USFREEDOM911
MAKE AMERICA GREAT AGAIN
This is what happens when there is no steel, like mesh or rebar, in the concrete, it will fracture and then begin to move. Concrete slabs are said to be able to last 500 years. There's usually a 'City Code' that mandates the 'First Floor' (the concrete slab) be a minimum of 18" ABOVE the crown of the road in front of the House so the rain water runs -----------> that way.
I don't even pour a 4" shed floor, without putting mesh, rebar, or both in it and not a single one has ever cracked or split.