Ah, it looked like timbers on my phone, but on a large screen it does look like precast. Definitely not unreinforced concrete though, and not poured in place.

Ah, it looked like timbers on my phone, but on a large screen it does look like precast. Definitely not unreinforced concrete though, and not poured in place. You can see how its made up of 6 individual beams https://i.imgur.com/Kt85XFR.jpg https://i.imgur.com/Kt85XFR.jpg