Aluminum in concrete?

[SpikeMorgan]

I am looking for alternative uses for an aluminum alloy metal that is particularly difficult to recycle using normal methods. I understand that there is a certain percentage of Alumina utilized in some concrete mixtures. Would it be feasible to substitute Aluminum solids for the Alumina?

 

[hokie66]

No, aluminum metal in concrete is a definite no-no! The aluminum damages the concrete. All codes prohibit it.

 

[dik]

Concrete reacts with aluminum, 'dissolving' it and causes the concrete to 'swell'. About 40 years ago, I used aluminum foil for a conductor to determine the crack propagation of concrete beams due to torsion for my thesis... There was no continuity for the first samples... that's when I learned that tin foil was not a good material...

Dik

 

[concretemasonry]

Aluminum is used in the manufacture of Autoclaved Aerated Concrete (AAC).

It helps to increase the volume by a significant amount (normal concrete at 145 pcf and 40 to 65 pcf for AAC). This aluminum is in a different form (podered). The scrap aluminum is much larger, but the chemistry is the same.

Dick

 

[reddog99o]

The advice given about aluminum being a no-no in concrete is precise. If you want to see aluminum corroded, check out some that has been embedded directly in concrete for a while. That is why most handrails and like embeds are usually sleeved through the concrete and set in a non-reactive epoxy or equal.

R.A. Hassett, P.E.

 

[NerdSE]

In college one of us had the bright idea to reinforce our concrete canoe with aluminum mesh. Want to see a fast reaction just add water! Our canoe turned to mush before we could finish racing it.

 

[concretemasonry]

NerdSE -

Your professor actually allowed you to use aluminum in the canoe competition?

The last guidelines I saw pointed out the problems with reinforcement other than "normal" steel.

I bet is was a real learning experience!! Were you actually able to get it to the water? Many of the steel reinforced canoes never get to the water because of the weight distribution and strength out of the water even though they have the strength in the water.

I never had the chance to do the competition, but sounded like good fun. All we ever did was put rebars and sugar into cylinders during the lab.

Dick