I'm doing a 30x60' pole building floor with a 48'x24' apron in front of building. Going with 6 bag 4000# mix, 4" thick with wire wielded mesh all, 2" foam under work area (30'x30'), 6" thick 2'x4' pads for 4 post lift in work area, re-rod ties every 2' between all slabs, saw cut expansion...