New Concrete over Old - Bonding Additive?

[Daffy D]

I want to patch up some old concrete and also increase a slab size by pouring new concrete over the old slab.

Googling came up with:- If you are using regular concrete, add a concrete bonding additive to help the old and new concrete join.

Sounds simple enough.

So is this bonding additive available here and what does it look like? Is it a powder or a liquid, in a bag or in a bottle? Who would have it?

Thank'yall

[Naam]

you have to drill holes in the existing concrete and attach steel rods (a special adhesive for this purpose is available). anything else will not work because you want to increase slab size.

[Goompa]

Really depends on the amount of overlay you require to finish the work intended , there are a few alternatives for this , depends if you are going straight on top or going out to the sides as well

[Daffy D]

you have to drill holes in the existing concrete and attach steel rods (a special adhesive for this purpose is available). anything else will not work because you want to increase slab size.

What is it called ?

The new slab is going to be bigger than the existing old one by a couple of feet. The new concrete over the old will be about 3in and I've dug down about 6in where the overlap will be

.

I intend to clean up the surface of the old concrete with an angle grinder and drill holes to hammer in 6in nails and attach rebar mesh over the area.

With the price of timber I'm planning to cover the shuttering boards with plastic so they can be used for another job.

I think that just about covers it. I was just wondering about the advantages of concrete bonding additive

[Ace of Pop]

you have to drill holes in the existing concrete and attach steel rods (a special adhesive for this purpose is available). anything else will not work because you want to increase slab size.

What is it called ?

The new slab is going to be bigger than the existing old one by a couple of feet. The new concrete over the old will be about 3in and I've dug down about 6in where the overlap will be

.

I intend to clean up the surface of the old concrete with an angle grinder and drill holes to hammer in 6in nails and attach rebar mesh over the area.

With the price of timber I'm planning to cover the shuttering boards with plastic so they can be used for another job.

I think that just about covers it. I was just wondering about the advantages of concrete bonding additive

GLUE.

[harrry]

Try searching for concrete bonding agent.....it may work better than additive.

[Goompa]

There is a product I have used in Aus for this called Bondcrete not sure can get this in LOS , I frequently use a product from Dulux called Acrabond , I use this in the application of render finish and it does provide some waterproofing capabilities as well , Maybe a good idea is to etch the surface prior with a hydrochloric solution to achieve a clinical clean environment as well.

[IMHO]

you have to drill holes in the existing concrete and attach steel rods (a special adhesive for this purpose is available). anything else will not work because you want to increase slab size.

What is it called ?

The new slab is going to be bigger than the existing old one by a couple of feet. The new concrete over the old will be about 3in and I've dug down about 6in where the overlap will be

.

I intend to clean up the surface of the old concrete with an angle grinder and drill holes to hammer in 6in nails and attach rebar mesh over the area.

With the price of timber I'm planning to cover the shuttering boards with plastic so they can be used for another job.

I think that just about covers it. I was just wondering about the advantages of concrete bonding additive

What Naam said - what you need to ask for to secure the metal bars in the old cement is "Resin" (said with a Thai accent - it's a loanword).

Edited August 27, 2013 by IMHO

[luudee]

Daffy,

I think this is what you are looking for:

luudee

[Daffy D]

That looks about the right stuff

Cheeres Luudee