My understanding is that Roman concrete recipe/technique is considered uneconomical for most uses today because it uses very little water and must be mixed onsite and packed into place, which makes it much stronger even without rebar. But that doesn't work so well for mixing in a truck and driving to job-site, so modern industry prefers a much wetter mix even though it means our structures crumble in decades rather than millenia.

Where the similar recipe/technique has been applied is in the construction of some large dams, where they call it roller compacted concrete.

see romanconcrete.com