Not once they are poured.

If already poured you can do thin polymer based topping layer. If they are not already poured it is critical to prepare the substrate properly with the correct material and adequate compaction. It will obviously cost more but I find a 6" slab with #4 bars at 24" on center each way makes for a solid slab. You will also want control joints that create somewhere around a 10'x10' grid. These joints are often cut while the concrete is green and provide a place for the concrete to crack down in the control joint which you don't see. Some people may use a 4" slab and welded wire mesh which can be fine in the right conditions but I usually try to over build slabs as I don't like cracks and there's no going back once it's poured - except for jack hammering it out and starting over! Also, more fluid/runny concrete is easier to pour but it's also weaker so use a quality contractor that knows how to place and finish the correct concrete mixture.