SWpisces,
This is not repairable without removing and replacing the concrete deck.
Muriatic acid changes the absorption characteristics of the concrete. Sealing the concrete after an acid wash compounds the problem.
Acid washing concrete can be beneficial. It can be used to open the pores, so to speak, and allow trapped water to escape.
My advise to you would be to tell the PB to make it right. Replace it!
Good luck.

thanks for your reply!
we will be in negotiations with our PB...they are trying everything to make us happy at this point. But soooo frustrating!
Do most PB's use muriatic acid to wash the concrete before sealing? He kept saying something about getting the moisture out of the concrete--which correlates with what you mentioned golfgeek....
Not sure I would ever do that again on concrete if we ever replace it. You must have to be very careful with the proper dilution, etc.

Our PB just told me that same thing...we have to get our Artistic Pavers acid-washed and we're holding off on landscaping around the deck until it's done so we don't kill everything.
We're not sealing, though. It's not recommended.

We had a similar problem but on a smaller scale. When our plaster was acid washed, muriatic acid was spilled on our stained concrete deck. It wasn't washed off quickly and resulted in two large discolored spots. The decking crew tried to fix the spots but it only made it worse. The PB agreed to cut out that section at the expansion joints and repour. After the first repour and acid wash the new section was way too dark. We repoured a second time and it was significantly lighter than the rest of the deck. The third try was closer but still stood out to the point where the PB agreed it wasn't acceptable. While waiting for the fourth repour I decided I couldn't make it any worse so I started experimenting with ways to change the color. I bought the same powdered release that was used on the deck and mixed a pinky sized scoop into an old windex bottle full of acetone. The acetone cut through the deck sealer and slooowly began to darken the new section. It took a few days with me on my hands and knees spritzing the deck but I eventually got the color to match. Once I had it where I wanted it I put another coat of sealer on top. It's now held up for a year and you can't tell that it wasn't part of the original pour.

When the decking crew came back for the fourth pour I was just finishing up and they couldn't believe it was fixed. Since I bought the release and fixed the problem the PB through in a couple of extra valve actuators. The stress wasn't worth it but I at least felt like it was a fair trade monetarily.

A few things I learned along the way:

- It is possible to change the color of the deck but it takes a long time and a lot of work.
- It's virtually impossible to match a repour to existing concrete considering all of the variables.

Sorry for the long-winded post. Based on your pictures I don't know if this approach might work for you or not but know that it is possible to change the color.

As I think back on it I know the feeling you're experiencing and it isn't pleasant even a year later. I sincerely hope you get this resovled.

Here are a couple of before and after pics.

Appreciate your post hwade....your concrete looks great. We had colored concrete (not stained), so not too sure if your solution will work for ours? But I sure see the difference you made with your acetone and powder!
We'll see what the PB negotiates with us. Thank goodness we have the final payment to negotiate with.
I'm inclined to think we might have to live with this. Did have it faux painted over and sealed (spots in first pic) and it looks good. Don't want to have to do it all over though---and then it's only a temporary fix anyway.