Create sidewalk and parking lot from concrete

It does not matter at the parking lot. There is only ground underneath, i.e. I can excavate deeply here. Only at the sidewalk do I have a maximum of 7 cm. Alternatively, 2 cm porcelain stoneware tiles for the sidewalk and the parking lot. So basically the substructure made of 5 cm concrete and then the tiles laid in there. However, this does not quite achieve the desired effect. The option of concreting the tiles / area came up for cost reasons.

Hello abc

7 cm of concrete is quite decent.
Definitely put reinforcement in. Nicely in the middle. Then there is 3 cm coverage.
Possibly coat the basement ceiling with thick layer bitumen, put a foil over it, and then pour the concrete. Everything that does not have a basement ceiling underneath should be excavated deeper.
For the parking lot, use 15 cm of concrete.
You won't manage WU concrete yourself. Make a strong mix 1:3. Always mix the same way. Don’t be sloppy. Then it will work.
Smoothing is always the problem for me.

Steven

That is also my consideration whether it will work at all without WU concrete. I could pick up the WU concrete from the concrete plant with a trailer. That way I would save the minimum quantity surcharge on the delivery.

In any case, I would still have treated the basement ceiling with thick-layer bitumen to be on the safe side.

I am very undecided because the opinions here really differ between doable and will hold or better leave it alone.

Hello abc

why WU concrete? You won’t have any pressing water so close under the surface. Make a horizontal barrier under the concrete, the water from above will run off.

Steven

okay, sounds plausible.

Does the concrete then still need to be treated in any way on the surface? What about efflorescence? You often read about efflorescence occurring with concrete pavers that are available for purchase. Does that happen here as well?

Hello abc

I don't think there will be any "efflorescence." With pure concrete, where would it come from? And even if it does, take a broom and sweep the stuff away. Efflorescence is to be expected with clinker bricks. If you have smoothed the surface of the concrete nicely, sprinkle some cement on it and rub it in with a trowel. Not too much cement, like when you pepper a piece of meat well. Then the surface will become crystal hard.

Steven