[HayZee518]

In general for a driveway or garage use a metal mesh screen - 6 inch square with 3/16" or 1/4" wire. The slab can be a mere 4 inches thick. Once the pour is in, use a vibrator to settle the aggragate and a hook to embed the screen about half way. just reach in with the hook and pull up on the screen about half way and un hook from it. go to another area and do it again. for the four inch slab, you really don't need a vibrator just whack the concrete with a 24 inch wood float. a slab like for a roadway is about a foot or a foot and a half thick with 1/2" rebar - go to your web browser and type in concrete slump.