Testing Wisconsin asphalt mixtures for the AASHTO 2002 mechanistic design procedure

Abstract

The intent of this project was to examine typical hot mix asphalt (HMA) pavements that are constructed in the state of Wisconsin. The analysis compares the suggested pavement structures based on the 1972 pavement design guide currently used in Wisconsin and the same ones based on the new Mechanistic-Empirical Pavement Design Guide. In order to develop the pavement structure as outlined by the new Design Guide, the mechanical properties of the HMA layers were measured from 21 field sampled mixtures. These properties include dynamic modulus and flow number, which have been found to be significant predictors of rutting and fatigue by Witczak et al. (2002). Properties of the other layers in the system have been obtained from the Wisconsin Department of Transportation pavement design inputs. The objective was to account for typical construction variability that occurs and to determine its impact upon both mechanical tests. Further, the authors examined these mechanical test results on pavement design to determine if the performance tests and new Design Guide, as they currently exist, are ready for implementation by owners/agencies.