Altitude is 230 m, we are standing on one of the high-rise buildings of Moscow-City.
This is a groundwork for interstation tunnels of two metro lines.
A service floor and an outrigger.
On the roof.
Mercury City Tower.
They use B90-class concrete for vertical constructions and B60-class concrete for horizontal constructions. Here's an example for you to understand how firm it is: the most solid kind of concrete used in underground construction is B30.