CleverNickName
Limit Break Dancing (He/They)
Concrete has been in use since ancient times. Poured-in-place concrete floors were used in Greece as early as 1400 BC, and cement grouting as early as 800 BC. Batch production of concrete was developed in the middle east in the 4th Century, and ancient Egyptians figured out how to get concrete to set underwater (by adding volcanic ash to hydraulic lime). In Medieval Europe, the kilns couldn't really get hot enough to slake the lime, so when the Romans came it took them a few hundred years to figure it out...but they were back to using concrete by 1200 AD, and by 1400 AD the quality was quite good.Civil Engineering - Absence of concrete limits the scope of constructions, with magic sometimes used as a replacement to create lasting aqueducts and other “marvels” of engineering equivalent to Roman constructions.
Anyway--I have no arguments at all about the tech levels that you mention and how you use 'em in your game. I only bring it up because I think concrete is an amazing material, and except for the occasional argument with my sister who watches too many episodes of "Ancient Aliens," I never get a chance to talk about it's history. Concrete as we know it (lime + aggregate + water) has been around since the Bronze Age, and I think that's rad.