# Granulated asphalt



## PMK (Oct 12, 2004)

This is an open question for more information about this reclaimed asphalt as a trail base. This is not pavement, but rather asphalt that has been removed from old roads by these huge machines that kind of grind it up into small pebbles. 

One of our local trails within a county park, is inside an old landfill. With the cost of roadbed and shellrock being fairly expensive, Solid Waste made the recommendation of utilizing granulated asphalt for the trail bed. It is a neat idea since cost is very low and in this application it utilizes another recycled product, similar to recycling the entire landfill into a county park.

However the park department has concerns and asked for more information...

So has anyone ridden a trail of this base? Anyone have any details on building with this stuff? If there are other locations that utilize it can you list them or link them?

Thanks
PK


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## was98strat (Jul 10, 2007)

Why whould you use anything for mountain bike trails? Usually we just clear the under brush and go. Are you trying to build "rail-trail"?


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## HarryCallahan (Nov 2, 2004)

Since the original poster's profile says they are in Florida, I'm going to guess that they might be using a base material for drainage in an area with high groundwater, poor drainage, lots of rain, high vegetative content in soils, or some combination of the above.

I haven't heard of this material being used as a base rock in trail applications, but it is a smart choice for road and parking lot base. In a park application, I think I'd want to know how inert it is and whether it will leach petro-chemicals or other toxins into the ground water.


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## ~martini~ (Dec 20, 2003)

Not everyone can 'build' a trail by clearing and sweeping.

I can see some valid use for something like that. I wouldn't totally rely on it, but for a highly sandy area, adding this to the mixture could easily and cheaply firm up the trail bed. The only thing I'd be really concerned about would be the oil content of the asphalt. I'd definitly find a way to have an EIS done with the material to see if it'll have an ill effect on foliage/fauna.


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## Francis Buxton (Apr 2, 2004)

First and foremost, my recommendation would be to contact a local geotechnical engineering firm or geologist. The geotech guys should be very familiar with it as a construction material, and should be able to give you a more solid opinion of its inertness. Geologists and soil scientists also spend a fair amount of time analyzing soil pHs and how soil and rock interact, etc.

My initial impression is that it should be pretty inert. It is simply ground up asphaltic pavement, which is simply a mixture of limestone (or other local rock) and bituminuous content (the oil/binder). It should be just as inert as "standard" asphalt pavement, b/c you haven't done anything to it to truly alter its makeup (other than grind it into basically the original rocks which are now covered in bitumen). If asphaltic pavement posed a danger of leaching into groundwater sources, etc., the environmental groups would have stopped it years ago. I'm a plain old civil engineer, so I've studied mix designs and done testing on asphalt, etc., but I don't really dive into the true "science" of asphalt, which is why I would suggest contacting a local geotech to see how they think it will interact with local soils, groundwater, etc. My initial impression is that it will be fine.


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## vtvirga (Aug 10, 2007)

*worth a shot*

I used this stuff several years ago building a multi-use/bike trail just outside Freeport, Maine at a state park and was impressed with it's ability to harden spots where the grade got a bit steep but re-routing was not an option, It's got great binding properties, it's cheap, easy to work with and recycled. You're in a Landfill, right? It might be there whehter or not you're making a trail with it so I can't imagine there would be a problem. Good Luck. 
MM


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## UncleTrail (Sep 29, 2007)

Those are called asphalt millings. They're leftovers after your local DOT grinds a road down for resurfacing. low cost = free + hauling to site.

For me, depends on the type of trail. Are you building sustainable singletrack or a multi-use trail? personally, i avoid them on commuter or multi use trails where you might see people riding road bikes or cross bikes because if they do "set up" it's like riding on a potholed street after they break down several years later. I'd rather have crushed limestone, or crusher fines.

You would also need to think about compacting them afterwards with a plate packer or roller.


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## PMK (Oct 12, 2004)

These are all superfantstic replies.

The trail is somewhat unique in that the entire park is on an old landfill (dump). This site was closed years ago and has since been covered with a protective membrane, which was then covered with soil and has over time grown grass and such.

Circa mid 1990's when the site was opened as a county park, it was considered one of these newer type landfills that was using the land wisely, allowing a second life, so to speak, of the land by having soccer fields, basketball courts, pavilions, baseball fields, rc model airport, and equestrian trails.

Getting to the cycling end, this huge pile of membrane protected debris, was considered a great location for off road cycling in an area with no hills. So with few trees for shade, a trail was laid out and built, providing a couple of miles of climbing and descending.

The original trail was a ribbon of crushed shellrock that snaked all over this hill.

After several years of use, wear had occurred from riding plus erosion on account of rainfall.

Leading back into the original question in regards to granulated asphalt, those suggesting various tests have valid points. The concept of this material was not conceived by the cyclists, the granulated asphalt was actually a suggestion from the managing authority of this landfill turned park, and his staff.

This park previously had two nearly separate trails. One occupied this reclaimed landfill hill, while the second is a singletrack around the entire facility. The trail which needs the granulated asphalt is on this hill. Shellrock or roadbed is expensive and difficult to obtain. Granulated asphalt is basically free, plus in this application is also recycling another material, kind of like the entire theme of this landfill.

The big question at this point though is, are there any other locations using this as a trail material? The park department is asking for more information, so at the moment I'm gathering some facts.

Just to clarify, the trail will not be multi use, and should see 99.9% MTB traffic. The layout will again be a winding ribbon approximately 18 inches wide with grass on both sides. With 100% situated on hillsides, errosion is a concern, obviously proper grades are key as referenced in IMBA manuals.

All said what should we expect if we attempt it, or would it be better to apply efforts elsewhere and not save this trail?

Thanks
PK


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## HarryCallahan (Nov 2, 2004)

Wow! I wish I cold add more technical info. My day job involves recycling, and I am a life long cyclist, so I've got work and play co-inciding here.

I bet there are some trade associations where you might get a hit on this topic: Trailbuilders, landfill operators, paving companies, etc.

I thought the post mentioning that this is material already in the landfill was a very good point. If you can't find a good example of this having been done somewhere else, why not try it? As you've mentioned, the material is basically free. Myabe there are some state or federal grants floating around for creative re-use, or maybe a local company would donate some expertise in exchange for some good PR.

I say do a little more research, but go for it!


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## PMK (Oct 12, 2004)

I must add a little more to clarify, the granulated asphalt is not on or in the existing landfill this park is built upon.

Solid Waste Authority, are the landfill owners. They suggested the use of the granulated asphalt.

The county which leases the landfill has built the park. The county is questioning the use of the granulated asphalt. They question it for not only environmental effects, which in my opinion seems odd since Solid Waste owns this land and why would they advise a detriment or enviro hazard to their own facility.

The county is also wanting more details in regards to it's ability to build a reliable trailbed, and one that is safe beyond safe for the balance challenged. This is their requests. 

After they have expended all methods of why it might be bad, then maybe they will allow the trailbed to be rebuilt. It's not quite as simple as to just give it a go.

At the moment, the entire trail is no longer ridden or used. The club would like to get it reopened, but restoring it to original is cost prohibitive using shellrock. Solid Wastes method seems to make a lot of sense.

BTW, it is difficult to get shellrock as was used originally, one issue is cost of material, the second issue is that the county utilizes most of the shellrock they dig, for base materials for their new golf courses.

PK


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## Fishtoes2000 (May 28, 2004)

Our local rail trail had great success using recycled asphalt tailings. The trail is wider than 18" but they still did a great job and got great results. One trick they used was to trench the trail then fill it the tailings. By doing that, the trail didn't have crumbling edges and looks very natural.

For more information, contact Mike Hartner, the head of Parks and Forestry for Rochester Hills, Michigan. His email is hartnerm -at- rochesterhills -dot- org. Tell him Todd Scott sent you.


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## Francis Buxton (Apr 2, 2004)

We had a 1/4 mile section of existing trail that went through a fragipan area (fat clay on top of an impervious dolomitic limestone "bowl", so it doesn't drain) that we needed to stabilize when adding an additional 9 miles of singletrack. We used local rock from a local quarry, but your net construction application is pretty much the same. We walked it in with wheelbarrows and spread it with McLeods or rakes. We then vibrated it in with a vibratory plate compactor.

So far, it's holding up very well. I will warn you, though, that it's a fairly time consuming task. We had about 15 people with about 6-8 wheelbarrows ferrying it from the parking lot to the install location (which constantly got farther from the parking lot). Make sure the soil is a bit damp/wet when you do the install so that you can "punch" it into the soil.


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## alxbrsk (Oct 8, 2006)

we used road millings here in western new york to harden short feeder trails that came from a parking lot on flat land (no drainage). They harden into an excellent trail surface that is almost like riding on pavement (or rock). 
I would suggest trying it out


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## ickyickyptngzutboing (Mar 30, 2005)

I'm not sure how much of a say you have in this, but from working in heavy site-work/civil construction, these asphalt millings come in a variety of sizes. This varies with the particular road that's being milled, varies with the temperatures, and varies with the actual condition of the teeth and drum on the milling machine. So, before something is brought, see if you can take a look at the millings to make sure it's a size that's suitable to you. I highly doubt you'll get millings that are too small, but you may run into some rather 'chunky' millings (most likely from a machine traveling too fast) that can be a bit of a bear when it comes to spreading and long-term longevity of the trail.

Other than that, I think it's a fantastic idea, and I can't really think of any negative environmental impact (not that it's all-ruling, but I do have a Geosciences degree) and I would jump on the opportunity to try it out!


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## PMK (Oct 12, 2004)

Another day and more great information. This a huge help.

The issue of the size of this stuff was questioned, no answer yet. 

Also last night I spoke with another cyclist involved, I mentioned that it might not be a bad idea to get a small load (a pickup bed or two) of this stuff and see how well it performs with mtb tires, the efforts and techniques to install, and then gain an idea as to how well it holds up.

Those that have used it, or ridden it, can you list the specific details of the locations.

Those that posted contact information, thanks, I plan to get in touch with those people very soon. I'd want to see if anyone comes back with any real negatives.

Out of curiosity, any comments as to how well this material will remain placed on hills and slopes, especially in rain.

Someone mentioned it did pack fairly well, however when riding upon it, does it remain fairly soft and ride like loose gravel or over time will it bed in and be more of a hardpack easy rolling surface? I'm not wanting or expecting it to magically reform into pavement, which maybe it may try and do in the hot south Florida sun.

Few more replies and I'll stop bothering you guys.

Thanks
PK


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