USE OF INSULATION TO ATTENUATE FROST HEAVING

THE USE OF POLYSTYRENE INSULATION BOARD TO PREVENT DETRIMENTAL FROST HEAVING WAS EVALUATED IN THE RECONSTRUCTION OF A SECTION OF I-15 THAT HAD SHOWN DISTRESS DUE TO FROST HEAVING IN THE SUBGRADE. THE POLYSTYRENE BOARD WAS PLACED ON THE SUBGRADE, IN THICKNESSES OF 1, 1 1/2 AND 2 INCHES, IN THREE CONTIGUOUS SECTIONS, AND COVERED WITH A 1.3 FT. PAVEMENT SECTION. THERMISTORS AND FROST DEPTH INDICATORS WERE USED IN THE THREE TEST SECTIONS TO MONITOR TEMPERATURE AND FREEZING DURING THE WINTER SEASONS OF 1966-67 AND 1967- 68. VISUAL OBSERVATIONS AND THERMISTOR AND FROST DEPTH MEASUREMENTS WERE ALSO MADE IN CONTROL SECTIONS (NORMAL I-15 CONSTRUCTION AT EACH END OF THE INSULATED SECTIONS). FREEZING INDEXES, BASED ON AIR TEMPERATURE MEASUREMENTS, WERE DETERMINED FOR THE TWO WINTERS. BENKELMAN BEAM DEFLECTION MEASUREMENTS WERE MADE IMMEDIATELY AFTER CONSTRUCTION OF THE INSULATED SECTIONS AND ONE YEAR LATER. A CONSTRUCTION COST COMPARISON OF INSULATED SECTIONS WITH NORMAL (CONTROL) SECTIONS WAS MADE. IT HAD BEEN ESTIMATED THAT THE FREEZING INDEX WOULD BE ABOUT 2,000 DEGREE-DAYS AT THE CONSTRUCTION SITE. HOWEVER, THE MEASURED FREEZING INDEX WAS ABOUT 400 DEGREE-DAYS LESS THAN NORMAL DURING THE TWO WINTERS IN WHICH OBSERVATIONS WERE MADE. VISUAL OBSERVATIONS INDICATED NO FROST HEAVE IN THE INSULATED SECTIONS AND CONSIDERABLE HEAVE IN THE CONTROL SECTIONS AND OTHER SECTIONS BEYOND THE EXPERIMENTAL AREA. ALTHOUGH FREEZING TEMPERATURES WERE MEASURED BELOW THE 2-IN. INSULATION IN THE SECOND WINTER, IT WAS CONCLUDED THAT 2 INCHES OF THE INSULATION WOULD PREVENT EXCESSIVE FROST PENETRATION OF THE SUBGRADE UNDER THE CLIMATIC CONDITIONS AT THIS TEST SITE. /BPR/

  • Corporate Authors:

    Idaho Department of Highways

    P.O Box 7129
    Boise, ID  United States  83707

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Hatch, L M
  • Publication Date: 1969-1

Subject/Index Terms

Filing Info

  • Accession Number: 00215900
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Report/Paper Numbers: Hpr-1(5)
  • Files: TRIS, STATEDOT
  • Created Date: Mar 18 1994 12:00AM