete. The Hoover dam was made with a very dry mix of concrete and it is still getting stronger after over 100 years.
Well yes and no there’s taking the time and effort to use water at the right times and to wet cure it witch almost no one does
Romans mostly copied the greeks and other european cultures. Made some improvements here and there. I would say the greatest feat of the romans was capitalization through the temple of saturn.
In northern Italy, in the mountains, the olive garden walls are still built and repaired using the old ways - they still add rough stones, caulk stone, hot ash to portland premix, and pour it almost dry. The old men say it takes a month for the terraces to harden, and millennia for them to crumble. Roman cement was never really forgotten by the old, there was just this cheap alternative.
interestingly east Germans working on private projects also use bigger aggregate, like rocks found on the fields (or from the dirt they excavated before making the foundation), smashed bricks, and other things.
this mainly started as a way to keep cost down, by subtly getting rid of garbage which would have been expensive to get rid off and reducing the amount of cement needed, but the benefits have not been lost on us.
Nice
Short answer: they didn't have to deal with modern priorities and the resulting budget constraints.
If you want to build stuff that will last for thousands of years, like the Romans did, you theoretically can, in the sense that we know the underlying physics of how to do it. But it changes the nature of the project, considerably.
Among other things, you can't use steel reinforcing wire in your concrete if you want it to last that long, because steel encased in concrete corrodes over time. Without reinforcing wire to bear tension, you have to build compression-supported structures (like classical arches), and you can't build tension-supported structures (like a flat rectangular bridge held up by a few small pillars spaced far apart). This greatly increases the total amount of concrete you need, which increases your costs for materials and labor, as well as the timetable for the project. On top of that, it places a lot more load on the ground underneath, which greatly increases the amount of soil and subsoil that you have to dig out and replace with something less compressible (like concrete or stone). Now your foundation is also ten times as heavy-duty as it would have been, so add up more materials, labor, and time for all of that. Perhaps you can see where this is going.
When all is said and done, you've taken an two-year project and turned it into a multi-decade project, and the cost has ballooned correspondingly. If you want to do that sort of thing in the public sector, you need thirty-year terms of office, which are (for very good reasons) not common in the developed world. And if you want to do it in the private sector, all your funding has to come from sources that share your build-for-the-ages vision, which instantly rules out shareholders and venture capital.
We don't build like that these days, because leaders with a god complex who want a monument to their administration that will last for thousands of years, tend to get voted out or overthrown.
But two year projects already balloon into multi decade projects with costs increasing accordingly.
-cries in Indianapolis
Pay a lot now, pay next to nothing for decades.
I think it's time we reevaluate our math. It looks good at first when we can build a bridge for "just" 10 million dollars. But they we have to spend 200,000 every year to maintain it, and have to replace it in 20-50 years. Or, we could spend 50 million to build, which okay, ouch, but then we pay like 10,000 a year to maintain it, if not less, and never have to replace it.
Cries in California. I want high speed rail 5 years ago.
@@jaysmith1408 Ok, but do you really want to make that ten times worse?
@@forestwells5820 Your figures are a bit off.
Building in the Roman fashion, you can't build that $10 million bridge for $50 million. You can't build it for $100 million either. $500 million, maybe. Also it will take about twenty times as long to build as the $10 million version, which is probably the larger problem. Modern people get impatient waiting two minutes for a microwave oven to warm up a plate of food. They don't want to hear "This bridge will end up being better, so just be patient while we take twenty times as long building it. Sure, you'll be retired by then and won't need to drive to work over the bridge any more, but you can just suffer through going the long way around for your whole life so that your grandchildren can inherit a masterwork bridge. It'll be great." There's going to be an election at some point, and the geniuses who pushed for the build-for-the-ages project will likely be out of office, and their successors will scrap it and build the $10 million bridge that can be done in three years.
Imagine all the knowledge lost over time. Not just ancient technologies like roman concrete and greek fire but all the literature, poetry and philosophical teachings that burned in the library of Alexandria. How far were we set back by that? Centuries? Millenia? We'll never know.
Eh, the Library of Alexandria is a bit overrated, especially with how it was at the time it finally shut down. By that time it had long been in decline thanks to the rise of other large insitutions of learning in the region, as it was no longer The Place to go to learn
@@dragon12234 Finally! Someone who was actually there when it happened!
@@machupikachu1085 one does not have to have witnessed something personally to know of it, material evidence exists.
The library of Alexandria being some long lost fountain of knowledge and wisdom is just as bad of a modern myth as that of Nikola Tesla's exploits vs the reality of his life.
The truth is that the LoA would have been vastly more oriented towards TRADE records than any other source of written material.
Alexandria was a trade city - a harbour for ships and a place where land caravans would pass through on a circuit around the north coast of Africa, up the coast of Canaan and west along the south coast of Europe.
Because of this they would have mostly got shipping and caravan manifests.
That's not to say that such information does not have power all by itself, but it's not the secrets of the ancients in any way that you want it to be either.
@@machupikachu1085
😂😂
Thx bro
*In colder region, imagine an asphalt that is self-healing and instead of creating bigger and bigger pothhole, the cracks just never happen. Every non-greedy city/companies would start using this mixture.
Asphalt is not concrete.
It's very nature as a traction material for automobiles makes it more prone to erosion over time.
The best you can do is slow it down by mandating lighter vehicles - given EVs are going to make cars significantly heavier (in the short term) that isn't likely to happen soon.
Another day where I’ve thought about the Roman Empire.
They used an ash from a volcano that set it quickly. It even set quickly under sea water. The salt water even made harder. They broke the code of the concrete a few years ago.
As to the done, they made it lighter and lighter as it went toward the center by tossing in clay pottery and straw.
Bingo ^ For those wondering that volcano is called Campi Flegrei, in the Bay of Naples. A Volcano with a highly active hydrothermal system that provides the conditions to almost instantly mix the ash with needed materials. I'll give them credit in the sense they managed to find a solution that not only worked but has held out very well for them. However, to say it didn't require an insane amount of luck and however many bodies the roman's were willing to throw at, would be a complete lie.
You also forgot about the addition of quick lime.
@@deathninja16 They probably didn't watch the video. For years, many just assumed that using volcanic ash instead of coal ash was the key. I don't understand why people leave comments like this - assuming they know better, throw out their two cents and just leave without actually paying attention to what they're commenting on.
How often does Simon think about the Roman Empire?
Never. He lets it go in the eyes and out the mouth hahaha
Whenever his writers tell him to.
Yes
@@shopshop144I'm quite certain he has a hand in picking topics to present, at least some of the time, he's said he's asked writers to produce scripts based on his own ideas
I knew this comment would be here. As soon as that meme started I thought of all the goddamn Rome videos he’s done.
During the late 19040's thru 1960's the US build Nuclear Bomb shelters in government building , hospitals, and the like. That concrete is the strongest , hardest , and virtually undamageable material ever made from a mix. I would like to see a video/documentary on the making of that concrete . And I wonder why all structures are not made from it?
Spread less propaganda
That's why the old missile silos are cracked and full of water?
@@atodaso1668they said bomb shelters not missile silos.
Ah yeah Im sure they used weaker concrete on missle silos and stronger on government building bomb shelters...@@TheTachmeter
@@atodaso1668No, that’s because the old silos weren’t water tight and ground water seeped in over time. The walls themselves are virtually unbreakable.
Pumicecrete is by far the best building material on the planet Pumicecrete is a mixture of pumice cement and water mixed and poured into a set of reusable forms walls are poured from 12"to 24" thick pumicecrete is fireproof termite proof rust rot and mold proof non toxic and has a high R value and good sound attenuation solid poured walls means no critters can live in your walls Pumicecrete can be built for a fraction of the cost and time and pumice is one of the few building materials that can go directly from the mine to the job site ready to use without any additional possessing and zero waste
My goal is to build a pumicecrete home for Community First in Austin Texas
Can you help?
Take care Ray
Older buildings look so much nicer than modern ones. Amazing how they could make such beautiful designs without the technology we have today.
Architecture seems like a lost art today. Just about all I see being built today is plain concrete boxes for commercial buildings and residential areas with the same stucco house repeated over and over again.
Probably because they actually cared what their buildings and cities looked like, instead of today when all that the powers that be care about is the bottom line. Who cares if it looks like shit, it's cheap.
difference between an artisan and a builder.
I don't fully disagree, but there's still some very beautiful architecture around today that's not necessarily what you'd call ancient. European castles and palaces, American art deco skyscrapers like the Empire State and Chrysler Buildings and Old South plantation houses, the Sidney Opera House, Asian temples and pagodas, Scandinavian stave churches, more bridges than I can name, etc.
@@pikachuchujelly7628 Most buildings were trash back then too, you just don't know about those because they're long gone.
Because of its unusual durability, longevity and lessened environmental footprint, corporations and municipalities are starting to explore use of Roman-style concrete North America.
Does it release less CO2?
@@bedhead4728who gives a shit
Co2 is not harmful to the environment.
@@ChrisWijtmans Is water harmful when you're drowning?
Co2 is not harmful to HUMANS until 2000ppm, go back and read your stupid comment now. @@erinmorash9334
This is why history and chemistry are important for architects and engineers
Well that and biology.
Nature is an unending source of inspiration for advancement in many fields of science and engineering.
Chacnes are high in more than half a billion years of evolution can wild that natural selection has provided a solution to most problems.
Case in point the coming optics revolution of metalenses based on a new field of research stemming from discoveries about the way light interacts with the wings of a buttefly.
There you go thinking about the Roman empire every day. I don't know how women don't think about the Roman empire at least weekly.
They do, they just pretend they don't to seem superior.
Maybe we think of the Egyptian empire, a culture and lifestyle that was way less cruel and lasted way longer than the Roman one? I know I do.
@@Rasputinskalol, lmao even
@@Rasputinska NOT less cruel.
@@AveCaesar2025 I actually do study Ancient Egypt daily and yes, in the light of the evidence it seems it was less cruel. Not uncruel (authoritarian government, social inequality, malnutrition etc), but way less cruel than Romans, who on top of having those things fought endless wars, had huge arenas dedicated to torture and killing for entertainment, whose whole economy relied on slaves (for example pyramids were not built by slaves and it seems that slaves were a relatively rare commodity in pre Roman times), and whose females could only dream of the kind of rights the ancient Egyptian women had. Actually it seems that Egyptian women had it quite good compared to the rest of the antiquity (that we know of), especially compared to their sisters in Greece (excluding Sparta maybe) or in the kingdoms of the middle east.
Simon has made a video about the exceptional cruelty of the Romans, check it out if you have not.
There's a huge misunderstanding about Roman concrete. The kind that survived millennia was their _best_ variety. You can have that today and better if you're willing to pay for it. But then, as now, the vast majority of projects wouldn't or couldn't buy that quality.
IIncredible, well done. All the knowledge, the technology just zipped in 12 minutes video!... Also I think the .75 play speed just invented for us to understand you :) Thanks alot.
Because we realized that if we made our concrete that good it would mean less jobs for city employees
No, it’s mainly cost and federal regulations requiring rebar reinforcements
That's not the way it works at all.
If a city council realised it could save a ton of money on infrastructure maintenance due to longer lasting concrete they would do it in a heart beat.
Just look at how much US infrastructure was falling apart and in desperate need of repair or replacement before the big infrastructure bills was passed by the current administration.
That shows just how little they want to spend money on these vital things, even to the point of waiting until people are literally dying from it.
@@mnomadvfxalso the truth of how Roman concrete functions was only discovered recently. Back in those days, the 30s and 40s, the US government actually cared about building things to last but were limited by the construction techniques and technology of the time. Now a days there's so much special interest, legalized bribery, and lowest bidder nonsense that building to last is literally the last thing in their minds.
The use of steel in modern concrete is the number 1 reason for it’s short lived usefulness. The moment the chloride crystals reach the steel, it starts rusting which expands and causes cracking and spalling.
Actually the alkaline environment "inside concrete" provides steel with corrosion protection.
Before the coming of steel spanning bridges and other structures was very limited and challenging. How the Romans could achieve these things is amazing.
The Romans still couldn't do what we can today with bridges.
Like the guy said - modern concrete IS stronger, can span greater distances and take more weight.
Roman concrete is just more durable long term and better without steel reinforcement than modern concrete without reinforcement (the chemical processes that make Roman concrete so attractivee do not work so well with current reinforcing materials like steel rebar).
The trick will be to try and meet somewhere in the middle to get the best of both worlds in one material with reinforcing materials that can stand the higher temperatures of the quick lime reaction.
@@mnomadvfx Yes, that’s what I meant to say. Steel changed the world more than most people know. Thanks for the comment.
They were very determined, like that one time where a general was crossing the Rubicon.
I agree, but I've also got to point out the only reason that style of building was even remotely viable is because the Roman Empire clearly didn't mind throwing as many bodies as they needed for such a grand scale projects. Nowadays, I seriously doubt that would be easy to do.
@@Akechi_The_Phantom_Detective Thanks for the reply. Yes indeed, workers were expendable.
Even later in Medieval times, many lives were lost building Castles and those beautiful churches.
It is important to recognize that Roman concrete is much, much weaker than modern concrete rendering it unusable for any applications that requires high strength. Roads, bridges, and buildings cannot use it in any efficient manner. Dams, retaining walls, piers, foundations, etc could potentially benefit.
Fair enough - unless we allow the Roman concrete to "age" for a year or 2 after the end of the construction to obtain the physical strength it needs.
Remember: Italy is a country prone to earthquakes, so the great problem in certain structures would be vibration, not weight
@Jamhael1 we should then
Lived in Rome on a student visa for 6 1/2 years attending AUR ( The American University of Rome) after serving active duty USN in Naples Italy for 4 1/2 years.
Had they figured out that there was lead in their drinking water pipes and not reacted so very harshly to monotheism we might've well had the industrial revolution almost a full millennia earlier , via avoiding the "dark ages".
We also might all be speaking a modern form of latin and learning "rhetoric" in schools instead of English loL
who knows
Why do you consider the harsh reaction to monotheism something which held the Romans back? After all Christianity coming in force was one of the reasons the Roman empire in the west fell.
Hmmm, lead pipes were commonly in use until around the end of last century, and according to others they are still commonly found in many parts of THE DEVELOPED world even today. Largely because the cost and inconvenience of replacing them means they are left until they HAVE to be replaced. And the amount of lead you imbibe from said lead pipes is also amazingly small according to a programme I was watching on the subject recently. However it is also accumulative and came from more sources than just water pipes.
@@northumbriabushcraft1208 My view would be, because of the internal turmoil caused by religious conflict. Of course they also had economic turmoil, succession & political turmoil, & perennial barbarian problems.
I would like to note that the automatic closed caption function accurately captured Simon's pronunciation of 'Utar'
Sounds great except that "1/10th the compressive strength of modern concrete" might be a bit of an issue unless we can find ways to maintain the new benefits while still achieving modern strength standards. Or maybe it will simply have niche uses.
I'm assuming it's a combination of the brittle lime clasts and the lack of steel/etc rebar.
I'm sure that with additives like small CMC rods and larger scale bars that they could increase it's strength a lot.
It wouldn't be cheap though.
I like all your videos, but this one was the best !! Both historical and greatly educational. I will be sharing this and discussing it with my brother in law, who builds dams and just built the biggest in Laos which broke the world record for the most concrete poured in a day 6 times in just a few weeks ! He will love this as he is just about to start a new dam in the Philippines. Thanks !
I've been building with pumice cement and water for 25 years
Take care Ray
This is a fascinating episode. The only thing I knew about concrete is how much damage it can do to you both externally and internally if you fall on it or crash into it. Most concrete, primarily outdoor structures, has deliberate inclusions from little pebbles to large stones as big as 2" long. I have always wondered what reason is behind this and what the optimum mix is for any given structure. We constantly conceive of the "ancients" as being more primitive than we are with all our machines and sophisticated chemistry, but I loved your vid on 5 Chinese inventions from ~2,000 years ago without which Western civilization would never have advanced; written pages (invention of paper), seafaring (the compass), irrigation and flood control, (pumps, making rivers navigable) and of course gunpowder.
Do you even realize,
that as you talk about the Pantheon in Rome,
at 0:19 you showed images of The Panthéon in the Latin Quarter of Paris ... built in the 1750's?
... ya ... you actually did that.
Thank you for pointing out that in old Latin, C is hard, like K. I remember that from parochial school and seminary. And the secret ingredients for Roman concreta!
I think the biggest reason the Romans developed concrete that would cure underwater and last so long was that they only wanted to build it once. Modern contractors want to insure they have a future so they don't want concrete that last forever, because they would put themselves out of work after about 10 years. Not entirely true but the demand would basically be limited to solely new construction and they would loose all the work they get tearing out old concrete and pouring new concrete.
Almost forgot to think about the Roman Empire today
Limestone not being turned to powder with less power gives their limestone better surface area and binding to each other and the hydration process.
The Pantheon was originally built by Agrippa, Brain Boi. His name is on the façade. Hadrian completed a reconstruction after a fire.
could you power clinker kilms wih electricty or is the teperaure rquires too hot that the elctric wire would melt.
Pozzolana being what it is, I reckon there is some opportunity for nations with a lot of volcanoes, as that silica is generally found there. If I lived in Japan or on Hawaii for example, I would be looking into that.
It has been 0 days since I last thought about the Roman Empire.
Thanks!
I really started listening when you mentioned coffee!🤔🙌🇬🇧
Interesting review.
Two points.
Concrete cures, rather than dries. This is a chemical reaction which also creates heat.
Roller Compacted Concrete, or RCC is used in dam construction worldwide.
Nothing new there.
The ancient Romans were indeed, fine engineers. 👍
Great research, Admir
Why was I wondering bout this last night , and today a video is up? Serendipitous
Seen a nether video saying they add hey to it as well. Also that sound a lot like aircrete or styrofoamcrete it's got a lot of names but it's concrete mix with foam.
One thing that's been found though is that even our modern concrete, over time, pulls about all the CO2 output by its creation into it (especially in buildings that we're leaving for decades longer than roads) and this property of concrete makes it stronger over time and is something that makes concrete far more environmentally friendly than we ever imagined.
While everyone needs as revenue, more ads and discussion about ads and ads and ads and discussion of ads than USA network TV. That reaches greedy level
You smart folks probably will not care about this but I am going to post anyway. I lived in New Brunswick on the Atlantic Coast. It was where my Dad’s BFF poured CEMENT for a living. He did this all year round! In that cold & snowy climate. He gave the secret recipe to my Sister who had her contractors license in Massachusetts. She was able to get a basement poured in November by sharing the recipe with her concrete guy. Unfortunately all 3 have passed away and I have no clue what they did to the concrete.
FYI Going to Pompeii is on my bucket list!
Simon is a great speaker, and he’s very literate too. Too many people use the word Why when they should be using the word How.
Brilliant life of Brian quote there at the end
In the healing process, what keeps the material from overcorrecting thereby creating bulges/spikes?
I wonder if the Roman mixture can hold up to the chemicals that get splashed around and on concrete today?
It would hold up fine but actually creating big buildings using it is a collosal pain in the ass.
Urggg....the real answer is 'by accident' and 'trial and error' -they had little 'chemistry' theory knowledge, they tried stuff and if it worked or was noticeable better than what they had; they kept doing it.
Also 'Survivorship bias' (wiki)-"Just as new buildings are being built every day and older structures are constantly torn down, the story of most civil and urban architecture involves a process of constant renewal, renovation, and revolution. Only the most (subjectively, but popularly determined) beautiful, most useful, and most structurally sound buildings survive from one generation to the next. This creates another selection effect where the ugliest and weakest buildings of history have long been eradicated from existence and thus the public view, and so it leaves the visible impression, seemingly correct but factually flawed, that all buildings in the past were both more beautiful and better built."
Another thing, though it was a bit vague -they seem to have compared modern reinforced concrete with non reinforced; which are very different animals and have different properties.
This is honestly kind of true. I'll give them credit in the sense they found a formula that worked and kept on using it but I can't honestly say it was a feat of intelligence as it was pure luck. The fact they managed to source Ash not only from a volcano but a super volcano with a hydrothermal system that would've allowed them to mix and heat that is kind of insane. It also didn't hurt in their case that they were willing throw as many bodies as they needed to get these projects done.
Can't help but imagine trying to do this with Ash from any other volcano would take a lot more prep and A LOT more bodies. That said, Volcanic Ash actually seems like a really good material abeit not a practical one.
If you are willing to make your walls 20 feet thick, like the Pantheon and the Colosseum, it's easy to skip reinforcing your concrete structures. That's okay for a couple huge public buildings but isn't a practical strategy for homes, businesses and roads
Actually roads built with such methods would FAR outlast the current ones
@@Matt-yg8ub sure, but if you are laying slabs 10 feet thick you are going to have to first construct a roadbed strong enough to keep thousands of tons from sinking into the earth. That's gonna cost you, durability and economics are always an engineering compromise. Fast, cheap, good...best case you get 2
@@Adiscretefirm considering that I design roads, most of the problem is the federal requirements that makes us have to make them cheap and brittle….. and the water department, demanding that everything be less than 18 inches thick so that they can dig through it and patch pipes a month or two after we resurface a road. If they had designed the road to be a road, and not a poorly paved surface covering all the utility pipes…. They would last longer.
@@Matt-yg8ub probably so, but do we want to repeat the Roman experience and only have running water to the rich people's house?
@@Adiscretefirm you are missing the point, instead of running the pipes under the road where the water department has to cut through the road on a regular basis, run them alongside the road in the right of way. You end up with bigger trees in the right of way, more forestation, lower temperatures, less urban heat island effect, less global warming, and you don’t damage the road repairing pipes.
The Romans built a sturdy road base that could sustain a road for 2000 years because they didn’t bury their pipes under the road
The perfect material for sea walls and coastline preservation against erosion , especially considering the amplified effects caused by global warming.
The fact that fly ash (which my laboratory regularly tests and just from the amount we receive is very abundant in the industry) could be used to help make better concrete is astounding… my only question would be if Roman concrete could stand up to Minnesota winters. If the answer is that they can… I’m going to be severely disappointed in the concrete industry, cuz we obviously need more durable roads but that wouldn’t negatively impact them financially because roadwork is a never ending process.
Yeah, American roads are laughed at globally... tbf they're put through harsh conditions
i’ll sum it up, roman concrete is not strong, but it lasts longer, modern concrete is built to handle the weight of skyscrapers and modern vehicles. also the sea salt in rome helps harden it
You are the cement that anchors the concrete of youtube
I picture someone roasting each individual bean with a pair of tweezers and a Bunsen burner. 😂
When cement came along in the 20th century the advantage was a faster setting time than using lime.
They truly made things to last forever where as modern inventions are built to break and be rebought because money is the primary focus. Imagine how advanced the world could be if we werent selfish were community based
The reason why our concrete is different has to do with water. Our 'wet' concrete is necessary to pour huge foundations for modern buildings. As well as bridges and dams. We can build big things fast but our concrete has weakness like expanding and contracting do to temperature. It doesn't do well in humid environments & needs more maintenance.
On the other hand the romans could never make a colossal structure like the hoover dam.
So in essence, the volcanic ash solution simply isn't as adaptable unless you're willing to throw a shit ton of bodies at it. It's good for it's insulative properties just not practical for any grand scale projects.
while we're on the subject of concrete, there is another type which is a mystery to this day: german WW-II flack towers.
these were apparently so sturdily built that they not only survived allied bombing raids, but even after the war, with full access, allied attempts to demolish them failed, with most of them having simply been covered under a hill of dirt after they just gave up.
I love this channel and constantly think I'm leaning by watching it, today was the first time you've ever covered anything I know about: the properties and differences between lime and cement used in construction, and frankly I'm horrified, this is historical story telling interspersed with half truths and misleading information.
People don't understand that the way we build things today is not only to be the most cost effective way but is designed to be knocked down and replaced within a few decades. We can make all these things to much higher qualities but that's just not how we build things.
Sure, if you say so.
In regards Roman concrete, a volcanic element was used in the mix. A suprising side effect of this addition was it was even stronger under water!
Its been speculated that Chuck norris' beard is also made of this material.
Thank you for explaining why concrete doesn't dry, but it requires hydration. Most people don't know that, or even if they do, they don't know why.
The next video should explain why some people have the urge to raise their arm when they’re trying to sleep.
Does that mean this would be good for a garden based on collecting rain water from your roof and funneling it into your garden spaces over time? Would this be hard to make at home?
what have the Romans ever done for us...nice touch to finish on...love the Life of Brian reference 😁
It always baffles me when you hear of a new bridge or similair project and they say "This has a lifespan of 100 years", when roman bridges and other projects last 2000 years.
They only have that lifespan if maintenance is kept up.
How strong is it WITH reinforcement?
Pronunciation tip: hyperbole is pronounced like hyper-bowl. The word you said, sounding like hy-PER-bolee, is the plural of hyperbola, which is a geometric shape, one of the conic sections.
Sorry but you’re incorrect here. No one pronounces it like that.
It comes from Greek, and uses Greek pronunciation. The "le" at the end isn't a silent letter, it's meant to be pronounced. It's like how the name Hercules is pronounced Herk-u-lees, not Herk-yewls.
Love the monty python reference at the end .. bloody marvellous
So very interesting. Knowing what we now know, they should make this standard practice for making concrete.
Ye but no.
There are simply too many current uses for concrete where the Roman recipe would be inadequate to purpose.
For somethings it would work fine, but for others you would make even worse problems from concrete that just can't take the same weight over it from 10x lower compressive strength.
Those lime clasts are brittle and decrease the overall strength of it vs modern portland cement based concrete.
OMG…this storyline was just on the Billions episode on Showtime on America on September 22, 2023. The episode dealt with a modern inventor replicating the bacteria to creating self-healing concrete and the lead character of the show then went in and started “patent sharing” all of the subsidiary and tangential patents when the main inventor rejected the buy out offer. They explained the science behind the concrete really well and now you have an episode about it just two days later. Small world of coincidences.
Watch less tv
@@fastinradfordable Seriously…that was uncalled for.
@@fastinradfordable Smart Ass
Look up crystalline waterproofing admixtures. We’ve had self-healing concrete for awhile now….
Bacteria has nothing to do with it.
That stuff pops up in the media every other year. It's not like it hasn't been investigated, it is just not economically viable. And as long as this is the priority, nothing will change.
I hope that the use of durable self healing concrete is taken into consideration during the construction of nuclear power stations in the future.
The Roman's didn't dig up the cement and asphalt 13 times per year (from a lifelong resident of Connecticut, USA).
I’ve always wondered why people say broom and concrete was so much better. I love working with concrete. I love the pressure. I love that you cannot screw up if you do well, nobody likes chipping concrete.
That's an only adorable way of looking at concrete.
honestly with all the alleged advancements in material science since then i find it hard to believe how they haven’t come up with something in our time that would mimic this behavior.
Why’d you show asphalt at the beginning?
Anyone out there know of any good books or papers on this subject? Thanks.
That dam in Utah will last millennia waiting for the recipe to hit the mainstream market. I'll be building an elevated small house near the ocean and want to use this material for the piers holding up the house, as well as footers for the dock. I need durable and as cheap as possible.
So what's the recipe for Roman concrete (using ratios)?
"What have Romans ever done for us" "The wine we sure would miss the wine if the Romans ever left."
Concrete also requires a certain kind of sand to be produced, and we're running out of that. Hopefully, we can find a substitute.
What kind of sand?
Can be crushed to produce a FM of 2.600 from rock !1
Low slump concrete made with fly ash has been a staple of runway building for decades.
Interesting video, but some weaknesses.
- It's not true to say that Roman concrete used materials fired at much lower temperatures. After all, a key component came from a volcano!
- Your description of mixing modern concrete was wrong. Lime is not involved and all the ingredients (typically cement, sand and gravel) are mixed together with water at the same time.
- The construction industry has been using fly ash as a partial replacement for cement for decades. However, that material will become increasingly scarce as coal fired power stations are phased out.
- Low water content giving increased durability is well recognised. The additional water is largely to be able to pour the concrete into the formwork (mould). It is then vibrated to try to eliminate voids. The way the Romans placed their concrete would be immensely labour intensive and quite unsuitable for many of the ways that concrete is used in buildings today.
- The main cause of modern concrete failing is because it has rebar inside it. Ultimately this will corrode and expand within the concrete mass, causing damage.
As a final thought: Would we really want modern concrete buildings to last 2,000 years?
You know I will give the Roman's credit for the innovation especially so long ago but I feel like it's fair to point out them even figuring out how viable volcanic ash even is took a fair amount of pure luck. Not just to experiment with Volcanic, but to do so at a volcano that would just so happened to have a hydrothermal system where it would be so readily available in such a state, that Volcano being Campi Flegrei. Kind of feels they used whatever mass material they could use as a cement mixture and ended with a very fortunate result.
Of course, I may not be giving them enough credit but I can't help but think if you tried this with Ash from any other volcano it would take WAY longer and probably require more man power.
I heard that the coffers of the Pantheon were gilded as in Oro.
Love the Monty Python reference at the end!
.... and today schools and hospitals in UK are about to crumble after 40 years.............
Using shitty concrete = job security. Why would builders switch over?
Ideally because it’s the right thing to do, but this is capitalism so that will never happen
Lime is a brilliant material that should be used a lot more in construction. Especially in mortars and plasters.
3:52 Thousands of Tons of Concrete was transported. How did they do that? If we look at Modern Populations and look at back then. I mean. This is as almost mind blowing looking at the White House and see how they got all that Lime Stone to that location and man Penn Station. That place is Massive. Who did they get it to there location with horse and buggy. Just food for thought.
Namaste
Dave Ross
Dammit! When I was visiting Rome the place was shut down for maintenance.
Fly ash was used here as a cheap, lightweight & easy to work self compacting material for building pads. In the decades to follow, this material has grown crystalline structures within it that has been lifting the structures built on top of it. Used incorrectly, flyash is a very bad long term solution.
Well said. So it's the quality of how the ash is developed rather than what it is. Good to know.
when I grow up ... I'm want to be just like this genius ... UTube channels like this better get compensated fair ... it's a ton of work and better than anything on streaming other things