New studies of ancient concrete could teach us to do as the Romans did
One thing I recall reading is that rebar-reinforcing concrete is a major factor in concrete deterioration. So while concrete structures today don't last nearly as long as the Roman Pantheon (poured in the second century AD), they're also really cheap to build, can go really high, and last for 40 or more years (which given how cheap it is, the architects probably thought was long enough).