I want to pour a concrete pad between two small outbuildings so i can park my tractor, and have a place to work out of the dirt on my property. The outbuildings have concrete footings and stem walls and are around 18 feet apart. The pad will 4 inches thick and 20 feet long and fit between the stem walls, wire mesh reinforced. My Small Tractor is about 3500 Pounds dry. NOW THE QUESTIONS. 1.Do I need any type of expansion joint at the building walls, if so how thick, what material, and wont concrete shrink a little over the curing time. 2. I want a ramp like transition such as you would have where your drive way reaches the road across a sidewalk. Should the pad be thicker at this edge?, it will transition to gravel.