FROST PENETRATION AND MOISTURE CHANGES RELATED TO HIGHWAY PAVEMENT SHOULDER COLOR

THE OBSERVATIONS ARE REPORTED OF TEMPERATURE AND MOISTURE UNDER AN INSULATED AND NONINSULATED PORTLAND CEMENT CONCRETE PAVEMENT SLAB RESULTING FROM SHOULDERS PURPOSELY MADE WHITE AND BLACK FOR COMPARISON. THE SEALED SHOULDERS ON EACH SIDE WERE MADE IDENTICAL IN ALL RESPECTS EXCEPT FOR SURFACE COLOR. THE STUDY PERIOD EXTENDED FROM LATE FALL THROUGH THE SPRING OF ONE SEASON FOR A TEST ROAD EXPOSED TO A NORTHERN NEW YORK CLIMATE. DETAILED TEMPERATURE DATA FOR THE CROSS SECTIONS WERE COLLECTED FROM 53 THERMISTOR PROBES. DETAILED MOISTURE DATA AT 6-IN. INTERVALS WERE COLLECTED FROM 23 ACCESS TUBES USING A NUCLEAR DEPTH MOISTURE GAGE. PATTERNS OF TEMPERATURE AND MOISTURE FOR THE PAVEMENT CROSS SECTIONS ARE PRESENTED IN A SERIES OF ISOLINE PLOTS FOR SELECTED DATES TO SHOW KEY INFORMATION. SUBSTANTIAL DIFFERENCES WERE OBSERVED THROUGHOUT THE TEST ROAD, ESPECIALLY LATERALLY, INDICATING THAT STUDIES OF PAVEMENTS EXPOSED TO ACTUAL CLIMATES SHOULD INCLUDE INSTRUMENTATION GIVING MUCH MORE DETAIL THAN IS COMMONLY AVAILABLE. THE TEMPERATURE PATTERNS SHOWED BLACK SHOULDERS TO BE SUBSTANTIALLY WARMER THAN IS COMMONLY AVAILABLE. THE TEMPERATURE PATTERNS SHOWED BLACK SHOULDERS TO BE SUBSTANTIALLY WARMER THAN WHITE SHOULDERS (DUE TO ABSORPTION OF SOLAR ENERGY), AND TO BE AFFECTED ESPECIALLY BY MIDWINTER THAWS. TEMPERATURES UNDER WHITE SHOULDERS WERE COOLER, CAUSED EARLIER FREEZING, LATER THAWING, AND WERE GENERALLY ASSOCIATED WITH LOWER MOISTURE CONTENT. THE LARGE MOISTURE INCREASE OBSERVED UNDER THE BLACK SHOULDER AND PAVEMENT EDGE DURING A BRIEF MIDWINTER THAW WAS SHOWN CAUSED BY GRAVITATIONAL MELT WATER FROM ADJACENT SNOW BANKS FLOWING THROUGH THE SHOULDER. THIS DID NOT OCCUR UNDER THE WHITE SHOULDER BECAUSE IT REMAINED SOLIDLY FROZEN DURING THIS SAME BRIEF PERIOD. FURTHER STUDY IS NEEDED TO UNDERSTAND HOW TO PREVENT RAPID INCREASES OF MOISTURE UNDER PAVEMENTS AND SHOULDERS DURING THAW PERIODS, PERHAPS BY THE USE OF SURFACE COLOR TO CONTROL THE UNDER- LYING TEMPERATURE REGIME. /AUTHOR/

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 39-49
  • Monograph Title: Pavement design: soil strength values, subgrade moisture, frost action, and area concepts
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00237788
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 22 1994 12:00AM