Mystery of why Roman buildings have survived
so long has been unraveled, scientists say

Were the Romans this smart, or did they accidentally come up with the best concrete? I'm banking on accidentally stumbled upon the best concrete. And from what I know about pumice, it's extremely soft. Not sore how that makes durable concrete. And....... not sure how heating your concrete mixture to high temps in any way reduces the carbon footprint.

Hey CNN, it's not a mystery. The Romans documented their concrete formula. The formula was written down. All the ingredients and steps were documented. Meanwhile modern day construction contains planned, built-in obsolescence. Golly gee CNN, get your Shite straight. Do some real reporting.

The article mentions standing structures in Rome - - and one in Privernum - - but in Italy today there are many more examples - - such as in Verona, Luni, Lecce, Pietrabbondante, Saepinum, Lucus Feroniae, Assisi, Aquilea, and many, many more - - not to mention the ones outside Italy, as in Arles, Trier, Orange, Merida, Belmonte, etc., etc. As for "stumbling" onto the formula - - isn't that how every invention, every advancement happens - - through rigorous trial and error? Anyone who denigrates the amazing achievements of the Romans - - especially their greatest achievement, the centuries-long Pax Romana - - is an ignorant fool.

They built things to last with their own ingenuity.... not some cheap Chinese copy with planned obsolescence! Another example is how that some parts of the Appian Way are still able to be used even today-- We are now in many ways in parallel with the downfall of Roman culture with the debasing of our standard of money, from the gold standard, to the gold and silver standard, to taking the copper out of our pennies in 1982 (substituting aluminum) to now just spending without restraint and PRINTING MONEY to replace the old money with money that is worth less- "worthless" that losing its value every time the demonrat socialist Marxists float spending bills--- As Cicero said "O, Tempora! O, Mores!" Oh the Times! Oh the Customs! So many Charlatans who gaslight us into believing the unbelievable with the notion that old, FAILED socialistic ideas that haven't worked in THOUSANDS OF YEARS, will NOW work because NoBama is in charge--- those of us who remember when a Dollar was a Dollar know how hard it is to "get ahead" when we have added close to $10 TRILLION dollars of debt since NoBama took over in 2009 hastening our fall.... We are headed in the same direction as Rome, only at a faster pace! The things they built still stand in many cases, but CORRUPTION kills societies when there is no "Separation of Powers" and when there is a puppet Tyrant and one-party (or uni-party when Repubicans work with the Socialists running up the debt) and society in general being morally corrupt.

This seems like a pretty obvious discovery that I would guess would’ve been made a very long time ago. What the hell of these archaeologists science has been doing?

Surprising they didn’t sneak in a comment on Climate Change.

Too bad the Romans didn't build such concrete walls around their empire.

i was going to send this to a lot of people, but googled "roman concrete" and found the same thing on Fox (cleanest shirt in the dirty laundry) so i sent THAT

Great engineers. Hard to believe their descendants built Fiats!

Also, the Romans used volcanic ash to add great strength to their concrete. Today some special, high strength concretes use fly ash from coal fired power plants to increase strength of concrete. And IMO as an engineer, one of the major problems with modern concrete is that we use it with large amounts of internal steel reinforcing bars, which the Romans did not do. This steel reinforcing of our concrete is a double edged sword. On the one hand it permits greater strength, making large concrete beams possible that the Romans COULD NOT do, because unreinforced concrete can sustain only very small tension loads, must be used only in compression. This means arches, barrel vaults and domes, no flat beams. They used it only in compression, as in the magnificent dome in the Pantheon. We are able to use it in long horizontal beams, like highway bridges, because of the internal steel reinforcing bars. But there is only a small fraction of the steel in a steel-reinforced concrete beam that would be required if the beam was all steel. This makes steel reinforced concrete cheaper than steel. But here's the downside to that benefit of being able to make concrete beams (horizontal beams have tension on the bottom, compression on the top) - the normally bare steel reinforcing bars will corrode over time, especially in highway bridges where salt is used in winter, and the corrosion of these steel rods destroys the steel reinforced concrete structure in two ways. First, because the corrosion products (rust) are greater volume than the original steel, the internal steel rods literally force the concrete apart as they corrode, causing severe, destructive cracking of the concrete, coming from the inside. And the corrosion directly destroys the steel rods, which weakens the steel/concrete system. Both of these were the cause of the horrific apartment building collapse in Miami a few years ago that was all over the news, and much reported and discussed on this forum. Salt from sea air did it in Miami. If we made our concrete structures with corrosion proof reinforcing rods rather than bare steel rods, they would last much longer. So - much more expensive stainless steel (which can still corrode, just more slowly), or galvanized coating, or other protective coatings on the steel rods may increase the life of the steel/concrete system. I see some highway repairs which appear to be using steel rods with a green coating, which I guess to be a corrosion protective paint to extend life. And testing work is being done with fiberglass/epoxy reinforcing rods which don't corrode, and carbon fiber/epoxy rods. All these changes are more expensive than bare steel, and nobody is willing to spend the extra money for longer lifetime of the structures. So we get cheap, easy concrete structures - that don;'t last long, because nobody is willing to spend the extra bucks. They apparently last "long enough".....until those concrete condos fall down, as in Miami. And then it's not "build shoddily" in the reports, but "not inspected often enough, should have been torn down". And it appears that the highway bridge process of "build, use, salt, rot, repair, use, salt, rot, repair....." is a nice "welfare" program for highway bridge construction companies, so nobody seems to care to change anything. I suspect that efforts to make highway bridges last longer would be secretly fought by the construction/repair companies, with money behind the scenes to protect their cash flow from these endless repairs. Can't interfere with "orange barrel season" cash flows. And remember, as much as Roman construction is magnificent and amazingly durable, they could only use their concrete (and brick/mortar - LOTS of that, most of the Pantheon is brick, only the dome is concrete) in applications where it is only in compression, which means NO horizontal beams, only arches, barrel vaults and domes. Great, very useful and good for centuries, but limiting. But barrel vaults and arches are magnificent, too. There are Roman era arched bridges (and aquaducts) that are still standing, all over Europe and Turkey, small and large 2000 year old bridges with moderate, occasional repair, lasting tens of centuries. But they are stone and brick arched structures, not concrete, in most cases. If you have never been to the Pantheon, you should make an effort to go. When Rome fell into disuse in the 400s and later, much of the "destruction" of Roman buildings was due to them being used as quarries for stone, and/or the metals used to tie the blocks of stone together. Most of the destruction was INTENTIONAL work of thieves and 'recyclers'. One of the reasons that the Pantheon still stands so magnificently intact and original is that it was converted to a church very early, never abandoned and protected from vandalism by the Popes, because they were using it. It has been in constant use since it was built in, IIRC, 79 AD, about 30 years after the death of Christ. And the original doors still swing open each morning and are closed each night. An absolute "must see" of ancient architecture.

Re #1, most likely an accident. They made very small batches of hand mixed mortar/concrete and added the rubble and rock aggregate by pounding it in after a layer of concrete was poured from a basket. They would have wanted very fast cure since they were layering their concrete "pours", not literally pouring huge semi-liquid masses as we do today.

The Romans, Greeks and Egyptians had it all going on.

#10’s article is better than CNN’s.

I always pay attention to #10's posts and I have learned alot!

Thank you for your insights, #10. I’m married to an engineer and we enjoy reading about ancient engineering techniques and discussing them. Your knowledge adds more spice to the discussion.

Perhaps these projects were BEFORE the concept of awarding to the lowest bidder?

If only The Roman Empire had been as strong as their concrete. Imagine the World in a 21st Century Rome encompassing the entire Solar System under The Pax Romana. If the theory of Alt/Verses is true that would be an Earth to visit.

Re #15. If anyone is really interested in ancient engineering by Greek and Roman people, Prof. Steven Ressler, PhD, retired from teaching at West Point has put out a magnificent "Greatest Courses" course on this topic. He covers it at a level that requires no great math expertise, with lots of wonderful and fun handmade demonstration pieces that he uses on a tabletop. I have lived and traveled extensively in Italy and Europe, often taking trips to specifically study some of the engineering marvels they left. https://www.thegreatcourses.com/courses/understanding-greek-and-roman-technology-from-catapult-to-the-pantheon And read about the HUGE water powerered grain mill complex in Spain at Barbegal are amazing, too. I have not yet been able to visit that site, but just studying the material online and Prof. Resseler's coverage of it is amazing. http://waterhistory.org/histories/barbegal/

In the eight grade, living in Italy, my parents took the family to Rome and I saw the confusing, yet magnificent Collusseum, and then the Pantheon. I had difficulty grasping that this wonderful building wasn't "restored" or "rebuilt" or some sort of a replica....but a 2000 year old original Roman building in excellent condition. It lit a fire in me to understand how such magnificent works could be made so well. And look at Trajan's Market, too. The first shopping mall, also very intact. All brick.

Yep. Those ancient builders came up with a concrete that was not only strong, but got stronger the older it got. They made great concrete for their buildings, and it is a shame that modern builders refuse to use their recipe. The things one learns on documentaries and even CNN never ceases to amaze me.

Those Romans should have built that condo that collapsed in Miami Beach

As the Greeks would say: 'Eureka!!'

Plus, they didn't employ union labor.

I think the Parthenon and Coliseum were severely damaged during wars, or they would be in even better shape today.

Re #24. I am pretty sure that the Pantheon was not harmed during WW2.

Sorry for confusion and misspellings. I thought the article intended the Greek Parthenon (which did sustain war damage). There is another structure, the Roman Pantheon. From what I read the Colosseum sustained damage in 1687 from an Ottoman war. They are still remarkable structures.