Aluminum Corrosion

[bentwoodbox]

I have been told never to embed aluminum in concrete but I havent been able to back this up in writing. Does anybody have any input or maybe know where I could find some info on this?

 

[swall]

Aluminum is resistant to many corrosive media but alkaline media are a problem. Fresh concrete (and lime) are alkaline.

 

[bentwoodbox]

So, is it only corrosive when the concrete is green?

 

[swall]

From "Corrosion and Corrosion Control" by Uhlig: "...aluminum surfaces in contact with wet concrete my evolve hydrogen visibly". "The corrosion rate is reduced when the cement sets, but continues if the concrete is kept moist..."

 

[bentwoodbox]

where did you find that info?

 

[bentwoodbox]

I found that book... Its expensive.. I'm going to the library.

 

[strider6]

try this source.. probably the best on Aluminum on the net..


aluSELECT is a computer-based reference database containing technical information on the most widely used aluminium alloys. This freely accessible web-site allows the user to obtain information about the mechanical, physical and chemical properties of aluminium alloys. At present, 35 wrought alloys and 12 casting alloys are indexed.

http://aluminium.matter.org.uk/aluselect/default.asp

hope this help u

S

Corrosion Protection & Corrosion Control

 

[bentwoodbox]

Thanks Strider.... I will check it out. This is the first time I have used this forum and it has been pretty helpful. Thanks again....B.

 

[saberblue]

In general aluminum is very pH sensitive once you get below 6 or orver 8 you need some sort of active corrosion protection in play

 

[bentwoodbox]

What is the pH of rain? How do I test?

 

[saberblue]

You can get pH paper at any lab supply or a good pharmacy but the issue will be not the pH of the rain water but rather the pH of the concrete when it is wet --- I am a long way from being an expert on concrete but my experience is that it can be very basic.

 

[LittleWheels]

Concrete is quite alkaline unless carbonation has occurred, usually taking many decades (assuming decent quality and strength).

 

[bentwoodbox]

Thanks for all the info everybody...