Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway for
a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel into
one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

On 8/30/2010 11:46 AM, Bob wrote:
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway for
a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel into
one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

A: asphalt pavement is not liquid
B: the gravel is for drainagek and stability.

--
Steve Barker
remove the "not" from my address to email

On Aug 30, 12:06*pm, Steve Barker wrote:
On 8/30/2010 11:46 AM, Bob wrote:





Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway for
a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel into
one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

A: asphalt pavement is not liquid
B: the gravel is for drainagek and stability.

snip

Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of finer
fillers). Next time you drive by a highway surfacing project note the
big dump body trucks lined up there filled with hot mix. No liquids
there.

Joe

On 8/30/2010 1:31 PM, Joe wrote:
On Aug 30, 12:06 pm, Steve wrote:
On 8/30/2010 11:46 AM, Bob wrote:





Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway for
a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel into
one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

A: asphalt pavement is not liquid
B: the gravel is for drainagek and stability.

snip

Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of finer
fillers). Next time you drive by a highway surfacing project note the
big dump body trucks lined up there filled with hot mix. No liquids
there.

Joe

The liquid, sticky, or plastic part (asphalt cement) is only 5% of the
total mix. The rest is aggregate.

Joe wrote in
:



Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of finer
fillers). Next time you drive by a highway surfacing project note the
big dump body trucks lined up there filled with hot mix. No liquids
there.



Then there's "hardtop", which is common in my area on lightly-loaded roads:
You lay down the usual packed-aggregate roadbed, then spray really runny
tar on the surface. Then you spread pea-gravel on top of that, and just let
passing traffic roll it in the rest of the way. Excess gravel gets pushed
off to the shoulder over time. It's fairly durable if you keep heavy trucks
off of it.

--
Tegger

"Tegger" wrote in message
...
Joe wrote in
:



Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of finer
fillers). Next time you drive by a highway surfacing project note the
big dump body trucks lined up there filled with hot mix. No liquids
there.



Then there's "hardtop", which is common in my area on lightly-loaded
roads:
You lay down the usual packed-aggregate roadbed, then spray really runny
tar on the surface. Then you spread pea-gravel on top of that, and just
let
passing traffic roll it in the rest of the way. Excess gravel gets pushed
off to the shoulder over time. It's fairly durable if you keep heavy
trucks
off of it.

This is the classic Macadam-type of paving.

Micajah

"Micajah" wrote in
:



"Tegger" wrote in message
...


Then there's "hardtop", which is common in my area on lightly-loaded
roads:
You lay down the usual packed-aggregate roadbed, then spray really
runny tar on the surface. Then you spread pea-gravel on top of that,
and just let
passing traffic roll it in the rest of the way. Excess gravel gets
pushed off to the shoulder over time. It's fairly durable if you keep
heavy trucks
off of it.

This is the classic Macadam-type of paving.



I didn't know that. We just call it "hardtop". That's to differentiate it
from the softer gravel/sand mix which goes on roads that are lesser to
hardtopped roads. The big advantage of hardtop is that it's really cheap to
install compared to asphalt, but is a lot more durable (and cleaner and
washboard-resistant) than gravel/sand.


--
Tegger

Tegger wrote in
:

Joe wrote in
:



Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of
finer fillers). Next time you drive by a highway surfacing project
note the big dump body trucks lined up there filled with hot mix. No
liquids there.



Then there's "hardtop", which is common in my area on lightly-loaded
roads: You lay down the usual packed-aggregate roadbed, then spray
really runny tar on the surface. Then you spread pea-gravel on top of
that, and just let passing traffic roll it in the rest of the way.
Excess gravel gets pushed off to the shoulder over time. It's fairly
durable if you keep heavy trucks off of it.

This is a terrible way to surface roads. It really plays havoc on your
skates after a icestorm. DAMHIKT!

--
Best regards
Han
email address is invalid

On 8/30/2010 7:31 PM, Tegger wrote:
wrote in
:



Steve's right...you're confusing paving asphalt (contains a lot of
gravel aggregate) and roofing asphalt (contains minor amounts of finer
fillers). Next time you drive by a highway surfacing project note the
big dump body trucks lined up there filled with hot mix. No liquids
there.



Then there's "hardtop", which is common in my area on lightly-loaded roads:
You lay down the usual packed-aggregate roadbed, then spray really runny
tar on the surface. Then you spread pea-gravel on top of that, and just let
passing traffic roll it in the rest of the way. Excess gravel gets pushed
off to the shoulder over time. It's fairly durable if you keep heavy trucks
off of it.


This is known as "chip and seal" (although in actuality it's seal and
chip) in my area.

--
Steve Barker
remove the "not" from my address to email

Bob wrote the following:
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway
for a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel
into one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

To prevent or minimize frost heave for one.

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

"Bob" wrote in message
...
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway for a
residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel into
one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

The folk responding about asphalt are right, so I won't duplicate their
effort. However, you might also be recalling the old Macadam road technique
with the modern version. http://en.wikipedia.org/wiki/Macadam

In my home town, many of the streets were Macadam and they did very well.
Occasionally, the street department would employ a tractor with wheel disk
to turn up the streets, and then they'd be rolled smooth, with a thick layer
of asphalt then applied. The final touch was a new coating of pea gravel to
reduce tar pick-up by car tires. The streets held up beautifully and the
technique most likely would be considered, "Green," in today's world.

Micajah

On 8/30/2010 1:56 PM, Micajah wrote:


"Bob" wrote in message
...
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway
for a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel
into one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

The folk responding about asphalt are right, so I won't duplicate their
effort. However, you might also be recalling the old Macadam road
technique with the modern version. http://en.wikipedia.org/wiki/Macadam

In my home town, many of the streets were Macadam and they did very
well. Occasionally, the street department would employ a tractor with
wheel disk to turn up the streets, and then they'd be rolled smooth,
with a thick layer of asphalt then applied. The final touch was a new
coating of pea gravel to reduce tar pick-up by car tires. The streets
held up beautifully and the technique most likely would be considered,
"Green," in today's world.

Micajah

Where is your hometown? I noticed you used the word "Macadam", that is
a rare word in the US. Named for a man named John McAdam. The first to
use stone and roll it to lock the stones together to make better roads.
Later he added oil/tar on top to help it last through heavy rains.
That is were the word "Tarmac" became popular and is still used at
airports. I come from a part of PA, USA where the outdated word
"Macadam" was still used to describe asphalt/blacktop. If I use the
word today not many people will know what it means.

"Tony" wrote in message
...
On 8/30/2010 1:56 PM, Micajah wrote:


"Bob" wrote in message
...
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway
for a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel
into one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

The folk responding about asphalt are right, so I won't duplicate their
effort. However, you might also be recalling the old Macadam road
technique with the modern version. http://en.wikipedia.org/wiki/Macadam

In my home town, many of the streets were Macadam and they did very
well. Occasionally, the street department would employ a tractor with
wheel disk to turn up the streets, and then they'd be rolled smooth,
with a thick layer of asphalt then applied. The final touch was a new
coating of pea gravel to reduce tar pick-up by car tires. The streets
held up beautifully and the technique most likely would be considered,
"Green," in today's world.

Micajah

Where is your hometown? I noticed you used the word "Macadam", that is a
rare word in the US. Named for a man named John McAdam. The first to use
stone and roll it to lock the stones together to make better roads. Later
he added oil/tar on top to help it last through heavy rains. That is were
the word "Tarmac" became popular and is still used at airports. I come
from a part of PA, USA where the outdated word "Macadam" was still used to
describe asphalt/blacktop. If I use the word today not many people will
know what it means


The hometown is a small farming community in central MO, but dates back well
before the War of Northern Aggression. The streets there are nowadays a
typical mixed bag of asphalt, concrete and Macadam, but as far as I know,
the Macadam ones are still maintained by the occasional wheel disking,
rolling, new tar and a coat of pea gravel. FWIW, most of the older curbs
are cut granite.

Micajah

On Aug 30, 11:37*pm, "Micajah" wrote:

The hometown is a small farming community in central MO, but dates back well
before the War of Northern Aggression. *The streets there are nowadays a
typical mixed bag of asphalt, concrete and Macadam, but as far as I know,
the Macadam ones are still maintained by the occasional wheel disking,
rolling, new tar and a coat of pea gravel. *FWIW, most of the older curbs
are cut granite.

Micajah

Sounds like the "War" isn't over yet?

On Aug 30, 9:37*pm, "Micajah" wrote:
"Tony" wrote in message

...



On 8/30/2010 1:56 PM, Micajah wrote:

"Bob" wrote in message
...
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway
for a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel
into one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

The folk responding about asphalt are right, so I won't duplicate their
effort. However, you might also be recalling the old Macadam road
technique with the modern version.http://en.wikipedia.org/wiki/Macadam

In my home town, many of the streets were Macadam and they did very
well. Occasionally, the street department would employ a tractor with
wheel disk to turn up the streets, and then they'd be rolled smooth,
with a thick layer of asphalt then applied. The final touch was a new
coating of pea gravel to reduce tar pick-up by car tires. The streets
held up beautifully and the technique most likely would be considered,
"Green," in today's world.

Micajah

[...]

The hometown is a small farming community in central MO, but dates back well
before the War of Northern Aggression.

That's funny -- I thought it was the war to hold the Union together,
and secondarily
to free the slaves.

*[...]

Tony wrote:
-snip-

Where is your hometown? I noticed you used the word "Macadam", that is
a rare word in the US. Named for a man named John McAdam. The first to
use stone and roll it to lock the stones together to make better roads.
Later he added oil/tar on top to help it last through heavy rains.
That is were the word "Tarmac" became popular and is still used at
airports. I come from a part of PA, USA where the outdated word
"Macadam" was still used to describe asphalt/blacktop. If I use the
word today not many people will know what it means.

I'm in upstate NY & grew up in Schenectady, Schoharie & Greene
counties in the 50s-60s. I used the term last year and was amazed
that none of the folks I talked to knew what it was. My wife grew
up in Saratoga county- and the folks I was talking to were all from
the NY city area. [and a bit younger]

I didn't think to look it up back then, but when Micajah used it I
Wiki'ed it. I knew it was named for Mr. McAdam- but didn't know
the specifics of *his* roads.

I've always used the term[improperly, it appears] to refer to any
asphalt surface.

Jim

On 8/31/2010 6:27 AM, Jim Elbrecht wrote:
wrote:
-snip-

Where is your hometown? I noticed you used the word "Macadam", that is
a rare word in the US. Named for a man named John McAdam. The first to
use stone and roll it to lock the stones together to make better roads.
Later he added oil/tar on top to help it last through heavy rains.
That is were the word "Tarmac" became popular and is still used at
airports. I come from a part of PA, USA where the outdated word
"Macadam" was still used to describe asphalt/blacktop. If I use the
word today not many people will know what it means.

I'm in upstate NY& grew up in Schenectady, Schoharie& Greene
counties in the 50s-60s. I used the term last year and was amazed
that none of the folks I talked to knew what it was. My wife grew
up in Saratoga county- and the folks I was talking to were all from
the NY city area. [and a bit younger]

I didn't think to look it up back then, but when Micajah used it I
Wiki'ed it. I knew it was named for Mr. McAdam- but didn't know
the specifics of *his* roads.

I've always used the term[improperly, it appears] to refer to any
asphalt surface.

Jim

That is how I grew up using the name. Macadam meant Asphalt. I used
the word Macadam around some friends a few years ago and got strange
looks and questions, that's when I looked it up.

"Tony" wrote in message
...
On 8/31/2010 6:27 AM, Jim Elbrecht wrote:
wrote:
-snip-

That is how I grew up using the name. Macadam meant Asphalt. I used the
word Macadam around some friends a few years ago and got strange looks and
questions, that's when I looked it up.

Huh. I'm late 50s in upstate NY and that's what EVERYone around here calls
it, both younger and my age. Or, at least, I've never had any strange looks
or questions. Probably because I'm in the boonies. I'll admit, though, "Red
Asphalt" is a sexier title for a drivers' ed video than "Red Macadam".

The asphalt material is slightly pliable. The surface underneath needs to
be a hard compacted surface -- I think it is compacted modified stone (or
something like that). That creates a solid surface for the asphalt
material. The first layer of asphalt material needs to also be compacted
with at least a 5,000 pound roller and is called a stabilizing layer. Then
a second coat of asphalt goes on top of that and is compacted.

Bob wrote:
Hello,

Was just wondering about this.

It is pretty well accepted, apparently, that a new asphalt driveway
for a residence should be laid over about 4" to 6" of gravel.
Never over soil directly.

Why ?

The hot, liquid, asphalt I would pretty much think makes the gravel
into one, solid, "clump" underneath (the asphalt).
So, it's hard to see that any improved drainage results.

Increased "stability" perhaps ? If so, how ?

So what does the gravel add as a benefit over just laying the asphalt
on top of well compacted soil ?

Thanks,
Bob

"RogerT" wrote in message
...
The asphalt material is slightly pliable. The surface underneath needs to
be a hard compacted surface -- I think it is compacted modified stone (or
something like that). That creates a solid surface for the asphalt
material. The first layer of asphalt material needs to also be compacted
with at least a 5,000 pound roller and is called a stabilizing layer.
Then a second coat of asphalt goes on top of that and is compacted.

If you don't put something down first and compact it, you will have a roller
coaster surface once traffic has run on it a year or so.

Steve

read about heart surgery and how to prepare for it at:
http://cabgbypasssurgery.com

The enemy of a road, driveway or parking lot is water under the surface.
The inevitable vertical movement of the surface, when a vehicle passes over
it, creates what's called "Pumping" of the dirt under the pavement. It
liquefies dirt, clay or other fine material, removing even more support for
the surface layer with the inevitable cascading result of alligatoring and
pot holes. Compacted and drained stone doesn't lose support for the surface
when moved about by traffic and if the water can be turned away at the
surface level, then the underlying dirt doesn't liquefy. Just as important
as the water-turning ability of the road surface is the ability for the
water that makes it through to escape. That's why there are ditches and
stone underlayment. They're just as important in draining out water under
the roadway as they are to carry off rainwater to prevent roadway flooding.

I know of at least one very long stretch of an Interstate highway where the
designers failed to understand this. The cure was to trench deeply
alongside the concrete roadway of both lanes, on both sides, install drain
tile and then backfill with coarse stone to carry the undersurface water to
ditches.

By the way, expansive soils are also an enemy of roads, just as they are an
enemy of basements. One lady, who was an NCSU graduate engineer, didn't
understand what expansive soils were and approved an entire highway
interchange to be constructed using expansive soil for the ramps. It never
even opened before the concrete began to crack and fail.

Micajah

"Steve B" wrote in message
...

"RogerT" wrote in message
...
The asphalt material is slightly pliable. The surface underneath needs
to be a hard compacted surface -- I think it is compacted modified stone
(or something like that). That creates a solid surface for the asphalt
material. The first layer of asphalt material needs to also be compacted
with at least a 5,000 pound roller and is called a stabilizing layer.
Then a second coat of asphalt goes on top of that and is compacted.

If you don't put something down first and compact it, you will have a
roller coaster surface once traffic has run on it a year or so.

Steve

read about heart surgery and how to prepare for it at:
http://cabgbypasssurgery.com