Typical concrete exposure type for freeze/thaw for outdoor concrete pad in Austin

[TXengineer-1]

I am designing a concrete pad for some electrical equipment outside. It is exposed to weather. Under peer review for my foundation design, it was mentioned that my concrete specification should have an F2 exposure category. I live in Houston and typical concrete design, we don't specific any freeze, thaw specification for concrete for outdoor use. Even if we have a few days of freezing weather once in a while in the winter time. Austin is further up North but still relatively warm. It may have some occasional freezing weather for a few days, but not sure if it will justify specifying F2 exposure for outdoor concrete. Concrete is not in contact with water. I just have the normal exposure to rain and what not. Or it can be exposed to a short duration of snow for a short period of time if temperature happens to drop. Just wanted to get some input from engineers who has work in the Austin area what the common practice is for outside exposed concrete in terms of any freeze thaw exposure categories that needs to be specified.

 

[structural-eng]

I have run into similar problems with freeze/thaw exposure categories in Texas, Louisiana and California. The way that the categories are described in ACI most exterior foundations could be considered F2. I'm in MN so we deal with F2 all the time but the last thing you want is to try to force a ready mix supplier to provide a mix with air if they're not used to doing it.

I have found the best approach to be to call the local special inspection/testing companies (Terracon, Braun Intertec, etc.) and ask them what is commonly done. I've had ready mix suppliers tell me that they never use air in their area only to have Terracon tell me that the ready-mix supplier is just being difficult and that it's done all the time.

 

[TXengineer-1]

I have run into similar problems with freeze/thaw exposure categories in Texas, Louisiana and California. The way that the categories are described in ACI most exterior foundations could be considered F2. I'm in MN so we deal with F2 all the time but the last thing you want is to try to force a ready mix supplier to provide a mix with air if they're not used to doing it.

I have found the best approach to be to call the local special inspection/testing companies (Terracon, Braun Intertec, etc.) and ask them what is commonly done. I've had ready mix suppliers tell me that they never use air in their area only to have Terracon tell me that the ready-mix supplier is just being difficult and that it's done all the time.

Hi Structural-eng,

Thanks for your input. I will need to check with any local vendor to see if air entrainment is available. Also may have to check with other third party to see if the answer is honest or the vendor is just being 'lazy' or difficult.