Alkali Testing for Concrete Aggregates

[gsroy2]

I work on a government contract with the FAA and the DoD. We are currently installing a radar facility in Pensacola Florida. We specify that all aggregate be tested for Alkali reactivity per ASTM C227. Our contractor is claiming that if he uses a Type I cement, that he would not have to "worry" about this testing. Has anyone run into this? Is there any circumstance where this testing would be a waste of time?

 

[JedClampett]

It's a waste of time when the area your construction is being done has no history of reactive aggregates. However, you can find reactive aggregates in almost all regions of the country.
We do work nationwide and get this comment occasionally. We're inclined to trust local suppliers until they burn us. However, I don't think type I cement has anything to do with it. Low alkali (<.6%) cement helps. Fly ash helps.

 

[gsroy2]

Thanks a lot for the comments. My conclusion is also that the Type of cement used makes no difference. I appreciate the comments.

 

[dicksewerrat]

Tell the contractor tp provide the test results. Or no concrete work will be paid for. He read the spec. and still bid the project.

 

[Ron]

gsroy2...make the contractor supply the results. I routinely ask for the information and I practice primarily in Florida. We have some reactive aggregates in Florida, though they are less likely to be used in that area of the state.

He should be able to get the info readily from his supplier.

 

[Ron]

gsroy2...make the contractor supply the results. I routinely ask for the information and I practice primarily in Florida. We have some reactive aggregates in Florida, though they are less likely to be used in that area of the state.

He should be able to get the info readily from his supplier.

The type of cement has little to do with the reactivity problem, except that the alkali content in other types can be a bit lower. Type I will cause as much problem as any other type, moreso in some cases. Yes, fly ash helps.