INFLUENCE OF STRESS LEVELS AND SEASONAL VARIATIONS ON IN SITU PAVEMENT LAYER PROPERTIES

Presented is a small-scale investigation of how stress levels and seasonal variations affect pavement layer characteristics. Monitoring such effects is basic to the effort conducted under the Strategic Highway Research Program (SHRP) Long-Term Pavement Performance (LTPP) studies currently under the FHWA jurisdiction. Illustrated are the influences of stress levels, seasonal temperature variations, seasonal moisture variations, and accumulated equivalent single axle loads (ESALs) on (a) center deflection (D sub o) measured by the falling-weight deflectometer; (b) in situ asphalt concrete modulus (E sub AC); (c) in situ granular layer modulus (E sub g); (d) in situ subgrade resilient modulus (MR); (e) in situ AASHTO effective structural number (SN sub eff); and (f) variability within a section for each of the structural factors above. Analysis of results suggests that MR is the parameter most affected by a change in stress level, followed by E sub g, E sub AC, and SN sub eff. On the other hand, E sub AC is the parameter most affected by the change in temperature, followed by D sub o, SN sub eff, E sub g and MR. Variations in MR and E sub g with temperature are believed to be associated indirectly with variations in E sub AC and temperature. Changes in E sub AC and temperature result in changes in stress levels imposed on the underlying pavement layers that cause variations in MR and E sub g. Accumulation of ESALs under dry conditions affect E sub AC, followed by D sub o, E sub g, SN sub eff, and MR, in order of diminishing effect. In addition, seasonal moisture variations affect D sub o and MR, followed by E sub g, E sub AC and SN sub eff. And variability within a section for each of the structural factors increases with an increase in temperature, moisture level, or accumulated ESALs. Among the structural factors, SN sub eff has the lowest within-section variability, whereas E sub g has the greater within-section variability.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 16-24
  • Monograph Title: Strength and deformation characteristics of pavement sections
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00674325
  • Record Type: Publication
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 23 1995 12:00AM