Poured in ‘flats’.
If the dams had been poured in one shot, it would take several decades for it to cure.
Now, these days, chemical concrete can be poured and cure in days.
My understanding was that pipes were run through it to carry off the heat. It was in a course on engineering economics, not structures, so I won’t be adamant. The problem was how do you calculate how many spare truck to have on standby. I only have the most cursory adquantaince with the dam, but I do have the souvenier hard hat, and took the hard hat tour. Very cool.
From I have read in the past and now in a look-up, the concrete of Hoover dam is still curing.