CFA cut off 1

[KenP10]

What depth of contaminated concrete on the top of a, say 450mm diam., 20m pile, could be anticipated in "poor" soil conditions?

 

[civilperson]

None if built correctly, the bottom has three inches of concrete contaminated by soil.

 

[InDepth]

What is the real question/concern? Are you suggesting that you chip the top of a CFA pile prior to pouring a pile cap?

 

[KenP10]

Yes. Often have to break-out poor quality concrete at top of pile, even beyond cut-off level. Want to know if there are any codes/standards which advise on acceptable depth of any such "wastage".

 

[pba]

I don't know of any codes, but we specify at least 1m above cut off level. We then require the contractor to submit proposals on how to remove that concrete safely. Currently hydraulic munchers seem to be used most often. There are proprietary techniques available to remove the concrete in one piece...