Ancient Roman builders were “hot-mixing,” which means that they dumped volcanic ash and powdered quicklime together dry, then added water later, triggering a chemical reaction that cooked the mixture from the inside.
the heat unlocked chemical pathways impossible with the standard method of “slaking” lime first — “slaking” being the process where the lime is first mixed with water before it’s poured out.
The hot-mixing method has faster setting times, and most importantly, creates something called a lime clast, which are little white chunks of minerals common in ancient Roman concrete that was at one point thought to be a sign of poor mixing but is now being viewed as the key to its absurd durability. These lime clasts effectively give ancient Roman concrete a self-healing ability that can keep it going for generations.
Very interesting!
Imagine being a historian looking at masonry older than everything else, outlasting 2000 years of weather, and thinking that what we have now is better and the Romans can’t mix concrete. Absolute foolishness.
My aunt was watching “The History Channel” and the whole day was nothing but “ancient alien” theories, so it’s not surprising.
I love how the website names linked get more specific as you go down the list
Survivorship bias?
