we are going to do a pump on next tuesday down a cason 30'wide and 120 feet deep the floor we are pouring is 10'deep we have a 42m reed z boom with a 20' mud snake at the end  any suggestions or is there something out of the ordinary we should watch four 5 section boom section 1 will be app level and everything else down the hole thanks any advice would be helpfull thanks 

Do you have an 'Air Cuff' to [help] keep the mud from falling the rest of the way to the bottom when you stop?

120 feet deep x 1.1 psi/ft = 132psi of pressure to hold the column od concrete above the air cuff, that's about the maximum pressure in a truck's air system, and the directions for an air cuff state the regulator be set at 90 psi. (to avoid blowing out the rubber bladder)  So it may not work 100% but might be better than nothing at all when you don't want mud to keep coming.

How are you priming?  If the slab is thick like you say, then 1/2 yard of cement-rich grout should be OK.

Be sure to catch some pictures for us, if possible maybe even video.

Guys I have to ask a question why do you guys waste a contractors money on grout what a waste, use water or Bentonite mix with water in two 5 gallon buckets put a sponge behind the primer  and prime out before you put it down in the hole.Stop wasting money cause a 1/2 yard of grout delivered cost a couple hundred bucks.

There is always someone saying you need grout, and others saying you dont. In FL if was about $300 for a yard of grout including min load charge taxes etc. In TX, it was about $70.00. If you dont have system I dont know why you would want or need it. Big boom or little, any make any model. Using a 20' mudsnake on a pour that thick they must have some reason for it.

See if you can have someone watching your knuckles when you are doing the sides closer to the pump, good opertunity to hit the sides if your not real careful. Will your pump make it 120' deep? you loose all of your main and only have the rest plus your tip hose to reach all of it.

Biged, this sounds like a "high-specification" job. Bentonite and other primes may not be compatible. I'm sure the engineer has the last call on what materials are in the slab, my guess is that bentonite doesn't make the cut. Priming straight down is a tricky prospect, this is a high-dollar project, not a block-fill job, there is no such thing as a minor failure. I'm quite sure SDpumper has a plan already, he's just wanting other's thoughts, he'll take yours into account too.

holes are lovely...like being at the dentist.  Then you get to go home with a kink in your neck from looking down--

pumpjockey ,biged said prime out before you put the boom down the hole!!

Good idea i think , personally i cant see why you need any extra help to get it through the boom!! We use half a bucket of sand and water , works every time!

Im sure the super or engeneer would be more than happy to have you prime up top if they knew it was going to save them money

i have to disagree with no grout.a small price to pay for any job to help with eliminateing the posibility of a plug up.not saying you ever will,just saying posibly could.if the customer ask's. yes i would use it .usually grout is same strength as the concrete to be placed,so why not? with that being said i have still plugged using grout .via build up in elbows or driver pouring concrete in before strokeing .i've never had a complaint primeing with grout and placeing in pour,but some seem to think slic-pac,fritz-pac ect..has a lasting efect in the poured concrete .there is proof that there isn't but they still believe it.with grout there isn;t any question .so WHY NOT????

Prime it with water before you stick it down the hole and you'll be fine.
Grout is of course better and almost idiot proof, but not necessary with just the boom in use IMHO.
Slickpak and others shouldn't and almost never do anything to the strength of the concrete, but the finish might be different, and the finishers don't like it on floors...
But it all depends on what type of mix you are using.
And never had any problems with the aircuff holding the concrete back on my 40 with only 6 bars, do the math, all about pressure pr squares.

putz 63... 5" rubber 20 metre tremmie..  primed with just water no problems at all...

Since the first section is flat, I would say put a sponge in front of you prime to hold it back so your down hill sections get coated, and the air cuff will help slow down the free fall of mud, the main thing is be safe.

nice pic's kitty.

Great pictures I wish someone had a video of unfolding into that hole got to be tricking.

Like threading cotton through a needle - easy

Easy when the shafts empty bit trickier when the shafts full of water

you could put a large wet sponge in front of your slurry and then push it through slow the sponge will hold the slurry back and it has always worked well in the past for us