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Re: Effect of salt water on masonry walls

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As a guess, I would say that the flaking may be the result of something other than salt.  Salt in general should not have an effect on the concrete but could promote corrosion of the rebar inside.  However, if the rebar is a single layer in the center of grouted cells I would think you have plenty of cover to protect the rebar assuming no significant cracks.  A half inch of flaking seems like a lot.  You may want to scrape off some the flaking CMU or better yet drill a core sample and send it to a laboratory for a chemical analysis.  If you go this route I would pick a lab that has experience in testing concrete products and would include tests for chlorides (salts), sulfates, pH, and carbonation.  If the problem looks real bad you may go for a petrographic analysis which will include some of the above and would also provide some conclusions and possible causes.  If you go with a petrographic analysis you will need to be very specific what the problem looks like and what you want the test to determine.  A full blown petrographic analysis can be very expensive and most of it would not help you with your specific problem.

Thomas Hunt, S.E.
ABS Consulting

"Jesse D. Moore" <jdmse(--nospam--at)>

09/03/2002 12:02 PM
Please respond to seaint

        To:        "SEAINT" <seaint(--nospam--at)>
        Subject:        Effect of salt water on masonry walls

I'm working on a project with an 8" partially grouted cmu wall which was exposed to salt in some form or another (adjacent to some vats in a Culligan water softener building). Culligan has since moved out. Some wall flaking has occurred in places, ¼" – ½" thick or so. No evidence of exposed reinforcement. The wall ht is about 10' to the roof (one-story), few openings and no big-time loads. Should I be concerned with this damage, is it an ongoing process like rust, and where can I find some guidance for mitigation?
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Jesse D. Moore
Oceanside, CA