[0]https://twitter.com/Paul_Denney/status/1397132479144812544
[1]https://www.punchline-gloucester.com/articles/aanews/glouces...
Graphene has its own set of problems. Namely, it can be toxic to humans. [1] And who knows what massive quantities of graphene in concrete will do to an environment 10-20 years after the building's construction. Even demolition with explosives will probably be problematic due to potentially massive clouds of nanoparticles it could create.
Uhhhh the rest of the stuff in Concrete isn't great for human health, either, or as my cousin likes to say, "it sure ain't vitamins."
Quartz dust and silica sand are really bad for the lungs, likely carcinogens. Lime is caustic. Dust in general is bad to breathe.
These are well-known hazards in demolition and mitigation techniques already exist.