Has anyone ever made their own Concrete?

[tessiers]

I've done a fair amount of concrete work in my life both professionally and home work.

Portland cement is only a bonding agent. It adheres what is called aggregate together. Aggregate is sand, stone, fly ash, ect. Cement will not bond to organic and un-stable materials. The fact that the granite is decomposing should give the clue that it is not a acceptable aggregate. It will continue to decompose and cause breaks in the concrete. I would not even consider using dirt or even dirty soil. The sand and stone used in most mixing plants is washed before use. How much are you really going to save, $10 or $15 per yard will seem insignifigant when you are trying to fix the results.

I poured a slab 16x22 a couple of years ago with a portable mixer, it was not pretty. The small batches set up at different rates making it next to impossible to finish.

Redi mix concrete is about $100 per yard.

Protland cement is about $7 per bag times 5
Sand or gravel about $12 per yard
$50 dollars per yard to mix it yourself, at 3 to 6 cubic feet at a time

For less than a yard mix it at home with good materials but large amounts call a Truck.

Just My 2 cents, take it for what its worth.

 

[bandit67]

I have to come up with a system to make mixing it myself work, taking into account setting rates, etc. Basically, I'll need to mix up enough to get me to each control joint before it sets up too much. Should make finishing easy enough, and should work out ok based on past concrete experience. Getting a truck into where I need it isn't feasible, neither is hauling wheel barrow loads and/or FEL bucket loads from the truck to where I need it.

If I could get a truck in without it getting stuck or rolling over, I'd be all over it, but I'll have to use a small mixer on location and do it all by hand. Probably won't really save much, but like I said, it's not really about the $$, but about logistics.

 

[MtnViewRanch]

I have to come up with a system to make mixing it myself work, taking into account setting rates, etc. Basically, I'll need to mix up enough to get me to each control joint before it sets up too much. Should make finishing easy enough, and should work out ok based on past concrete experience. Getting a truck into where I need it isn't feasible, neither is hauling wheel barrow loads and/or FEL bucket loads from the truck to where I need it.

If I could get a truck in without it getting stuck or rolling over, I'd be all over it, but I'll have to use a small mixer on location and do it all by hand. Probably won't really save much, but like I said, it's not really about the $$, but about logistics.

You don't have concrete pumps in Colorado? Most guys can pump 2-300 feet, some farther. Around here concrete pumpers get about $300 per average job. Usually 20-30 yards.

 

[dfkrug]

Brian beat me to it. I had one pump job here where the pumper used
500' of hose and pumped up 150' of elevation. What a nightmare that
was.

The readi-mix operators around here are so spoiled by having most jobs
pumped.

 

[Donman]

This thread reminds me of an article in Pop Sci or Pop Mech maybe 35 yrs ago where they showed how to make what they called a "soil cement" driveway. I was always tempted to try it but never did. It works only with lighter type soils something like this: Mark out nine foot squares and use one bag of portland cement per square,then rototill to a depth of 6 inches and follow with a plate compactor to smooth and compact. Then cover with burlap and keep wet for 21 days. This slow cure was supposed to cure and harden the weak mix to what they claimed would last for many years with light to moderate traffic.

 

[MtnViewRanch]

Brian beat me to it. I had one pump job here where the pumper used
500' of hose and pumped up 150' of elevation. What a nightmare that
was.

The readi-mix operators around here are so spoiled by having most jobs
pumped.

I am actually shocked if and when I see a job that isn't pumped. A few months ago I saw a sidewalk getting poured. The cement truck was next to the sidewalk loading into the pump when all they had to do was use the chute to put the concrete down. But no, why would you want to use that 1 extra length of chute and forget about the pump.

 

[bandit67]

Ok, when I said it wasn't necessarily about the money, I didn't mean that I wanted to hire a concrete pumper, plus order a truck full of concrete to lay a couple of 10'x15' dog kennel pads. That's Tim the Toolman going overboard kind of stuff. I'd spend almost as much getting that little bit of concrete put in, as the kennel roof structure will cost me to build.

I'm sticking with either bags or bulk materials, from the local supply house, and will mix it with a small portable mixer that I can set up right there.

You guys love to get other folks to spend their money, don't you? Spending too much on a tractor is one thing, but spending too much on all this other stuff is getting out of control. I'm already going to be in trouble once the CFO sees my tractor & attachment wish, I mean need, list.

 

[MtnViewRanch]

Bandit, when you go to mix and pour, any chance of getting some help? If you could get 2 other guys, it won't be so hard, and the job will come out better because you will have more time to work with the pour. The two times that I have had help, the jobs have turned out a lot better than when I have to do everything by myself. Not that what I did by myself wasn't ok, but you can tell where every batch was next to the previous one because of drying times. It's all smooth, just doesn't blend as well. Does that make any sense, anyway, get some help if you can.

Good luck

 

[bandit67]

Yep, that was the plan. Have some help to keep things moving at a pretty good clip and there shouldn't be any problems. The dogs won't really care if they can see the batch breaks, either.

 

[dfkrug]

Ok, when I said it wasn't necessarily about the money, I didn't mean that I wanted to hire a concrete pumper, plus order a truck full of concrete to lay a couple of 10'x15' dog kennel pads. That's Tim the Toolman going overboard kind of stuff. I'd spend almost as much getting that little bit of concrete put in, as the kennel roof structure will cost me to build.

Yeah you are looking at 4cy of concrete for both slabs, and you don't
have to do them all at once. There is a time and place for readi-mix
trucks and pumpers, and a time to DIY. Although I have had the readi-mix
trucks and pumpers here when I built my all-concrete house, I have done
many loads by myself with my PTO mixer, including sidewalks, stucco, and
piers. DIY mixing also means you can design your own superior mixes, too.
My PTO mixer is great, but it does only a bit less than 1/3 cy at a time.
If you ever go with one, do not get a sub-compact CUT as they are not
tall enough for proper dumping.