If you say no, wait a few hundred years.

Next mystery why does broken old glass mixed with a new batch of molten glass make it even stronger? Hades if I know but it does!

Oh your first mystery was blood. Air pockets allow for expansion and contraction.

Good stuff! Thanks for the link!

which are self healing in the Roman stuff. Water gets in to the rebar. Rust takes up more room than iron does, so the rusty rebar exerts force on the concrete and creates big cracks, and eventually the whole business fails and the bridge or the building drops like a rock.

I wonder how soon we're going to see lime clasts in structural concrete.

or that it took so long to figure out.

...and not as a component of self-healing concrete. Something along of the lines of "this lime is so contaminated with impurities! We can do much better now!"

Rebar doesn't just corrode as iron rusts all the way through, I think the only element to do that. Copper piping gets pinprick holes after awhile, but that may be another process. Another interesting option maybe synthetic egg whites. The ancient Mexican Olmec concrete has lasted so long as they added ostridge egg white to theirs.