The ‘Microseal’ Mystery on Interstate 81

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LUZERNE COUNTY -- When you make repairs to your home, you expect them to last, especially if you invest a lot of money.

The same thing goes for roads. That's the reason PennDOT is now investigating why pavement less than two years old on Interstate 81 is already breaking apart.

Newswatch 16 drove on a stretch of Interstate 81 near the Pittston exit that was paved over less than two years ago. Anywhere you see blacktop - approximately 20 miles in Luzerne County - was resurfaced starting in 2012 and completed in 2013.

PennDOT calls it microseal, a thin layer that's used to preserve the pavement underneath.  It is supposed to last three to four years.

But what you see right now all over I-81 from Luzerne to Susquehanna counties are divots here and there.  Some are the size of your fist.  Others are much bigger.

"It's just going to be a big pothole (if we don't take care of this)," said PennDOT construction engineer Harold Hill. "The whole interstate."

But in order to fix the problem, PennDOT engineers first have to find out why the new layer of pavement has failed.

The state gave us an exclusive look at some core samples PennDOT just removed from the pavement in question.

The bottom part of the core goes back to when the interstate was first built.

The top of the core is the microseal with an important purpose.

"Basically, the idea of this microseal is to keep the water from soaking down into the pavement.  We always say potholes are created when water gets down into the pavement. It freezes then expands and causes potholes and more water gets in it and it becomes exponential.  So the idea of this microseal on top of here is to keep the water from getting down into the pavement," explained PennDOT spokesman James May.

But the microseal - the newly paved top portion - is deteriorating.

PennDOT is now testing the material in these core samples to see if the top portion is to blame or the foundation of the interstate itself is collapsing.

One thing is for sure: PennDOT wants answers, especially when the paving in Luzerne County alone cost taxpayers over $10 million.

"Until we do testing and they do more testing at the lab, we can't definitely say what the issue is," said May.

PennDOT insists it does quality control inspections all the time when paving work is done

Some theories for the deterioration include the extreme weather we had this past winter, and perhaps less than ideal conditions when a lot of that paving work was done at night.

Whatever it is, PennDOT will have to do more testing before there are answers to the microseal mystery.


  • Nick

    For those of you who think PennDOT should rebuild all their roads with concrete – understand that the cost and time associated with rebuilding a 1 mile stretch of road with concrete versus hot mix asphalt or a surface treatment like microsurfacing is much higher. If that’s what you want, get ready for exponentially higher taxes and worse construction delays than you already experience.

    Also important to understand that treatments like microsurfacing or chip seals (oil and chip) are treatments meant to be applied to roadways that are starting to show signs of deterioration (oxidation, minor cracking, some loss of aggregate). They are meant to preserve the existing roadway and prlong the lifecycle of the base asphalt wearing course. Too often agencies like PennDOT try to utilize these treatments as band aids on pavements that have sever distresses and failures until the funding can be found to do complete remove and replace with new hot mix asphalt. What’s troublesome is that they (should) understand that when they do this, the probability of early failure is higher – but when it occurs they act surprised and outraged – likely because they don’t want to deal with the understandable public outrage.

    • dr jones.

      what they should do it only fix a small portion at a time or focus on only one road at a time! why have construction projects on every road in the state at once -who plans this stuff? how many ‘years’ are they going to have pittston/avoca and dickson city under construction? look at the wide load signs going in to dunmore/dickson city 81northbound / by the time a wide load truck sees the signs saying ‘no wide loads’ he’s got no place to get off the highway and can’t fit through the construction! … and yeah, seriously they should fix it right – they should put a 1 or 2 foot deep gravel layer down then pave over it as the frost pops the same rocks up creating the same pot holes every year. the heavy trucks tear it up in congested truck traffic areas – ever notice around the state reps, senators houses in clarks summit the roads are nicer? why is that?

      • Ass Hole

        The main problem is the interstate (also mentioned in the article), and it is very wide and long, so fixing “a small portion at a time” will delay traffic, take a long time, cost money, and take a long time. The road will weather again, anyway, so that’s why they’re looking to find a cause. If you want to pay millions every year for a new road which breaks for an unknown reason, you’re insane.

  • Nick

    I am a civil engineer in the road building industry and am very familair with this treatment. This treatment is called microsurfacing, not microseal. It is used with a great deal of success throught the country, not just Pennsylvania and in fact PennDOT has treated several million square yards of roadway in the last 5 years with it – most of which has held up and performed to expectation. The real issue here is the condition of the underlying pavement that the microsurfacing was placed on top of. Because microsurfacing is a thin surface treatment, it cannot be reasonably expected to withstand a good deal of subbase movement and failure. Knowing what the condition of the interstate was prior to the paving with microsurfacing, you could see this failure coming from miles away. Wrong treatment given the distresses and existing failures in the road.

    This is what happens when you have a combination of limited funds to do road repairs, inexperienced engineers doing the pavement designs at PennDOT and weak inspection and QA/QC plans during actual construction. PErfoect storm of a number of issues

  • Joseph Yakoski

    PennDot loves to spray the brine on our roadways. My brother runs a garage and PA inspection station in Susquehanna county and has told me of 3-4-5 year old cars and trucks RUSTING out underneath. Brake lines, brake cables and under body and suspension parts are RUSTING through in such a short period of time. PennDot should be made to STOP this dangerous practice. The brine spray seems to do the roadways no good either.

    • Choppy (@choppinfirewood)

      but they still have to do the job to the specs of the engineer regardless of how much they are getting paid. Inspectors are on the job to make sure this happens and they take specimens of the road to make sure it has the proper fail specs.

  • Coal

    The liquid chemical is “brine”. Sprayed on the road surface prior to a winter event and helps to keep the ice/ snow from getting a better hold. While it works , and well, it also can and does get into the road surface cracks deeper and better not to mention it also adheres to your car and also gets into deeper places in the car. Which will most likely make cars rust more and quicker at places without or untouched by undercoating. I also heard they are adding something like “beet juice” to lower the working temperature. Brine and salt stop working at certain temps below zero. (@ -24 F I heard) The beet juice makes the brine and salt work in colder temps. Or so I was told.
    Just my 5 cents, ( Inflation…LOL)

  • bobc74

    Why didn’t they ever investigate why several years ago I-81 from Scranton to just below Moosic was repaved and then a year later was in such bad shape they had to repave it again and then it had to be redone last year? If memory serves me correctly it was in 2006 and 2007.

  • Jonathan

    I’m not an expert on roadway engineering or pavement, but I will say that in Mass they usually take a highway down to a concrete base and then pave over it twice. The first layer always seems loose, rough, and think. The second layer is usually much thinner, tighter, and smooth. When I lived up there, they seemed to repave on a 5-year rotation but it could have been more.

    I know PA has a different climate… up there, winters get cold and usually stay cold. Down here we have so many frosts and thaws that it does cause major issues with roadways.

    What I really don’t understand is why PennDOT seems to favor things that seem like short-cuts. From oil and rock chips thrown down on roads to “resurface” them, to this Microseal fiasco… it just doesn’t seem to make much sense.

    I also don’t understand why our Interstates change between concrete and asphalt. A few years ago they repaired I-81 south past Wilkes-barre, which is nearly all asphalt. It has held together much better it seems. North it seems to be nearly all asphalt and degrades so much quicker.

  • eddie

    There are a few dozen of these ‘divots’ on 81 South between the Arena Exit and the Mt. Top Exit in Wilkes-Barre. That stretch of highway has been slowly breaking up since almost immediately after the work was completed.

  • NEIL

    Don’t feed the public a line about the extreme cold this past winter.
    It was Colder in up New York State and their roads are in way better condition tha PA roads!!

    On the Turnpike blue route from Norristown south, construction was done and the highway was removed down to the dirt and rebuilt.
    In NEPA on 81 they just throw a “Skim coat” on … What a Joke.

    • CCKM

      Wow dude, I was just thinking that when I read this article. I live in NEPA now, but in NY most of my life, and roads upstate if memory serves me correctly, were in much better condition. Just was visiting family in Jersey, Rt. 18 is a nightmare! I was thinking who’s lining their pockets on this one?!?
      Then you said, “In NEPA on 81 they just throw a “Skim coat” on … What a Joke.”

    • Choppy (@choppinfirewood)

      exactly right….it is way colder…meaning the roads do not go through the freeze/thaw cycle that is the death of all roads. PA is in a unique spot weather wise for roads (and not to mention the extreme mileage of roads that we have) we get cold, but not cold enough for the roads to stay frozen the entire winter, and it thaws. This cycle is what damages the roads so much and there is little to do about it. It is just the way it is.

  • Joe

    over the winter i noticed White LINES along the road to treat the roads BEFORE a snow storm. It wasn’t salt it was something else. Anyone know what i am talking about? Some kind of chemical used to keep the roads from freezing i suppose? I feel like once i noticed those chemical lines the pot holes increased dramatically.

    • Jonathan

      This is called brine, and PennDOT has done it for quite some time. It’s a salt-water mixture that they put down to prevent moisture from freezing when it hits the roadways. A few years ago there was a guy trying to get them to stop doing it, saying the brine was destroying his truck.

  • LYNN

    The truth is in the testing of the road surface. When they are found out, they should be forced to repave at no cost to the taxpayer. If they are forced to do it TWICE, they will do it RIGHT the first time from now on!

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