Seasonal variations in the moduli of unbound pavement layers.

Details

• Creators:
  Richter, Cheryl Allen
• Corporate Creators:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Pavement design
  • Pavement performance
  • Service life
  • Weathering
  • Pavement layers
  • Moisture content
  • Performance tests
  • Pavements--Performance--Testing
  • Pavements--Design and construction
  • Pavements--Service life
• Publication/ Report Number:
  FHWA-HRT-04-079
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Federal Highway Administration
• Abstract:
  The in situ moduli of unbound pavement materials vary on a seasonal basis as a function of temperature and moisture conditions. ; Knowledge of these variations is required for accurate prediction of pavement life for pavement design and other pavement ; management activities. The primary objective of this study is to advance the rational estimation of seasonal variations in ; backcalculated pavement layer moduli using data collected via the Seasonal Monitoring Program of the Long-Term Pavement ; Performance Program. Principal components of this endeavor included: evaluation of the moisture predictive capabilities of the ; Enhanced Integrated Climatic Model (EICM); development of empirical models to predict backcalculated pavement layer moduli ; as a function of moisture content, stress state, and other explanatory variables; and trial application of the models developed to ; prediction backcalculated moduli for unbound pavement layers. ; This investigation yielded two key findings. First, it provided the impetus for developing EICM Version 2.6 by demonstrating the ; practical inadequacies of EICM Versions 2.0 and 2.1 when applied to the prediction of in situ moisture content, and then ; demonstrated that substantial improvement in the moisture predictive capability of the EICM had been achieved in Version 2.6. ; Second, the research identified fundamental discrepancies between layer moduli backcalculated using linear-layered elastic ; theory and the laboratory resilient modulus test conditions. ; Other important findings included (1) variation in moisture content is not always the most important factor associated with ; seasonal variations in pavement layer moduli, and (2) a model form that fits linear elastic backcalculated moduli reasonably well. ; The overall accuracy of the modulus predictions achieved in the trial application of the predictive models was not fully acceptable. ; Several avenues for further research to improve upon these results are identified.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25582/dot_25582_DS1.pdf
• File Type:
  [PDF - 2.23 MB]
• Collection(s):
  US Transportation Collection ; Federal Highway Administration
• Main Document Checksum:
  urn:sha-512:af54d0e4f3a80991a87c922b36729fb17d0ec2426ff28a89abae30295a47cd095864255cb49caef06f1090f1ec51eed248695f56dc08f325d0d5dfc352222e6e