Why isn't Roman Concrete used today?

Roman concrete redefined the limits of architecture. But could it be used to build a modern skyscraper? Find more Toldinstone content on Patreon: https://www.patreon.com/toldinstone Check out my other YouTube channels, @toldinstonefootnotes and @scenicroutestothepast Chapters: 0:00 The origins of concrete 1:25 Building with Roman concrete 2:49 Why the Romans didn't build skyscrapers 3:33 A hypothetical modern project 4:20 The "Insula" method 5:23 The "Colosseum" method 7:17 Possible, not comfortable