The City of Caesarea was the earliest known example to have made use of underwater Roman concrete technology on such a large scale.
Vitruvij določa za cement razmerje 1 del apna do 3 dele pozolana, kar naj se uporablja v stavbah in razmerje 1:2 apna in "pulvis Puteolanus" za podvodna dela (v istem razmerju danes mešamo za beton, ki se uporablja na morju).