How long to dry out wet concrete sub floor?

[JP_]

I had a leaking waste pipe that has been fixed for over week. The concrete below and around it (in the hole) still seems a bit discoloured, although much drier to touch. I have left a small fan blowing the area for a few days to try to speed up evaporation. The plumber that fixed the waste pipe was surprised how wet it seemed and suggested water might be rising up or getting in through the wall and finding the lower point. I am hoping it just needs more drying time.

Some pics:

The air brick is new, and the blown pebble dash has only recently (1-2 weeks) been removed.

Drain looks OK, cannot see how water would be getting in, so hoping it is just a case that the concrete was really saturated and it is taking time to dry out completely.

How long do I leave it before investigating further? Plumber suggested the concrete outside where the manhole is needs to come out too - I removed the rest of the path a few months ago.

this was a on 4th July, so it has certainly dried a bit

 

[sircerebus666]

You might find that the concrete has-been stained by the waste water so it looks wet when it's not
Have you wrapped kitchen towel around and flushed the toilet , ran water to see if the paper gets wet?

 

[JP_]

Yeah, the pipe is def. dry. Put plastic sheet under it with kitchen towel for 24 hours after it was sealed, all dry.

It is looking a bit lighter on the side under the fan, so maybe starting to dry out.