Influence of Rejuvenator on Selected Characteristics of an Asphalt Concrete Containing 50% Reclaimed Asphalt

The use of reclaimed asphalt has become a common practice and necessity in many developed countries whereas there are several options how to deal with elevated content of such material which is typical for some level of degradation and heterogeneity. Well-developed and widely used are solutions where reclaimed asphalt is cold fed by up to 20%. Higher portions of reclaimed asphalt are still challenging and need additional focus. Quite common in last few years is use of rejuvenators which are understood as special chemical compounds which help to partly restore the degraded bitumen and secure sufficient performance behavior of asphalt mix containing higher portions of reclaimed asphalt. Recent study focused on use of several market established rejuvenators and some newly developed variants which are predominantly based on renewable materials. A typical asphalt concrete AC16 has been selected and 50% natural aggregate was replaced by reclaimed asphalt of 0/8 mm grading. Rejuvenators were added in a content of 5–7% of the bitumen content presented in the reclaimed asphalt. Several tests have been performed focusing on water susceptibility, deformation behavior (stiffness) and resistance to crack propagation. At the same time bitumen extracted from the reclaimed asphalt was mixed with rejuvenator and selected bitumen tests were done to find some relation between binder and asphalt mix behavior.