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.

  • hallettj@beehaw.orgEnglish
    25·
    1 year ago

    I remember finding this Practical Engineering video on Roman concrete to be informative: https://youtu.be/qL0BB2PRY7k?si=5exDGyEK_LTfGNOy

    Veritasium also has a chapter on ancient concrete in this video: https://youtu.be/rWVAzS5duAs?si=EJ8rPDTPHlq90kgW

    My memory is fuzzy, but I think some of the details are:

    • We know how to make Roman concrete, but it’s not necessarily the best choice, and it might be more expensive than is appropriate for a given project.
    • Ancient structures don’t have rebar, so they don’t degrade due to rust causing expansion. But rebar is so useful that it’s often a worthwhile trade-off.

    Definitely see the other comments here about survivorship bias, and higher demands on modern structures.