pressured water wash also ok.

acid is no no on such floor.

those ceiling stuffs are just powder isnt it?

Your pic you provided not really clear either it's pebble/- aggregate concrete floor or coated concrete floor.
Acid is pretty strong & might damage it.

I believe your contractor who did the ceiling work isn't using those industrial paint for wood or steel, so it's ok. Dont need acid, as it's possible to be wash away with metal scrubs or pressure water washer.

This post has been edited by KVReninem: May 7 2011, 02:23 PM

do you still have your developer contractor & warranty?

I suggest you not to caused more damage to the floor. & since you are the one going to live in it; the next time you know you will invite more work which you dont prefer to do.

ATM,
1. try get your developer contractor to tell you the material they used for it.Material which they sourced the pebble floor from.
2. then google up the material company supplier.
3. then figure out the solution.

Putting more damage on it just gonna make your life harder. Sooner or later also you will hack it out cos its too ugly of the stains.