Concrete project: will this work?

[Sodo]

No matter what, I still have to move the bag, cut the bag, drop the bag contents and then add water.

Sorry FTG but it kinda looks like you missed the most important feature of this method ,,,,the entire reason it works!

--- water goes in the FEL first ---- 3 qts per 80 lb bag

Lets say you are doing 7 of 14 bags. Almost ALL of the the pre-measured water goes in the FEL first (5 gallons?). Then you dump 5 bags into the water, which mixes very easily, because it's like soup. 5 of your 7 bags are done, with very little effort. Only the last 2 bags are hard work. You set your final mixture once per batch, at the end with the remaining measured water.

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OK have at it, forms are lookin' good. 6x6 is not a big deal it will go quick even one at a time. I understand asking on the forum first - I do it too.

 

[s219]

I think you'll do fine. But it will be work! One of my hardest days this summer was mixing, pouring, and finishing concrete for the apron on my barn. Didn't help that it was super hot and humid, and I was sweating like a pig. Anyhow, I learned to setup as many shortcuts as possible! One was to subdivide the apron into smaller sections, so that I could work on smaller sections and finish each one separately, but that's probably not feasible for a 6x6 square like you're pouring (mine was a long rectangle).

To me, the hardest physical part was moving the sacks, mixing, and then dumping the mix (did it all by hand with 80# sacks, mixing 5-6 sacks at a time in the plastic dump wagon for my lawn tractor). Used about 24 sacks total. Troweling was fun and went well -- I liked seeing the results unfold right in front of my eyes. The only tricky part was knowing when to apply the broom finish -- it's all about timing but it was the first time I ever did a broom finish so I had to guess. I got it perfect on the first section, but the other two sections didn't broom as well (probably still too wet). When everything dried, it was hard to tell the difference, so perhaps it's somewhat forgiving.

 

[ultrarunner]

Rarely use pre mix bags , I always get sand / gravel mix from a local rock place and mix it 4 shovel fulls of that with 1 cement shovel . Add water accordingly . Most of the time I mix 16 to 4 , which when dumped into a double tire wheelbarrow is about all you want to push around . Last slab I did was 14' x 8' x 5.5" . Wife helped scree it off but the mixing , dumping was all me . That shed still stands this day without a crack any were .

For that amount , I think you will be fine . Don't mix to wet or to dry . The way you talk about dumping it into your bucket will work since you will have some settling of the mix . but no water loss . So before you dump into your form , just use a garden hoe to stir it a little before dumping .

Images below are similar to the type mixer I have

Fred H.

View attachment 400776View attachment 400777

I had/have the same mixer as your white one... did a good job until I loaned it out and it came back with a cracked yoke... did not notice it until I started to use it... thankfully, a neighbor had a Harbor Frieght he was long done with and it's been a trouper as long as I mix no more than 2 60# sacks at a time.

 

[FTG-05]

Sorry FTG but it kinda looks like you missed the most important feature of this method ,,,,the entire reason it works!

--- water goes in the FEL first ---- 3 qts per 80 lb bag

Lets say you are doing 7 of 14 bags. Almost ALL of the the pre-measured water goes in the FEL first (5 gallons?). Then you dump 5 bags into the water, which mixes very easily, because it's like soup. 5 of your 7 bags are done, with very little effort. Only the last 2 bags are hard work. You set your final mixture once per batch, at the end with the remaining measured water.

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OK have at it, forms are lookin' good. 6x6 is not a big deal it will go quick even one at a time. I understand asking on the forum first - I do it too.

What do you use to mix it with? I don't have a hoe, another reason I don't want to mix it by hand. Oh, I also planned to use the FEL to hold all the bags of concrete so I don't have to bend over or drive my truck into my back yard..

Either way, I think I pretty much decided to pour right at the pad site, rather than mix one place, then transport and pour all at once.

Put plastic down first - Yes/No?

 

[CurlyDave]

I wouldn't put plastic down. I would put enough gravel, 1" -2", under it to make what an engineer would call a "capillary break", just so that the slab isn't constantly in a puddle.

Raise the forms a little bit so the concrete thickness is not reduced by the gravel.

I would not use bricks to hold up the rebar. They swell up more than concrete when they are soaked in water and may crack the concrete after it has cured. Get some dobes (pronounced dough-bees) which are small concrete cubes intended for this purpose. They are really inexpensive.

Even pieces of a broken-up cinder block are better than the bricks.

Don't make the pad exactly level. About 1/4" per 12" of slope will let rainwater drain off.

 

[FTG-05]

Ha! Learn something new every day! Didn't know that about bricks. Fortunately, I have plenty of both old bricks and concrete blocks. In fact, I was wondering what to do with one that I was tripping over the other day. it looks like I now have a use for it.

Ok, no plastic, one less thing to worry about. I do have gravel to put down, but not a lot.

The pad is not exactly level, it generally follows the original slope albeit not quite as steep, obviously. Not sure about the 1/4" per 12" but it definitely slopes down a bit.

And now it looks like the rainy season has hit central TN: NOAA is predicting rain all week. The good news is that this will quiet the woods down for still hunting.

 

[BuilderML]

What was i ever thinking???? You don't want to use plastic under your slab. You don't want to have the slab in water or have the concrete stay wet. It will only last about a month before it all falls apart thanks to the plastic under it. I wonder how the Hoover **** has lasted so long??? Did the engineer forget that it was going to hold back just a little water? Or is every bridge around the world on the brink of failure due to the concrete holding it up happens to be sitting in water? Forget the plastic its going to hold back gallons and gallons of water. Maybe you should have a tap built into your slab so you could have a drink just in case your thirsty while your out having some fun. Funny thing is concrete will only take on so much water and that is it. So if you place your slab on the ground it will wick up the moisture out of the ground. Looks like your slab will fail both ways. What is one to do???? I think concrete is out of the question. Sorry i tried to give you an idea on how you could get some more "open time" on your pour. Looks like i'll keep my comments to myself next time. Good luck with your project.

 

[FTG-05]

About the only thing I got done today was a trip to HD for more concrete and some concrete tools (I lost all mine in the last move - or they're still packed which is essentially the same thing, but I digress). Don't tell Sodo but I also got a hoe with those holes in it; it's designed to mix mortar etc.

Removed the rebar assemblies and added some gravel, and then tamped it down until it started raining. There's about an inch of water in the pad right now. I'll tamp it again tomorrow until it feels right. Sorry, no pics.

Got the tabletop out of it's form; the lifting eye worked perfectly, although it's not near the COG. Weight was right at 310 lbs, see pic.

 

[FTG-05]

Well, not much to do around here with all the rain we've had plus some more on the way.

So I decided to install a 24/7 tamping project! Basically, the 12 concrete blocks that will form the columns for the tabletop, plus some wood and my tractor ballast weight on top.

Pics:

In this pic, you can see the location of my shooting bench with my 110 yard range and the corner of my shop/orgy bar/Skeeter Pee Production Center/reloading room:

And I am not happy with the way the top of the tabletop turned out!!! I had made a concerted effort to ensure the tabletop concrete form was a smooth as possible, using a visqueen/plastic sheet between some (formerly) very smooth plywood surface. Not Happy!

 

[Sodo]

Plastic squirmed under the mud. Dang thats disappointing.

Heres an idea. Level it up deadnuts flat and float it with some concrete driveway resurfacer.

Maybe you can make a little dam all the way around with a strong tape like 2 thicknesses of Duct tape. Try that & see if it sticks to your concrete. You may have to let it cure further or warm the whole slab up inside a heated garage? Then pour it 1/4" thick or less, being very careful to just let it flow to the tape dam on its own. Remove the tape dam after it sets then sand (while surfacer is still green) until the edge is round and comfy.