Foundation Encasement

[IceVol]

I have an issue with an existing tower built in the 70's. The foundation has some severe spalling (don't know if thats a good word, but its what we call it around here...i.e. flaking deterioration of the concrete) likely due to poor air content in the mix. I have cored the foundations and discovered they strength is adequate, but I must do something to mitigate the weather deterioration. I have read about concrete foundation encasement. I am trying to find a spec or some general guidelines. Its a concrete footing that gets wider as you go deeper so more embedment means a wider diameter form around the foundation. I'm trying to reduce the size of the encasement as much as possible so I'd rather not go very deep. How deep below grade do I need to go? Please direct me to some references I am at a loss as to where to look.
Forgive me if this belongs in another forum.

 

[Cloudancer]

If what you are talking about is strictly above ground and you are simply worried about the appearance then build a simple form around the exposed area and pour a cap. You can drill the existing concrete and insert rebar pegs to help the cap adhere to the existing concrete.

If there is a problem with the actual foundation below grade where the actual foundation load is occuring then you have a different problem. If this problem extends to areas that are not effected by weather, i.e. below grade the entire mix is suspect.

 

[towerengr]

http://www.balvac.com/project_profiles.asp

I have performed repairs using the above company/product. I would recommend giving them a call. A microwave tower with poor air entrained concrete foundations (vintage -1960) in Niagara Falls, NY was repaired with this method. Of course, the company was only 10 miles from the job site. So, this may not be a cost effective suggestion. I agree with the post above, if you want to go with simple methods.