Headed to the job in New Market, Virginia.  Was supposed to be a gravy job, 35 yds bull float finish on a sump basin at a waste water treatment plant. Got close to the job and called the Supt and told him to release the mud. Send It Back to Back!!!!. When we pulled on the job 1 load already there. Thought ok !!!  get done sooner!!!    Got the pump set up.  No time too oil it down, figuring  it would go quick enough it wouldnt set by washout time.Backed in the 1st truck, started to prime with water, plugged in the 1st section, reversed it 3 strokes, back forward, plugged in the 2nd section.  Stopped the mixer driver from discharging into my hopper. Pulled him away from the pump. continued moving it back and forth till i got mud out the end. pulled all the mud out of the boom.  The Rep with the Redi Mix Company was standing there the whole time. I ask him what kind of mix is this.   4500psi  100% Manufactured sand!!!!   DAMN IT MAN!!!     3 loads on the job.   The only way i could get the mix thru the boom was to suck air with it.   Testing Lab telling me I'm running out of time on the trucks..  Takes me 2 hours to get 14 yards unloaded.  Had to throw 2 loads away.  Got the mix changed to blended sand 5000 psi. Waited an hour and a half on 3rd load.Kept the pump alive without washing out. mud got there pumped like butter!!!   7:30 on the Job Pulled off at 2:30  , 37yds

What is manufactured sand?

Fine ground limestone,they are not close to a river, that was some bad looking mud.

if the sermac wouldnt pump it then it must have been bad! bet you had crete flyin always pumpin air with it!!

How right you are biged,  most of the natural sand here is brought in by truck or train,  Bad thing is were doing a job for the same contractor 30 miles from here and useing the same concrete supplier,, Different Engeneers!!!    If I would have thought I would have checked on the mix ahead of time!

OH and murf,    those SURMACS are some Bad Mamma Jammas

good times;

Oh, thats new to me. I suppose the fine sand mixes into a cream with no body, then under pressure the rock gets left behind to pile up and pack.

I feel for ya brother! Got a concrete company I deal with a lot that has been using man sand in their "cheaper" mix design. That stuff suck sooooo bad. I even considered changing the name of my company to 4T Septic Pumping cause of all the sh*t I been putting in my hopper lately. And of course, the concrete company won't admit it's the mix causing problems. "Its your pump. What's wrong with it?" Jackasses!!

I know how you feel it say inch and a half rock, inch and a half one way and 4 inches the other, we call it vegas crap cause you crap out everytime you pump it. haha

Don't want to be a asshole,But I would love a bad of concrete pumping.

And the redi mix companies always tell ya that we've never had this problem

BLEND SAND RULES

Some days those telebelts are the cat's azzz(lol) Terry

Send the telebelt and get r done.  How do you guys take pictures?  When I try they all get nervous and make me put it away.  Don't want evidence showing up later I guess.

When I first started pumping in Knoxville TN nine years ago. You had to special order river sand all the ready mix company's carried manufactured sand only. So I have had my share of nightmare stories with that stuff. When we would have guys come in from outta town to work for us they would say O it doesn't make any difference. I would just laugh at them. After spending the afternoon beatin on there boom pipe then they started to understand. I tell guys like this. Take a hand full of granulated sugar and pour it out of your hand then take a hand full of powdered sugar and pour it out. The granulated sugar is round and flows nice Powdered sugar is jagged and plugs.   

half a pack of slick willie in each mixer and she pump like ice cream

putzman,.   I tried 2 slick packs in a 7 yard load,,,  no help

ive been up pumping around knoxville an nashville couple times..there mud sucks ass

"it's a concrete pump,not a rock crusher" Please crush it before it gets to the pump.

Dude, they did crush it and it turned into SHARDS of rock!! The biggest thing with mfg'd sand is that the surface area of the sand particles is about 5 times what it is with natural sand, therefore, it needs more cementitious, not for the strength, but for the lubrication. The water demand would be very high too, the pumping pressure would push water into nano-pores of the mfg sand, much like lightweight aggregate. Flyash and cement, and a lot of luck is needed. blend sand is likley the best admix. Concrete gets hard, pumping it shouldn't be.

Your kidding,right? That's all we pumped in the mountains,man sand.That's where the term came from,put some cream in it.Alas,it was always the pump.For that reason I loved the 801's !!!

Looks like Shockey concrete? If so I have pumped alot of their mud. Actually did several hundred yards in Winchester with 100% manufactured sand. They used some chemical in the mix and as long as they kept it above a 4" slump it pumped fine. But I have been in the same boat tryin to pump a lil footer in Mount Jackson. All day for 3 loads and a lotta slick pack!!