I’ve built several 25 story and up post tension highrises
The cables or tendons are very different than bridge suspension cables and serve a different purpose.
The tendons in a post tension slab are there to reduce the amount of reinforcing steel necessary. They are pulled tight after the concrete in the slab has reached a specified strength, usually 75% of the 28 day design strength.
I’m thinking they were tensoning cables, not doing a “stress test” whatever the hell that is, because we never did them, or were required to.
If they were pulling cables that could mean the concrete slab was not even up to full strength.
Thanks for presenting an angle I didn’t think of: that the cables (whether all or some) weren’t tensioned AT ALL before the span was placed.
I’ve read a bit, and understand that the tendons are tensioned while the concrete is partially cured.
And, I could understand hypothetically that they might have been checking the cable tension, and/or possibly bringing it up to spec. Maybe an anchor pulled.
But, if they were tensioning the cables for the first time after placing the span, that strikes me as truly idiotic. Without tensioning before elevation, you’d essentially have a long concrete, weak, partially cured span with inadequate reinforcement and no tension. Who would authorize that?