"Richard Casady" wrote

There is something called ferroconcrete. Instead of rocks, it is made
with so called boiler punchings. No longer the metal from rivet holes,
it is now punchings from bolt holes. Popular for radiation shielding,
sailboat ballast, and crane counterweights.

Casady

Wouldn't the embedded iron and steel be likely to corrode, possibly causing
the surrounding concrete to fracture, if the ferroconcrete mixture were
exposed to continuous submersion, especially in a salt water environment?

Just curious.

Alex