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Seal Coat Melting SH 6 Erath County Texas

Started by Brian556, May 28, 2017, 10:44:11 AM

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Brian556

News Report:
http://www.nbcdfw.com/traffic/stories/State-Highway-in-Erath-County-is-Melting-in-the-Texas-Heat-424708714.html?_osource=SocialFlowFB_DFWBrand

I took this pic on FM 543 in Collin County. It shows the more typical problem with seal coat that occurs in curves:



I remember when I worked for TxDOT they sent out sand trucks to apply sand to several newly seal coated roads due to melting tar


froggie

Several northern states will put a layer of crushed rock on top of the seal coat (called "chip sealing" if you're not familiar with that term).  Does Texas not do this?

Brian556

Quote from froggie:
QuoteSeveral northern states will put a layer of crushed rock on top of the seal coat (called "chip sealing" if you're not familiar with that term).  Does Texas not do this?

Yes. Without it, the road would be extremely slippery when wet, and be more prone to tar sticking to tires during hot weather. The rock separates tires from the tar.

Tar often bleeds to the surface making certain areas very slippery when wet. Also, it very frequently get damaged in curves, like in my pic above.
For these reasons, and also the fact that it is very loud to drive on, I dislike it.

wxfree

I complained about something similar a while back on this forum.  The recent round of chip sealing has been garbage.  I've noticed that brand new roads start looking worn out in spots in days, often less than a week.  After a few weeks it has smooth areas and pretty soon it has significant damage, especially in curves.  On some busier FM roads they went through and put some good pavement around the curves, spending more money instead of doing it right the first time.  I've been driving long enough to have seen roads recovered multiple times, and I've never seen such crappy workmanship.

Two egregious examples happened near Granbury.  FM 4 toward Lipan and part of US 377 were beautifully rebuilt with good high-quality black pavement that would have lasted for years.  Then they came up with make-work projects (I think it might have been stimulus money) and chip sealed over them.  FM 4 is now crappy, but just a layer of crappy covering some good pavement.  US 377 has a lot of traffic and heavy trucks.  Chip seal for that road was ridiculously stupid.  It quickly had sections that were repaved and eventually they just decided to repave the whole stretch, restoring it to the way it was before.
I'd like to buy a vowel, Alex.  What is E?

Brian556

The purpose is to seal the pavement, making it last longer. In my opinion it has so many drawbacks that it is not worth it.

They even have it on I-35 just south of the Red River. I think its ridiculous to use that crap on an interstate highway.

froggie

Doesn't sound like TxDOT is using best practices for chip sealing...

wxfree

#6
Quote from: Brian556 on May 29, 2017, 12:33:07 AM
The purpose is to seal the pavement, making it last longer.

That's how they described the reason at the time.  I'm sure the pavement on FM 4 is in great condition, but it's covered with garbage so the road surface is bumpy and slippery.

How would a road be restored, like they did on US 377 (where brand new pavement was covered)?  Can the stuff be peeled off?  Does it require a new layer of pavement on top of the old layer?
I'd like to buy a vowel, Alex.  What is E?

Brian556

In the news report, they are using graders to scrape off the defective seal coat. They could then re-seal coat it, or overlay it with asphalt.

It looks like the tar was not the proper mixture of ingredients / quality

J N Winkler

This story (and the subsequent discussion in this thread) is why I describe Texas as being chip-sealed to death.

Chip sealing requires attention to detail to obtain a good result.  Besides the factors already mentioned, such as proper composition of the binder, satisfactory adhesion of the chips requires dry weather with low humidity.

I also question the use of the technique, even for pavement preservation, on high-speed and high-volume roads because the past fifteen years' worth of changes in speed limits have created an expectation of 75+ as the default, and chip seals need a day or so of traffic moving at 20 to bed in the chips, which allows the loose ones to be swept off and collected so that they don't damage vehicle paint.  I have a small patch of missing paint on the hood of my roadtrip car that it picked up somewhere on US 281 en route to San Antonio, I think as a result of a chip thrown up by an overtaking vehicle.
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini

wxfree

Quote from: J N Winkler on May 29, 2017, 11:16:42 PM
This story (and the subsequent discussion in this thread) is why I describe Texas as being chip-sealed to death.

Chip sealing requires attention to detail to obtain a good result.  Besides the factors already mentioned, such as proper composition of the binder, satisfactory adhesion of the chips requires dry weather with low humidity.

I also question the use of the technique, even for pavement preservation, on high-speed and high-volume roads because the past fifteen years' worth of changes in speed limits have created an expectation of 75+ as the default, and chip seals need a day or so of traffic moving at 20 to bed in the chips, which allows the loose ones to be swept off and collected so that they don't damage vehicle paint.  I have a small patch of missing paint on the hood of my roadtrip car that it picked up somewhere on US 281 en route to San Antonio, I think as a result of a chip thrown up by an overtaking vehicle.

There's something different about the way they do it now.  They knew how to do it well in the past (although I doubt it's ever a good idea on major highways).  I've seen individual roads chip sealed multiple times over the years, and while it obviously wasn't as good as or last as long as better pavement, it was usually pretty good.  The past few years were different.  Roads that are the same as they've always been were suddenly of very low quality after being repaired.  Smooth spots and pits appear quickly, and rocks keep hitting the bottom of the car for months, long after the unbound ones should have been gone.  Previously bound pieces keep working loose for a long time.  I really don't know enough to have an opinion on whether the practice itself is a good idea, but I do know enough to have seen a major drop in quality recently.  Depending on what the conditions were like previously, "fixed" roads are pretty often worse than before the repair pretty quickly.  This low quality is pretty consistent on all of the roads I've seen reworked this way for the past several years.
I'd like to buy a vowel, Alex.  What is E?

Brian556

Quote from wxfree:
QuoteThere's something different about the way they do it now.  They knew how to do it well in the past (although I doubt it's ever a good idea on major highways).  I've seen individual roads chip sealed multiple times over the years, and while it obviously wasn't as good as or last as long as better pavement, it was usually pretty good.  The past few years were different.  Roads that are the same as they've always been were suddenly of very low quality after being repaired.  Smooth spots and pits appear quickly, and rocks keep hitting the bottom of the car for months, long after the unbound ones should have been gone.  Previously bound pieces keep working loose for a long time.  I really don't know enough to have an opinion on whether the practice itself is a good idea, but I do know enough to have seen a major drop in quality recently.  Depending on what the conditions were like previously, "fixed" roads are pretty often worse than before the repair pretty quickly.  This low quality is pretty consistent on all of the roads I've seen reworked this way for the past several years.

The tar formula has obviously changed. I'm wondering if it is due to environmental regulations.

When I worked for them, they said that the tar that they put down before overlaying a road with asphalt was much stickier in the past.

I think the tars used for the two different purposes are different thicknesses, but the concept may be the same.

J N Winkler

I have had a look at the TxDOT standard specifications (2004 and 2014 editions) to see if I can put Wxfree's hypothesis to the test.  The sections (Item 300) dealing with the asphalt-rubber binders that are typically used for chip seals are essentially unchanged between those two editions:  the tables of criteria are the same and reference the same groups of ASTM, AASHTO, and TxDOT standards.  The sections (Item 316) dealing with equipment and procedure for application of seal coats are more or less the same, with unchanged temperature cutoffs.

2014 standard specifications (PDF p. 191 deals with asphalt-rubber binders; pp. 205 ff. deal with seal coats):

ftp://ftp.dot.state.tx.us/pub/txdot-info/des/spec-book-1114.pdf

2004 standard specifications (PDF p. 223 deals with asphalt-rubber binders; pp. 238 ff. deal with surface treatments):

http://ftp.dot.state.tx.us/pub/txdot-info/des/specs/specbook.pdf

It is certainly possible that binders have been redesigned to accommodate environmental regulations (as Brian556 suggests) or, alternately, to allow inferior input materials to be used to expand the processors' profit margins.  But, assuming that TxDOT is consistently enforcing its specifications, I see no changes between the 2004 and 2014 books that would explain why chip seal quality is now so bad.  It is a mystery.
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini

US-175

Could any differences be weather (mainly heat) related?

I very much dislike gravel/chip-seal roads.  There always seems to be too much gravel or too much tar after a project is 'done'--and always too loud and rough.  Concrete or asphalt/blacktop, please!

Road Hog

Chip-(and)-seal (as I grew up knowing it) is a preferable upgrade to the dusty gravel road I lived on in 1997.

As a surface on a major state or US highway, it's absolutely substandard and it's inexcusable corner-cutting. I don't know of any chip-seal on an interstate, but that's massive malpractice.

Brian556


codyg1985

I have seen some agencies (ALDOT's Huntsville District and the Army DPW at Redstone Arsenal) seal cracks in a road with a tar material, which seems to to extend the life of the road.

I have also seen chip seal be applied during a resurfacing project after milling just a small portion of the pavement, then followed by a thin wearing surface layer. I have only seen it on lightly traveled roads, so I guess it is a cost-cutting measure which works in that instance.

I also wonder how well chip seal would hold up under heavy truck traffic? I would imagine the right lane of I-35 south of the Red River would get rutted pretty quickly.
Cody Goodman
Huntsville, AL, United States

Marc

Lord yes, Texas is covered in chip-n-seal. If you're not on an Interstate highway, you're likely driving on it if you're in a rural area. And as others have mentioned, there are even some Interstates paved with the stuff (I-20 in Sweetwater comes to mind). As a matter of fact, Williamson County just did a layer of chip-n-seal throughout our entire neighborhood. I'd give anything to go back. The rocks have even made their way into the house! It just seems like an antiquated way of sealing roads. Maybe for very rural roads, but that stuff has no business near any moderate to major population area IMHO.

Quote from: Brian556 on June 22, 2017, 11:54:05 AM
^^^I-35 at the Red River, Texas side

I have to admit, I-35 south entering Texas from Oklahoma is one of the few state crossings where the Texas side leaves much to be desired. ODOT has done an amazing job with I-35. The pavement has been replaced with new concrete for the first few counties (at least) in southern Oklahoma.



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