The difference between Asphalt and Concrete.

[Tonytone]

So I seen that Asphalt and Concrete have both Pro's and Con's. My question is,
Which of these are better? and also in Delaware Del-dot has Experimented with a new type of roadway surface, with grooves. Is this roadway also better then the two mentioned above?
Also what causes deformities in these roadways that were just laid out 5-10 years ago? I know about the alkali—silica reaction but that's only in certain roadways that have that chemical mixture in it. 

[I-90]

Concrete roads are highly durable and more environmentally friendly as compared to asphalt roads. However asphalt paving costs far less than concrete paving. Also, asphalt road provides a little better safety of the vehicle against snow and skidding.

[Buffaboy]

Me personally, I like roads built with longitudinal concrete like part of I-90 outside of Syracuse. It's quiet and feels like I'm flying in the air.

[kphoger]

Asphalt is a type of concrete.

Bam!

[intelati49]

Asphalt is a type of concrete.

Bam!

... You're not wrong.

(Asphaltic Concrete vs Portland Cement Concrete)

[7/8]

Asphalt is a type of concrete.

Bam!

[Tonytone]

Me personally, I like roads built with longitudinal concrete like part of I-90 outside of Syracuse. It's quiet and feels like I'm flying in the air.

Concrete can be nice unless it has many potholes. (any road can.) But asphalt is smooth and quiet when they first put it down.
It also makes the surrounding area look nice. especially with the pavement marks.

[Rothman]

Here in NY, we are mostly an asphalt state now, because NYSDOT has found concrete too expensive to maintain...unless the soil conditions require it (and, even then, crack and seat was favored for NY 85).

[Max Rockatansky]

Out here in California concrete was used in copious amounts during the big building era of freeway construction.  The concrete generally holds up very well, but it is loud and definitely isn't exactly something that probably been maintained as well as it should have over the decades (see $5.2 billion thread in Pacific Southwest).  Other states like Arizona use rubberized asphalt in major urban areas which seems to be holding up decently out in the drier climates.  Personally I like it because of how quiet and it made things commuting when I lived in the Valley, I was really surprised to see there actually some detractors who didn't like it.  I can't imagine that the surfaces will hold up as well as the concrete in California, but ADOT has the money why not use it for maintenance?

[froggie]

Concrete's biggest weakness IMO is its noise....something that there's been a lot of research on in Minnesota and Iowa to find ways to tweak the concrete surface to reduce road noise.  One idea that came out of Minnesota about 2 decades ago was dragging artificial turf across the surface as it's curing.  MnDOT tested this on I-35W through Richfield when it was rebuilt ca. 1999.

I found Rothman's comment regarding NYSDOT and concrete maintenance to be intruiging, because the Upper Midwest has generally found the opposite to be true.  Especially for heavier duty roads or roads expected to see heavy haul rates (like agricultural harvest for example), concrete tends to hold better...even some Minnesota counties use concrete (and most of Iowa did as well though they lagged on the maintenance part).

Meanwhile, I cannot think of a single roadway in Vermont that uses concrete.

[jeffandnicole]

So I seen that Asphalt and Concrete have both Pro's and Con's. My question is,
Which of these are better? and also in Delaware Del-dot has Experimented with a new type of roadway surface, with grooves. Is this roadway also better then the two mentioned above?

I think that roadway is still concrete - just with a different groove pattern.

NJ constantly experiments with various types of asphalt.  From my perspective, some may be louder or quieter than others, but they all tend to have about the same lifespan.  The only one I dislike is what I believe they term 'microseal', which is milling and repaving just an inch of pavement.  That seems to give out sooner than traditional 2 or 3 inch milling and repavings.

[paulthemapguy]

Asphalt roads are usually cheaper, and they are paved without initial cracks or joints (except where one section of road meets another section).  Asphalt cement is a byproduct of petroleum refining, so its cost increases as the prices for oil increases.  I remember when gas prices were really high, more and more road projects switched over to concrete pavements rather than asphalt.  Since asphalt pavements are more flexible, you need to have a very sturdy and sometimes deep base to make sure the pavement stays consistently sturdy.  Asphalt pavements are also more susceptible to ripples, spalling, bleeding, and rutting.  Concrete's main problems come from their costs and their joints between slabs which invite a whole bunch of problems.

With concrete, you can disambiguate even further; concrete pavements can be split into a few different categories:

1) Jointed Plain Concrete Pavement...................The cheapest and most typical form of concrete pavement, where slabs are 10 to 15 feet long held together using only lubricated round dowel bars.  Since joints are planned every 10 to 15 feet, I wouldn't recommend the use of this method in wetter climates with a lot of freeze-thaw cycles, because the water that gets into the cracks expands when it freezes, pushing up the ends of each slab and creating a wave-like pattern to the roadway as you drive down it.  (This doesn't stop the ISTHA from using this method, and because of that, their roads often make people seasick.)

2) Jointed Reinforced Concrete Pavement...........Slabs are about 40 to 100 feet long, and both dowel and tie bars are typically used.  (Dowels are between a slab and the next slab ahead of it; tie bars hold together slabs in adjacent lanes.)  All concrete slabs will develop cracks, especially if the slabs are larger, so once the slabs reach sizes like this, engineers employ the use of internal reinforcing steel to prevent cracks from forming and opening to an excessive extent.

3) Continuously Reinforced Concrete Pavement...Concrete is continuously placed with no planned joints whatsoever; the lane is just one continuous slab.  As stated before, all concrete cracks, so reinforcing steel is used to provide tensile strength that keeps the inevitable cracks from opening up to become too wide.  You might not even notice the plethora of cracks that form on CRCP, but if you look closely, you will see a whole lot of them--they're just held together so tightly that they don't disrupt the smoothness of the road.  The amount of reinforcing steel makes this type of pavement expensive, so this method is usually only used on high-profile roadways.

When concrete roads are finished, they are raked with brushes or a literal rake outfitted with an array of sharp tines like on a fork.  Sidewalks are often brushed with a broom with soft bristles, similar to those you use to sweep a garage.  This doesn't provide enough traction for automobile tires, however--that's why they're raked with something more robust.  Most roads in the past have been raked across from right to left (transversally), but newer research is suggesting that it's more effective to rake concrete roads longitudinally (with the grooves parallel with the path of traffic), for the best traction.  That's probably what those small grooves are for.

If you want to learn more on this, you can read stuff...or take college classes lol: http://www.idot.illinois.gov/assets/uploads/files/transportation-system/research/pavement-technology-advisories/design-construction-and-materials-seriesnew-folder/ptad3.pdf

[Buffaboy]

Me personally, I like roads built with longitudinal concrete like part of I-90 outside of Syracuse. It's quiet and feels like I'm flying in the air.

Concrete can be nice unless it has many potholes. (any road can.) But asphalt is smooth and quiet when they first put it down.
It also makes the surrounding area look nice. especially with the pavement marks.

Generally I find this to be true.

What I like most is when I'm driving on a road with noisy asphalt, and then I hit the point where there's a newer layer of it. It's so quiet.

Like Rothman said though, the conditions of upstate weather does much harm to the concrete roads, which crack easily.

[Tonytone]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

[intelati49]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

Steel grates, brick, high friction treatments?

[kphoger]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

No, no, paulthemapguy just identified three different types of hydraulic concrete alone.  I've also driven on graded dirt, oil-sealed, gravel, river rock, cobblestone, and brick roads.  Et cetera.
And we haven't even discussed the different kinds of whitetopping yet.

[Tonytone]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

No, no, paulthemapguy just identified three different types of hydraulic concrete alone.  I've also driven on graded dirt, oil-sealed, gravel, river rock, cobblestone, and brick roads.  Et cetera.
And we haven't even discussed the different kinds of whitetopping yet.

Whitetopping? Please continue.

[intelati49]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

No, no, paulthemapguy just identified three different types of hydraulic concrete alone.  I've also driven on graded dirt, oil-sealed, gravel, river rock, cobblestone, and brick roads.  Et cetera.
And we haven't even discussed the different kinds of whitetopping yet.

Whitetopping? Please continue.

Thin layer of concrete portland cement concrete over existing asphaltic concrete

[kphoger]

All these years and we only have two types of road to lay down.  I think our people at Dot need to go back to the writing board.

No, no, paulthemapguy just identified three different types of hydraulic concrete alone.  I've also driven on graded dirt, oil-sealed, gravel, river rock, cobblestone, and brick roads.  Et cetera.
And we haven't even discussed the different kinds of whitetopping yet.

Whitetopping? Please continue.

Click here.

[paulthemapguy]

I was discussing the types of PCC typically used on high-profile highways.  I never meant to imply they are the ONLY FORMS out there lol.  I knew someone would come out and say I was oversimplifying, but like, dude.  This is the internet.  Did you see how long my post was in the first place?  You want me to drone on for longer?   

Yes "concrete" is colloquially short for PCC.  Yes "asphalt" is colloquially short for "asphalt concrete."  I speak colloquially, for the normies.

[kphoger]

I was discussing the types of PCC typically used on high-profile highways.  I never meant to imply they are the ONLY FORMS out there lol.  I knew someone would come out and say I was oversimplifying, but like, dude.  This is the internet.  Did you see how long my post was in the first place?  You want me to drone on for longer?   

Yes "concrete" is colloquially short for PCC.  Yes "asphalt" is colloquially short for "asphalt concrete."  I speak colloquially, for the normies.

I didn't mean to imply you were oversimplifying.  In fact, I was using how specific you were as an example of how many types of pavement there are.  I personally wouldn't mind you droning on for longer, as it is an interesting topic that doesn't get much discussion on here.  One of my best friends is an engineer who designs bridges here in Kansas, so I occasionally end up having discussions about concrete with him; the more knowledge I glean here, the better I am at discussing.

Edited to add:  I think the misunderstanding came from my use of "just identified."  You thought I meant "only identified," but I actually meant "recently identified."

[Big John]

lso, PCC is considered "rigid" and can also be used for structural work, while AC in considered "flexible", while good for surfaces, it can't hold up for structures.

[J N Winkler]

There is a philosophical dimension to the asphalt versus concrete divide that has not yet been mentioned.  In some countries, including the US, the choice of pavement type is to an extent driven by a desire to compensate for inadequate bearing capacity of the subgrade.  In others, such as Germany, bearing capacity is considered too important to compromise, no matter how much it costs to excavate muck and other highly compressible soil and replace it with competent borrow.  There was an Autobahn project in the late 1930's that essentially consisted of building a "buried dam" across a swamp (replacing bad soil more than 50 feet deep across a considerable length) just to provide a suitable subgrade.

In these countries, the asphalt versus concrete choice boils down to economics and to technical considerations other than subgrade bearing capacity, such as noise (taking into account the extent to which this can be controlled given available construction techniques), absolute volume and weight of traffic, climate, expected costs of subsequent necessary upkeep, etc.

As a general rule, it is possible to design "perpetual pavements" (pavements that, if properly maintained, never need full-depth reconstruction) in either asphalt or concrete, but asphalt "perpetual pavement" still needs periodic renewal (typically replacement of the top layer in a mill-and-overlay operation) while the concrete version tends to need just spot attention such as joint repair.  In locations where traffic is expected to increase to levels that justify widening, a "perpetual pavement" can cause problems with excess durability that prevent it being the appropriate or economic solution.

Factor endowments are also ulterior considerations since the market in oil products is not completely deregulated and Portland cement takes a tremendous amount of energy to produce.

[Rothman]

"Just spot attention such as joint repair."

In NY, we have found such attention to be problematic.  Any drive across "repaired" concrete proves how difficult it can be to return a concrete surface to a smooth condition.

Decades of hearing "kadunk kadunk kadunk" as drivers drove across misaligned joints and then trying to mill them down only led to a greater use of asphalt here.

[I-90]

https://www.aaroads.com/forum/index.php?topic=20256.0