Statics for the reuse of an existing floor slab

Good day,

first of all: I know that no one in the forum can assess a static calculation – and I do not want that either. I am interested in a general approach for my case.

Initial situation: "solid" concrete floor slab 10x10m from 1980 present, currently built on with a simple shed in post-and-beam construction; documents are currently not available; request for the building file is not yet completed;

Project: residential building on existing floor slab in the form of a small, simple bungalow.

Question: How can an existing floor slab be assessed to determine if it is load-bearing without any documents available? How does something like this work? How expensive is such a building survey – or is demolition and re-pouring cheaper anyway? Or is it fundamentally technically possible to "overcast" the existing slab with concrete and thus reinforce it?

As I said, I am not looking to get a statement for my construction project, but rather to get possible solution ideas in general. For the final assessment, a structural engineer has to be involved anyway – I would just like to know beforehand if it is an (economically) hopeless endeavor anyway.

Thank you very much in advance for your constructive contributions!

thanatos

Initial situation: "solid" concreted floor slab 10x10m from 1980 present,

Documents are currently not available;

Well; that's the crux of the matter. Without the planning documents no one knows how thick the slab is; whether there are strip foundations; what amount/thickness of reinforcing steel was used.

If you have a lot of time to read - there was already a thread here from someone who absolutely wanted to continue building on a slab: - in this case, however, it was already planned for a residential building (whose plans he did not want to continue using).

Well; that's where the problem lies. Without the planning documents, no one knows how thick the slab is; whether there are strip foundations; what amount/thickness of reinforcement steel was used.

...and that's exactly why I asked my question. It was about whether something like that can be determined economically - or if it is easier to just tear everything down. Or whether one can simply pour concrete over it, because it should be at least as stable as compacted gravel. In that respect, the statement was only of limited help to me...

You can extract bore cores and test their strength in the laboratory. However, I only know this in connection with the presence of planning documents (but an actual proof has to be provided due to limit values).

Just call 1-2 civil engineers/structural engineers in your area. And put pressure on the authority because of the building file.

because it should be at least as solid as compacted gravel.

No; that is a bold assumption if the substructure is not known.

It will probably come down to demolition. Breaking on site and reinstallation can save costs.

...It was about whether something like that can be determined economically sensibly...

Supply and drainage pipes would have to be installed in the existing floor slab, which would severely limit the planning flexibility here and there.

For demolition and removal, you can estimate one day and two to three people (one truck driver and a maximum of two machine operators).
If there are no building materials to be separated, it should not be that expensive.