On Sun, 31 Jul 2005 16:22:43 -0600, Fuddzy wrote:

Hello.
Does anyone know the Brand Name of a "chemical" that would assist in
adhering of new concrete to old concrete.?

I am going to try and replace a broken part of a concrete wall by
jackhammering out the broken stuff and then build a form for the pouring
of new concrete.

Appreciate any help or suggestions

Several years ago I did something like that, and there is a liquid
adhesive in the same area as the concrete in the store. IIRC, I
replaced 1/2 the required water with the adhesive, per some advice
from an old guy who had done a lot of it in the past. Seemed to work
pretty well, and didn't cause any apparent problems with it setting,
but I didn't get much follow-up on it, because the house was sold
right after I finished the job.

But in your case, that may not be necessary at all- if you're
jackhammering the old stuff out, and there's a rough edge left behind,
that may be enough to hold the new "plug" in place. If you're really
worried about it, you could get a hammer drill, drill some holes all
around the perimeter of the hole, and sink some big lag bolts in so
that they protrude into the cavity, sort of like partial rebar.