The purpose of this investigation is to evaluate the sensitivity to permanent deformation of mixes containing different modifiers using the repetitive simple shear test at constant height (RSST-CH). The variables for this study were two aggregates, three asphalts and four modifiers. All tests were executed at 40C and most of the specimens were tested with a void range between 10 to 11%, measured using the with-parafilm method. The results show that some asphalts are relatively improved with the modifications while others are less sensitive to the effect of modifiers. Some modifiers did not appear to improve mix performance. This paper will also present results indicating the importance of comparing mix performance from results from mixes compacted to the same air void content as well as guidelines for the execution of further comparisons of this kind. A tie between binder rheology and expected mix performance in permanent deformation will be suggested. This study suggests an approach to evaluate the effect of adding modifiers to improve rut resistance through the use of a bridge procedure to evaluate permanent deformation of asphalt-aggregate mixes in situ. (A).
Abstract