PHYSICOCHEMICAL CONSIDERATIONS IN THERMAL SUSCEPTIBILITY OF A BASE-COURSE MATERIAL (ABRIDGMENT)

The importance of predicting the magnitude of the freeze coefficient in the relation of freeze contraction and pavement damage becomes evident as a base-course layer contracts during a freeze. This produces a buildup of tensile stress (1), which, when it exceeds the tensile strength, causes the base course to crack. Reported freeze cycles will propagate the crack through the asphalt surface. The larger the freeze coefficient is the higher the stresses and the greater the damage will be. The granular materials investigated in this study show contraction on freezing the climatic area of west Texas and much of the Southwest. This contraction is controlled by the properties of the clay minerals and the unique, membranelike clay particle structure they form around the larger silt particles. The freezing process forces the clay particles to reorient, which produces the noted volume contraction shown in the scanning electron microscope study. The amount of reorientation, and thus of volume change, is controlled by the specific surface area and the ion concentration. The specific surface area is a property of the clay fraction of the material. The ion concentration (resistivity) is a property of the granular portion of the material and represents the relative durability or solubility of the material. The ability of these two properties to model the freeze behavior is important because it shows how the coarse and fine-grained fractions of a material fit together and influence the environmental behavior of the material under freeze-thaw activity. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References;
  • Pagination: pp 36-38
  • Monograph Title: Soil taxonomy and soil properties
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00179008
  • Record Type: Publication
  • ISBN: 0309026717
  • Files: TRIS, TRB
  • Created Date: Aug 19 1978 12:00AM