Roman concrete has mostly stood the test of time. The Pantheon for example was dedicated in 128 CE and has the world’s largest unreinforced concrete dome. Today, it’s still intact.
Even some ancient Roman aqueducts still deliver water to Rome.
On the other hand – In your town or city you probably have at least one piece of brutalist architecture. Big in the 50s and 60s, these now controversial concrete structures were considered utilitarian and long lasting. Yet today, without restoration, some of these reinforced concrete buildings have begun to crumble.
