"Tony Polson" wrote in message
...
Douglas de Lacey wrote:

ahem a contemporary of mine did a PhD on how concrete sets: I believe
his results had an impact on the industry.


If you want to know how concrete sets, ask a civil engineer. It was
an essential part of my education and training over 30 years ago, and,
I expect, of all civil engineers'.

Heck, even the Romans knew how it worked!

Perhaps, my point was that we don't need to know HOW it works :-)

Mary