Mixing concrete - "Mud mixer" alternative. Steele mixer

[quicksandfarmer]

While we're on the subject, Rockbadchild mentioned retarding admixtures. When I'm working by myself my fear is always I'll be too slow and the mix will start setting up before I'm done mixing. Is there any downside to using retarders? When working on my own property I'd much rather have a long working time and then wait for a long cure time. I understand why pros might feel differently.

 

[Rockbadchild]

While we're on the subject, Rockbadchild mentioned retarding admixtures. When I'm working by myself my fear is always I'll be too slow and the mix will start setting up before I'm done mixing. Is there any downside to using retarders? When working on my own property I'd much rather have a long working time and then wait for a long cure time. I understand why pros might feel differently.

yeah that's the down side, the longer curing time and it can make it too liquid for certain application (slopes or what not) if they are not careful or if combine with some rain or high air humidity. But if you are specific on how long you need it shouldn't be a issue.

 

[paulsharvey]

Retardant, as I mentioned way above as 'tard, if fine, IF the mix is designed with it. You don't want to go just throwing stuff in and hoping for the best.

Years ago, me and 1 helper had to pour 36 CY, 10" thick, able straddle and screed, on a cold morning (45 degrees or so). Truck 1, fine, truck two placed, check on truck 1 still not ready, pour truck 3, and truck 2 (already screeded) has started to go. Helper said "we can try sugar to slow it down"... it turned into a blackish, sticky mess.

 

[5030]

Anyone ever tried a dry pour? I did it with a second genny pad and it worked really well.

 

[MAX-24-Dean]

Anyone ever tried a dry pour? I did it with a second genny pad and it worked really well.

I would think that the conditions and moisture available at the time you placed it dry were perfect for it to set properly.
The luck of the draw!
I would never recommend a "dry pour", to someone that had never poured concrete before. Your practical life experiences probably helped in making that successful.

 

[paulsharvey]

So, there is a Big difference between a non structural pad for an AC, that is going to be almost entirely hidden by the AC, and sidewalk (looks/smoothness), a shed floor (smoothness/maybe strenght, depending on whats sitting on it), and driveway (looks, smoothness, and strength). I would Not "dry pour" anything our OP is doing. Now, dry pour fence posts, or... we'll, that's about the only place I would do it. I know guys on YouTube have done pads dry and then hit with a hose, and I guess finish the top? With concrete, consistency is key. You want the whole mass to be uniform, and cure as a uniform mass.

 

[5030]

Not putting an AC unit on the pads. 2 Generac standby generators. one diesel and one propane.

The pads are 6" thick with metal reinforcement in the concrete.

 

[paulsharvey]

Not putting an AC unit on the pads. 2 Generac standby generators. one diesel and one propane.

The pads are 6" thick with metal reinforcement in the concrete.

Ok, but still, you are asking for aggregate segregation, honey comb, and uneven curing. I'm not arguing that it worked for you, but I just don't see the upside. You compromise on strength, texture, and appearance, and save nothing on material. Yes, it's easier, but it's not something I would do.

 

[paulsharvey]

For anything less than a yard, a mortar mix tub, available many places, and a hoe will do what you need, and you can probably solo mix and place 1/2 yard per hour, but you will know you worked. Mixing in a loader bucket works pretty OK too, but it's kinda hard to get into the corners, and mortar tubs have rounded corners to make it a bit easier.

For the specific tasks our OP listed, ready mix, or a site drymix truck are the right option, unless he's just stubborn

 

[dstig1]

While we're on the subject, Rockbadchild mentioned retarding admixtures. When I'm working by myself my fear is always I'll be too slow and the mix will start setting up before I'm done mixing. Is there any downside to using retarders? When working on my own property I'd much rather have a long working time and then wait for a long cure time. I understand why pros might feel differently.

Yeah. It's now midnight and the pour still isn't stiff enough to finish... Even in my limited concrete work, unless it is super hot (or maybe hot and in full sun) you should be fine on time in most situations. Heat, direct sun, and very large pours are where it gets a lot more challenging on time.