"Tim Killian" wrote in message
...
For the slab, consider having the plant add fiberglass or PP chop to the
mix. The chop acts like millions of pieces of tiny, distributed rebar,
and with a 4000 PSI (six-sack) mix and good curing, you can forget about
hairline cracks. The only downside is the finished surface is a bit
"hairy" -- but for a shop floor that's OK as it's less slippery.

All you need do is go over the surface with a propane weed burner and the
"hairy" stuff is gone instantly. I cast window sills from glass
reinforced colored concrete and did as I suggest. Works great and takes
almost no time.

Harold