How to solve sweating slab syndrome?
Moisture, (and more precisely “condensation”) is the cause of sweating slab syndrome. 

There are several causes: 1) lack of ventilation, 2) rapid change in Dew Point, 3) negative air pressure in living unit, 4) concrete slab sealed, 

1) Air movement will “dry” moisture. 

2) This is what I call, “The coke bottle effect.” If you take a coke bottle out of the refrigerator, it will immediately have condensation form on it. In your case, if your room is at 70 degrees with 50% relative humidity and a warm front moves in at 80 degrees and 80% relative humidity, then the Dew Point will change and NON-ABSORBENT surfaces will swear. 

3) We design most buildings to have “positive” air pressure. If you have a negative air pressure, you’ll allow damp air into your environment which you’ll need to treat. 

4) If your slab has been sealed, there’s no place for moisture to go, except lay on top of the slab. 

You’ll need to experiment with fixing these items to correct sweating slab syndrome.