3 Gorges as I understood it is actually a series of impoundments. Their size is such that it’s been noted semi-humorously before that it’s a precontructed strategic weapon for Taiwan.
I remember back during the construction days reports of contractors utilizing bamboo for concrete reinforcement. I’ve also noted articles and pics since that Asia in general is WAY tolerant of quantities of debris and crap in their concrete that we’d flip out about ( and among other things I inspect reinforced concrete).
I remember reading about some bridge or big highway overpass (can’t remember which) in China that fell apart the first time vehicles went over it. The concrete was mixed with crushed up styrofoam or something. People died.