Concrete Pump help

[mreynolds]

Rich,
I am getting ready to pour my basement and we are going to have a boom truck come out and pump the concrete in. What I have come to realize is that I really have no idea what type of man power I need. I know I need to have one person directing the nozzle, another to vibrate the cells of the ICF and we'll need to screed to top when we get there. What other help should I plan for? When the concrete comes, do they just dump it into a hopper on the pump truck? One of the guys that rents the pumps told me I need two guys raking? What is that for? Another concern he mentioned was the concrete may set too fast so we should request some kind of retarder. We're ordering 32 yards for a 54 foot x 30 basment with a small crawl space, 5.5 to 6 slump with 3/8 inch aggregate. Any wisdom here would be greatly appreciated here, I know you have some expertise in this area. By the way, right now, I have 5 guys, possibly six, so any ideas on how to best organize this would be great.

[Rich]

5-6 people would be pretty easy to do that job with. The only thing I can think of raking for is a slab where you'll need to rake / screed it level - we call them muckers.
I'll speak generally for this section - as you only have 30" walls. With ICF's you'll probably only want to do 4' lifts at a time and don't do less than an hour per lift. When you are vibrating the cells make sure you vibrate through the last lift. In other words, if you pour 4' in then another 4' on top of that - make sure your vibrator goes down at least 5'. A class that many of our concrete guys take for vibrating says to pull the vibrator up 1' a minute. Now that seems forever but it's guaranteed to get any air pockets out. For ICF's you could probably get away with a little faster than that as you don't have to see the concrete when you're done.
In your case I wouldn't worry too much about retarder with a 30" wall. If it does become a factor and it looks like it's going to have a cold joint I would pour half the wall and come back to your starting point and pour the other half.
The slump can become a factor also. The longer hose you have the more slump you will lose. If you don't have a pump over 32 meters you should be fine with 5.5" slump.

[mreynolds]

Thanks for the advice. Now all I need is the weather to cooperate and we will be in good shape! How much will a light rain slow us down?

[Rich]

Shouldn't slow you down at all - except for maybe the workforce :)
If it gets really cold I would consider holding off for a day or so. You'll want to keep the concrete at at least 50 degrees for 3 days. If it's going to be below that I would consider renting some concrete blankets. The ICF's themselves will give a pretty good weather barrier - it's the top that you'll have to protect.
If it's just raining I would probably throw a piece of plastic over top for a day or while it's raining. Otherwise - go for it and have fun :)

[mreynolds]

I think we will have some good fortune. The pump service called and asked if we could do it tomorrow afternoon, which turns out to be a much better day, 74 and partly cloudy. These were the guys I was hoping to get in the first place, but we weren't sure because they do 95% commercial work and fill in the gaps with residential jobs. We will be a little short handed, but this service we will use has a good reputation for checking forms and making sure everything is right before the pour. Not to mention the charge a flat $650.00 fee regardless of how long the pour takes or how many yards you do (for residential, they bring home the bacon with their commercial jobs)

[mreynolds]

Well we survived the pour. There are pictures on the album side. It took us about five minutes to lift our jaws off the ground when the boom truck got there to set up. That is a cool machine, and not to mention pretty big. We didn't have any blowouts, one near miss. I was amazed at how good the operator was, that guy had some skill, I hardly had to move the hose at all.

[Rich]

Right on.. glad everything worked out for you. When's the framing start? :)

[mreynolds]

I just got all the decking materials, so I will be laying out the sill plates today. Now the fun stuff begins :D