Rethinking Asphalt Millings - Addressing Washout

[MGH PA]

About a year ago, I had rolled asphalt millings installed on my ~1/2 mile driveway. They were supposedly screened millings, and they were put in with a paver and rolled. Initially, they held up well. Over time, they have started to unbind and the top layer is a very fine material that gets tracked into our garage/house all of the time. Not to mention, we are having wash out events with some crazy heavy rains we have had this summer. The guy who installed them has been out and keeps recommending chip sealing or at the very least, fog sealing, but even he admits the latter won't help much with heavy rain events. The problem is that worst section is in the last 800' through the woods to the house (see photos). The excavator who built the road 4 years ago opted to no build up the rd and run pipe, but rather, rely on the heavy shale base, and natural topography to shed most of the water. This was never an issue when it was compact shale the first three years, but the millings can't handle the heavy water.

I'm on the fence as to what to do next. chip seal is too much $$, and fog sealing isn't going to address the issue. I had one excavator tell me I would be looking at $6-$7K to fix the 800' section (build up a crown, run a ditch down both sides with a pipe at the bottom). My gut tells me to fix this issue first, but it's a bit irritating to have the road torn back up after just putting that money down with the millings. At least if I had went with compacted sub base, I could work it up with a blade after these storms unlike the millings.

Thoughts?

 

[scootr]

Very nice looking base. I would asphalt pave it.

 

[LittleBittyBigJohn]

I wonder if you could fog seal then use a smooth drum vibratory roller compactor on it after the fog seal tar had time to "soak in"?

 

[Torvy]

Looks like driveway sealer is a little more than $1 a square foot. Assuming 12' wide X 800' long...about $10k to seal yourself. That should give you a few years (it worked for us in Wisconsin).

Not suggesting you do that, just numbers for comparison.

 

[paulsharvey]

Commonly done on state roads that 'stabalize' existing dirt drives, millings (RAP), rolled, then primed and sanded. Any paving company should have a tack truck or atleast a tack wagon, and also a sand truck and traffic roller (not 100% needed). It does help, however, anything short of double application chip seal, asphalt, or concrete will erode if high velocity water flows on it. Should be pretty cheap. Keeps the dust and fines down, and does slow down erosion.


Millings are a great product, But there are a lot of people who say, "on a hot day, it turns back to asphalt"; that's complete BS. The AC (asphalt cement) content is low (thats why it was milled off, cause it was failing already), and an asphalt plant isn't running at 110-130 degrees; it's running 350-385... If millings where "just as good as asphalt" we would build roads with it as surface coarse.

 

[bdhsfz6]

I maintain 1.5 miles of private road and over the years, have tried about everything you can think of. Washouts are a constant problem on the sloped sections. Rolled millings worked well for 2 years or so but it would eventually "chunk out" leaving potholes to fill.

The road was originally built with a thick layer of red shale which wasn't bad at first but it eventually began to wash out in places. Surface wear also caused a dust problem and it would get into everything. I applied calcium which fixed the dust issue but I would have to apply it every couple of years and the cost became prohibitive.

I've been here 40 years now and the best solution was to apply a 4" over layer of local blue stone modified on top of the red shale base. I get it delivered for $13/ton. It packs down hard, wears like concrete, looks decent, has minimal dust and is easily worked to repair washouts. I keep a maintenance pile on hand and touch up any bad spots with a stone rake.

On an annual basis, the cost to maintain the road with modified is less than half what it was using any other material, with about the same amount of labor involved.

Obviously what works in some areas won't for every location so YMMV.

 

[ponytug]

I maintain 1.5 miles of private road and over the years, have tried about everything you can think of. Washouts are a constant problem on the sloped sections. Rolled millings worked well for 2 years or so but it would eventually "chunk out" leaving potholes to fill.

The road was originally built with a thick layer of red shale which wasn't bad at first but it eventually began to wash out in places. Surface wear also caused a dust problem and it would get into everything. I applied calcium which fixed the dust issue but I would have to apply it every couple of years and the cost became prohibitive.

I've been here 40 years now and the best solution was to apply a 4" over layer of local blue stone modified on top of the red shale base. I get it delivered for $13/ton. It packs down hard, wears like concrete, looks decent, has minimal dust and is easily worked to repair washouts. I keep a maintenance pile on hand and touch up any bad spots with a stone rake.

On an annual basis, the cost to maintain the road with modified is less than half what it was using any other material, with about the same amount of labor involved.

Obviously what works in some areas won't for every location so YMMV.

Can you elaborate on what your "blue stone modified" product is exactly? Thanks!

All the best,

Peter

 

[bdhsfz6]

Can you elaborate on what your "blue stone modified" product is exactly? Thanks!

All the best,

Peter

Local industry around here calls it 2A or 2RC modified. It is a crushed Pennsylvania blue stone mix, 3/4" diameter down to stone dust. It's mixed at several quarries around here with a high percentage of dust which packs & holds very well. If it's put down wet and rolled, it is almost like concrete.

 

[LittleBittyBigJohn]

Sounds a little like our SB2 Grade 7. It's 1.5 minus with fines. Local vernacular is "Road Base" it's what I have for my driveway.

 

[Paddy]

We fought wash outs for years on our steep hill. Our drive is what we call "53's". It's chip, dust and stone. In southern IN, it's all limestone. It does pack like concrete, but heavy rains can over whelm it and cause ruts.

Parks departments use a swale/speed bump system to divert the water off the road. The height of the "speed bump" is not so high and works just fine to direct the water to a ditch I scraped going perpendicular to the drive. The down hill side of the speed bump should gently extend 6 feet + down hill. By this, you only feel one side of the speed bump as you go up.

You do have to adjust your drive habit, but it works long term