The Anthony and Cleopatra thing was about Rome’s growing reliance on Egyptian grain.
Ships went down in ballast from Naples carrying volcanic ash which was tipped into the sea. It was found to set underwater making excellent quays and breakwaters – Roman concrete, pozzolana, had been discovered.
Environmental concerns increasingly lead to substitutions of pozzolanic materials for cement in modern mixes. The Flavian concrete beneath Novium has proportions 1/2/1, lime/sand/broken tile. The new museum superstructure has proportions 1/1/2/4, cement/man-made ash/sand/gravel. It is relying on the old chemistry.