I was unable to help due to urgent hive-dicking obligations…
One must after all have a sense of priorities.
FYI I read somewhere recently (Vaclav Smil?) that if you add up all the human-made things ever made, concrete constitutes the heaviest category. And that modern concrete, cost-effective as it might be, is neither as strong nor as durable as the concrete of ancient Romans. They made it to last; we make it just good enough.
I dread to think how much water is in that concrete.
I hadn't really given the quality of concrete much thought TBH!
It will hopefully last a few decades at least then.