Repairing concrete walls

[MatBirch]

I don’t have cracks, but large sections that need to be patched, leveled and skim coated. It’s an exterior foundation wall. As you can see, I’ve removed all the loose, spalling concrete. Still need to wire brush it and vacuum it, but I’m looking for the best product to resurface it with. Bonding agents? Sealers? Etc.
the foundation was done in 1905, so it’s given pretty good life! I realize that the likely cause is moisture migration. The primary areas are the first 18” or so below grade on the outside. I’ve repaired a leaking exterior faucet on this wall and added gutters that it never had. Climate here is high desert, so continual moisture shouldn’t be an issue, but I know any kind of coating on concrete is susceptible to being “pushed off” by moisture within the wall.

 

[ConCretin]

You seem to have a good handle of the situation. If the remaining concrete is sound and moisture is under control, you have a reasonable chance of a successful repair. There are any number of good repair mortars you might use but I'll suggest Silpro TDQ. It's strong, quick setting, easy to work with and unlike many products, it's able to handle thick sections right down to a feather edge. It comes in bags and you just mix it with water.

I'm also going to suggest Armitec 110 bonding agent. It's a 3 part product that's a little pricey but unlike epoxy products, It has a long working time and won't harden up on you too soon. Unlike weldcrete and similar products, Armitec won't re-emulsify if water shows back up. As a bonus, if there happens to be any steel present, the Armitec will encapsulate any rust. We've used it extensively on deteriorated bridge decks with great results.

As always, proper prep is just as important as the product selection. Good luck!

 

[Skinny_Blinky]

You seem to have a good handle of the situation. If the remaining concrete is sound and moisture is under control, you have a reasonable chance of a successful repair. There are any number of good repair mortars you might use but I'll suggest Silpro TDQ. It's strong, quick setting, easy to work with and unlike many products, it's able to handle thick sections right down to a feather edge. It comes in bags and you just mix it with water.

I'm also going to suggest Armitec 110 bonding agent. It's a 3 part product that's a little pricey but unlike epoxy products, It has a long working time and won't harden up on you too soon. Unlike weldcrete and similar products, Armitec won't re-emulsify if water shows back up. As a bonus, if there happens to be any steel present, the Armitec will encapsulate any rust. We've used it extensively on deteriorated bridge decks with great results.

As always, proper prep is just as important as the product selection. Good luck!

Is the Armatec product a primer type product to be used before adding primary repair material or is it a primary stand-alone product?

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[egdede]

https://can.sika.com/content/dam/dms/ca01/9/SikaTopArmatec110EpoCem_pds.pdf

 

[ConCretin]

Is the Armatec product a primer type product to be used before adding primary repair material or is it a primary stand-alone product?

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It's a primer. It increases the bond of the repair mortar to the existing substrate. It's not absolutely necessary to use a bonding agent and to be honest, it will add significantly to the cost and complexity of the repair. The TDQ is pretty good stuff. Might be worth trying it by itself product first.

I don't recall if TDQ is one of them but many repair mortars allow for a scrub coat. You mix up a wet batch and scrub in into the substrate before applying a thicker patch right after. The surface is usually pre wet with water until it's saturated before applying the scrub coat. Maybe egdede can help us out with some more literature.

 

[Daniel Dudley]

This stuff soaks into porous concrete and rehardens and strengthens it. That is more important than cosmetic repairs in my eyes. You can always throw some tapcons in there as pins and patch it, but I think you need to try to stabilize what is left.

Go to the link and read the description. https://www.radonseal.com/product/110.html

 

[stillnostrebor]

As a fellow concrete contractor that is late to the party, I support the advice given above!

 

[Skinny_Blinky]

Thank you all for the information.