Sorry if this is an unbelievably rudimentary question, but what is
concrete? more specifically, what's the difference between the Greek
and Roman forms of concrete?
I heard on TV that the Greeks invented a form of concrete, but it
wouldn't harden underwater. The Romans pefected concrete, changing the
formula to make it both more durable, and to allow it to harden
underwater. So my questions to any who'd care to respond are:
1) what was the Greek formulation of concrete?
2) what was the Roman form of concrete?
3) Have any improvements been made to the formulation of concrete
since Roman times (besides the addtion of rebar, which doesn't change
the formula of the concrete itself, of course)?
4) why does concrete harden? What's the chemical reaction?
Thanks in advance, Bruce