Without  really being more precise, there's another way to use these concretes... By projection!
In fact these new "high-tech" concretes work best in thin layers. A projected layer of about 5mm and 1 cm in the angles of a room would give you a fairly decent ductile shell. You could then clad it with plaster (or whatever) as it would be a bit "hairy"...
Of course it works best for small rooms of 5m to 6m span. And it depends of how the original building was built !

This projection technique is used for example on existing posts when you want to add some levels to an existing building and that the foundations are good enough.
You spray this concrete as an outward layer of the existing post, boosting it to the desired section, while people are still working in the office, the works being behind plastic sheets...

In conclusion, there are numerous ways to achieve the re-furbishing of stressed buildings. The "meccano" one being the less obnoxious in use and time and quantities... So surely the cheapest!

Two millimeters is quite easily obtained in a prefabrication controlled process (pressure molds).
Some, today, are thinking of designing window frames with this concrete. They would be as thin as the steel one's but with no corrosion and with a thermal resistivity nearer to wood. And we could leave aluminum to planes and boats...!

"What can I do, What can I write, Against the fall of Night". A.E. Housman