What is overlay concrete?

[PontusWi]

Hi! As the title suggests: what is överbetong? How does it differ from concrete? I've come across this term but can't find a definition.

 

[petterovski]

I would guess that it is an overlay/pouring of some kind. For example, that a slab has been poured, then some type of filling has been added, and finished with a layer of "överbetong". But that is a guess.

 

[PontusWi]

Here is how it looks in my textbook, a cast-in-place slab. Since there is nothing between the concrete types, I don't understand why it's not all cast in one go. Is it perhaps 'finer' concrete in the top layer?

 

[petterovski]

Yes, in the case of cast-in-place, it's a bit strange not to pour the entire thickness at once.

But isn't it possible that it's been added during a renovation to improve the acoustic properties?

 

[kungfuu]

Sometimes there is a layer of insulation between the castings, but not in the textbook.

There can be several reasons:
- You write in situ casting, otherwise, there may be prefabricated elements at the bottom
- Floors with slope are sometimes done as a separate casting
- A more durable wear layer is desired compared to the overall structural requirement (it can still be done simultaneously, but anyway)
- It's mentioned about sound and fire class, it can be added concrete for enhanced performance or the "top layer" lies as a floating floor