Properties of a reclaimed asphalt surface?

[awl51]

Surfacing the driveway/parking area at the new place in Maine was the last major item after all the heavy trucks were finished with their building supply loads. The base rock was all down and well compacted, and I had decided that I wanted a reclaimed asphalt top course. I had 16 yards of RAP delivered the first week of December - much later than I would have liked, but there you go -- spread it with the loader and box blade, and went over it twice with a plate compactor, resulting in a 3-4" layer over about 1000 sf. When I got finished, it looked pretty good, was reasonably smooth, and was pitched well, so I was happy with the result. However, we had a downpour the next week, and the RAP turned soft - I could lightly drag a spadepoint shovel across it and start gullying the surface. When it dried out a little, I ran the compactor over it again and it firmed up somewhat. Shortly thereafter, the ground froze over, so I'm done experimenting with the drive until spring.

So, my question is, what can I expect for eventual performance for this type of surface? What's been the experience of other folks out there? I initially expected a surface that was pretty solid once it got compacted and consolidated. Do I just wait for warm weather or more traffic for it to set up with a firmer surface? And, if so, will the surface firmness likely be permanent, or should I expect it to vary with conditions (e.g., would it regularly tend to be more friable in spring?)

Oh, and one more question for those of you with reclaimed asphalt drives - has anyone been tempted to use a slurry sealer (the thick heated commercial stuff, not the 5 gal brush-on asphalt driveway 'sealers') to really smooth out the surface?

Thanks in advance.

 

[PILOON]

I did a portion of my drive some 12 years ago and the only compaction was a loaded dump truck with bald tires. That material was chunky and needed to be broken and spread with a backhoe.
It has held up very well! Everything kinda fused together like real pavement.

Recently I purchased a couple of yards of 'prossesed' recycled and it is just not the same. Almost looked like they added 'dusty dirt' and it would not stick or compact.
Only advantage over gravel is that it does not wash out in heavy rains.

As to sealing, my opinion is that only a solvent type sealant would be of use as most commercial sealants seem to be water based.
I inquired as to buy what they use commercially and found that there exists a liquid that they use when they overlap paving runs.
Here they call it "collase'. I'm shure that is a local term.
You probably have seen workers with watering pails dribbling that stuff at laping joints.
Being fairly costly I did not try it.
What I have observed is whenever I might spill gas or fuel on pavement it first disolves but later sets up nicely.
My guess is that that seam joint liquid is a mixture of tar and solvent that quickly evaporates.

Heat and sunlight is your friend with that recycled material, so come hot summer you could just be in great shape.

 

[Raspy]

We had our steep asphalt drive that was 20+ years old and cracking, coated with that slurry stuff. It really improved the surface and I'm sure it greatly extended the life of the driveway.

Out in front of my other place, the city had a slurry put on a couple of years ago and it seems to be a great thing. It was soft for a day or two and it set up to a kind of stretchy/sandy tar. It has now settled in and seems very good.

At first that stuff just seems like a thin coating that won't do much, but it seems like a good way to stop cracking and moisture damage.

 

[Egon]

Talk to a local paveing contractor and find out what they use for "Tack Coats".

 

[dodge man]

Don't expect it to be like a true hot mix ashpalt driveway. They can kind of pack in a seal pretty good. A lot of it depends on how "rich" the used ashpahlt is. Ashpalt kind of dries out over time and breaks down. If it is a mix that is dried out and doesn't have a lot of asphalt in it, don't expect it to be much better than gravel.

 

[ITHINKICAN]

Please post some pictures - so those of who are stuck in a cubicle dreaming about the weekend have something to look at

Hope it works out. We hope to do a driveway this summer.

 

[crashz]

Like the 1st reply mentioned, you won't see much benefit over the gravel until you get some heat. The remaining asphalt will soften, and if you compact again this summer (wait till its a scorcher), the mix will gain more density and will actually smooth out some more. After that, the mix will act as solid as normal blacktop during the cooler seasons.

Tack Coat is an asphalt water based emulsion that is used at joints and between layers of pavement as a bonding agent. Do not use this as a top coat. It will stick to everything and cover your tires, car body, shoes, floors, etc. Its very tough to clean.

 

[Egon]

Spread sand over the tack coat.

 

[crashz]

True - a fine sand will keep it from sticking to you. We've also used sand blastin slag (Black Beauty) as its very fine and black.

 

[beenthere]

A top coat of seal and pea gravel rolled on will set it up quite well, if it is an oily seal.
Be sure to have the surface packed and level before applying the seal coat. Reclaimed can make a very fine driving surface. But not until it is sealed.

Just spraying used motor/hyd oil on it will also tack it together.

 

[kub32guy]

I work for a paving company in pa. What you have is recycled asphalt products (RAP), old shingles, tires etc. The state requires so much RAP in the asphalt that is used a state roads. RAP may include so ground up blacktop but to the best of my knowledge is not blacktop. PiLOON described what you are looking for, it is referred to as millings. When resurfacing roads they sometimes mill off the top inch and a half, then lay a new layer of asphalt. Millings generally do have chunks in them, and when reused and rolled , especially in the heat of summer will become a very nice hard surface. If you can get your hands on some milling it should suite your need very well. Hope this helps.

 

[Egon]

Just spraying used motor/hyd oil on it will also tack it together

It may look good short term but long term very negative affects.:thumbsup:

 

[Egon]

Just spraying used motor/hyd oil on it will also tack it together

It may look good short term but long term very negative affects.:thumbsup:

Engine/hydraulic oils are paraffin based. Asphalt is Bitumen based.

 

[Scotty370]

Kub-Thank you for clearing that up for me. I thought that they might be talking about 'millings'. I not familiar with RAP. I hear 'millings' are super, but tough to come by (unless you 'wired in with the Hwy Super) and you should grade them out, and roll them, relitively soon after delivered... ~S

 

[beenthere]

It may look good short term but long term very negative affects.:thumbsup:

What "very negative" affects (effects)?

 

[MMH]

I work for a paving company in pa. What you have is recycled asphalt products (RAP), old shingles, tires etc. The state requires so much RAP in the asphalt that is used a state roads. RAP may include so ground up blacktop but to the best of my knowledge is not blacktop. PiLOON described what you are looking for, it is referred to as millings. When resurfacing roads they sometimes mill off the top inch and a half, then lay a new layer of asphalt. Millings generally do have chunks in them, and when reused and rolled , especially in the heat of summer will become a very nice hard surface. If you can get your hands on some milling it should suite your need very well. Hope this helps.

Yep, I'll be looking for blacktop millings myself for a driveway project.

 

[woodlandfarms]

This spring we had our mile long driveway/road covered with grindings. Compacted with a roller.... This was done by some of the neighbors, done with best intentions but not a ton of skill.

This winter, more pot holes than ever before.

It is ALL about the road base. If you don't make a good road base that drains properly this stuff is no better than gravel.

 

[Don87]

What "very negative" affects (effects)?

oils and gasoline/diesel will 'eat' thru asphalt

 

[Joel888]

In NC "RAP" is what we call millings that have been processed through a crusher to most of the time a minus 1/2" size and millings are straight from the milling machine...both will work for driveways albeit both can have a very high minus #200 content (dust). They will compact but if you can get them to hold out to very hot day and roll them the residual Asphalt in them will be more fluid and compact alot better. A few paving contractors have had success with running RAP through a paver with the screed very hot and get compaction that way. If your stone base has been compacted to a reasonable density then i would think they should hold up till warm weather. I have not seen the slurry sealer do very much when applied to RAP but i have also not seen every product that is available.