Here's another collage of balustrades. I asked a friend about them, and yes, they're made of poured concrete. Even though I've never seen this style of balustrade on a newly constructed building, my friend told me that balustrades like this are still made in Lebanon. I'd love to see the process.
Seeing how a balustrade is made would clear up a lot of things for me. For example, how do you get set concrete out of a mold? Do they make the mold to measure, or are the balconies designed around set sizes of balustrades? How do you decide which will be reinforced with rebar and which won't? Sometimes, you just have to see it to know.