Thursday, then again today I got loads of concrete that wouldn't pump very well. Thursday it was footing mix (from the same plant) yes it was very stiff but? it was pressuring out with little flow (not a solid blockage) I loosened it up mixed well and it pumped ok. Today doing ICF walls 3500lb wall mix. The first truck plugged right off but again not a solid plug. I had to work it, then the last part of the load plugged again. Second truck did the same. My pipes are shinny clean. Pump is in great shape. I'm thinking the material temperatures are dropping and with flyash the mud is not mixing? The other plants mud is pumping fine. Just this one isn't? They use fly ash.

E, it seems like spring and fall. Once they start using warm water it pumps great.

Brian, probably the difference is the amount of 'natural air' that gets entrained in a non-entrained (dosed) mix, and you're right, it likely has to do with colder mixes as opposed to when they start using hot water to batch.

Air may be a problem,however.Somehow I have always felt fines played a key roll.Once the loader has gotten into the pile they are getting what's needed.I'm supprised there isn't any more thoughts on this.

I pumped a 100 yards today no problem. But on a different note, the mud was very rich and thick. What Bar is normal to push with heavy commercial mixes? I know it depends on speed but what is the average Bar. I pump mostly residential and only push around 80 bar. These commercial higher volume jobs I'm pushing 120-220 bar?