Susceptibility of Asphalt Binders to Rutting: Literature Review

Abstract

This paper presents a literature review covering the most used parameters and rheological properties for the characterization of the rutting resistance of asphalt cements (AC), or binders. They include the original Superpave parameter G*/sinδ and the nonrecoverable compliance Jnr obtained in the multiple stress creep and recovery (MSCR) test. To draw typical examples of the differences between the rutting performances of binders as a function of the specification criterion, a 50/70-penetration grade AC was modified with crumb rubber (AC+rubber), low-density polyethylene (PE), and linear styrene-butadiene-styrene copolymer (SBS) such that the high PG grade is the same (76-xx) for all the formulations. The rankings of binders from the less to the most susceptible material to rutting showed some similarities for the selected parameters. However, the MSCR test was able to underline marked differences in the rheological responses of the formulations that could not be directly observed for the other procedures, as well as the stress sensitivity of the AC+rubber. Thus, the MSCR test was recommended as the best protocol for analyzing the rutting potential of binders.