On Monday, June 7, 2021 at 5:25:30 PM UTC-5, John B. wrote:

Or maybe the Hoover Dam? Constructed some 85 years ago and still
standing. Up to this time, the largest scale concrete project ever
completed.

Wasn't that Chinese Three Gorges Rivers Dam bigger than Hoover Dam? I think it was. Didn't they use concrete making it?
You wrote up to "this" time. Not up to "that" time.


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Cheers,

John B.