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Re: Air Entrainment in Concrete

[Subject Prev][Subject Next][Thread Prev][Thread Next] If you only have 1500 psi at 7 days,  you will almost certainly not get 4000 psi at 28 days.  It will probably be more like 2000 psi.

Even if this is acceptable for your design loading,  I would think you would want to have the ready-mix supplier certify that there will be no long term durability or other problems.  This would probably entail them getting this certification from the admixture supplier (who might not be willing to give it.)   

Potential problems are likely to be a function of the service environment (exposure to chemicals, moisture, salts, etc.)  as well as the mix design (other admixtures,  cementitious materials, etc.)

There was a project here in DC which ended up with an air meter reading of 20% (probably for the same reason as your project).  Since nobody was paying attention during the pour, they ended up jackhammering out the entire pour which was not pretty since there were post-tensioning tendons which continued from the previous pour.


Gail S. Kelley, P.E.