Yeah, one of the issues I’ve read about happening for concrete failures was that some construction crews are under enormous pressure to salvage concrete that had been mixed too early, or delayed in pouring, or whatever, and where the concrete pouring characteristics cause issues (or crews add unauthorized water or things to slow down curing and then alter the characteristics of the poured concrete without the engineers’ awareness).

It’s wildly counterintuitive to those of us who don’t work in the space.