Dynamic Modulus Predictive Model Incorporating the Effects of Confinement

In recent years, interest has grown in the stress dependency of the dynamic modulus (|E*|) of hot mix asphalt (HMA) at high temperature/low frequency combinations. Although researchers have used a few different approaches to consider the effects of confinement in the development of master curves, limited attempts have been made to develop a predictive model as a function of mix characteristics and testing conditions, including the effect of confinement level. This paper reviews the different approaches used and presents the derivation, specification and estimation of an enhanced comprehensive predictive model for HMA dynamic modulus that incorporates the effects of confinement along with many other mix characteristics. The model is estimated using three different datasets and applying two advanced statistical techniques, joint estimation and non-linear mixed effects. The comprehensive model uses a different parametrization of the commonly used sigmoidal function that is advantageous from a statistical and engineering point of view. In addition to providing an excellent fit to the data, the enhanced model overcomes issues with master curves crossing at higher confining stress levels. The model suggests that the parameters governing the shape of the sigmoid and the shift factor parameters are stress dependent, that the effect of the confining level is binder and air voids dependent, that the binder type not only affects the minimum of the sigmoid but also its shape, and that the modulus decreases slightly but statistically significantly as the strain level increases even within the narrow range at which testing is performed.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFK50 Standing Committee on Structural Requirements of Asphalt Mixtures.
  • Corporate Authors:

    Transportation Research Board

    ,    
  • Authors:
    • Archilla, Adrian Ricardo
    • Corrales, Jose
  • Conference:
  • Date: 2019

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 10p

Subject/Index Terms

Filing Info

  • Accession Number: 01698454
  • Record Type: Publication
  • Report/Paper Numbers: 19-02347
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 7 2018 9:25AM