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.

  • They are comparing roman concrete to portland cement, the most common formula. The kind of strength being emphasized is durability, because roman concrete has unique chemistry that allows small cracks to fill themselves. Modern special-purpose concrete blends can outperform roman concrete in other measures of strength, however.

    • Thats right. I remember the engineering dept. of my university would hold “concrete boat” competitions to highlight this point exactly. Concrete is a mixture, and different mistures are used for different purposes. Im not a civil engineer, but I wonder how well would roman concrete perform in 100+ floor buildings or expansive multi-floor complexes. Even if it performs “well”, is it cost effective? I doubt it will be better than a min-maxed mix determined by project/area/budget/etc