Auger Cast Pile Mix Design

[Geocontractor]

We are working on the project where the contractor is attempting to install the auger cast pile test pile and is struggling. Today, the mix seemed to pump fine, but the grout set up very fast and the rebar only went down 2/3 of the full length. Can anyone help me help him with a suggested mix design for 4,000 psi ready mix grout?

 

[GeoPaveTraffic]

You really need to work with the local ready mix supplier. I don't have the mix design any more, or I would gladly provide it; but on a project 8-9 years ago it was something like:

8 sack total mix with 40 to 50 percent fly ash
site added high range water reducer
sand, no stone

Modified flow cone rates were on the order of 30 seconds.

Have you checked with DFI for a local mix design?

Also, what kind of full lenght cage are you trying to install? How long is the pile? What type of soils and what are the groundwater conditions?

Full length cages can be very difficult to install in some ground conditions. I'll be happy to post more, once I have some additional info.

 

[civilperson]

Try a small aggregate concrete, (not grout), with a slump greater than 4". Grout requires very high percentages of cement to achieve strength compared to concrete. A six and a half sack mix with 3/8" maximum aggregate size and high range water reducers will achieve the specified strength and still have 70-90 minutes of time to pump and install rebar cage.