Filling sono tubes - buy bags or mix my own concrete?

[newbury]

Finally got the bamboo cleared and am about to embark on setting 9 sono tubes for the shed base. As I've written before, the shed is inaccessible by concrete truck.
It's going to require 40 to 50 80lb bags or equivalent.

Since we are doing this on a very flexible schedule (only a few hours/day due to other demands) mixing w/ a mixer I own will be the way to go.

But reading up Quickcrete and Sakcrete it seems their bag mixes may be variable

Just did a small job with 10 bags of Quikrete. Two bags were not mixed correctly. One bag was completely unusable - the bag was nothing but cement (no sand or aggregate). 20% is not an acceptable failure rate.
Not my first experience with bad mixes ... used a Quikrete stone veneer mix for a previous job and gave up and returned everything. Mixes were way short on cement.

from Shop QUIKRETE 80-lb Gray High Strength Concrete Mix at Lowes.com

And personal experience with bags recently that seemed to use well rounded, small river run gravel for the aggregrate.

At $4/ bag I'm wondering at the tradeoffs between doing it from raw material the way I did it in 1963 (one shovel cement, a few sand, a few gravel, add water) and buying the bags.

What's the TBN advice?

 

[ErikVann]

That's a lot of Crete to mix. How deep are you going? Do you live in a region prone to frost? It seems that you have limited time to work on this project. I would purchase pre-cast bases. I have used two varieties with great success.
EZ Crete - Precast Footings
If you have the means to move around a 1200lb precast pier they are easy to use and look good.
If you don't have a means of setting the one piece units they make a modular system using 12" concrete cylinders which are held together with a threaded rod.
Both systems will save you time, and you can start building your shed much sooner. They cost a bit more than bagged Crete but you will save considerable time with either system. Good luck

 

[Deere Dude]

Anything over 5 or 6 bags of Quickcret, I use Portland cement. I just take the trailer to the redi-mix plant and they scoop 1/2 yard of sand and 3/4 yard of gravel into my trailer. I or my wifey does, shovel into the cement mixer right from trailer if I set it up right and add Portland. But that's my take.

 

[Looking4new]

If you cannot get a concrete truck in to do the pour, then how are you going to get the sand and stone in to mix your own?
I poured a new floor in one of my sheds 6" deep with drains, a concrete truck would have had no problem getting to it. I like to work at my own pace and not have to 'march to a different drummer'. I used 120 bags of quickcrete. Started at 6 A.M. and finished at 4 P.M. with a stop for lunch.

 

[Deere Dude]

If you cannot get a concrete truck in to do the pour, then how are you going to get the sand and stone in to mix your own?
.

A compact tractor and a trailer can go so many places a cement truck cannot go and with a whole lot less damage to driveways and lawn. In every job the size of pour must be taken into consideration and also the location plus the available equipment and cost must be analyzed to decide which is the better route to take.

Sand and stone or even quickcrete can be mixed a hundred feet away from a small job like the ops.

 

[KennyG]

Looks like a toss up. I've used a lot of sacks and never noticed any consistency issues. However, if getting the sand and gravel is easy for you, it would be a good alternative.

 

[Streetcar]

I agree with Kenny G. Sack mixes have been consistent for me, but if you can easily move the sand and gravel to site it is cheaper

 

[4570Man]

If you cannot get a concrete truck in to do the pour, then how are you going to get the sand and stone in to mix your own?

A cement truck weights 32,000 pounds empty. I can drive my tractor a lot of places a cement truck can't go even with a load of gravel in the loader. When we poured our sidewalk we left the cement truck in the road . Then we poured the concrete in the tractor bucket and drove to the sidewalk.

 

[clemsonfor]

i would worry that some of it would be drying and then not form uniformly togeather as it takes so long.

 

[KennyG]

i would worry that some of it would be drying and then not form uniformly togeather as it takes so long.

Doesn't look like a problem in this particular case. The job is 9 separate tubes, each with about 5 cubic feet. Anyway you do it, each tube is only an hour or two of work. As long as you are putting wet concrete against wet concrete, there won't be a problem. Large continuous pours sometimes go for days. If you ever have to pour wet against dry (set up) then you need to make a cold joint and allow for the inevitable cracking at that point.