Inventions & Discoveries · Building and engineering

Roman concrete

c. 150 BCE · 2nd century BCE · Also known as opus caementicium

Roman concrete, or opus caementicium, is a building material used in ancient Rome: a hydraulic-setting cement mixed with an aggregate, in widespread use from about 150 BCE. The Romans first used it in coastal underwater structures, probably in the harbours around Baiae before the end of the 2nd century BCE, and around 25 BCE Vitruvius recommended volcanic pozzolana for structural mortars. Its aggregates often included larger pieces than modern concrete, so it was laid rather than poured. The dome of the Pantheon, the world's largest and oldest unreinforced concrete dome, is built of it.

Roman concrete
Image: matankic, Original by Kleon3 · CC BY-SA 4.0 · Wikimedia Commons

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First known
c. 150 BCE
Where
Rome (first in the harbours near Baiae)
Credited to
Roman Republic

NoteSome scholars think it was developed a century earlier.

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See also

Cite this entry
APA
The Epoch Institute. (2026). Roman concrete. In The Epoch Institute Encyclopedia. https://the-epoch-institute.org/encyclopedia/roman-concrete
MLA
“Roman concrete.” The Epoch Institute Encyclopedia, The Epoch Institute, 2026, https://the-epoch-institute.org/encyclopedia/roman-concrete. Accessed .
Chicago
The Epoch Institute. “Roman concrete.” The Epoch Institute Encyclopedia. 2026. https://the-epoch-institute.org/encyclopedia/roman-concrete.
Harvard
The Epoch Institute (2026) ‘Roman concrete’, The Epoch Institute Encyclopedia. Available at: https://the-epoch-institute.org/encyclopedia/roman-concrete (Accessed: ).

Last reviewed October 2026Random entry ↻