Mixing concrete powder into the gravel - driveway

[paulharvey]

Yes just have creek rock. I also think the reason it doesn't pack now is #1 it's on a grade, #2, there are a lot of large stones in there. I'm going to try to get some off the bigger stuff out of it, drag it with the box blade then get a load of crusher run and see what happens. I will take a photo next time I'm out there.

If you add rock, I would rip or scarify the existing and the new; and reshape. It's helps the whole mess act as one cohesive mass rather than a thin layer on top of another thin layer.

 

[vtsnowedin]

If you add rock, I would rip or scarify the existing and the new; and reshape. It's helps the whole mess act as one cohesive mass rather than a thin layer on top of another thin layer.

What I have added that works well is inch and a half concrete stone. No fines or dust. You already have more then enough of that in the drive already. Use 0.17 tons of stone per square yard. That will make a layer about three inches deep. Scarify and mix it into a nine inch layer then water and roll or let traffic compact it.

 

[EddieWalker]

I have a steep part of my driveway that does not pack down. I'm looking at option to make it more "packable". It currently has creek gravel on it. I plan to top dress with crushed limestone one was get the building done. Can I just spread a couple bags of portland cement on that to help it pack?

Creek gravel, or riverbed rock as it's called here is smooth and round. It is absolutely the worse type of rock you can use for a road. What you need is rock that has been crushed with jagged edges. The rock needs to be a variety of sizes from an inch or two down to fines. This mixture when spread out 4 to six inches thick will compact into a solid surface that will shed water and support heavy loads. You can leave your river rock in place as a base, but you need to top it with the proper type of rock and make sure it's thick enough to lock together.

Once it locks together and is compacted, it will not come apart or move. I use my backhoe to break it apart when I want to run a line under it. It comes up in chunks similar to blacktop pavement.

Eddie

 

[Gafn]

there are a lot of large stones in there. I'm going to try to get some off the bigger stuff out of it, drag it with the box blade then get a load of crusher run and see what happens. I will take a photo next time I'm out there.

The larger rocks are there as a base, removing them will allow your smaller rock to settle to the bottom, and in my case - we have red clay as dirt - the smaller rocks just disappear into the clay. I would not remove any of the larger rocks, I would not disturb them any more than dragging, if you break up the base/foundation, your small stone will start to settle, and you may turn that section of your driveway int o a muddy mess until the settling stops.
Just my opinion, this is what has happened with the red clay soil where I live.

 

[Threepoint]

Creek gravel, or riverbed rock as it's called here is smooth and round. It is absolutely the worse type of rock you can use for a road. What you need is rock that has been crushed with jagged edges. The rock needs to be a variety of sizes from an inch or two down to fines. This mixture when spread out 4 to six inches thick will compact into a solid surface that will shed water and support heavy loads. You can leave your river rock in place as a base, but you need to top it with the proper type of rock and make sure it's thick enough to lock together.

Once it locks together and is compacted, it will not come apart or move. I use my backhoe to break it apart when I want to run a line under it. It comes up in chunks similar to blacktop pavement.

Eddie

+1 on Eddie's advice. The river stone

 

[Threepoint]

Creek gravel, or riverbed rock as it's called here is smooth and round. It is absolutely the worse type of rock you can use for a road. What you need is rock that has been crushed with jagged edges. The rock needs to be a variety of sizes from an inch or two down to fines. This mixture when spread out 4 to six inches thick will compact into a solid surface that will shed water and support heavy loads. You can leave your river rock in place as a base, but you need to top it with the proper type of rock and make sure it's thick enough to lock together.

Once it locks together and is compacted, it will not come apart or move. I use my backhoe to break it apart when I want to run a line under it. It comes up in chunks similar to blacktop pavement.

Eddie

+1 on Eddie's advice. Short of bringing in faceted stone that can lock together, you'll forever be trying to get that river stone to compact and stay in place, unfortunately.

 

[rtimgray]

I'm just curious, and maybe msparks can answer this - are you guys talking about the same type of "creek rock". When we do roads with creek rock here, it is not clean, washed rock, but rather rock that is dug out of a creek (also known as "bank gravel/rock"), and it has rocks in it from all sizes from grains and pebbles to bigger than footballs. It makes a pretty decent road base or rough road, because it does have a lot of fines (and mud/sand) in it, so after it's smoothed (as much as is possible) and driven on, it packs down well.

It sounds like what Eddie is talking about is what I've always heard called "washed rock" - that is river rock, creek rock, bank rock, whatever that has been screened, sieved, and washed and is relatively uniform and has no fines at all. I usually see it used for decorative rock rather than a road bed. Like Eddie said, it would be awful for that.

I don't know that it matters much, I'm just curious if those of us from different parts of the country use the same name for completely different products, thus perhaps causing some miscommunication.

Or I might be the only one thinking different...sure wouldn't be the first time!

Good luck and take care.

 

[vtsnowedin]

There is a lot of differences regionally. Up here in the north glaciers covered the ground 10,000 years ago and as they melted back the melting ice left large deposits of sand and gravel sometimes quite a distance away from any running water today. Some of it was deposited by fast moving water that sorted out all the fines leaving a clean often cobbley deposit of "washed gravel" in a bank. which we call bank run gravel. it is good for road base but you have to sort out the cobbles that are bigger then six inches usually by running it over a screen with bars set six inches apart. Almost all the rocks in this are well rounded from millions of years of water and ice action. This same material run through a crusher to break all the rocks bigger then two inches makes an excellent crushed gravel with the sharp edged fractured faces Eddie is talking about. Spec calls for at least 50 percent of the rocks held on a one inch screen to have at least one fractured face and for half the weight of the sample to be rock bigger then 1/4" and half or less sand with less then 12% passing a number 200 screen. Concrete can be made with screened and washed bank run stone but crushed river stones or crushed ledge make higher strength concrete due to the fractured faces and rougher contact surfaces. They usually use all crushed ledge here as we have plenty of it. Out in the plains states you have to go miles to get a load of good hard stone and they often make do with what is available locally.

 

[PILOON]

Years ago I was pouring a foundation and ordered what I calculated was the correct amount of concrete.
Smart a-- sales rep insisted on coming to measure and quote.
The result was about 1.5 yards more than I wanted but had to pay for.
Told the driver to pour on the steep part of the drive and that I'd spread with a rake.
OK, he spread as best as he could and I raked it to about 3-4".
Great traction for that first year,
Well, for the next 3-5 years I kept plucking clumps of untamed messy concrete.

Moral is that you must have wire grid to hold it all together or it simply breaks up.
Naturally frost did not help.

 

[paulharvey]

Years ago I was pouring a foundation and ordered what I calculated was the correct amount of concrete.
Smart a-- sales rep insisted on coming to measure and quote.
The result was about 1.5 yards more than I wanted but had to pay for.
Told the driver to pour on the steep part of the drive and that I'd spread with a rake.
OK, he spread as best as he could and I raked it to about 3-4".
Great traction for that first year,
Well, for the next 3-5 years I kept plucking clumps of untamed messy concrete.

Moral is that you must have wire grid to hold it all together or it simply breaks up.
Naturally frost did not help.

For concrete yes; but we are really talking about making a soil cement out of his existing base/subgrade. Portland cement concrete typically has 2500-5000 psi compressive strength (and higher for special mixes); soil cement is (in florida) rated at 300 psi or 500 psi. It's not meant and a final product, but as a base to pave over. It is hated by some, liked by others; but it's the only realistic option in some areas far from rock. It is generally a good option in clean sand soils, far from limerock mines.