Create slope towards drain with fine concrete at once or afterwards?

[Grillen]

Currently finalizing after replacing the sewage in the basement and wondering what would be best for the sewage area.

I have Weber fine concrete that I will use in the grooves I’ve opened up. But I'm a bit unsure about what would be easiest to do around the sewage and the slope there.
Should I create a boundary around it with, for instance, a bucket or something else circular and then create the slope afterward when the rest of the trenches are poured, or should I pour everything at once and arrange the slope at the same time as the casting?

And if so, how should I proceed then?

I have only filled in some trenches and holes before but never with a slope. So that's why I'm a bit unsure how to proceed.

 

[BosseHansson]

Hard to say, but if it needs to be sloped within the open area, I would have done it with concrete. Then I would probably have chosen coarse concrete instead of fine concrete. Make sure to mix it firmly so you can shape it, then there shouldn't be any problems.