The possibility of using the dynamic shear rheometer (DSR) with 4 mm parallel plates and 3 mm gap is investigated as an alternative experimental method to measure the rheological properties of asphalt binders at low temperature. A special butterfly silicone mold was prepared for this purpose and the corresponding testing procedure was also developed. Five different asphalt binders, which are part of two active research projects, were selected. Frequency and temperature sweep tests were conducted using the DSR with three plate–plate geometries: 4 mm, 8 mm, and 25 mm. The new testing procedure was used to measure at low temperatures. The method recently proposed by the Western Research Institute and based on DSR tests with 4 mm parallel plates and 1.75 mm gap was also used for comparison purposes. Black diagrams and Cole-Cole plots were then used to evaluate the experimental data. Complex modulus and phase angle master curves were generated, and the rheological parameters compared. Finally, the two spring, two parabolic elements, one dashpot (2S2P1D) model was selected to investigate the rheological properties of the binders. Results indicate that the proposed procedure is a simple and reliable experimental method and represents an alternative experimental option to measure and analyze the rheological properties of asphalt binders at low temperature.
Study of Asphalt Binder Fatigue with a New Dynamic Shear Rheometer Geometry
