Using Superpave Performance Tests To Evaluate Asphalt Mixtures

The original intent of the Superpave performance tests was for the results to be input into performance models developed during the Strategic Highway Research Program that would output a prediction of various forms of pavement distress as a function of time or traffic. Unfortunately, recent research has indicated that the Superpave performance models, and some of the performance tests, have critical errors that make performance prediction impossible. Still, a substantial amount of testing has been conducted since 1994 to analyze the performance properties of asphalt mixtures. Although these data cannot be used to predict pavement performance as originally intended, the output of the Superpave performance tests can be used to calculate mechanical properties that permit relative determinations of an asphalt mixture’s stiffness and estimations of its ability to withstand permanent deformation. The objective of this study is to provide documentation of performance test results of various asphalt mixtures tested since 1994. This information is a portion of a developing database on mechanical properties of asphalt mixtures tested with the Superpave shear tester. It is intended that these values can provide guidance to the user indicating how a project’s asphalt mixture compares with other mixtures with a performance history. The study also considers the effect of changes in mixture components, sample reheating, and type of Superpave gyratory compactor on the mechanical properties of an asphalt mixture.