Concrete floor question

[danetj862]

Hi, so my garage floor was poured one week ago, 1200 Sf, 5" thick, on top of taped VB, & 2" taped foam board. Calcium added to trucks for accelerator.

The crew came back two days later to cut the slab and apply super Diamond 350 cure & seal to slab. However the concrete was solid but still bleeding off so they cut it and left me to seal it when it dried.

It dried over the weekend by use of fans and now it is covered in the white efflorescence spots.

I told contractor about it but he's not too concerned said seal over it and it will go away. Is that true? Will the spots disappear or if sealed over will I have them forever?

Tried vinegar and that helped some but not enough to make me happy.

Let me know what you think. (Pic shows floor damp from me trying to clean it with just brush and water first.)

 

[MongoTA]

The addition of the calcium can contribute to the efflorescence.

I'd let the slab fully cure and dry, give it at least a month. With a VB under the slab, additional moisture migration from below, which can contribute to efflorescence, should be nil.

Sealing the slab prematurely can exacerbate things.

Once the slab has stabilized, then clean and treat as needed.

If staining, dark concrete will show any future efflorescence (if there is any) more than a light colored concrete.

 

[Armorpoxy]

Depending on where you are located and temps this time of year, curing could take well more than a month, we have seen 3-4 months for slabs to cure in cooler weather.

Acid etching may help to get rid of the effloressence, and per above staining and sealing would greatly help to mask it.

 

[danetj862]

Thanks for your help guys I decided to just apply the cure and seal product which certainly helped cover the blotchy-ness on the slab.

8 days now won't park any vehicles on til Monday. Overkill given the temps we've had this week but better safe than sorry

 

[akpolaris]

Thanks for your help guys I decided to just apply the cure and seal product which certainly helped cover the blotchy-ness on the slab.

8 days now won't park any vehicles on til Monday. Overkill given the temps we've had this week but better safe than sorry

I'm not sure that it will cure correctly if you seal it, but it's done

 

[danetj862]

I'm not sure that it will cure correctly if you seal it, but it's done

The product I used is literally meant for fresh concrete. It does not create a solid un-permeable seal on top. It allows vapor to breath out but not let new moisture back into the slab