Volume 39, Issue 1 (January 2011)
A New Static Strength Test for Characterization of Rutting of Dense-Graded Asphalt Mixtures
A new static-test protocol was developed for measuring the deformation resistance of asphalt mixtures at high temperature, 60°C. A round edge loading head was used for estimating rut-related performance by statically pressing a specimen at the flat top center. The value measured by this test is considered as a strength against deformation or deformation strength and designated as “SD.” The SD has shown a high correlation with the rut depths of wheel tracking (WT) and the asphalt pavement analyzer (APA) tests. In this study, the feasibility of utilizing this test method to predict the rutting potential of asphalt mixtures is shown. Stiffness (G∗/sin δ) test data for asphalt binders, two rutting tests’ (WT and APA) data, and SD data for various laboratory mixtures were used in this evaluation. More than 50 field mixtures were also used for APA and SD tests. Correlation analyses showed that the SD had very high correlation with the stiffness of the binder (R2=0.9), with rut depth of WT (R2>0.90) and somewhat less with rut depth of APA (R2=0.77). It was concluded that the newly developed test is comparable to WT and APA and that the SD is a property providing a reasonable estimation of rut potential of asphalt mixtures at high temperatures, even though it is a static-test property.