Rheological properties and anti-aging performance of asphalt binder modified with wood lignin

This study evaluated the potential use of wood lignin as partial substitute and performance modifier in asphalt binder. The rolling thin film oven (RTFO) and pressure aging vessel (PAV) methods were performed on asphalt samples to simulate different aging conditions. The Rotational Viscosity (RV), Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR) tests were utilized to explore the influence of adding lignin on the rheological properties of asphalt binder. The Fourier Transform Infrared Spectroscopy (FTIR) was used to evaluate the anti-aging performance of lignin on asphalt binder. The rutting resistance of lignin modified asphalt binder at the high temperature was evaluated using Multi Stress Creep and Recovery (MSCR) test, while the fatigue life of asphalt binder was characterized using Linear Amplitude Sweep (LAS) test. The viscosity test results showed that the addition of wood lignin into asphalt binder caused stiffening effect. The DSR and BBR test results implied that adding lignin positively affected high-temperature rutting performance without adversely influencing low-temperature. The MSCR results indicated that the lignin improved the elastic recovery and reduced non-recoverable deformation of asphalt binder. The FTIR results indicates that the presence of lignin can help resist the formation of carbonyl structure in the aging process, and thus improved aging resistance of asphalt binder. The LAS test results showed that fatigue resistance of asphalt was negatively affected by lignin. The study results suggest that wood lignin is a promising modifier for asphalt materials with economic savings and environmental benefits.