Efflorescence on concrete
Efflorescence on concrete
(OP)
I was recently sent to the task of evaluating several old structures (mostly concrete) and reporting on their conditions. In my inspection I noticed a lot of "efflorescence" deposits on beams and around cracks in walls. I always heard this to be a bad sign but after doing a little research before putting it in my report I'm not sure anymore.
PCA only had reference to salt deposits on concrete (http://www.cement.org/tech/faq_efflorescence.asp) and said it was of little structural significance. The only source I found that offered any structural concerns was wikipedia (http://en.wikipedia.org/wiki/Efflorescence). They noted primary efflorescence as likely salt deposits and secondary efflorescence as an "osteoporosis" of concrete weaking the structure.
Any ideas or suggestions?
PCA only had reference to salt deposits on concrete (http://www.cement.org/tech/faq_efflorescence.asp) and said it was of little structural significance. The only source I found that offered any structural concerns was wikipedia (http://en.wikipedia.org/wiki/Efflorescence). They noted primary efflorescence as likely salt deposits and secondary efflorescence as an "osteoporosis" of concrete weaking the structure.
Any ideas or suggestions?






RE: Efflorescence on concrete
Not that it is strictly a structural concern, but it can certainly turn into one.
RE: Efflorescence on concrete
The concern isn't so much the deposits but rather what that represents.
StrutcuralEIT is correct that rusting of reinforcing steel is a concern as well as chlorides inhabiting the concrete itself and breaking down the integrity of the concrete matrix.
FIrst job is always to find the source of water infiltration and stop it. Secondly, test the concrete for chloride contamination as this would result in continued degradation of the rebar.
ACI has a good concrete repair manual out that is very helpful. Here's a link to it:
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RE: Efflorescence on concrete
RE: Efflorescence on concrete
RE: Efflorescence on concrete
Obviously, as others have stated, the source of the moisture should be determined. If can be corrected and the volume appears intermittant or is minor, you could be seeing many years accumulation, which may not be a concern. Eliminating the source of the moisture, should stop the process.
You cannot eliminate the source of the salts since they are probably from the free lime that exists in all concrete until it getts tied up by carbonization, which takes moisture and long exposure to carbon dioxide.
RE: Efflorescence on concrete