Aluminum embedded into concrete

[UFeng]

Hello all,

I am looking for a material to use for embedding an aluminum post into a concrete slab. The rectangular post does not have a base plate.

Does anyone here have any experience with: Kwixset Exterior Cement

I would prefer to use a known working material (epoxy resin) and a warrantied product from a reliable manufacturer i.e. an oven dried silica mix w/ Sikadur 32 hi-mod, however properties of Kwixset have sparked my interests in the product.

Any information regarding the matter will be helpful- Thank you

 

[JedClampett]

Whatever you use, make sure you coat the aluminum with an isolating coating (bitumastic?) or it will spall off the concrete.

 

[dik]

and the high alkali concrete will dissolve the aluminum. Not really a good idea if you can avoid it. As Jeb mentions, you have to isolate it. For my thesis, I was interested in determining crack propagation through concrete beams in torsion (50 years back and only the Russian research had any significant progress). First kick at the cat, I used aluminum foil, because it broke easy with almost no elongation... It was a really dumb idea.

Dik

 

[Ron]

yes...as JC noted, isolate the aluminum from the cementitious material. Coat with Bitumastic (preferred) or at the least, clear acrylic. I've done hundreds of embedded aluminum structures...all were isolated...all still performing...some are over 30 years old.

 

[UFeng]

Wow, you guys are great. I appreciate the quick feedback! Yes the aluminum corrosion is my main concern. I will make sure to isolate regardless of anchoring material used. Any strong personal preferences between the two anchoring materials- fast setting kwixset or warrantied sikadur32?

Hopefully I will be able to contribute at least a fraction of the amount I am learning here. Thanks again!

 

[JedClampett]

I don't think the Sika material is really appropriate for this use. Sikadur 32 is more of just an adhesive, used for crack injection. I have no doubt it will work, but I bet if you call them, they'll have something better. For instance, SikaGrout 212 is a non-shrink grout that might work nicely. The Kwikset material will likely work too, but it's a more low tech material.
Basically, this is really not that demanding of an installation. If you can fill the hole, and not have it totally shrink away (kind of hard dimensionally), it will lock the post in there.

 

[bimr]

A clear methacrylate coating properly applied will protect the aluminum and need not be removed. The addition of chlorides can aggravate galvanic corrosion of aluminum in concrete. Galvanic corrosion can be prevented if aluminum is not allowed to contact other metals such as steel reinforcing rods. Coating the aluminum with an asphalt or bituminous paint are also another possible prevention method.

Link

https://www.eng-tips.com/viewthread.cfm?qid=146335

SikaGrout 428 FS is a non-shrink, non-metallic, cementitious precision grout.

Grout

Sikadur 32 Hi-Mod can also be used to insulate potential areas of contact by coating aluminum.

Aluminum Coating

 

[Ron]

UFeng...Sikadur 32 Hi-Mod is overkill. It is expensive as well.

Any good quality non-shrink grout should be fine.

Go Gators!