Assertion: roman concrete | /r/MadeOf | an aggregate of pumice
Facets:
value: during the roman empire
type: TEMPORAL
Source sentences:
text: During the Roman Empire, Roman concrete (or opus caementicium) was made from quicklime, pozzolana and an aggregate of pumice.
text: During the Roman Empire, Roman concrete (or opus caementicium) was made from quicklime, pozzolana and an aggregate of pumice.