One thing is that China’s quality control absolutely sucks. Not just the junk they export, but internally. I remember reading a few years ago about some large bridge that was opened with great fanfare. As soon as the first batch of vehicles started crossing, it collapse.
The contractor had mixed a bunch of ground up styrofoam in with the cement to save money.
China is also massively corrupt with each layer of beaurocracy/government people ripping off and cheating their downlines, from top to the lowest provincial guy. It’s a society based on cheating and ripoffs.
We use lightweight foamed aggregate concrete for structures like that here. I wonder if there was something lost in translation? 🤣