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  • 1.  Cracks Perpendicular to Pavement

    Posted 09-19-2018 03:27 PM
    Edited by Tirza Austin 09-19-2018 03:26 PM
      |   view attached
    I am looking for advice from pavement experts regarding the possible cause for the transverse cracks that have occurred at uniform space intervals as shown in the attached image. This roadway is almost 20 years old, but other than these, and some other minor cracks, it is in excellent shape. Is the likely cause low temperature thermal cracking? Are these surface cracks or could they be deeper than the top course?

    Alfredo Vargas P.E., M.ASCE

  • 2.  RE: Cracks Perpendicular to Pavement

    Posted 09-20-2018 07:52 AM
    Edited by Tirza Austin 09-20-2018 07:51 AM
    ​Do you know what the pavement section is?  Is it concrete base?  If so, it is likely reflective cracking.

    Cindi Fitzpatrick P.E., M.ASCE
    City of Grove City
    Grove City OH

  • 3.  RE: Cracks Perpendicular to Pavement

    Posted 09-20-2018 10:04 AM
    Edited by Tirza Austin 09-20-2018 10:04 AM
    Sorry that I didn't provide this information originally. This is in Connecticut, so it is susceptible to freeze and thaw, and the pavement section is made out of a bituminous concrete surface course, over a bituminous concrete binder course, over a bank-run gravel sub-base, over the original ground.

    Alfredo Vargas P.E., M.ASCE
    Design Engineer
    Newton MA

  • 4.  RE: Cracks Perpendicular to Pavement

    Posted 09-21-2018 10:46 AM
    Edited by Tirza Austin 09-22-2018 12:46 PM
    Are the cracks visible in aerial photos? If so, let's look how far the pattern repeats or if there is similar cracking on  adjacent streets

    Ronald Koehn P.E., M.ASCE
    Paving Engineer
    City of Austin
    Austin TX
    (512) 974-8777

  • 5.  RE: Cracks Perpendicular to Pavement

    Posted 09-20-2018 10:05 AM
    Edited by Tirza Austin 09-20-2018 10:04 AM
    If the cracks are at regular intervals, then it's likely reflective cracking from an underlying concrete roadway.  I've found that applying a Mirafi (or equivalent) fabric over the cracks before repaving tends to reduce reoccurrence of the cracks.

    If the cracks are irregularly spaced, I had something similar appear in a new-ish roadway several years ago and it was determined to be reflective cracking from an over-application of cement in a cement-stabilized, clayey subgrade.

    Jack M. Daniels P.E., M.ASCE
    Charleston SC

  • 6.  RE: Cracks Perpendicular to Pavement
    Best Answer

    Posted 09-20-2018 11:51 AM
    Edited by Alfredo Vargas 09-21-2018 08:14 AM
    If no concrete below as just mentioned, transverse cracks in cold areas like CT are mostly caused by repeated low temperatures.  Over time the asphalt stiffens and this also contributes of course. Better selection of PG binder will reduce occurrence.  Another cause, especially when aggregates have higher absorptivity, is a permanent shrinkage of the HMA mixture over time with cycles of temperature.  There are many transverse cracks in cold freeze and warm no-freeze climates that keep getting wider over time due to this continual shrinkage of the mixture.

    Michael Darter Ph.D., P.E., M.ASCE
    Michael I. Darter
    Sandy UT
    (217) 356-4500