Fatigue and Permanent Deformation Models for Polymer-Modified Asphalt Mixtures

Abstract

For the past 2 decades, significant research has been conducted on polymer-modified asphalt (PMA) mixtures. Polymers can successfully improve the performance of asphalt pavements at low, intermediate, and high temperatures by increasing mixture resistance to fatigue cracking, thermal cracking, and permanent deformation. Most of the research has been concentrated on the characterization and relative comparison of neat and PMA mixtures, and little work has been done toward the development of fatigue and permanent deformation models for PMA mixtures. A 3-year study that was sponsored by the Michigan Department of Transportation was conducted at Michigan State University to characterize PMA mixtures. It was found that the rheological and engineering properties of PMA mixtures largely depend on the polymer type and content. The improvements in the fatigue lives and resistance to permanent deformation are mainly due to the improvements in the rheological properties of the binders. Fatigue life and permanent deformation models were developed. These models show that the laboratory fatigue life and permanent deformation are strongly related to the rheological properties of binders and the engineering properties of PMA mixtures.