Not too many that I know of have cement slab. We have been to Stand Rock Campground for the last 2 years. This place is now our favorite place in the Dells. 2 miles from Downtown Dells and 4 miles from Wisconsin Dells Parkway that has all the water parks.
The Jellystone has paved sites but it is pricey and the noise from the interstate is kind of on the loud side.
Best thing to do is get a Wisconsin Dells vacation guide or go to
wisdells.com and look at it on line. They will have a list of all the campgrounds in and around the Dells area.
If you have any specific questions just ask. We've been to quite a few campgrounds in the Dells. I know the place very well, almost like I live there!