Effects of aging on rheological properties of asphalt materials and asphalt-filler interaction ability

Abstract

The rheological properties of asphalt mastics and asphalt-filler interaction play key roles on the performances of asphalt mixtures. However, the rheological properties of asphalt mastics and asphalt-filler interaction are significantly influenced by aging which exists in the compaction stage of asphalt mixtures. In order to analyze the effects of aging on rheological properties of asphalt binders, asphalt mastics and asphalt-filler interaction, the Dynamic Shear Rheometer (DSR) tests and Bending Beam Rheometer (BBR) tests were conducted for unaged and aged specimens. Results indicate that the aging can enhance the cohesion properties of asphalt binders and mastics, and so the rutting resistance of asphalt binders and mastics is better with an increase in aging degree. However, the low temperature properties of asphalt binders and mastics are worse with an increase in aging degree. The two indices K-B-G∗ and K-B-δ were selected to evaluate asphalt-filler interaction ability. Results show that these two indices have the consistency to evaluate asphalt-filler interaction ability. And also the two indices can reflect the difference of interaction ability of different aged asphalt binders and fillers. The deeper aging degree of asphalt binders is, the worse asphalt-filler interaction ability is. Within the same aging degree, the interaction ability of asphalt 70# with higher asphaltene and resins contents is stronger than asphalt 90#. Therefore, the aging affects the asphalt-filler interaction ability via changes of asphalt active components.