Orange Concrete Efflorescence

[smaxemow]

Hello All,

Does anybody know why a concrete parking garage beam may be leaching orange efflorescence? I found that multiple of the main framing beams have an orange dust on them, and there are orange drip marks on the ground surface below.

I have a couple theories:

-The project is a LEED Certified project and the original designer may have specified an odd admixture that would be causing the problem.

-Contamination from the form work debonding chemical.

-Thanks for your help
Shane

 

[charliealphabravo]

From the color it could be from steel oxidation. Is that prescast or cast-in-place?

 

[SLTA]

I thought rust, too. Can you have a sample analyzed?

 

[smaxemow]

That's what I thought at first, however there are no pipes around to stain the beams and the coloring/pattern doesn't seem to match reinforcing leaching (to me anyway). It was a very fine dust almost.

Its just for a proposal at this point. I'm probably going to add in a line item for testing.

 

[charliealphabravo]

I wonder if there are steel fibers in the mix. Also if steel forms or form nails were used this might be a source for trace oxidation.

 

[TXStructural]

It looks like rust from steel forms. How old is the structure and in what kind of climate is it located?