Any of you guys out there ever pump the stuff.  Had a request today.  If so, what kind of mix designs and or slumps have you had the best success with?  Minimum hose diameters?  Any advice would be greatly appreciated.  I'd imagine some kind of pumping aid like Slick Pacs would be needed.

what s that ?

Control Density Fill.  I've heard it called flowable fill as well.  Usually about a 2 sack mix with sand, no rock.  Its used to cover utiliies that may need to be accessed later as it packs very hard but is still removable with a machine.  At least thats the reason behind the few times I have delivered it in a mixer, but I've never had anyone ask me to pump it before.

Pump it Sloppy sloppy wet 

10"+ slump with 4 in hose is how we always pumped it

Thanks.  Sloppy wet seems to be the consensus I'm getting.  I'll be pushing through 3" but sounds like it's not going to be to big a deal.  I'm going to add some air to the mix to help with lubrication.  With that and a soupy slump, I'm feeling fairly confident.

Don't sit long without moving it. The sand will settle and you will dry pack the whole system. When I have pumped it and need to wait for a truck, I move it more regularly than concrete.

I backfilled around a Nuclear Processing building with about 50,000 yards of that stuff. Pumps great but can make for some nasty washouts after a long day of pumping it. As they said keep it moving

Wear a raincoat.

I highly recommend 3 to 4 hundred pounds of fly ash per yard with good fines for sand two sacks per yard is more than enough and you should be able to pump it through 2 1/2 inch hose at a six inch slump easily we do it all the time here in seattle

Agree with Chris and funnyboom! Just like with any grout it seems to build up in your hopper... And with any sand mix if it sits and settles then you push it again it will pack.. That happened to me and another guy doing flowable together and it's pretty messy when you gotta break it open

OK.  Soupy slump, stay moving, watch the hopper buildup, stay moving.  I figured it probably wont sit to long with water replacing the cement as lubricant.  Unfortunately fly ash is not an option.  I'm actually the redi-mix producer as well as the pump operator and fly ash is not something I carry unless ordered special.  That being said, theres no way this guy will pay and wait for it to be delivered.  Extra soupy with some air entrainment for extra bubbles and away we go!  I'll let ya know how it turns out.  Thanks again for all the info. and suggestions gentlemen.  I appreciate the help!

Pumped a lot of it and not pumped a lot of it.  I wouldnt go below a 4" hose and tell the customer that pumping it is doubtful, though they don't listen and try to blame you when you sand plug the pump or the pipe if you are filling pipes which we do a lot of..  We generally insist that they spend a little more and add cement and flyash.We usually talk them into a 7 sack grout that we can reliably pump through a 2" hose.

400 pounds cementuous material , and wet and less cementuous, you are gonna find that it eats your piston cups and material cylinders.

I pump it all the time through 2.5 " hose.. atleast a 5 slump 

PEHS,

The flowfill we have you won't pump on a 5" slump , I can guarantee that, this has got to be unslumpable , its almost like water, now the more cement or flyash you put in it surely it could be pumped at a 5" slump , but the stuff we do has a low break strength so it can be excavated. Thats the reason its called flow fill , now CDF may very well be something all together different.