INSULATED TAXIWAYS FOR ANCHORAGE AIRPORT

TWO INSULATED TAXIWAYS WERE CONSTRUCTED AT ANCHORAGE INTERNATIONAL AIRPORT TO FIND NEW WAYS TO OVERCOME THE PROBLEM OF DAMAGE TO RUNWAYS CAUSED BY FROST HEAVE. THESE TAXIWAYS WERE DESIGNED TO INSULATE THE FROST SUSEPTIBLE SUBGRADE FROM FREEZING TEMPERATURES. THE INSULATED RUNWAYS WERE DEVELOPED IN AN EFFORT TO ELIMINATE PAVEMENT ROUGHNESS CAUSED BY THE FORMATION OF ICE LENSES IN FROST-SUSCEPTIBLE SOILS COMMON TO MANY ALASKA AIRPORTS. FROST ACTION PROBLEMS OCCUR WHEN THE FOLLOWING CONDITIONS EXIST TOGETHER: FREEZING TEMPERATURES, FROST-SUSCEPTIBLE SOIL AND A SUPPLY OF FREE WATER. ICE LENSES ARE FORMED IN FREEZING WEATHER. WHEN THEY THAW, A SUPERSATURATED SUBGRADE CONDITION DEVELOPS WHICH REDUCES THE SUBGRADE'S BEARING CAPACITY, RESULTING IN A WEAKENED FOUNDATION FOR THE RUNWAY AND PREMATURE SURFACE FAILURE. THE INSULATED TAXIWAY WAS INSTALLED BY EXCAVATING TO A DEPTH OF THREE FEET, AND BY INSTALLING A TWO-INCH LAYER OF STYROFOAM HI BRAND PLASTIC FOAM INSULATION WHICH WAS ATTACHED TO THE SUBGRADE WITH FOUR-INCH SKEWERS. A SECOND LAYER OF ONE-INCH STYROFOAM INSULATION WAS ADDED. JOINTS WERE LAPPED AND THE SECOND LAYER WAS TIGHTLY BUTTED AND FASTENED TO THE FIRST LAYER. THE THREE INCHES OF INSULATION WERE COVERED WITH 20 INCHES OF AGGREGATE SUBBASE AND AN ADDITIONAL 12 INCHES OF CRUSHED, GRADED BASE, WHICH WILL BE CAPPED WITH FOUR INCHES OF ASPHALT SURFACING.

  • Availability:
  • Corporate Authors:

    Public Works Journal Corporation

    P.O. Box 688
    Ridgewood, NJ  United States  07451
  • Publication Date: 1970-6

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 87
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00232926
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 26 1971 12:00AM