The concrete dome of the Pantheon in Rome remains stable enough for visitors to walk beneath, and some Roman harbours have underwater concrete elements that have not been repaired for two millennia – even though they are in regions often shaken by earthquakes.
Whence this remarkable resilience of Roman concrete architecture? It’s all down to the chemistry.
This article is about research on self healing properties of Roman concrete. It’s not all about a one on one comparison. The chemistry behind the self healing properties is interesting and not definitively established.