Do you think it is possible to get remove of the gypsum found in the demolished building so that it can be reused as crushed aggregate or any other use?
I think it's hard to separate it from concrete .there is special factories for broken demolished concrete for used as aggregate in concrete . There for most demolished construction can be used in subgrade succesfully
This is fundamentally possible. But you need a good waste management on site and an appropriate disposal/treatment facility. I have seen a couple of examples in the praxis