AARoads Forum

I ponder the question, why the northeast states repaved most of their interstates with blacktop when concrete seems to last longer?

States such as NY  and CT started to repave their interstates over with asphalt starting in the 80s and 90s.  Since then cracks appear within a couple of years and in some cases have to be repaved 10 years later.

Meanwhile there are concrete sections of highway that have never been repaved and are still fine.

Example:
I-84 in Manchester CT is still cement and the DOT will be smoothing out the cement instead of repaving it over with asphalt. So in 40 years this is the first time it will be "repaved" and I'm sure it will last another 40 years before it has to be done again.

There are many considerations governing the choice between Portland cement concrete and asphaltic concrete (where high-type pavements are concerned, both "cement" and "asphalt" are really different types of concrete), but in general it comes down to which type provides the most benefit relative to cost for a given location.

*  Because PCC lasts so long, it can create a problem of excess durability.  It is not, for example, a very good investment to lay fresh PCCP down on a road which is expected to need widening sometime in the next 10 years or so because the investment won't produce returns at the far end of its natural lifetime.  On the other hand, if you expect a road not to need widening or reconstruction for a period ranging from 40 years to forever, it can pay to lay down a PCCP (designed for indefinite durability) since the high initial cost will be recouped over a very long period.

*  First cost of either type of pavement can be influenced by availability of raw materials.  For example, in the period of first Interstate construction, most of I-70 in Kansas west of Salina was paved in asphalt because aggregates for Portland cement concrete were in short supply in western Kansas.  On the other hand, when the price of oil (the input material for asphalt binder) goes up, this tends to tilt calculations in favor of Portland cement in marginal cases.

There are many other factors that can be considered and can be incorporated into cost-benefit analysis, but are too much to go into here--I'd suggest Roland McKean's Efficiency in government through systems analysis as a good general guide to the issues that are involved.

From what I've read, asphalt is usually cheaper during the construction phase even though in the long term it winds up costing more. Many governments' regulations these days mandate using the cheapest means of construction, even though that's short-sighted if it winds up costing more in the long term. (The debate in the DC area about putting the Metrorail in a tunnel or on an elevated structure through Tysons Corner is a well-publicized recent example of this argument.) Concrete repair costs more and is somewhat more complex, even if it's less likely to need repair. Finally, some places with particularly bad weather are known to be less likely to use concrete because it provides somewhat less traction in rain and snow. I saw an article talking about road-paving in Colorado that mentioned that they prefer asphalt for the mountain roads because its higher heat absorption (inherent in black surface versus white surface) helps a bit with melting snow and ice.

No doubt public opinion factors in as well. While many newer concrete surfaces are reasonably quiet and smooth, almost everyone's encountered older ones where the surface is coarse and noisy and the joints are far more noticeable than they are on asphalt roads so you get that "clopping" sound as you cross each one (or, as my brother once said, it feels like you're driving down a flight of stairs). I know quite a few people who profess to hate concrete roads because of noise. If their experience with them comes from I-66 between Fair Oaks Mall and the Beltway or with some of the older concrete roads in Maryland, then I understand their opinion, but I'd encourage those people to drive on I-66 west of Fair Oaks Mall or on US-50 between DC and Annapolis and then reconsider their comments.

Quote from: 1995hoo on July 15, 2011, 12:29:07 PM
Many governments' regulations these days mandate using the cheapest means of construction, even though that's short-sighted if it winds up costing more in the long term.

why not just smear some feces on the side of a hill and call it a road, then?  that's cheaper.

Probably because they can just slap a layer of asphalt on the highway and claim they did something without actually repairing the road.  There are several sections of highway in NY that need total reconstruction but instead just get patched over with asphalt every 10 years.

QuoteNo doubt public opinion factors in as well. While many newer concrete surfaces are reasonably quiet and smooth, almost everyone's encountered older ones where the surface is coarse and noisy and the joints are far more noticeable than they are on asphalt roads so you get that "clopping" sound as you cross each one (or, as my brother once said, it feels like you're driving down a flight of stairs). I know quite a few people who profess to hate concrete roads because of noise. If their experience with them comes from I-66 between Fair Oaks Mall and the Beltway or with some of the older concrete roads in Maryland, then I understand their opinion, but I'd encourage those people to drive on I-66 west of Fair Oaks Mall or on US-50 between DC and Annapolis and then reconsider their comments.

But I LOVE that sound!

Also, lets not forget considerations of traffic control when paving with concrete vs. asphalt.  Asphalt can be applied overnight, and the lanes opened up in time for the next day, while concrete often requires more extended lane closures.  Depending on the nature of the roadway, this could be done over a weekend, but some roads have enough weekend traffic and few alternate routes so this is just not possible. 

The best example I can think of is the Cross Bronx Expressway.  The pavement is in horrible shape because of all the heavy truck traffic starting and stopping on it (that's why they typically put concrete pads where heavy vehicles start and stop, like bus stops or weigh stations), its cracked, rutted, etc.  Seems like a perfect candidate for concrete pavement.  Unfortunately, there is only a tiny window of time (maybe a few hours in the wee hours of the night) where you can close down any lanes without causing all of NYC to be in absolute gridlock, and weekend traffic is just as bad as weekday traffic...and there's no shoulder to be used to allow for lane shifts...and the bridge piers come way too close to the roadway to allow using any kind of zipper wall/express lane configuration.....and that means you have to repave in asphalt quite frequently.

Another consideration is the type of climate the pavement will be laid in. In desert climates, one has to look at the type of asphalt & binders used and whether that will stand up to desert heat. Asphalt is more flexible, and is more succeptible to rutting when temperatures are high and traffic loads are heavy (especially if there's lots of braking, like at an intersection)--see some intersections around the Vegas area for bad rutting examples. PCC doesn't have this problem, but if conditions are right and there's some problem, the slabs can blow out in hot weather (as discussed in another thread).

Designers will typically do a cost-benefit analysis over a time span of 30-50 years or so. (At least, this is what I learned in a pavement design course several years back.) Asphalt is cheaper initially, but typically requires overlays and other preventative maintenance every 8-10 years (depending on the mix design). Taking the initial costs plus preventative maintenance out that far, sometimes PCC will win out over AC. The points JN Winklyer brought up, as far as what future traffic demands, road expansion possibilities, and availability of materials, also play an important part in the cost-benefit analysis.

Quote from: agentsteel53 on July 15, 2011, 12:32:00 PM

Quote from: 1995hoo on July 15, 2011, 12:29:07 PM
Many governments' regulations these days mandate using the cheapest means of construction, even though that's short-sighted if it winds up costing more in the long term.

why not just smear some feces on the side of a hill and call it a road, then?  that's cheaper.

If you did that, you'd have I-66 between Fair Oaks and the Beltway!

Ooooh this is my thread!

I personally think the advantages of PCC almost universally outweigh the benefits.

As for the future widening issue, existing concrete pavement doesn't necessarily have to be torn out to facilitate that.  I've been plenty of places where I drove down a road and it was blatantly obvious that it had originally been done in PCC then it was widened, as the outer or inner lanes depending on which way they widened (inward or outward) were also PCC but pretty obviously newer.

While we're discussing concrete, I used to like the whine noise "newer" PCC pavements used to make, but now it seems in the newest ones, they've started to randomize the grooves so it doesn't whine anymore - well they got what they wanted there, but I don't think they quite achieved their desired effect, as most of them now just make a real loud and ugly sound that's notably louder and more annoying than the whine was.  Seeing as how I actually liked the whine, that really irritates me.

Heading south on I-65 south of Louisville, you have a rare opportunity to study all four current major types of pavement.  You go from diamond-ground concrete to transverse grooved concrete to longitudinal grooved concrete to asphalt.  I recently had to drive that entire stretch in an incredible rainstorm.  My observation is that diamond ground surfaces are HORRIBLE in the rain and worn asphalt is about as bad especially where rutted by heavy truck traffic as the water pools up in the ruts, while transverse grooved concrete disperses the water amazingly well and longitudinal grooved concrete is almost as good.

I can't understand New England's aversion to it.  The upper midwestern states use it extensively with no major issues, their temperatures hit worse extremes than just about anywhere in New England.

It's also a great way to reduce dependence upon oil, since it's not a direct component of the pavement like it is asphalt. (Ever wondered why fresh asphalt STINKS so bad?)  Additionally, it takes less energy to properly illuminate it at night.

Asphalt may be quiet, smooth and good-looking when it's first put down, but it deteriorates far quicker.  Down here in the hot, sunny climates, it loses that fresh new look in about a month.

Ashpalt would be no problem if our roads got proper funding. Notice you rarely see a European Motorway that has concrete, yet they still look amazing because they have funding to be rehabilitated when needed.

New Cement done right can look just as nice though, and I think we can all agree that pavement doesn't look pretty when it's been beat up for years, cement or asphalt.

Kansas has been reconstructing I-35 from Emporia to Kansas City in concrete for the past decade or so. It's the best-quality road I've ever driven on. Looking forward to tackling it for the first time at 75 MPH next week.

Quote from: Riverside Frwy on July 15, 2011, 11:57:59 PM
Ashpalt would be no problem if our roads got proper funding. Notice you rarely see a European Motorway that has concrete, yet they still look amazing because they have funding to be rehabilitated when needed.

New Cement done right can look just as nice though, and I think we can all agree that pavement doesn't look pretty when it's been beat up for years, cement or asphalt.

I don't really understand Europe's aversion to concrete either.  Yeah, all the European motorways look great because they repave them ALL THE TIME.  That's just too much and too frequent of an interruption to the flow of traffic.  Just do it concrete and snarl traffic once every 25 years for pete's sake.

Quote from: Riverside Frwy on July 15, 2011, 11:57:59 PMI think we can all agree that pavement doesn't look pretty when it's been beat up for years, cement or asphalt.

yes it does.

(//www.aaroads.com/shields/blog/photos/045355.jpg)

you don't want to drive this road at more than 45mph or so, but it sure does look pretty.

Quote from: doofy103 on July 15, 2011, 11:49:50 AM
I ponder the question, why the northeast states repaved most of their interstates with blacktop when concrete seems to last longer?

States such as NY  and CT started to repave their interstates over with asphalt starting in the 80s and 90s.  Since then cracks appear within a couple of years and in some cases have to be repaved 10 years later.

Meanwhile there are concrete sections of highway that have never been repaved and are still fine.

Example:
I-84 in Manchester CT is still cement and the DOT will be smoothing out the cement instead of repaving it over with asphalt. So in 40 years this is the first time it will be "repaved" and I'm sure it will last another 40 years before it has to be done again.

I often thought the cement in Manchester was original, but it's not.  I 84 went through major reconstruction throughout the 1980's there adding HOV lanes, which are also concrete.  This cement section in Manchester That still remains was poured in the 1980's, probably one of the last times the state used concrete.  Though it's not original to the "Wilbur Cross Highway", it has still held up over 25 years, unlike the asphalt which seems to be in perpetual rotating sections of "milling and paving" every 5 years.

Quote from: wytout on July 16, 2011, 05:11:26 AMI often thought the cement in Manchester was original, but it's not.  I 84 went through major reconstruction throughout the 1980's there adding HOV lanes, which are also concrete.  This cement section in Manchester That still remains was poured in the 1980's, probably one of the last times the state used concrete.  Though it's not original to the "Wilbur Cross Highway", it has still held up over 25 years, unlike the asphalt which seems to be in perpetual rotating sections of "milling and paving" every 5 years.

The fact that it's held up so well has me scratching my head as to why CT no longer uses it.  I went through CT more times than I could count in the 15 years I lived in NH, and while the asphalt sections are always deteriorating and being rehabilitated, the concrete segment in Manchester has never really needed much of anything as far back as I can recall.

Concrete is so much more worth it than asphalt. There's a three-mile stretch of I-80 in Salt Lake that's still has the original concrete from 1966. It's not the quietest ride on that pavement, but UDOT maintains the concrete well so it's at least a smooth ride. What's also nice about it is that all new concrete in the state is noiseless. Smoothest, quietest ride ever.

There is a lot of short-sightedness with regards to surface materials.  Obviously the asphalt is cheaper and has a much faster cure time, but to me the long term costs must actually be higher, because the asphalt needs to be milled and repaved so frequently.  I think I'd rather have a highway closed 1 lane at a time for several days for concrete to cure once every 30 years, then have to go through resrufacing zones every 5 years on the same stretch of road.  Even the older concrete that isn't too quiet still seems to give a generally uniform tolerable ride.  

Moving away from concrete in favor of asphault is the same as everyting else and can be summed up with one simple cliche :  They sure don't make things like they use to.

This is not only true when discussing asphalt vs. concrete.  It's also true with regards to 30 year old asphalt vs. today's asphalt.
Case in point: My grandparents driveway is a large square 3 cars wide, 2 deep.  It was paved w/ asphalt years before I was born.  It was fine without more than a crack or two until I was about 25.  They had to have the driveway turn up do to a sewer line about 6 years ago.  My grandfather was adamant that the base materials be properly packed in to that when the driveway was repaved, again it would hold up for years.  Well it was repaved about 8 years ago... it's flat, good base, but it's got about a million cracks in it. 

My Point:
CONCRETE > ANY ASPHALT
YESTERDAYS ASPHALT > TODAYS ASPHALT
TODAYS ASPHALT IS PURE GARBAGE.

In Illinois, it used to be dictated by the construction lobby.  :banghead:

Quote from: agentsteel53 on July 16, 2011, 02:40:27 AM

Quote from: Riverside Frwy on July 15, 2011, 11:57:59 PMI think we can all agree that pavement doesn't look pretty when it's been beat up for years, cement or asphalt.

yes it does.

(//www.aaroads.com/shields/blog/photos/045355.jpg)

you don't want to drive this road at more than 45mph or so, but it sure does look pretty.

Sorry, but pretty scenery doesn't make I-80 through the sierras look or feel any less $hitty.

Didn't know I-80 was a two lane road with a double yellow line.

Quote from: deanej on July 17, 2011, 01:52:02 PM
Didn't know I-80 was a two lane road with a double yellow line.

No, the point he was making(atleast that is what I took from it) is that pretty scenery makes crappy pavement look better. That is obviously the picture is not I-80, I was just saying I-80 has pretty scenery too while it travels through the sierras, but that doesn't change the fact it has crappy pavement.

Alot of the problems from state to state is that each state uses a different chemical compound for asphalt.  Illinois for example likes to use a dirt cheap mix that needs to be resurfaced about every 4 years.  Part of the problem is also the type of salt used for snowplowing that eats up the road quickly.  The city of Naperville for example has resurfaced Washington St at least 3 times now in the last decade.  I think concrete lasts longer.  The roads in Wisconsin that use the concrete don't seem to need to be reconstructed more than once every 10-15 years and sometimes even longer.  I wish though when we build major highways, we would do what the Germans do.  The Autobahns are built to last almost double that of American roads because the foundations are much thicker.

Quote from: US-43|72 on July 16, 2011, 04:00:18 PM

Quote from: wytout on July 16, 2011, 05:11:26 AMI often thought the cement in Manchester was original, but it's not.  I 84 went through major reconstruction throughout the 1980's there adding HOV lanes, which are also concrete.  This cement section in Manchester That still remains was poured in the 1980's, probably one of the last times the state used concrete.  Though it's not original to the "Wilbur Cross Highway", it has still held up over 25 years, unlike the asphalt which seems to be in perpetual rotating sections of "milling and paving" every 5 years.

The fact that it's held up so well has me scratching my head as to why CT no longer uses it.  I went through CT more times than I could count in the 15 years I lived in NH, and while the asphalt sections are always deteriorating and being rehabilitated, the concrete segment in Manchester has never really needed much of anything as far back as I can recall.

In fact, the DOT smoothed out the concrete on I-691 and it's so smooth. In fact I actually think it speeds up the mph b/c it's so smooth.

I think to find out the reason the state DOT paved over all the concrete we would have to ask the guys that were in charged back in the 80s and 90s.  Today, the DOT seems ready to preserve the remaining concrete sections as there are plans to preserve the concrete on CT-25 (as well as take out the odd slow vehicle lanes on a flat portion of road), as well as I-84 in Manchester.

Been on 691 many times, even have some pics from that stretch from about 2004 or so.

What about I-84 in Waterbury?  Or is that too far gone?  It doesn't seem to be cracked, just a rough pour.

I do remember sometime in the 1990s when CT was replacing several blocks of PCC on the northeastern section of I-84. A lane or two was blocked off for miles as workers dug into the concrete. Brought back non-fond memories of Pennsylvania where miles and miles of I-80 and I-81 were single-lane because of this type of rehabilitation.

Quote from: doofy103 on July 15, 2011, 11:49:50 AM
I ponder the question, why the northeast states repaved most of their interstates with blacktop when concrete seems to last longer?

Short answer: asphalt is cheaper.

--
About 20 years ago, Fayetteville, AR was expanding their street system at a rapid pace. One street, Township Road was scheduled to be extended east. There were 2 bids: one contractor offered to pave it in asphalt, the other in concrete. The concrete contractor won the contract and the asphalt contractor sued the city because his bid was much lower. The city explained why they chose concrete (uneven terrain, lots of hills) and won. Then again, the concrete contractor is an 800lb gorilla, but I'm sure that had nothing to do with it :|

A couple of other things to consider:

There are often political factors involved. Do not underestimate the power of the asphalt (or PCC) lobby in a particular region. Not that engineering decisions would ever be made for political reasons...

There is also some volatility in the prices of raw materials. In particular, in periods of construction booms, PCC becomes more expensive because concrete is used for building footings, etc.

Quote from: wytout on July 17, 2011, 05:43:45 AM
My Point:
CONCRETE > ANY ASPHALT
YESTERDAYS ASPHALT > TODAYS ASPHALT
TODAYS ASPHALT IS PURE GARBAGE.

I agree with "concrete is better than asphalt" up to a point and I disagree with the other two points.

While concrete lasts longer (much, much longer) than asphalt, when it rains, the spray kicked up by the vehicles can just about blind a driver.  Over the past 4-6 years, Caltrans has used a new type of asphalt on some Bay Area freeways (most notably US 101 between San Jose and S.F. and I-880 from San Jose to Hayward) that contains ground up tires mixed in with the asphalt.  This surface provides a nice smooth, quiet ride and when it rains, there is very minimal spray because the rubberized asphalt allows the rain water to drain through the pavement.  IIRC, I-880 was repaved about 5 years ago and the rubberized asphalt is still in very good condition.

Obviously, this type of pavement works in California due to our mild climate but I suspect it's not really an option in harsher climates (freezing cold or blistering heat).

There's still several concrete overpasses in Connecticut. Here are the two I know:

• Route 8 NB after Exit 39, Thomaston
• I-84 Exit 39 ramp to Route 4, Farmington

And in Massachusetts:

• The I-91/I-90/US-5 connector, overpass over US-5, Holyoke

Quote from: Riverside Frwy on July 17, 2011, 12:08:33 PM
Sorry, but pretty scenery doesn't make I-80 through the sierras look or feel any less $hitty.

Caltrans had been doing multiple projects over the last several years repaving PCC pavements along I-80. Much of the PCC pavement near Donner Pass appears to be of original Interstate construction--it's held up well but is horribly rutted due to trucks and chain controls. Caltrans is currently working on a couple sections in this area, completely reconstructing the old concrete with new.

Quote from: myosh_tino on July 18, 2011, 03:44:35 PM
While concrete lasts longer (much, much longer) than asphalt, when it rains, the spray kicked up by the vehicles can just about blind a driver.  Over the past 4-6 years, Caltrans has used a new type of asphalt on some Bay Area freeways (most notably US 101 between San Jose and S.F. and I-880 from San Jose to Hayward) that contains ground up tires mixed in with the asphalt.  This surface provides a nice smooth, quiet ride and when it rains, there is very minimal spray because the rubberized asphalt allows the rain water to drain through the pavement.  IIRC, I-880 was repaved about 5 years ago and the rubberized asphalt is still in very good condition.

Obviously, this type of pavement works in California due to our mild climate but I suspect it's not really an option in harsher climates (freezing cold or blistering heat).

It's not necessarily the rubber in the asphalt that allows the rain water to drain through the pavement. With asphalt pavements, the top layer or "lift" is often designed as open graded layer ("open grade" being rock material containing very small fines or pebbles and bigger rocks or crushed aggregate pieces). The open grade material bonds together with asphalt binder, but since there's no small stone material in the mix, the result is a top layer (typically about 2" thick for major roads) that is porous. This allows rainwater to drain down slightly from the pavement surface and travel between asphalt lifts off to the side of the road or gutter due to the natural cross slope of the roadway.

Just found this thread and although it was already said, I will reiterate:

The concrete sections of roadway throughout Connecticut are 100x smoother and have held up much better than asphalt.  The concrete sections are:

I-84 in Waterbury, from the Naugatuck River crossing to the Hamilton Avenue (CT 69) overpass
I-84 in Manchester from Exit 59 to Exit 63
I-95 in New London, from Vauxhall Street overpass to the start of the Gold Star Bridge in New London
I-691 from the Route 10 overpass in Cheshire to the Route 322 overpass in Southington
CT 9 from Exit 25 (Ellis Street) to Exit 29 (Route 175) in New Britain
CT 25 north of the Merritt Parkway, to its northern terminus

I too never understood why they repaved the concrete sections with asphalt.  I remember when I-91, I-95, CT 9, and others were concrete.  Seems like a simple milling every now and then would be cheaper and last longer than repaving - which seems to be anything from a mill-and-pave job to just a new top layer.


Another unbelievably stretch of smooth concrete is I-95 (New England Thruway) north of NYC.  In one spot, near I-287, the concrete surface has been patched and looks bumpy but is unusually smooth.

84 in Waterbury isn't what I'd call smooth; not all of it anyway, but I doubt it's anything a diamond grind couldn't fix or at least help.

Quote from: myosh_tino on July 18, 2011, 03:44:35 PMI agree with "concrete is better than asphalt" up to a point and I disagree with the other two points.

While concrete lasts longer (much, much longer) than asphalt, when it rains, the spray kicked up by the vehicles can just about blind a driver.  Over the past 4-6 years, Caltrans has used a new type of asphalt on some Bay Area freeways (most notably US 101 between San Jose and S.F. and I-880 from San Jose to Hayward) that contains ground up tires mixed in with the asphalt.  This surface provides a nice smooth, quiet ride and when it rains, there is very minimal spray because the rubberized asphalt allows the rain water to drain through the pavement.  IIRC, I-880 was repaved about 5 years ago and the rubberized asphalt is still in very good condition.

Obviously, this type of pavement works in California due to our mild climate but I suspect it's not really an option in harsher climates (freezing cold or blistering heat).

California's never done transverse grooved concrete, it's always been longitudinal, which seems to spray much worse than transverse in all of my experiences.  I'm sure depends on the cement formulation as well.  Diamond ground concrete sprays horribly.

Quote from: US-43|72 on July 19, 2011, 01:34:25 AM
California's never done transverse grooved concrete, it's always been longitudinal, which seems to spray much worse than transverse in all of my experiences.  I'm sure depends on the cement formulation as well.  Diamond ground concrete sprays horribly.

Does transverse grooved concrete produce that annoying whine that I hear on concrete sections of I-5 in Oregon and on I-15 in Nevada?  If that's the case, then I'm glad Caltrans does not groove their concrete that way.

Quote from: myosh_tino on July 19, 2011, 04:10:26 AMDoes transverse grooved concrete produce that annoying whine that I hear on concrete sections of I-5 in Oregon and on I-15 in Nevada?  If that's the case, then I'm glad Caltrans does not groove their concrete that way.

No, it doesn't.

And unless they do the transverse grooves completely wrong (i.e. try to "randomize" them to make it not whine - result is usually a polar extreme opposite of what they're going for - see Indiana concrete from the 1980s and 1990s, for instance) the whine is not annoying.  NY and PA did it right, with the grooves more or less evenly spaced.  I always found that noise more pleasant than the toneless growl of asphalt - cheap coarse asphalt especially

There's some stuff in NY with no sound, which is actually disappointing, though if you drive 40 mph instead of 65 on it you'll hear the whine.

Case in point - "did" it right.  It's the 80s/90s stuff that whines, much newer than that, it doesn't.

Quote from: shadyjay on July 18, 2011, 09:33:55 PM
Just found this thread and although it was already said, I will reiterate:

The concrete sections of roadway throughout Connecticut are 100x smoother and have held up much better than asphalt.  The concrete sections are:

I-84 in Waterbury, from the Naugatuck River crossing to the Hamilton Avenue (CT 69) overpass
I-84 in Manchester from Exit 59 to Exit 63
I-95 in New London, from Vauxhall Street overpass to the start of the Gold Star Bridge in New London
I-691 from the Route 10 overpass in Cheshire to the Route 322 overpass in Southington
CT 9 from Exit 25 (Ellis Street) to Exit 29 (Route 175) in New Britain
CT 25 north of the Merritt Parkway, to its northern terminus

I too never understood why they repaved the concrete sections with asphalt.  I remember when I-91, I-95, CT 9, and others were concrete.  Seems like a simple milling every now and then would be cheaper and last longer than repaving - which seems to be anything from a mill-and-pave job to just a new top layer.


Another unbelievably stretch of smooth concrete is I-95 (New England Thruway) north of NYC.  In one spot, near I-287, the concrete surface has been patched and looks bumpy but is unusually smooth.

Here is a press release from CTDOT:  Does this mean they are ripping up asphalt for concrete?

Pavement Preservation Project on Interstate 84 in the Towns of New Britain and Farmington is Scheduled To Start Sunday, July 24, 2011


The Connecticut Department of Transportation is announcing that a pavement preservation project that includes the milling and resurfacing of I-84 in both directions is scheduled to begin Sunday July 24, 2011, weather permitting.  The project starts in the vicinity of the Route 72 interchange (exits 35/36) and extends easterly to the Route 6 Interchange (exits 38/39) in the towns of New Britain and Farmington.

The project consists of the removal of the existing deteriorated pavement surface and resurfacing with a new layer of bituminous concrete followed by the installation of new pavement markings and rumble strips.  Only the travel lanes are being resurfaced under this project.

Something that needs to be asked is why a particular paving material is more or less expensive than another.  Yes, asphalt is more susceptible to rises in the price of oil, because the asphalt emulsion itself an oil byproduct.  On the other hand, concrete requires a very large amount of energy to produce.  To make portland cement requires the raw materials to be crushed and then heated to a very high temperature, which requires a lot of electricity and natural gas.  

There's also things like the type of labor and equipment necessary.  I believe a good part of the cost of a concrete road is in the finishing.  In order to do it properly requires strict timing, quick action, and special equipment, or else you end up with a rough road.  Here in Cincinnati (within the city limits anyway), when a road goes through a major rehab it will be paved first with concrete, then two lifts of asphalt on top (though they raise the concrete up for bus stops).  I figure that by doing this, they get a good solid base of concrete that also holds all the manhole covers and other utilities in place properly, while allowing quick milling and replacement of the asphalt wearing surface.

Quote from: doofy103 on July 19, 2011, 06:38:27 PM

Here is a press release from CTDOT:  Does this mean they are ripping up asphalt for concrete?

...

The project consists of the removal of the existing deteriorated pavement surface and resurfacing with a new layer of bituminous concrete followed by the installation of new pavement markings and rumble strips.  Only the travel lanes are being resurfaced under this project.

Bituminous = Asphalt, so the answer to your question is 'No'.

Quote from: jjakucyk on July 19, 2011, 06:39:34 PM
Something that needs to be asked is why a particular paving material is more or less expensive than another.  Yes, asphalt is more susceptible to rises in the price of oil, because the asphalt emulsion itself an oil byproduct.  On the other hand, concrete requires a very large amount of energy to produce.  To make portland cement requires the raw materials to be crushed and then heated to a very high temperature, which requires a lot of electricity and natural gas.  

FYI: PCC requires raw material to be heated to a high temperature to get the basic mix, but can otherwise be applied cold when it is mixed with water. Asphalt, on the other hand, has to be heated to a high temperature during mixing and applied to the roadbed hot in order for it to set properly.

I'd say a major difference in cost is that PCC incorporates structural steel (rebar, often epoxy coated) in order to give the pavement its strength and tie the slabs together. Rebar can be very expensive, and its price also varies based on factors such as the demand for structural steel. It also takes more labor time to prep a PCC pavement due to the placement of the rebar.

sorry to bump....
What is the point of this:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fimg.photobucket.com%2Falbums%2Fv704%2Fpackerfan386%2F43d72043.jpg&hash=88a961796ac3905cc28c1e207d99c21179ce6281)
You see those six grooves/ lines all the time, yet everyone I ask doesn't known why DOT's do it.

They're putting rebar between the slabs which makes them less likely to shift out of place from one another.  Preventing that shifting also reduces the ka-thump ka-thump noise when you drive over the joints.

But I LOVE the ka-thump ka-thump noise!  Could we get them to stop?  Putting in the rebars defeats the point of having a concrete road (the cool sounds) in the first place!

Quote from: deanej on October 05, 2011, 11:38:33 AM
But I LOVE the ka-thump ka-thump noise!  Could we get them to stop?  Putting in the rebars defeats the point of having a concrete road (the cool sounds) in the first place!

You'll like this video (http://www.youtube.com/watch?v=leiQ6niMT-Q) then.  I like the whistling noise, myself.

When I was reading US-43|72's post (reply #8 on the first page) about different pavement types, I did some Googling, and found this page (http://www.wsdot.wa.gov/Business/MaterialsLab/QuieterPavement/QuieterPavementPhotos.htm) from WSDOT about pavement types.

Quote from: deanej on October 05, 2011, 11:38:33 AM
But I LOVE the ka-thump ka-thump noise!  Could we get them to stop?  Putting in the rebars defeats the point of having a concrete road (the cool sounds) in the first place!

It'll still make the noise.  That's caused by the joints themselves, not by the pavement slabs offsetting from each other.  If they stopped doing that, they'd have to pave over the road (which I'd rather them not do) or rebuild it completely (which takes a lot more time) when the slabs begin to offset.

Quote from: deanej on October 05, 2011, 11:38:33 AM
But I LOVE the ka-thump ka-thump noise!  Could we get them to stop?  Putting in the rebars defeats the point of having a concrete road (the cool sounds) in the first place!

The big issue is preventing too much of a shift. It doesn't necessarily eliminate the annoying noise, but it reduces it. Consider how it would mess up your suspension or your alignment if the slabs were really uneven with each other and it became like hitting a curb.

I believe it has to do with now asphalt is recycable where years ago it was not.  Now they mill it over again and re-apply!  I do belive that asphalt is cheaper than concrete as well.

As a child I remember most NJ roads were concrete and still NJ 35 in Monmouth County has some places.  Then slowly from the 70's into the 80's it was changed just like the original white post cable guard rails were over the same period.   That was righ after the oil embargo that it started so that may have to do with it.

Quote from: deanej on October 05, 2011, 11:38:33 AM
But I LOVE the ka-thump ka-thump noise!  Could we get them to stop?  Putting in the rebars defeats the point of having a concrete road (the cool sounds) in the first place!

The point of having a concrete road is that concrete lasts longer than asphalt. The noise, both the expansion joints and the whine, is annoying.

Quote from: hbelkins on October 05, 2011, 08:34:31 PMThe noise, both the expansion joints and the whine, is annoying.

I've never found that so. (excepting Indiana's pavements from the '80s and '90s, that is.)

It may not be so annoying to you as a driver, but you have to consider the people who live or work near that road too.

Quote from: jjakucyk on October 05, 2011, 09:15:26 PM
It may not be so annoying to you as a driver, but you have to consider the people who live or work near that road too.

Only if they were there first.  If the road was there first and they moved near it, that's their own damn fault.

While we're on the subject of noise, has anyone driven the newly rebuilt part of I-64 in St. Louis?  That's the quietest concrete I've ever driven on.  It makes almost no noise, period.

Quote from: US-43|72 on October 05, 2011, 10:47:06 PM

Quote from: jjakucyk on October 05, 2011, 09:15:26 PM
It may not be so annoying to you as a driver, but you have to consider the people who live or work near that road too.

Only if they were there first.  If the road was there first and they moved near it, that's their own damn fault.

That's the dumbest thing I've heard all week.  It's not a problem limited to interstate-level highways, but even surface arterials and other lesser streets.  It could've been an asphalt road rebuilt with concrete, or an existing road that was widened or converted to an expressway, or any number of other situations.  

That's not even the point anyway.  The point is that regardless of who or what was there first, roads don't just affect the drivers on them, they impact their surroundings too.  Considerations must be made for everyone, whether that's for noise, pollution, accidents, flooding, or whatever.  

Quote from: jjakucyk on October 05, 2011, 10:55:28 PMThat's the dumbest thing I've heard all week.  It's not a problem limited to interstate-level highways, but even surface arterials and other lesser streets.  It could've been an asphalt road rebuilt with concrete, or an existing road that was widened or converted to an expressway, or any number of other situations.

All of which would technically mean "they were there first" - would they not?

Quote from: jjakucyk on October 05, 2011, 10:55:28 PMThat's not even the point anyway.  The point is that regardless of who or what was there first, roads don't just affect the drivers on them, they impact their surroundings too.  Considerations must be made for everyone, whether that's for noise, pollution, accidents, flooding, or whatever.

Fair enough.

I just find myself increasingly annoyed with people who get annoyed by little things.  For those who have no real choice where to live, such as the poor in the inner cities especially, it's a legitimate concern.  But out in the middle of the desert in, say, west Texas, or the middle of nowhere in Pennsylvania, what's a little kla-klunk and whine going to do to anyone, especially today, when cars' interiors are quieter than ever?  I guess that's more or less what I was getting at.

Quote from: US-43|72 on October 05, 2011, 11:12:39 PM

Quote from: jjakucyk on October 05, 2011, 10:55:28 PMThat's the dumbest thing I've heard all week.  It's not a problem limited to interstate-level highways, but even surface arterials and other lesser streets.  It could've been an asphalt road rebuilt with concrete, or an existing road that was widened or converted to an expressway, or any number of other situations.

All of which would technically mean "they were there first" - would they not?

Quote from: jjakucyk on October 05, 2011, 10:55:28 PMThat's not even the point anyway.  The point is that regardless of who or what was there first, roads don't just affect the drivers on them, they impact their surroundings too.  Considerations must be made for everyone, whether that's for noise, pollution, accidents, flooding, or whatever.

Fair enough.

I just find myself increasingly annoyed with people who get annoyed by little things.  For those who have no real choice where to live, such as the poor in the inner cities especially, it's a legitimate concern.  But out in the middle of the desert in, say, west Texas, or the middle of nowhere in Pennsylvania, what's a little kla-klunk and whine going to do to anyone, especially today, when cars' interiors are quieter than ever?  I guess that's more or less what I was getting at.

Car interiors may be quieter, but trying rolling at 70+ mph from Concrete to newly asphalt section of the same freeway and you will realize how loud Concrete really is. It's like when the air conditioner goes off and then it's super quiet, then you realize how much sound the AC really makes-you just don't notice it. Same goes for Concrete vs Asphalt.

Considering that something like 80% of all highway noise is tires and the surface, the disparity of sound with asphalt vs concrete is obvious.

Quote from: jjakucyk on October 05, 2011, 11:07:12 AM
They're putting rebar between the slabs which makes them less likely to shift out of place from one another.  Preventing that shifting also reduces the ka-thump ka-thump noise when you drive over the joints.

Additionally, the rebar between slabs helps to transfer the vehicle loads from one slab to the other. This improves durability, and reduces pivoting between the slabs. It also helps prevent blowout conditions where slabs angle upwards.

Often times, the slabs are tied together with rebar before initial concrete is poured. So the cuts that would be visible here when the project is finished would not be seen as in this case. When retrofitted as seen here, agencies usually only do some of the pavement (i.e. the lanes most likely to have trucks) as otherwise it might not be worth the effort.

Quote from: Riverside Frwy on October 06, 2011, 02:06:12 AMCar interiors may be quieter, but trying rolling at 70+ mph from Concrete to newly asphalt section of the same freeway and you will realize how loud Concrete really is. It's like when the air conditioner goes off and then it's super quiet, then you realize how much sound the AC really makes-you just don't notice it. Same goes for Concrete vs Asphalt.

Considering that something like 80% of all highway noise is tires and the surface, the disparity of sound with asphalt vs concrete is obvious.

I've done it more times than many... and so long as the concrete produces a nice whine (i.e. uniform tining, not random) I've never once been bothered by it.  Some random tined pavements make a really bad noise...see Indiana's older pavements, for instance.

NEW asphalt is quieter, but it quickly gets louder.  Nevermind that the "quieter" asphalt pavements (finer aggregate) are not as durable as the "louder" ones, which are still not as durable as concrete.  The new concrete I mentioned above on I-64 in STL is as quiet, if not quieter than, most asphalt I've been on.  I believe it has the "carpet drag" texture as outlined in the WsDOT page linked earlier in the thread.

Of course that's how it always used to be, prior to '78 or so when all new concrete roads got for texture treatment was a burlap drag.  Transverse tining is what makes concrete so loud.  Diamond-ground concrete is also very quiet.

Diamond grinding does help immensely, but there's also exposed aggregate concrete as well.  This isn't like the decorative exposed aggregate (which is way too rough and washes away too much of the "cream"), it's more specifically engineered, and it looks like tan asphalt.  In fact, in some cases it's even laid down more like asphalt.  It has much of the same noise and traction properties as asphalt as well, but the same durability of traditional concrete.  I believe it's used a lot more in Europe than over here, but the main advantage is that it eliminates the whine from grooved concrete and can be very quiet.

http://www.eupave.eu/documents/graphics/inventory-of-documents/febelcem-publicaties/noiseless-concrete-pavements.pdf

 

I'm not sure how the DOT did it, but I-490 between Bushnell's Basin and Victor is noiseless at 55-65mph; you don't hear it unless you're doing under 40.

Quote from: deanej on October 07, 2011, 12:05:11 PMI'm not sure how the DOT did it, but I-490 between Bushnell's Basin and Victor is noiseless at 55-65mph; you don't hear it unless you're doing under 40.

Looks like carpet drag texture to me: http://g.co/maps/k4ma7

No transverse tining is evident, so that would explain it.

The noise you hear under 40 is probably more to do with your tires than anything.

And uniform transverse tining on a bridge on the same route for comparison's sake: http://g.co/maps/f593n

The southwest quadrant of I-270 in Columbus is paved in PCC.  I think they're going to repave it soon, probably also in PCC – I conclude this because they appear to be preparing to run two-way traffic on one side of the freeway, with crossovers.  Curiously, these crossovers are also PCC, possibly even incorporating rebar.  Why build such durable pavement in a place where its usefulness is temporary?  Maybe I'm missing something...

Don't be fooled by crossovers.  Many agencies are going to crossovers regardless for worker safety reasons.  It could very well be an asphalt overlay; knowing Ohio, it will be.

Quote from: US-43|72 on October 10, 2011, 03:32:03 PM
Don't be fooled by crossovers.  Many agencies are going to crossovers regardless for worker safety reasons.  It could very well be an asphalt overlay; knowing Ohio, it will be.

I found a brief description of the project on ODOT's website. They will rebuild the highway one side at a time, with two-way traffic on the other side.  They will also be widening bridges; currently the highway (particularly its bridges) doesn't have full-width breakdown lanes on the left, as the current standards prefer when there are more than 2 lanes each way.  I don't know if the bridges will be widened to accommodate 4 lanes (plus full breakdown lanes), but that would be wise IMO.  If ODOT thinks widening the whole highway to 8 lanes (effectively paving the whole median) is likely within 15 years, and doesn't mind leaving the crossover pavement in place in the meantime, then building the crossovers for longevity makes sense.

Quote from: roadfro on October 06, 2011, 06:29:08 AM

Quote from: jjakucyk on October 05, 2011, 11:07:12 AM
They're putting rebar between the slabs which makes them less likely to shift out of place from one another.  Preventing that shifting also reduces the ka-thump ka-thump noise when you drive over the joints.

Additionally, the rebar between slabs helps to transfer the vehicle loads from one slab to the other. This improves durability, and reduces pivoting between the slabs. It also helps prevent blowout conditions where slabs angle upwards.

Often times, the slabs are tied together with rebar before initial concrete is poured. So the cuts that would be visible here when the project is finished would not be seen as in this case. When retrofitted as seen here, agencies usually only do some of the pavement (i.e. the lanes most likely to have trucks) as otherwise it might not be worth the effort.

They did the rebar on I-405 between California 55 and the El Toro "Y" some years ago.                                                                                               

Quote from: US-43|72 on July 19, 2011, 05:20:25 AM

Quote from: myosh_tino on July 19, 2011, 04:10:26 AMDoes transverse grooved concrete produce that annoying whine that I hear on concrete sections of I-5 in Oregon and on I-15 in Nevada?  If that's the case, then I'm glad Caltrans does not groove their concrete that way.

No, it doesn't.

And unless they do the transverse grooves completely wrong (i.e. try to "randomize" them to make it not whine - result is usually a polar extreme opposite of what they're going for - see Indiana concrete from the 1980s and 1990s, for instance) the whine is not annoying.  NY and PA did it right, with the grooves more or less evenly spaced.  I always found that noise more pleasant than the toneless growl of asphalt - cheap coarse asphalt especially

Hey US-43/72, I know exactly what you mean by "trying to randomize the grooves". This problem happened on some bridge decks here in Illinois on I-270, I-55/70, and Route 255 (all within ten miles of one another).

The grooves on the bridge decks I mentioned are not uniformly spaced, but they form a pattern that goes, wide-narrow-wide-narrow-wide-narrow. The pattern breaks, but then repeats again, and so on. The spacing between every other groove is 3 inches, so the pitch of the sound is three octaves lower than the "whining" sound on a typical transverse-grooved pavement with 1 inch spacing. Likewise, the texture or timbre of the sound is very unusual, almost sounding like an alien.

Here are some links to videos that I uploaded of the weird-sounding bridge pavement. Tell me if they sound similar to the ones in Indiana:

video one (going 63 mph) http://www.youtube.com/watch?v=etktVDvKhbc&feature=relmfu

video two (going slow 45 mph) http://www.youtube.com/watch?v=CFFTIus8-NU&feature=channel_video_title

video three (going 63 mph) http://www.youtube.com/watch?v=FaGqm-QAiMA&feature=channel_video_title

video four (also going 63) http://www.youtube.com/watch?v=FvUF1Nma3Ec&feature=channel_video_title

Quote from: roadfro on July 18, 2011, 09:23:44 PM

Quote from: myosh_tino on July 18, 2011, 03:44:35 PM
While concrete lasts longer (much, much longer) than asphalt, when it rains, the spray kicked up by the vehicles can just about blind a driver.  Over the past 4-6 years, Caltrans has used a new type of asphalt on some Bay Area freeways (most notably US 101 between San Jose and S.F. and I-880 from San Jose to Hayward) that contains ground up tires mixed in with the asphalt.  This surface provides a nice smooth, quiet ride and when it rains, there is very minimal spray because the rubberized asphalt allows the rain water to drain through the pavement.  IIRC, I-880 was repaved about 5 years ago and the rubberized asphalt is still in very good condition.

Obviously, this type of pavement works in California due to our mild climate but I suspect it's not really an option in harsher climates (freezing cold or blistering heat).

It's not necessarily the rubber in the asphalt that allows the rain water to drain through the pavement. With asphalt pavements, the top layer or "lift" is often designed as open graded layer ("open grade" being rock material containing very small fines or pebbles and bigger rocks or crushed aggregate pieces). The open grade material bonds together with asphalt binder, but since there's no small stone material in the mix, the result is a top layer (typically about 2" thick for major roads) that is porous. This allows rainwater to drain down slightly from the pavement surface and travel between asphalt lifts off to the side of the road or gutter due to the natural cross slope of the roadway.

From what I remember the rain performance of this top layer of "open-graded" AC is superor to any other type of pavement, and acoustically the openings in the fines also cause the roadway surface to be very quiet indeed. However I remember that after just a few years 3-5 or so, this roadway surface had deteriorated down ehough that the noise was much louder to the more exposed agregate and also the rain performance was also greatly diminished. In these cases water spray from tires can actually be worse than PCC pavement. Since Open-graded asphalt has such improved safety benefits initially it seems to make sense to use it where possible although it will need to be replaced every 5-6 years versus 10-12 years for regular AC-Overlays. It is too bad that this pavement will not work for mountainuous or snowy regions as the freezing and thawing and plowing would likely damage the roadway after one or two seasons.

Quote from: Mamba205 on October 11, 2011, 05:16:58 PMHey US-43/72, I know exactly what you mean by "trying to randomize the grooves". This problem happened on some bridge decks here in Illinois on I-270, I-55/70, and Route 255 (all within ten miles of one another).

The grooves on the bridge decks I mentioned are not uniformly spaced, but they form a pattern that goes, wide-narrow-wide-narrow-wide-narrow. The pattern breaks, but then repeats again, and so on. The spacing between every other groove is 3 inches, so the pitch of the sound is three octaves lower than the "whining" sound on a typical transverse-grooved pavement with 1 inch spacing. Likewise, the texture or timbre of the sound is very unusual, almost sounding like an alien.

Here are some links to videos that I uploaded of the weird-sounding bridge pavement. Tell me if they sound similar to the ones in Indiana:

video one (going 63 mph) http://www.youtube.com/watch?v=etktVDvKhbc&feature=relmfu

video two (going slow 45 mph) http://www.youtube.com/watch?v=CFFTIus8-NU&feature=channel_video_title

video three (going 63 mph) http://www.youtube.com/watch?v=FaGqm-QAiMA&feature=channel_video_title

video four (also going 63) http://www.youtube.com/watch?v=FvUF1Nma3Ec&feature=channel_video_title

Some of those bridge decks sound a lot like those in Tennessee, actually.  Nothing like Indiana.

Quote from: US-43|72 on October 11, 2011, 05:30:59 PM

Quote from: Mamba205 on October 11, 2011, 05:16:58 PMHey US-43/72, I know exactly what you mean by "trying to randomize the grooves". This problem happened on some bridge decks here in Illinois on I-270, I-55/70, and Route 255 (all within ten miles of one another).

The grooves on the bridge decks I mentioned are not uniformly spaced, but they form a pattern that goes, wide-narrow-wide-narrow-wide-narrow. The pattern breaks, but then repeats again, and so on. The spacing between every other groove is 3 inches, so the pitch of the sound is three octaves lower than the "whining" sound on a typical transverse-grooved pavement with 1 inch spacing. Likewise, the texture or timbre of the sound is very unusual, almost sounding like an alien.

Here are some links to videos that I uploaded of the weird-sounding bridge pavement. Tell me if they sound similar to the ones in Indiana:

video one (going 63 mph) http://www.youtube.com/watch?v=etktVDvKhbc&feature=relmfu

video two (going slow 45 mph) http://www.youtube.com/watch?v=CFFTIus8-NU&feature=channel_video_title

video three (going 63 mph) http://www.youtube.com/watch?v=FaGqm-QAiMA&feature=channel_video_title

video four (also going 63) http://www.youtube.com/watch?v=FvUF1Nma3Ec&feature=channel_video_title

Some of those bridge decks sound a lot like those in Tennessee, actually.  Nothing like Indiana.

Quote from: US-43|72 on October 11, 2011, 05:30:59 PM
Some of those bridge decks sound a lot like those in Tennessee, actually.  Nothing like Indiana

Interesting. I'll have to make a trip to Tennessee. I do know of an area on I-70 in Indianapolis that makes a low-pitch "rumbling" or "wah wah wah" sound. I heard it on my way from Illinois to New Jersey and back last November.

Here's a link to that video of I-70 rumbling pavement in Indianapolis. Is this the sound you're talking about?

http://www.youtube.com/watch?v=8PqZxswqo2E&feature=channel_video_title

That spot is a good example, but try the left-most lane.  It's loudest there, I verified this when I was in Indy back in December 2010.  It's particularly bad on the southwest quadrant of 465, too. figured that out when I was on my way up to Wisconsin to pick up my latest car.

The tining, on I-70 here: http://g.co/maps/6bvcg

Next time I'm in Tennessee, I'll be sure to have my HD camcorder running for at least one bridge deck.

Quote from: US-43|72 on October 11, 2011, 07:43:31 PM
That spot is a good example, but try the left-most lane.  It's loudest there, I verified this when I was in Indy back in December 2010.  It's particularly bad on the southwest quadrant of 465, too. figured that out when I was on my way up to Wisconsin to pick up my latest car.

The tining, on I-70 here: http://g.co/maps/6bvcg

Next time I'm in Tennessee, I'll be sure to have my HD camcorder running for at least one bridge deck.

Here you can see the pattern in the grooves on an Illinois 255 bridge deck:

http://maps.google.com/?ll=38.792813,-90.045077&spn=0.001269,0.002747&t=m&z=19&vpsrc=6&layer=c&cbll=38.792687,-90.045078&panoid=lANgzrKpu1SK2sycBVKzSg&cbp=12,266.89,,3,26.55

This pattern was done on several bridges in the area, so the same weird "droning" sound is heard on them. The pattern of the grooves looks similar to the ones on I-465 and 70. I wonder why they even bother trying to randomize the spaces. It should be easy to avoid a pattern.

Quote from: Mamba205 on October 12, 2011, 05:52:07 PM
I wonder why they even bother trying to randomize the spaces. It should be easy to avoid a pattern.

I don't think they're trying to randomize as much as they just want to avoid a consistent spacing. Having a consistent spacing starts to produce a harmonic vibration that can be harmful to the pavement over time due to, I believe, oscilation effects. It's for similar reasons that the expansion joints between adjacent PCC slabs in a lane are made at different lengths.

Quote from: Mamba205 on October 12, 2011, 05:52:07 PMHere you can see the pattern in the grooves on an Illinois 255 bridge deck:

http://maps.google.com/?ll=38.792813,-90.045077&spn=0.001269,0.002747&t=m&z=19&vpsrc=6&layer=c&cbll=38.792687,-90.045078&panoid=lANgzrKpu1SK2sycBVKzSg&cbp=12,266.89,,3,26.55

This pattern was done on several bridges in the area, so the same weird "droning" sound is heard on them. The pattern of the grooves looks similar to the ones on I-465 and 70. I wonder why they even bother trying to randomize the spaces. It should be easy to avoid a pattern.

The tining on the Tennessee bridges looks basically identical, reinforcing my belief that they sound very similar.

Quote from: roadfro on October 13, 2011, 04:22:37 AMI don't think they're trying to randomize as much as they just want to avoid a consistent spacing. Having a consistent spacing starts to produce a harmonic vibration that can be harmful to the pavement over time due to, I believe, oscilation effects. It's for similar reasons that the expansion joints between adjacent PCC slabs in a lane are made at different lengths.

I've only ever observed this in Kentucky, and only on their 1980s/90s pavements.  The newest KY concrete pavements have evenly spaced expansion joints, the western-most section of I-275 for instance.

Quote from: Indyroads on October 11, 2011, 05:25:02 PM

Quote from: roadfro on July 18, 2011, 09:23:44 PM

Quote from: myosh_tino on July 18, 2011, 03:44:35 PM
While concrete lasts longer (much, much longer) than asphalt, when it rains, the spray kicked up by the vehicles can just about blind a driver.  Over the past 4-6 years, Caltrans has used a new type of asphalt on some Bay Area freeways (most notably US 101 between San Jose and S.F. and I-880 from San Jose to Hayward) that contains ground up tires mixed in with the asphalt.  This surface provides a nice smooth, quiet ride and when it rains, there is very minimal spray because the rubberized asphalt allows the rain water to drain through the pavement.  IIRC, I-880 was repaved about 5 years ago and the rubberized asphalt is still in very good condition.

Obviously, this type of pavement works in California due to our mild climate but I suspect it's not really an option in harsher climates (freezing cold or blistering heat).

It's not necessarily the rubber in the asphalt that allows the rain water to drain through the pavement. With asphalt pavements, the top layer or "lift" is often designed as open graded layer ("open grade" being rock material containing very small fines or pebbles and bigger rocks or crushed aggregate pieces). The open grade material bonds together with asphalt binder, but since there's no small stone material in the mix, the result is a top layer (typically about 2" thick for major roads) that is porous. This allows rainwater to drain down slightly from the pavement surface and travel between asphalt lifts off to the side of the road or gutter due to the natural cross slope of the roadway.

From what I remember the rain performance of this top layer of "open-graded" AC is superor to any other type of pavement, and acoustically the openings in the fines also cause the roadway surface to be very quiet indeed. However I remember that after just a few years 3-5 or so, this roadway surface had deteriorated down ehough that the noise was much louder to the more exposed agregate and also the rain performance was also greatly diminished. In these cases water spray from tires can actually be worse than PCC pavement. Since Open-graded asphalt has such improved safety benefits initially it seems to make sense to use it where possible although it will need to be replaced every 5-6 years versus 10-12 years for regular AC-Overlays. It is too bad that this pavement will not work for mountainuous or snowy regions as the freezing and thawing and plowing would likely damage the roadway after one or two seasons.

Alabama and Florida uses the open graded friction course AC on most of it's interstates, but they have had mixed results with it in terms of how well it stands up to traffic. There was a stretch of I-65 north of Birmingham around Gardendale that had the open-graded asphalt, and it deteriorated rather quickly (I think two or three years after it was resurfaced), so ALDOT had it repaved with standard Superpave on the wearing surface.

Quote from: US-43|72 on October 11, 2011, 05:30:59 PM

Quote from: Mamba205 on October 11, 2011, 05:16:58 PMHey US-43/72, I know exactly what you mean by "trying to randomize the grooves". This problem happened on some bridge decks here in Illinois on I-270, I-55/70, and Route 255 (all within ten miles of one another).

The grooves on the bridge decks I mentioned are not uniformly spaced, but they form a pattern that goes, wide-narrow-wide-narrow-wide-narrow. The pattern breaks, but then repeats again, and so on. The spacing between every other groove is 3 inches, so the pitch of the sound is three octaves lower than the "whining" sound on a typical transverse-grooved pavement with 1 inch spacing. Likewise, the texture or timbre of the sound is very unusual, almost sounding like an alien.

Here are some links to videos that I uploaded of the weird-sounding bridge pavement. Tell me if they sound similar to the ones in Indiana:

video one (going 63 mph) http://www.youtube.com/watch?v=etktVDvKhbc&feature=relmfu

video two (going slow 45 mph) http://www.youtube.com/watch?v=CFFTIus8-NU&feature=channel_video_title

video three (going 63 mph) http://www.youtube.com/watch?v=FaGqm-QAiMA&feature=channel_video_title

video four (also going 63) http://www.youtube.com/watch?v=FvUF1Nma3Ec&feature=channel_video_title

Some of those bridge decks sound a lot like those in Tennessee, actually.  Nothing like Indiana.

That does indeed sound like Tennessee bridge decks (TN 385 in Memphis comes to mind for me).

Here in Michigan, there's a type of concrete called Continuous Reinforced Concrete where the concrete was heavily reinforced. Around here, it was used in the construction of almost all of I-275 and some of I-696 in the 1970's. By the 1990's, many cars got damaged by driving on those two freeway segments, portions looked like the freeway had been bombed and some even said those freeways were paved with gravel!!! (including the webmaster of the Michigan Highways site, see it here: http://www.kurumi.com/roads/3di/i275.html#275mi (http://www.kurumi.com/roads/3di/i275.html#275mi))  :wow: So around 1997, MDOT responded and totally rebuilt those freeways, the last of which was completed by late 1999. And MDOT no longer uses CRC!!

More information is at http://www.michiganhighways.org/listings/MichHwys250-696.html#I-275 (http://www.michiganhighways.org/listings/MichHwys250-696.html#I-275) and http://www.michiganhighways.org/listings/MichHwys250-696.html#I-696 (http://www.michiganhighways.org/listings/MichHwys250-696.html#I-696).

Quote from: codyg1985 on October 13, 2011, 07:14:45 AMThere was a stretch of I-65 north of Birmingham around Gardendale that had the open-graded asphalt, and it deteriorated rather quickly (I think two or three years after it was resurfaced), so ALDOT had it repaved with standard Superpave on the wearing surface.

Some of it is still there.  It's so deteriorated that it has actually completely eroded away above all the concrete joints below, allowing the slabs to free-float again.  It literally now feels like concrete with offset slabs.

I'm willing to bet the Michigan "CRC" was actually jointed-reinforced.  If it had transverse joints, it was jointed-reinforced.  CRC doesn't have transverse joints, hence its name, Continuous Reinforced Concrete.  I-459 in Alabama has CRC and most of Texas' concrete pavements are CRC.  Illinois uses it some as well.  I-74 in Peoria was recently redone in CRC.  In any event, early CRC didn't work well because of design issues with the steel reinforcing mesh.  Properly-designed CRC will certainly outlast plain-jointed pavements, which are only seeming to last 15-20 years, as opposed to some of the older jointed-reinforced pavements that lasted 30-40.

Sorry, boys..... I'm an asphalt guy.  I don't like the low color contrast between pavement striping and surface material on PCC roadways, especially at night.  It drives me nuts to be stuck in head-to-head traffic on one side of a freeway while the other side lies completely ripped up; I'd rather have a quick resurfacing every 5-10 years than have a roadway totally undriveable for what seems like an eternity every 25.  In slick winter conditions, I actually prefer rough blacktop over anything really smooth, just for the added traction (shoot, if they could make a freeway out of gravel, I'd take that in some nasty weather conditions).  Pavement flaws in asphalt are usually small and avoidable (potting), whereas flaws in concrete threaten to send my car into orbit and are unavoidable.

Please don't throw things at me.  I know concrete lasts longer.  I've been on very smooth new concrete highways (some of which don't even produce a nasty whine).  I know, I know, I know.  But I still want to break out into song when I transition from a concrete portion onto a silky-smooth blacktop portion.

Quote from: kphoger on November 29, 2011, 09:30:22 PMPavement flaws in asphalt are usually small and avoidable (potting) . . .

Not necessarily true--badly maintained asphalt tends to rut under heavy traffic, and these ruts are both hard to avoid and likely to cause hydroplaning in wet weather.  Badly maintained concrete leads to other problems like ride roughness going over spalled joints, but at least it does not rut.

Quote from: kphoger on November 29, 2011, 09:30:22 PM
Pavement flaws in asphalt are usually small and avoidable (potting), whereas flaws in concrete threaten to send my car into orbit and are unavoidable.

Not at all. During winter in Salt Lake we have serious potholes forming on (older) asphalt surfaces, while our (old and new and anywhere in between) concrete roads do just fine.

Quote from: Coelacanth on July 18, 2011, 11:14:16 AM
A couple of other things to consider:

There are often political factors involved. Do not underestimate the power of the asphalt (or PCC) lobby in a particular region. Not that engineering decisions would ever be made for political reasons...

There is also some volatility in the prices of raw materials. In particular, in periods of construction booms, PCC becomes more expensive because concrete is used for building footings, etc.

Trying using solely one type could easily overcome the industry capacity of a region, leading to much higher unit prices for that type.  That is why that usually you see considerable use of both types in a region.

The multi-factor formula for life cycle costs of a pavement type, does not lead to a large difference.  It is close enough that each industry can claim that its type is a bit cheaper, by arguing over the exact value of each factor.  We're talking a total of about 5 to 10% at most.

The Hampton Roads area in Virginia mostly uses concrete pavement on Interstates, because the very high capacity of the concrete industry in that area, makes it more favorable on a cost basis.

Kentucky hadn't consistently used concrete for new highway construction in many many years until a few years ago. Just about every bit of new highway construction that I can think of used asphalt.

Now, many contracts for new construction include the line "pavement alternatives." This means they are considering both asphalt and concrete. I don't know what kind of formula is being used to compensate for concrete's initial higher cost, but they do have some sort of system developed to allow the Awards Committee to make a determination.

Quote from: J N Winkler on November 29, 2011, 10:06:34 PMbut at least it does not rut.

No, it does - you just have to give it a lot of time.  I've been on plenty of 30-40 year old concrete that was pretty well rutted.

^ Concrete doesn't rut the same way asphalt does. With the concrete, is more of a gradual wearing of fines and aggregates from the surface due to wear from tires (and chains in winter snow areas; see I-80 near Donner Summit) and is only surface rutting. Asphalt gradually ruts such that the entire pavement section (the various lifts in the asphalt concrete as well as the base or subbase layers) deforms causing the rut.

Quote from: roadfro on December 03, 2011, 04:01:46 AM^ Concrete doesn't rut the same way asphalt does. With the concrete, is more of a gradual wearing of fines and aggregates from the surface due to wear from tires (and chains in winter snow areas; see I-80 near Donner Summit) and is only surface rutting. Asphalt gradually ruts such that the entire pavement section (the various lifts in the asphalt concrete as well as the base or subbase layers) deforms causing the rut.

I have personally never seen concrete that was rutted deeply enough to overcome crossfall and accumulate enough standing water to cause hydroplaning.  The very few times I have hydroplaned on concrete have always been as a result of design faults such as undrained creases on bridge decks.  On the other hand, hydroplaning is such a problem on asphalt that I always look for glossy reflections in wheel ruts when I am driving on asphalt in or immediately after a rainstorm, and slow down when I see them.

We could more or less completely eliminate the risk of hydroplaning on asphalt by tightening pavement maintenance schedules, building high-speed roads with uniform 2.5% crossfall, and using surface textures which resist deformation under load and promote quick drainage.  This is more or less what the British have done since the late 1950's--hydroplaning is almost unknown on British motorways despite well over 90% of motorway mileage being bituminous-surfaced.

Quote from: J N Winkler on December 03, 2011, 11:53:20 AM

Quote from: roadfro on December 03, 2011, 04:01:46 AM^ Concrete doesn't rut the same way asphalt does. With the concrete, is more of a gradual wearing of fines and aggregates from the surface due to wear from tires (and chains in winter snow areas; see I-80 near Donner Summit) and is only surface rutting. Asphalt gradually ruts such that the entire pavement section (the various lifts in the asphalt concrete as well as the base or subbase layers) deforms causing the rut.

I have personally never seen concrete that was rutted deeply enough to overcome crossfall and accumulate enough standing water to cause hydroplaning.

I have ... some Pennsylvania highways in the 1970s, such as US-202 west of Valley Forge, and the Schuylkill Expressway, and some others.

In fact, when it rains on rutted asphalt, I typically ride either the center line or the shoulder line, depending on the road.  I also do this at railway crossings to avoid the worst bumps, whether the road is asphalt or hydraulic concrete.

Gee.....Our roads could be better if they were built the way they should be built and maintained the way they should be maintained.  If only it were free of cost! (-:

Quote from: J N Winkler on December 03, 2011, 11:53:20 AM

Quote from: roadfro on December 03, 2011, 04:01:46 AM^ Concrete doesn't rut the same way asphalt does. With the concrete, is more of a gradual wearing of fines and aggregates from the surface due to wear from tires (and chains in winter snow areas; see I-80 near Donner Summit) and is only surface rutting. Asphalt gradually ruts such that the entire pavement section (the various lifts in the asphalt concrete as well as the base or subbase layers) deforms causing the rut.

I have personally never seen concrete that was rutted deeply enough to overcome crossfall and accumulate enough standing water to cause hydroplaning.  The very few times I have hydroplaned on concrete have always been as a result of design faults such as undrained creases on bridge decks.  On the other hand, hydroplaning is such a problem on asphalt that I always look for glossy reflections in wheel ruts when I am driving on asphalt in or immediately after a rainstorm, and slow down when I see them.

We could more or less completely eliminate the risk of hydroplaning on asphalt by tightening pavement maintenance schedules, building high-speed roads with uniform 2.5% crossfall, and using surface textures which resist deformation under load and promote quick drainage.  This is more or less what the British have done since the late 1950's--hydroplaning is almost unknown on British motorways despite well over 90% of motorway mileage being bituminous-surfaced.

Quote from: Beltway on December 03, 2011, 12:34:43 PM

Quote from: J N Winkler on December 03, 2011, 11:53:20 AM

Quote from: roadfro on December 03, 2011, 04:01:46 AM^ Concrete doesn't rut the same way asphalt does. With the concrete, is more of a gradual wearing of fines and aggregates from the surface due to wear from tires (and chains in winter snow areas; see I-80 near Donner Summit) and is only surface rutting. Asphalt gradually ruts such that the entire pavement section (the various lifts in the asphalt concrete as well as the base or subbase layers) deforms causing the rut.

I have personally never seen concrete that was rutted deeply enough to overcome crossfall and accumulate enough standing water to cause hydroplaning.

I have ... some Pennsylvania highways in the 1970s, such as US-202 west of Valley Forge, and the Schuylkill Expressway, and some others.

And the old section of I-64 in Fayette County, Ky., just east of I-75, especially the westbound lanes. This was finally rehabbed in the late 90s and widened in the early 2000s.

Here in Louisiana I think that a good asphalt construction is a better plan in the southern part of the state. We have subsidence type soils there, as the roadway sinks concrete tends to buckle, crack and have sections sink in. Asphalt would flex with the settling better and it can be cold planed and repaved. Repairing concrete is much more expensive. What LA  DOTD generally does is put a "wad of asphalt" patch for a repair.

Some of their newer concrete roads that are on good clay foundations are crumbling apart. (must have used that hardware store "easy mix" stuff :paranoid:)

Quote from: pctech on May 29, 2012, 10:27:45 AM
Some of their newer concrete roads that are on good clay foundations are crumbling apart. (must have used that hardware store "easy mix" stuff :paranoid:)

Depending on the type of clay you wouldn't want to be building on that either.

Quote from: kphoger on November 29, 2011, 09:30:22 PM
Sorry, boys..... I'm an asphalt guy.  I don't like the low color contrast between pavement striping and surface material on PCC roadways, especially at night.  It drives me nuts to be stuck in head-to-head traffic on one side of a freeway while the other side lies completely ripped up; I'd rather have a quick resurfacing every 5-10 years than have a roadway totally undriveable for what seems like an eternity every 25.  In slick winter conditions, I actually prefer rough blacktop over anything really smooth, just for the added traction (shoot, if they could make a freeway out of gravel, I'd take that in some nasty weather conditions).  Pavement flaws in asphalt are usually small and avoidable (potting), whereas flaws in concrete threaten to send my car into orbit and are unavoidable.

Please don't throw things at me.  I know concrete lasts longer.  I've been on very smooth new concrete highways (some of which don't even produce a nasty whine).  I know, I know, I know.  But I still want to break out into song when I transition from a concrete portion onto a silky-smooth blacktop portion.

This 2000 article from TOLLROADSnews should warm the hearts of asphalt pavement fans:

PAVEMENT:New Jersey Turnpike asphalt nears 50 & strong (http://www.tollroadsnews.com/node/2673)

QuoteJohn Kunna, chief engineer at the New Jersey Turnpike says his predecessors did a superb job designing and constructing the turnpike's pavement. And he says the Turnpike has generally done a good job since then of maintaining it. Full depth asphalt, most of it, was laid in 1950 and 1951, so it is approaching its half centenary. And it's going strong. Kunna says there is no foreseeable need to rebuild the pavement totally, as has happened with many other portland cement concrete and asphalt pavements well before this.

QuoteThe NJ Tpk pavement structure is generally about a meter thick (40"). It started in 1950-51 with a 900mm (36") structure consisting of 450mm (18") of free draining sand with 150mm (6") of crushed stone, then 300mm (12") of asphalt. Most places have had a couple of 50mm to 60mm (2" to 2.5") overlays, giving it an asphalt depth of 400mm to 420mm (16" to 17") on top of a 600mm (24") sand and stone foundation.

Well, yeah, it was well engineered.  Not all states do that, sadly.

As for kphoger's comment, I'd probably like asphalt more if they could figure out a way to make it stay black.

Quote from: Crazy Volvo Guy on October 05, 2011, 10:53:37 PM
While we're on the subject of noise, has anyone driven the newly rebuilt part of I-64 in St. Louis?  That's the quietest concrete I've ever driven on.  It makes almost no noise, period.

Yeah, it's a nice pavement. I believe they did longitudinal diamond grinding on the new I-64 in St. Louis. Diamond ground concrete is my favorite driving surface behind asphalt. I also like the longitudinally tined concrete in Michigan.

I know I brought this up two years ago, but because we're talking about quiet roads I wanted to talk about it again. If you cross the river from St. Louis into Illinois, your tires make a really weird sound on some of the bridges. This is because the drainage grooves were cut with spaces of 1-1/8 inch, 5/8 inch, 1 inch, 5/8 inch, 1-1/8 inch, 3/4 inch, 3/4 inch in 6 inch repetitions. This is an example of poorly "randomizing" the spaces between the grooves to reduce the generation of harmonics by preventing a narrow-band frequency in the audible spectrum from being produced.

I've noticed in some states, the DOT will go through and mill down old uneven concrete surfaces to make a smoother ride. When you go over a stretch of shifted segments and then hit a stretch of milled concrete, it makes a huge difference. Not as commonly done as I'd like, though.

Quote from: deanej on July 15, 2011, 12:36:12 PM
But I LOVE that sound!

Yes, I like it too. Of course if you think concrete is 100% perfect you'd be deceiving yourself. In Middle Island, New York, the concrete sections of Old NY 25 near Artist Lake buckled and they have metal driveway gates closing it off. I told somebody about it who lives in the area, and he didn't even know it used to be part of Route 25. He thought it was just a residential frontage road.

That would be why concrete typically isn't used for two lane roads up here.  But a little wear gives it character.  I think some states re-mill these sections too often; if the damage isn't too bad, leave it be!  I've seen sections that look and feel new get re-milled, with the effect being that they look older and drive like asphalt.

Quote from: Road Hog on January 24, 2013, 11:15:53 PM
I've noticed in some states, the DOT will go through and mill down old uneven concrete surfaces to make a smoother ride. When you go over a stretch of shifted segments and then hit a stretch of milled concrete, it makes a huge difference. Not as commonly done as I'd like, though.

Quote from: deanej on January 25, 2013, 11:59:50 AM
That would be why concrete typically isn't used for two lane roads up here.  But a little wear gives it character.  I think some states re-mill these sections too often; if the damage isn't too bad, leave it be!  I've seen sections that look and feel new get re-milled, with the effect being that they look older and drive like asphalt.

IDOT has been milling and placing asphalt over the fairly new and already smooth concrete bridge approach pavements. There was faulting going on at the transition onto the approach slabs and that created a little "bump". What they should have done was diamond grind the pavement right at the joints, rather than resurfacing several hundred feet of good pavement. Not to mention the black asphalt made everything around it black and greasy looking.

Quote from: mtantillo on July 15, 2011, 01:00:06 PM
Also, lets not forget considerations of traffic control when paving with concrete vs. asphalt.  Asphalt can be applied overnight, and the lanes opened up in time for the next day, while concrete often requires more extended lane closures.  Depending on the nature of the roadway, this could be done over a weekend, but some roads have enough weekend traffic and few alternate routes so this is just not possible. 

Not only that, but with asphalt, it's a very easy matter to resurface only part of the road and leave the remainder open to traffic.  This is common practice on MassDOT interstate resurfacing projects.  Most three and four lane interstates (one direction) in Massachusetts are resurfaced two lanes at a time (the three lane sections use the shoulder for travel when the left and center lanes are being repaved).

For obvious reasons, you would do this work late nights or weekends, but it's far less disruptive than completely shutting a highway down.

Actually CT DOT just "diamond grinded" CT-25 in 2012, the first time concrete was touched since 1983.  Meanwhile, just to the north on I-84 around Exit 15 or so, the highway has been repaved with blacktop at least three times since 1988. 
Just think of all the money that would be saved if most roads were concrete, especially here in the northeast. 

Quote from: roadman on January 25, 2013, 08:22:15 PM

Quote from: mtantillo on July 15, 2011, 01:00:06 PM
Also, lets not forget considerations of traffic control when paving with concrete vs. asphalt.  Asphalt can be applied overnight, and the lanes opened up in time for the next day, while concrete often requires more extended lane closures.  Depending on the nature of the roadway, this could be done over a weekend, but some roads have enough weekend traffic and few alternate routes so this is just not possible. 

Not only that, but with asphalt, it's a very easy matter to resurface only part of the road and leave the remainder open to traffic.  This is common practice on MassDOT interstate resurfacing projects.  Most three and four lane interstates (one direction) in Massachusetts are resurfaced two lanes at a time (the three lane sections use the shoulder for travel when the left and center lanes are being repaved).

For obvious reasons, you would do this work late nights or weekends, but it's far less disruptive than completely shutting a highway down.

You can do the same in concrete. Just takes longer.

I'm curious if there's a known issue with snow melting more slowly on cement/concrete than on asphalt.

We recently got ice, followed by light snow, followed by bitter cold.  I noticed that all the blacktop portions of the parking lot at work are almost entirely clear of snow, while all the concrete portions are almost entirely covered still.

Quote from: kphoger on January 16, 2018, 03:02:45 PMI'm curious if there's a known issue with snow melting more slowly on cement/concrete than on asphalt.

We recently got ice, followed by light snow, followed by bitter cold.  I noticed that all the blacktop portions of the parking lot at work are almost entirely clear of snow, while all the concrete portions are almost entirely covered still.

Asphalt and Portland cement concrete have similar heat retention characteristics and asphalt has a lower albedo.

https://www.frostburg.edu/fsu/assets/File/clife/mscenter/FinalPapers/2008/Heat.pdf

But shade matters.  Over here concrete that is in the sun is mostly clear while asphalt that is in the shade is still ice-covered and excellent for testing ABS (which, thankfully, still works well in my 24-year-old daily driver).

Quote from: Road Hog on January 26, 2013, 01:40:30 AM

You can do the same in concrete. Just takes longer.

There's a street near me that is being rebuilt in concrete (it was asphalt). The first two lanes were finished fairly quickly and opened to traffic. The other two lanes are being done piecemeal.

Quote from: J N Winkler on January 16, 2018, 03:38:47 PM

Quote from: kphoger on January 16, 2018, 03:02:45 PMI'm curious if there's a known issue with snow melting more slowly on cement/concrete than on asphalt.

We recently got ice, followed by light snow, followed by bitter cold.  I noticed that all the blacktop portions of the parking lot at work are almost entirely clear of snow, while all the concrete portions are almost entirely covered still.

Asphalt and Portland cement concrete have similar heat retention characteristics and asphalt has a lower albedo.

https://www.frostburg.edu/fsu/assets/File/clife/mscenter/FinalPapers/2008/Heat.pdf

But shade matters.  Over here concrete that is in the sun is mostly clear while asphalt that is in the shade is still ice-covered and excellent for testing ABS (which, thankfully, still works well in my 24-year-old daily driver).

Heat retention isn't the same thing as reflection, though.  I still wonder if darker asphalt absorbs more radiant energy and helps to melt the snow/ice on top better than the lighter PCC.

Quote from: kphoger on January 17, 2018, 10:10:26 AMI still wonder if darker asphalt absorbs more radiant energy and helps to melt the snow/ice on top better than the lighter PCC.

This is what albedo means.  But actually with PCC you get more variation in it.  When it is dry, it generally ranges in color from cream to light tan (medium-high albedo), but when it is wet, it is generally dark brown in color (low albedo, close to that of surface water).  Fresh snow, on the other hand, has one of the highest albedos there is (as high as 80%).

This is why blading off a thin layer of snow on concrete allows you to get back to bare pavement relatively quickly, even if initially all this does is expose an ice underlayer.  The concrete is dark brown below the ice and direct sunlight will clear the ice in short order even if temperatures are well below freezing.  This mechanism doesn't work, of course, if the area of cleared pavement is in perpetual shade (e.g., is on the north side of a building), because the incident light energy due to ambient light during the day is typically far less than that of direct sunlight.  (A photographer's light meter will give you an idea of the disparity.  It will show the incident light energy on a reference target--typically a gray card--as a recommended f-stop at a given ISO speed.  Typically ambient light in shade results in readings several f-stops below that of direct sunlight, each f-stop representing half as much incident light as the next higher f-stop.)

I suspect your employer still has snow on the concrete portions of his or her parking lot as a result of some combination of the following:  (1) not paying for a commercial snow removal service; (2) liability concerns about sending out an employee to hand-shovel while cars are maneuvering in and out of the lot; and (3) shade.

Quote from: kphoger on January 17, 2018, 10:10:26 AM
Heat retention isn't the same thing as reflection, though.  I still wonder if darker asphalt absorbs more radiant energy and helps to melt the snow/ice on top better than the lighter PCC.

I think when you start to evaluate conditions at such a micro-level other factors would come into play as well.  Things such as pavement texture (whether asphalt of concrete) could conceivably play a factor in how snow and ice accumulates and subsequently melts from the surface of the pavement structure.

Quote from: J N Winkler on January 17, 2018, 11:50:45 AM
I suspect your employer still has snow on the concrete portions of his or her parking lot as a result of some combination of the following:  (1) not paying for a commercial snow removal service; (2) liability concerns about sending out an employee to hand-shovel while cars are maneuvering in and out of the lot; and (3) shade.

One of the VPs at my company has his own snow plow, so they certainly don't contract the job out to someone else.  But we didn't get enough snow to even plow it at all.  At any rate, I'm talking about large patches that were repaved from asphalt to PCC (due to rutting a couple of years ago) still having snow on them right up to the line, and then the asphalt being clear of snow right on the other side of the line.

I noticed in the Los Angeles area most freeways are paved in concrete because of durability and long term usage. But in parts of Northern California Asphalt is used like on I-80 in Solano county it used to be in concrete but was repaved in Asphalt due to budget constraints when the planning took place.

Does anyone else find the sound of driving on concrete relaxing?

Quote from: Hurricane Rex on January 17, 2018, 11:45:54 PM
Does anyone else find the sound of driving on concrete relaxing?

Yes. I also find concrete more visually pleasing than blacktop.

For some odd reason though, I do like blacktop in the deserts. It just goes with desert cities better.

Quote from: Hurricane Rex on January 17, 2018, 11:45:54 PM
Does anyone else find the sound of driving on concrete relaxing?

Are you referring to the sounds of grooved concrete on highways? If so then yes. I always thought those sounds to be pretty cool. There is a bridge in Pennsylvania on I-80 that had an extremely unusual grooving pattern. The bridge started out with a rather sci-fi sound produced by a randomized groove pattern. Half way over the bridge is grooved in the usual one inch even spacing producing that familiar howling sound you hear in states like NY and NJ, which is pretty uncommon for PA. unfortunately the bridge was paved over recently (even though ther were little to no signs of wear or tear of the concrete) so it doesnt make those awesome sounds anymore. Here is what it looked like...

https://www.google.com/maps/@41.0519072,-76.8540271,3a,15y,200.9h,60.28t/data=!3m6!1e1!3m4!1sl5p1V87OAR7-PMZo5_w6nw!2e0!7i13312!8i6656

Here is a video I took going over it.

https://www.youtube.com/watch?v=0jWCunZULEk

The grooves have to be crosswise for it to make the whining sound. I-15 in Salt Lake City has that sound as well. I especially like driving over places where the pavement switches to crosswise-grooved concrete.

Unfortunately, new concrete freeways around here all have lengthwise grooves, so no whining noises. There are a few newer bridges that might have it, but UDOT has started paving over a lot of concrete bridges with blacktop.

Quote from: Hurricane Rex on January 17, 2018, 11:45:54 PM
Does anyone else find the sound of driving on concrete relaxing?

Groovy, man ;)

New York seems to like to just put down a fresh coat of asphalt every few years. A prime example is the Northway. When I moved to the Clifton Park/ Saratoga area, they were replacing it. Just last summer they killed up the seams between lanes, and just replaced them with fresh material.

On the other hand, I used to travel I88 to Binghamton for work. It is mostly laid in concrete. This was only opened in the 1980s. There were a few sections which had asphalt, but the concrete portions seemed to heave. They seem to perpetually have a crew cutting out these sections, and repouring them. It must be a cash cow payoff to the construction company, since there always seems to be an area under repair.

In NYSDOT Region 1, they have had leaders that were focused on the interstates over the years.  Such focuses can ebb and flow as officials change.

There was one thin overlay project on the Northway near Exit 1 a couple of years ago that raised eyebrows at NYSDOT and may have led to a reorganizing of Region 1's program in that regard.

(personal opinion emphasized)

I believe I-4 reconstruction in Orlando is using concrete for the express lanes and asphalt for the general use lanes. I found that interesting and unusual. Is this done elsewhere (where its all being built at the same time)?

Quote from: UCFKnights on March 22, 2018, 10:36:33 AM
I believe I-4 reconstruction in Orlando is using concrete for the express lanes and asphalt for the general use lanes. I found that interesting and unusual. Is this done elsewhere (where its all being built at the same time)?

My guess would be that blacktop was used for the general purpose lanes in order to get them open to traffic quickly.  Express lanes can remain closed longer to allow the concrete to cure without as much disruption.

Quote from: UCFKnights on March 22, 2018, 10:36:33 AM
I believe I-4 reconstruction in Orlando is using concrete for the express lanes and asphalt for the general use lanes. I found that interesting and unusual. Is this done elsewhere (where its all being built at the same time)?

They didn't do that up here on the Beltway–it's all asphalt. Unfortunately, the express lanes have a lot more patches and other pavement issues in certain segments making for a bumpier ride (especially between Exits 54 and 52). The split pavement idea sounds interesting, but even if it had been considered here (which I doubt) I'm sure it would have been rejected. The existing road was asphalt and they basically widened it by two lanes on the outside and then put up pylons to separate the express lanes (which had previously been the two left lanes)–so, essentially, even though it was a massive rebuild they weren't building "new" road for the express lanes.

Quote from: 1995hoo on March 22, 2018, 11:08:59 AM
They didn't do that up here on the Beltway–it's all asphalt. Unfortunately, the express lanes have a lot more patches and other pavement issues in certain segments making for a bumpier ride (especially between Exits 54 and 52). The split pavement idea sounds interesting, but even if it had been considered here (which I doubt) I'm sure it would have been rejected. The existing road was asphalt and they basically widened it by two lanes on the outside and then put up pylons to separate the express lanes (which had previously been the two left lanes)–so, essentially, even though it was a massive rebuild they weren't building "new" road for the express lanes.

The I-495 Capital Beltway HOT lanes?  The pre-existing pavement is a composite design, asphalt overlaid over original concrete pavement, dating to the 8-lane widening project 1974-78.