using tractor to compact soil?

[LBrown59]

</font><font color="blue" class="small">( Rent a small walk-along compactor like the ones used in compacting the back-fill of utility trenches and stuff.

Not the vibrating plate kind or the bouncy pogo-stick kind, but the kind with the vibrating lumpy rollers.

Another method is to do all your fill work with sand and/or mixed crushed stone / fines. These materials will compact much easier and more reliably than random soil. )</font>
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1*Rent a small walk-along compactor like the ones used in compacting the back-fill of utility trenches and stuff.
2*Another method is to do all your fill work with sand and/or mixed crushed stone / fines. These materials will compact much easier and more reliably than random soil.
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1*I need to do the job gradually over a period of weeks or months so renting such a compactor for such an extended length of time would be pretty expensive wouldn't it?
2*What I don't like about using these materials is they will allow water to run in under the concrete floor inside the building because this material would be at a lower level than the yard on the outside of the building.
I hate to buy gravel or stone and pay for trucking it in when I already have all the free fill dirt I need here on site to fill in and bring things up to the desired grade.

I have the tractor. I have the free dirt. All I need is to find a practical way to compact it between layers.

I need a dam to block out water not a pit filled with gravel to collect water

 

[bugstruck]

See if you can locate a used plate tamper reasonably priced. They are the worst at compaction but if you keep your lifts small. Maybe 3 inches and make a few passes it should be adequate for slab on grade compaction for a typical garage. The load gets spread out some if the slab reinforcement is sensible. Exception would be heavy vehicles such as larger tractors or dump trucks. I wouldn't consider going this route for them.

You won't pass any geotechnical compaction tests with that method but it shouldn't move under small tractor or vehicle loads up to say a loaded pickup. This assumes your soil consistency and moisture content will promote good compaction. Run some heavier vehicles on top where you can ever 2nd lift or 6". It works for a little added insurance.

My L series Kubota sits on a slab which I didn't build that probably didn't get this much attention and I'm pushing 8,000 lbs with ballasted tires and BH. I can ring my slab at the perimeter wall backfill for about 2' in and the soil has settled away from the beneath the slab, but where the tractor sits was probably compacted with the machine that backfilled it. It's made it 33 years with no cracks.

HTH

 

[jim_wilson]

I've got a similar problem as yours. Last summer I put in a extension to my driveway where I had to dig out about 1.5 to 2 feet of organic soil, tree roots, and rocks to get down to virgin soil that I figured would not compact. I then backfilled this with sifted gravel that I compacted with the tractor. On top of this I laid 6-8 inches of 3/4 crushed gravel -rock dust mix. This was rolled out using a 1000 pound lawn roller. It stood up pretty good over the winter with some settling here and there. For the driveway part at least I figured this was good enough because it will be sitting for a couple of years before I get to pave it and it will get driven over a lot with big trucks as I work on my next project.

The next project is the garage - for this I have a compaction problem because the location is on a sloping yard where I am going to have to have 6ft foundation walls poured to compensate for the slope and to get below the frost line. I then have to fill in the interior of this foundation with 4-5 feet of fill to bring it up to the level where the floor pad will be poured. Since this needs to get compacted really well or I will have a cracked floor I figured I have a compaction problem. I can't use the tractor because I won't be able to get it into the foundation hole - that leaves something like a vibratory plate compactor. If you want more info on compacting soils check out this web page: Soil Compaction Article . I went around to the local rental places and asked on their rates for vibratory plate compactors and got quotes of $75 - $90 a day. Then I looked on Ebay and found used plate compactors for anywhere from $750 - $1200. So I sat down and did a little math and figured if I bought one - used it for my jobs - then sold it again, I could come out way ahead financially and not have to worry about running back and forth to the rental shop. I managed to score a Wacker 1550 plate compactor last week with the onboard water resevoir (for dusty soils and asphalt) late last week for $900. I figure if it would cost me $80 a day to rent even if I can only sell it for half of what I bought it for ( very unlikely) then I still come out money ahead in the end. And since I have the garage fill to compact, a patio to build, some sidewalks to build, and a few other odd jobs I probably have at least a week's worth of days that I will need the thing. So my advice is start cruising Ebay and get yourself a used plate compactor then sell it when you are done.

 

[gabby]

Saturate it with water and let it settle. And I mean saturate it! Let it dry and do it again. Wetting and drying and settling goes a long way.
gabby

 

[bebster]

Gabby, I agree with you on watering. Before I poured the slab in my barn, I watered the filled sand there for days and days (maybe for 20 days or so). By the time I was done, it was really compact and hard. That's the way that soil is naturally compacted, so by watering almost continuously you can speed up the process.

 

[keeney]

Compacting with water saturation is only recommended for sandy soil.

However, water compaction is not good at all for clay!

With clay, its hard to get the water to penetrate deep enough - that could take months depending on how deep. When it does penetrate, the clay turns to squishy muck - no good for supporting anything. Before you can build on it, it has to dry out again - that can also take months. When eventually it does dry, it shrinks a little bit, leading to less than 100% compaction.

- Rick

 

[gabby]

keeney,
I have used water saturation on clay with good results.
gabby

 

[bandit67]

An even better way than watering after the fill is placed is to place damp fill. As you drive back and forth over it, it will compact very well. I got 4 big loads of road base delivered to my pole barn site right after snow and/or rain, so each load was pretty damp when I was spreading it.

The concrete guy was very impressed with how well the fill was compacted by my little machine, and said he only needs to compact it around the edges where I couldn't get the tractor to. Last night, after a day of a good, steady, soaking rain, I drove my 7700# pickup onto the fill, and there was no additional compression from the tires, so it's ready for concrete. /forums/images/graemlins/cool.gif

 

[keeney]

The soil at my house is all clay.

Buildinmg our house during our rainiest summer ever, the 8 to 10' of backfill around my house had sunk a good 18 inches or more and had big puddles sitting on top and draining into it for months. By the end of the summer, I was pretty sure it was fully settled. I topped it off to the desired grade, sloping away from the house. Next spring after the freeze/thaw, it dropped another 6 inches.

Many months after all the grading was completed to drain everything away from the house. I have dug up portions of the foundatiion backfill (for various utilities, etc) and have found big pockets of water and muck trapped in the clay like it was just waiting to drain out and collapse someday.

Water compaction might be OK for a few inch layer of clay on top, but I would't use it for anything deep.

- Rick