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.
Concrete does heat up. Sometimes it needs help. Calcium or chemical.