Evaluating the mechanical properties of terminal blend tire rubber mixtures incorporating RAP

This paper documents the results of a laboratory testing program that was conducted to evaluate the mechanical properties of mixtures incorporating terminal blend ground tire rubber (GTR) modified asphalt binders and reclaimed asphalt pavement (RAP) and compare them to those produced using polymer modified binders. The laboratory testing program included ambient and cryogenic GTR modified asphalt binders as well as two polymer modified asphalt binders meeting specifications for performance grade (PG) 70-22M and PG 76-22M. The laboratory tests results indicated that the GTR mixing speed affects the low-temperature properties of the GTR modified binders. Furthermore, mixtures prepared with GTR modified binders had better tensile properties as well as resistance to low-temperature cracking and rutting than those prepared using the polymer modified PG 70-22M but similar to those with PG 76-22M polymer modified binder. In addition, the GTR modified mixes had comparable resistance to moisture-induced damage to those prepared using the considered polymer modified binders. In general, there was no significant difference in the performance of the considered cryogenic and ambient GTR modified binders and mixes.