How ancient Rome's concrete recipe can
help lower emissions

Emissions! Emissions! Emissions! Everything is all about emissions to the ignorant people who believe in anthropomorphic global warming (or cooling, or rainy, or drought). These people have the science knowledge of a 2nd Grader, and don't realize that THE SUN and its cycles of higher/lower radiation, sunspots, alpha emissions, etc is what determined the weather. And we are about to enter the cooling cycle, like every 1,500 years. WATER VAPOR comprises 95+% of greenhouse gases in the atmosphere.

The best way for these environmental cultists to stop or reduce harmful emissions is to tightly duct tape a plastic bag around their heads.

You could lower emissions more by not letting in millions of muslims. Give it a try.

Oversimplification. The root cause of most modern concrete breakdown is the corrosion of the bare steel reinforcing bars. If the rebars were something that would never corrode, perhaps the same durability could be achieved. And the author is misinformed. The majority of the Colosseum structure is BRICK, clad with travertine marble, but sitting on a massive, gigantic foundation of many feet of concrete. The site was originally a lake during Nero's time when he had the HUGE Domus Aurea built, the largest palace complex ever known. After Nero was gone, he was so hated that the entire Domus Aurea (Golden House) was destroyed. Only one small portion, with a magnificent double barrel vault, in brick, was found buried near the Forum, and is now excavated and has been studied. It is a superb example of Roman architecture. We are only left to wonder what other wonders were dismantled because they were built by Nero. In any case, Nero's lake required something like a 26 foot thick concrete pad be poured over the unstable ground to support the Coloseum. THAT has endured well. BUT - it is used in compression only and has zero internal iron reinforcing bars. Our modern steel-reinforced concrete would spall and crack apart due to the corroding steel bars, even if the concrete was self healing on it's own. And most of our use of concrete today is very different than Roman use because we can use it in tension and compression, enabling horizontal beams. The Romans could only use concrete in compression, so only arches, barrel vaults and domes. Look at what medieval architects did with cathedrals. They were stone, and similarly cannot endure tension, only compression. Barrel vaults of great complexity, and flying buttresses (all in compression) carrying those overturning loads caused by the vaulted ceilings pushing outward on the tops of the tall walls out and downward, always in compression, to the ground. Unreinforced concrete and stone are wonderful materials....but limiting in many ways. Ancient architects found beautiful ways to build when they had no ability to load any of their structural materials in tension. No horizontal beams other than wooden beams used in a few places, which rot or burn. Self healing concrete is no panacea for modern construction without corrosion proof reinforcing bars. Or we go back to all arched, vaulted and domed construction. Beautiful but expensive and limiting.

#4, thanks so much for your reply. Both interesting and enlightening! (OP)

Lower emissions? Put the Gorons in concrete overcoats and drop 'em to the bottom of the Mediterranean. They won't emit much there that won't be absorbed by ocean water first.

While we're on the subject, check out Bob Dylan's "When I Paint My Masterpiece." Grateful Dead do a terrific version, as well. https://www.youtube.com/watch?v=qWfaSle5sIs&list=PLPzMGx_wdfBA2yX0YT1liNXjye_ko4VGy&index=2

Correctuion to my post #4. Upon reflection, Trajan's Market has all it's barrel vaults in brick. The one surviving portion of the Domus Aurea does have poured concrete barrel vaults. They built wooden forms, poured their concrete and removed the forms, much like we do today.