Binder Rheological Relationships Depicting Wheel Tracking Rutting Parameter for Asphalt Mixtures: A Case Study

摘要

A number of wheel tracker devices are currently available worldwide to evaluate the rutting potential of the conventional and modified asphalt mixes. In the past, researchers have developed correlations between wheel tracker rutting parameter and binder-mixture characteristics. The main objective of this case study paper was to present the relationships established between the binder rutting G*/sinδ parameter and asphalt mixture permanent deformation rut depth characteristics obtained from a wheel tracker device. Sixteen asphalt mixtures encompassing virgin, polymer-, and rubber-modified binders with dense, gap-, and open-graded gradations were prepared with three replicate samples per mix for evaluation purposes. The wheel tracker device rut depth of the rubber- and polymer-modified gap graded mixes were about 12 %-20 % lower than that of the conventional dense graded mix produced with a virgin binder. Furthermore, a correlation of G*/snS of the three binders with rut depths of the corresponding three field practical mixtures revealed that the cumulative rut depth of a mix increased with decreasing G*/srS, with the modified gap graded mixtures best suited to counter rutting potential in comparison with the dense graded mixtures. The results of this case study investigation corroborated several previous laboratory and field findings that rubber- and polymer-modified mixes are best suited to reduce rutting problems in flexible pavements as simulated from the near-field wheel tracker device.