Blending Simulation of RA and Virgin Binders in Hot Recycled Mixtures

In this paper the results of a model study are reported in which glass beads covered with artificially aged bitumen are mixed with superheated bold beads and virgin bitumen. The goal of the study was to simulate how aged binder and added virgin binder would distribute over RAP and virgin aggregates. Furthermore the goal of the study was to determine whether high preheating temperatures would affect the rheological properties of the binder covering the RAP and virgin aggregates. The study showed that when preheating temperature was 300 or 400 °C, the shear modulus of the binder recovered from the super-heated bold particles was about the same as the G* of the binder that was recovered from the particles that were covered with aged binder before mixing. At 300 °C the log pen rule seemed to be applicable which was not the case when the preheating temperature was 400 °C.