Is this normal for concrete?

[Steppenwolfe]

It's soluble salts leaching out of the concrete, called efflorescence. On outdoor slabs, this will get washed off by rain or wetting. You should clean it off with water, and ventilate the building well until cured. It can cause a little bit of roughness in the surface if allowed to remain. It's common in indoor slabs, and even outdoor ones where excess humidity is present.

:thumbsup: Absolutely correct ...