Statistical Development of a Flow Number Predictive Equation for the Mechanistic-Empirical Pavement Design Guide

Over the past few years there has been significant interest in establishing a test method that could be employed universally to evaluate the material properties of a hot mix asphalt design, such that it would be indicative of field performance. The majority of interest has centered around dynamic modulus with primary efforts on refining associated predictive equations. However, some researchers feel that an additional test should be employed in conjunction with dynamic modulus within the Mechanistic-Empirical Pavement Design Guide. Currently, there is interest in incorporating flow number as the additional test method. If flow number is to be incorporated into the Mechanistic-Empirical Pavement Design Guide, a predictive equation relating flow number will need to be developed. In this paper, an initial predictive equation for flow number is presented. Seventeen mixtures were sampled around the State of Wisconsin, each with unique mix parameters. The flow number of these mixtures were evaluated at different air void and asphalt contents. Using the flow number test data, several statistical tools were employed to develop a model based on the given information. Aggregate characteristics were believed to affect flow number, hence the inclusion of aggregate characteristics in variable selection. The final model selected is based on six factors with a coefficient of determination greater than 0.90. The six factors found to be important for estimating flow number are number of gyrations, bitumen viscosity, voids in the mineral aggregate, percent passing the 4.75-mm sieve, percent passing the 1.18-mm sieve, and percent passing the 0.075-mm sieve.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044579
  • Record Type: Publication
  • Report/Paper Numbers: 07-1000
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 5:35PM