Can Styrodur 3035 CS used from a demolition be reused?

Why tick?

As said, expanding foam has nothing to do with that...

As I said, expanding foam has no place there at all...

This will also not be expanding foam that is used. However, the OP can relate to this terminology. Rhineland greetings

He does write that his site manager wants to use expanding foam...

And good that he knows - I asked you.

In structural analysis, it says "All strip foundations receive a ring reinforcement of 2ø10 at the top and bottom, laid unless otherwise designed higher." The client has already been told about the construction foam - and there are construction foam residues on the slabs, aren't there?

The contractor should confirm to you in writing that the structural engineer confirms in writing that the steel fiber concrete is equivalent to the specified ring reinforcement.

For the insulation, I would check (or have confirmed in writing) that the thermal conductivity group is the same. Or that the agreed performance is overall maintained (WLG times thickness). A substantial discount should be possible. Maybe for political/tactical reasons one should insist on "new". Otherwise, more might come from the demolition house, maybe the bathtub.

Building is somehow still an adventure.

Be sure to share the names of the involved companies here!

Good evening,

And nice that he knows - I asked you.

That must have escaped me; but I am not an insulation specialist either.

If I remember correctly, the subfloor insulation must be covered; this will sensibly be done at the height of the later base slab + insulation. I also seem to recall that the panels themselves probably have a tongue and groove. If glued, then probably only the joints and only spotwise. But what kind of adhesive that is, or what exactly it is called, I don't know. Normally, there are regulations for this in the DIN haumichtot, probably under waterproofing of structures. Also regarding the requirements for a foil below the insulation.

We will start the earthworks for a 55 construction project in 2 weeks. After that, my memories will be better, as they will be refreshed. We are currently not building that many 55 construction projects.

Rhenish greetings