Let s Talk About Crushed Stone

[MikeR 2018]

I am trying to understand crushed stone sizes and types but can t find a definitive guide or explanation. I realize that different parts of the country have different quarries so there may be no common definition but I thought it best to ask all of you.

What I know so far:
Gravel is rounded river rocks.
Crushed stone is big rocks that have been crushed to a specific size. Modified means the crushed stone was not washed to remove the rock dust it packs better.

What I DO NOT know
I thought that sizes like 2A meant the largest stone was 2 inches but I may be wrong. The letters confuse me. I hear that 2B is smaller than 2A. Huh?

Some is called AASHTO with a number after it, like AASHTO #57. How does that work?

I need some top dressing for my drive and in front of the barn. Our horse walks on this so the stone needs to be small enough so that it does not get stuck in their hooves.

I may need something for French drains. I assume that is washed but what size?

Finally, what is anything else about crushed stone that you know?

 

[Diggin It]

I've used something known to me as 'Quarter-Zero' which is basically more like very coarse sand. People tell me that if you do it right, well compacted and watered in, it will set up almost like concrete. I used it on a walk path and when I tried to change it later to a poured concrete sidewalk, I had to break a lot of it with a pick-axe. The surface stayed gravel like though with loose but very small stones.


Can't comment on the horse hoof issue.

 

[MikeR 2018]

I've used something known to me as 'Quarter-Zero' which is basically more like very coarse sand.

Sounds nice but I never heard of it. Maybe I can ask my quarry

 

[bcp]

This may help.

Bruce

 

[mikester]

Crushed stone is angular and packs better than crushed gravel.

For drainage you want something like 3/4 clear (no fines), crushed gravel works well for this.

My personal preference for making nice driveways and walk ways is at least four inches of 3/4 crusher run crushed stone topped with one inch of 1/4 crusher run chrushed stone. The fines help it pack nicely, easy to keep smooth and packs like cement - great for cars/motorcycles etc. Sorry I don't know how that would affect horse hooves/shoes.

Ask your local supplier for exactly what the differences are in what they supply.

 

[Shblack]

We have used a couple of products, all crushed limestone:
- Crusher run, which is smaller gravel through limestone dust. Packs well, gives a good driving surface but can be dusty when dry. We put it down when things are wet, then roll it - road surface holds up better
- Float rock - 2-3” pieces, good for a road underlayment, French drains
- Rip-rap, typically 6” to 12” pieces, good for stabilizing creek banks or controlling erosion
- Shot rock - What gets scooped up after blasting, no crushing, can be pieces >2’, good for fill and creek banks, lowest cost per ton.

When we redid our driveway (runs next to a creek, creek would flow over the driveway and wash it out), we built the level up 18” using rip-rap, then put down 6” of float rock to fill in the gaps between the rip-rap, then topped it off with 6” of crusher run

 

[MikeR 2018]

This may help.

Sure does. Thanks.

I m from Pa so this fits my area. I also work for PennDOT (computers - not roads). I should have looked for their documentation.

 

[Diggin It]

Looks like what we're talking about is their #10 or smaller. Others mentioned 1/4 crusher rock, or crusher run.

 

[Ford850]

Your stone will be similar to what we have here. I'd suggest 57's for the drainage. They are all similar size and no dust. For the drive topping, it depends what you're trying to do. We have what's called 411 size, which is approximately 3/4" down to fines and dust. It packs well and it's what I use for general repair, fill, and topping. If you want a clean small thin top coat, then go for 8's or 9's which provide a nice quiet and clean surface. But they don't pack so they stay loose... use as a thin coat only.

 

[herm0016]

another option, recycled concrete. it's usually cheaper and it packed very well. includes the aggregate and the concrete fines. I find it strange that each region has its own names for different grades / sizes of gravel.

 

[RedNeckRacin]

Sure does. Thanks.

I m from Pa so this fits my area. I also work for PennDOT (computers - not roads). I should have looked for their documentation.

Anybody in pa is going to use the penndot or aashto designations. All the other terms ppl like to throw out will get you a blank stare. Also, you can call the larger hauler in the area and depending where you are at hawbakers in pleasant gap will quote you a delivered price for a tri-axle load of stone of what ever size you want from anti-skid to R-8. They usually get around 25 ton on a truck and the last load I got of 2b was around 600 with an hour and a half in trucking.

 

[Tractor Seabee]

It was mentioned earlier about drainage rock. For that you want straight graded smooth river/pit run rock. Any crushed will pack together and ****** the flow of water through it. You want all the open spaces you can get. They commonly call it "drain rock". I never use anything smaller than 1". Drain rock is self compacting. Trying to compact just pushes it into the surrounding soil.

Ron

 

[DJ54]

Since you work for PennDot, check and see what they use for berm gravel (common term). It should be crushed limestone consisting of 67's (3/4") limestone, down to dust. Also known as 67D, and probably several other names. I'm retired from ODOT, so I know numbers can vary from different quarry's, and gravel pits. If you run cars, trucks & equipment across it, if put down pretty damp 2"-3" deep, it should pack well, and lock together. If it's in a circle drive, you may get a few stones to kick out. If straight, not so bad. But, it is best to have it wet, then roll several times with your tractor, and it will pack well.

With that being said, there are two types of limestone fresh water, and salt water. The fresh water stone is found closer to the surface, is softer, and will break down sooner, and basically turn to mud, under heavy traffic. Salt water stone is more preferred. It probably won't make that much difference in a driveway though.

If you have problems with a muddy paddock, #10, or, screenings limestone works great to keep a hard surface in there. I put it down approx. 4" thick, and rolled it in with my Bobcat. Again, this was put down wet. With the horses walking on it, compacts it even more. Some slope to shed water is even better. When it dries, it gets very hard. I clean the paddock with my Bobcat, and it's nearly like loading off concrete. I put the first down in 2012, and just now needing to top dress it.

In all of my French type drains here, I used #8 washed gravel, or, pea gravel. 99% of the drains we put in, when doing slip repairs on highways, this is what is used. For no more than it costs, I also put a 4" perforated pipe in, to keep it from silting in. The main concern is putting something on top of the gravel to keep dirt from sifting down through, plugging the drain. On the job, we used Geo-Tech cut in strips, and laid overt the gravel. It was left over from contractor jobs. They made it a policy to recoup materials left over from construction jobs. It came in handy for many jobs we did. Here at home, I use the better grade landscaping material. I've been called out on that one, but back years ago, when they put in leach beds around here, they covered the gravel with approx. 1' of straw for a dirt barrier. When dirt is put back, and finally settles, it won't be much over an inch thick mat. Same was done on the first few drains we put in years ago. We've had to go back and repair a few drains that were put in 10-15 years before I even started, and the straw was still there, although somewhat deteriorated, but still doing its job. As long as the air doesn't get to it, it will last for years. I put my drains in nearly 10 years ago, and all are still working like they should. All but one are covered with 6" to 8" of dirt, and sodded over. One in particular is in the one pasture. Water will pond in it after heavy rains, but will perk down through the sod and dirt within an hour. The one with gravel to the top, between buildings, I put the cloth down approx.6' to 8", then topped with gravel. It never ponds water, and has been in for 6 years or so.

 

[Diggin It]

I also put a 4" perforated pipe in, to keep it from silting in. The main concern is putting something on top of the gravel to keep dirt from sifting down through, plugging the drain. On the job, we used Geo-Tech cut in strips, and laid overt the gravel.

Thread morph. I need half-perf. I want water to filter in from the top and be carried away with no chance of it leaking out the bottom back into the ground. Last time, I made it by drilling a bunch of small holes into one side of a 3" pipe. I need a longer piece now and was hoping not to have to repeat that process.

For silt/mud, I wrapped it with fabric weed cloth.

 

[Streetcar]

Thread morph. I need half-perf. I want water to filter in from the top and be carried away with no chance of it leaking out the bottom back into the ground. Last time, I made it by drilling a bunch of small holes into one side of a 3" pipe. I need a longer piece now and was hoping not to have to repeat that process.

For silt/mud, I wrapped it with fabric weed cloth.

I have never seen factory half perforated pipe.

 

[PILOON]

I have never seen factory half perforated pipe.

Pipe used for septic fields, usually 3 or 4 inch, is just that.

 

[Streetcar]

Pipe used for septic fields, usually 3 or 4 inch, is just that.

My septic had the normal perforated pipe with perforations on all sides

 

[Diggin It]

This could be one of those Us and Them things. When I did a search for 'half perf drain pipe', I got a few hits from a UK site. So, maybe UK and CAN have it but not US?

Possible?

 

[FM504]

Here in Texas I used decomposed granite (DG) to build a half mile road in and circle drive in front of the house ...it packs really well and is pretty easily maintained with a box blade. Have horses as well and they sometimes get on it and doesn’t hurt their hooves at all.

 

[Diggin It]

If I find out I have to make it again, I may try a woodworking tool called a biscuit joiner. Has a small saw blade and is spring loaded. Position the work, push the cutter in, then release, reposition the work, repeat as needed. This would yield small saw cut slits instead of round holes. Water don't care, but combined with the fabric wrap, it might control silt better and maybe be stronger against collapse. Just WAG-ing on both though.

This would be along the base of a short retaining wall to direct water away so it won't want to seep under. I could lay a couple of inches of drainage rock before backfilling the trench.