Air Entrainment

[Klunker1]

Hi All!
Something I've never had to do so a little lost on who is responsible. I'm specifying a concrete mis with 6% air entrainment but the batch plant is only offering a mix of 2% and won't provide an air entrainment add mix design. The concrete contractor says he won't add a the mix in the field without guidance and testing. I can get the testing done on site by a 3rd party inspector, but can I expect the inspector to give direction on how much admix to use? Would this fall back on me as the SEOR? Thanks in advance!

 

[jhnblgr]

Do a mix design and run trials with the batch plant. I think you have a communication issue since most ares require 6% air if exposure in the area requires it. You are leaving out information.

 

[cliff234]

Hi All!
Something I've never had to do so a little lost on who is responsible. I'm specifying a concrete mis with 6% air entrainment but the batch plant is only offering a mix of 2% and won't provide an air entrainment add mix design. The concrete contractor says he won't add a the mix in the field without guidance and testing. I can get the testing done on site by a 3rd party inspector, but can I expect the inspector to give direction on how much admix to use? Would this fall back on me as the SEOR? Thanks in advance!

It's interesting how the concrete supplier is "offering" 2% air. This is entrapped air that is probably naturally in the concrete. I never heard of a concrete supplier refusing to put an air entrainment admixture in the concrete when it was needed. Was a mix design submitted? I would discuss this with the GC or CM and have them force the concrete supplier to add the air. Are there any other in the concrete? If so, call the sales rep for those admixtures and have them discuss how much air to add to the mix. And then make sure the inspector tests for air

 

[dik]

Do you have frost issues? If not the added air will not help, except make the concrete a little more 'workable' on site. Normally concrete without air entrainment has about 2% air, just from mixing. If you need air, then find a different supplier.

 

[ANE91]

Contractor’s right to be wary. Plants tend to sell mixes that are tried and tested. Find a new plant.

 

[Once20036]

Ive seen this type of problem in the southern US.
In my opinion, the contractor either needs to find a new concrete provider, or you need to remove the air entrained requirement. I wouldn't want to be involved in teaching a contractor how to add their own air...