O.T. New concrete adhering to old

There is a liquid that is used. I used some on stucco repair and it
worked excellent. You could either apply it to the old work to be
covered and then stucco, or mix it in with the new stucco and then
stucco, or do both. Home Depot might have it but I got mine at the
ready mix company which also had mason supplies. I think they call it a
"bonding agent". Sam

We used to call it Moose Milk. It looked like white carpinters glue.
Wet the old concrete first, then paint the glue on. Add some glue to
the concrete mix (unless you are doing several yards worth), and pour
into the forms.
robo hippy

If you don't use the glue, then a little masonry cleaner (muriatic
acid) helps the bond. The bond may not be permanent because a crack is
already there, and rebar dowels will hold it there if it does crack (or
I should say when) again. It depends somewhat on the size of the patch.

robo hippy

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

Ardex?
Tamspatch?

I think they may be more for resurfacing, but they may have a product
for your application.

> >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
>

Prometheus wrote:
> 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.

code for attaching old concrete to new can in some instances call for
rebar pins epoxied into the old with the new poured around it. the
epoxy is purpose formulated and dispensed in a double-barrel caulking
gun which mixes in the nozzle. it's a bit of a pricey system, but it
works well. the advice to leave a jagged mating surface to the old
concrete wherever you can is good, even to the point of roughing up
smooth surfaces.

Thank You all for your quick and helpful suggestions

I appreciate it very much.

Fuddzy

The type I used is a latex adhesive. I got it at the same location that I
bought the bagged cement. IIRC you should wet down the old cement so that
it will not wick the moisture out of the new cement too quickly.


"Fuddzy" <[email protected]> wrote in message
news:[email protected]...
> 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
>
> Fud

I can't give you a recommendation on a specific brand name but when you go
to your building/masns supply store, the the product you want to ask for is
called a "bonding agent."

Lee

--
To e-mail, replace "bucketofspam" with "dleegordon"

On Sun, 31 Jul 2005 16:22:43 -0600, Fuddzy <[email protected]> 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.

On 2 Aug 2005 11:27:20 -0700, "bridger" <[email protected]> wrote:

>
>
>> >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
>>
>
>Prometheus wrote:
>> 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.
>
>code for attaching old concrete to new can in some instances call for
>rebar pins epoxied into the old with the new poured around it. the
>epoxy is purpose formulated and dispensed in a double-barrel caulking
>gun which mixes in the nozzle. it's a bit of a pricey system, but it
>works well. the advice to leave a jagged mating surface to the old
>concrete wherever you can is good, even to the point of roughing up
>smooth surfaces.

Even without the epoxy, rebar pins aren't too easy to get back out
once you've hammered them in, especially if you whack them really good
with a sledge after they're set in the hole (the end will mushroom a
little inside, and act like a masonry anchor) Can work in a pinch if
you don't have the double-barrelled gun.

On Sun, 31 Jul 2005 16:22:43 -0600, Fuddzy <[email protected]> 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
>
>Fud


I used to use a product called "Crete-Weld", with good results.

Don't know if they are still around.

It's been a while.



Tom Watson - WoodDorker
tjwatson1ATcomcastDOTnet (email)
http://home.comcast.net/~tjwatson1/ (website)