Self-leveling concrete application - GIF

[BuffaloJohn]

maybe water with a little cement dust in it but Concrete? How would the slump of that mixture even be rated?

Sure, it may flow and look like glass for now when he is done, but as it dries will there be bubbles from out gassing?

We have this in our house (we have hydronic heating - long runs of PEX pipe in the floor with a concrete top). The concrete is batch mixed on site, sand and not gravel. It is pumped into the house. It is called self leveling concrete.

I found one picture that showed the pour:


You can see how runny it is. It dries very smooth, no bubbles, not a hot mix from what I understand, but I don't know much more about it.