[LeeWin]

I had a patio poured 2 weeks ago and I am getting a lot of the dust coming off it, is that calcium? I touch the patio and my hands are white with that dust. Will this go away or was it poured wrong?

[smearcase]

Here is some info from FAQ's on Portland Cement Concrete website:

"Why do concrete surfaces flake and spall?

Concrete surfaces can flake or spall for one or more of the following reasons:

In areas of the country that are subjected to freezing and thawing the concrete should be air-entrained to resist flaking and scaling of the surface. If air-entrained concrete is not used, there will be subsequent damage to the surface.
The water/cement ratio should be as low as possible to improve durability of the surface. Too much water in the mix will produce a weaker, less durable concrete that will contribute to early flaking and spalling of the surface.
The finishing operations should not begin until the water sheen on the surface is gone and excess bleed water on the surface has had a chance to evaporate. If this excess water is worked into the concrete because the finishing operations are begun too soon, the concrete on the surface will have too high a water content and will be weaker and less durable. "

[Twispinning]

I will assume that you used air entrained crete that was properly mixed and not painted over. A common misconception is that concrete is "hardened" or "solid" when it appears dry. This is not the case as concrete takes an average of 28 days to be fully "cured" (concrete "hardens" as it ages). What it sounds like is happening is that your crete is effervesing (or dusting) and is normal when calcium deposits caused by moisture moving in the concrete, rise to the top of the slab and appear as dust (during the hardening process). If the dusting continues after a month you will have a larger problem as described above.