One question, why do you construct concrete pads for the motorhome? Because of the fact that concrete tends to crack and break p after a while, I went a different route. I created a pad made of crushed limestone rock, and inserted treated 4 x 4 wood pads for the wheels of the motorhome. The limestone bed is about one foot deep and on each side three feet larger than the motorhome. I also installed a water, electrical and sewer connection at the pad.
The advantage of the crushed rock is very good water drainage and no cracks in the material. Once in a while I have to apply a spot treatment for some weeds that want to grow in the rock.
This approach was also way cheaper than a concrete pad, because I could do all the work by myself and with the help of my trustworthy John Deere tractor!