Can concrete be poured over crushed asphalt?

[Marion3]

Alright guys, Need some opinions.

Almost done framing in the 24x40x10. Neighbor came yesterday and ripped sod out with his tractor. Pouring concrete is out of the budget right now and might be for a couple years (newborn on the way, re roofing the house next year)

I would like to get some crushed asphalt for the driveway and fill the barn up to bottom of skirt board. Local concrete places said to pour sand until you do concrete. I didn't ask about crushed asphalt(new thought). I was thinking the crushed asphalt wouldn't be such a bad surface to work on for time being, and come winter I won be dragging in sandy snowy boots back into the house.

Is this something somebody has done before or is it not a good idea as future concrete base?

 

[bobscogin]

Yes, it'll work fine provided there's no organic material such as grass under it and you have proper compaction.

Bob

 

[Fatandre]

Why no organic?

 

[NUTTSGT]

Why no organic?

It will rot and decay over time creating a void under the concrete.

 

[Marion3]

I have already ripped the sod and three inches of dirt or so out of the barn, no organic material

 

[Justanoldguy]

Go for it.
By the time you do concrete, you will have a nice solid base.

 

[JRock10]

We have milled asphalt in our shop parking lot and some of it has compacted like it was paved.

Tapatalk...my downtime occupier

 

[Mike518]

Yes, it will be fine. Like the other members say, ensure that the asphalt is compacted fairly well.

Has it been grinded or milled? the smaller and more unified the asphalt mills are, the better compaction you'll get. Its nearly impossible to get adequate compaction with 1" material surrounded by 2"-3" material. It sounds like you're getting it from a pit so I'm sure its grinded properly.

It depends where you are but asphalt millings could be cheaper than sand. I'm stuck paying $35/ton for sand in some places but $14/ton for recycled asphalt.

Its sounds like it will be a temporary surface for a year or two before concrete. Structurally, your asphalt is stronger than a 3/4" minus base course you may use as a concrete base anyway.

 

[James-W]

If it were me, I would go with the sand. Crushed asphalt is probably OK, I don't know why it wouldn't be, crushed rock is probably OK too, but sand has been used as the base for concrete for a long time. I think if it were me, just to be safe, I would go with something that has been proven to work time and time again. Maybe crushed asphalt has been used before without any problems, I don't know, I didn't do any research on that. But I do know sand is the most common thing used for the base so if it were me, I would use sand. But that's just me and my opinion.

 

[Mike518]

If it were me, I would go with the sand. Crushed asphalt is probably OK, I don't know why it wouldn't be, crushed rock is probably OK too, but sand has been used as the base for concrete for a long time. I think if it were me, just to be safe, I would go with something that has been proven to work time and time again. Maybe crushed asphalt has been used before without any problems, I don't know, I didn't do any research on that. But I do know sand is the most common thing used for the base so if it were me, I would use sand. But that's just me and my opinion.

most concrete base is usually a (3/4" minus) crushed rock with fines in it. I've poured a many yards of concrete in my life and I would never choose sand over crushed base.

If he is going to have sand on it for a while, it will collect quite a bit of foreign material and make for a bad subbase when he goes to pour a year down the road.

If was me and those options, I'd choose asphalt millings hands down, use it for a year or two, then roughen up the asphalt and place concrete.

 

[joes169]

If it were me, I would go with the sand. Crushed asphalt is probably OK, I don't know why it wouldn't be, crushed rock is probably OK too, but sand has been used as the base for concrete for a long time. I think if it were me, just to be safe, I would go with something that has been proven to work time and time again. Maybe crushed asphalt has been used before without any problems, I don't know, I didn't do any research on that. But I do know sand is the most common thing used for the base so if it were me, I would use sand. But that's just me and my opinion.

You must live in a different part of SE Wisconsin than I do. I pour concrete for a living, and I'd say less than a fraction of 1% of flatwork here is placed on sand. Maybe the occasional homeowner, but that's about it.


As for the crushed asphalt, I've poured over it in the past with no problem, other than the complications that come with breaking it back up if it's too high for the concrete......

 

[James-W]

You must live in a different part of SE Wisconsin than I do. I pour concrete for a living, and I'd say less than a fraction of 1% of flatwork here is placed on sand. Maybe the occasional homeowner, but that's about it.


As for the crushed asphalt, I've poured over it in the past with no problem, other than the complications that come with breaking it back up if it's too high for the concrete......

Over the past years I have seen drive numerous driveways getting prepped to be poured, as well as garages being built on slabs. In just my neighborhood alone there have been several badly cracked old cement driveways, as well as "rough looking" blacktop driveways, ripped up and a new concrete driveway poured, mine included. Every one of them, not one exception, had sand as the base. Sand may be used 1 percent of the time where you are, but locally here it is used 100 percent of the time. Well, maybe not 100 percent because obviously I don't see EVERY site in my driving around town before it gets poured. But every concrete driveway and garage slab I have seen has used sand.

 

[joes169]

Over the past years I have seen drive numerous driveways getting prepped to be poured, as well as garages being built on slabs. In just my neighborhood alone there have been several badly cracked old cement driveways, as well as "rough looking" blacktop driveways, ripped up and a new concrete driveway poured, mine included. Every one of them, not one exception, had sand as the base. Sand may be used 1 percent of the time where you are, but locally here it is used 100 percent of the time. Well, maybe not 100 percent because obviously I don't see EVERY site in my driving around town before it gets poured. But every concrete driveway and garage slab I have seen has used sand.

I'm fairly confident you're confusing "gravel" with "sand".........

 

[Justanoldguy]

You pretty much CAN'T com pact sand, so you base will ALWAYS be unstable.
James ...( In just my neighborhood alone there have been several badly cracked old cement driveways, as well as "rough looking" blacktop driveways, ripped up and a new concrete driveway poured, mine included.) Maybe that is the original reason all them drives etc are being ripped up.
They were put on sand.

 

[Marion3]

I called and talked to the pit/concrete yard, The guy said crushed ashphalt would make a great base, he originally told me to get sand but then I asked about asphalt for a few years to work on, had 10 yards delivered this morning for 9.75$ a yard plus trucking.

It is an asphalt gravel sand mix, about 75% asphalt 3/4" down to fines.

 

[jhelrey]

Late to the party.... NM

 

[Nighttrain]

I would say why they use sand so much is because they expect to have to dig forms beams and plumbing in to it before they place the cement. Around here they use composed granet. It is compacted in and makes a great base. You just don't want to have to dig into it. Your idea is great.