Improvement on the high-temperature stability and anti-aging performance of the rubberized asphalt binder with the Lucobit additive

摘要

Applying waste tire rubber powder to modify the asphalt binder is a promising protocol to achieve sustainable pavement materials. This study aims to examine the feasibility of using Lucobit type asphalt additive in the rubberized asphalt and further enhance its performance. The 90# asphalt binder and the rubber powder with 30 mesh were selected to prepare the rubberized asphalt. Two Lucobit adding ratios (5% and 10%) were then selected for the modification of three types rubberized base binder (Rubber replacement ratios 15%, 20%, and 25%). The modified asphalt binder was prepared under 180 +/- 5 celcius by using the high-speed shear mixer under 5000 rpm for 2 h. Then the FTIR and TGA tests were conducted for the phase analysis of the asphalt co-modified with rubber powder and Lucobit. The test results indicated the modification mainly belong to the physical blending instead of chemical bonding. Further study with DSR test indicated the added Lucobit can further enhance the high-temperature stability of the rubberized asphalt. Further study based on Multiple Stress Creep Recovery (MSCR) test indicated the anti-rutting performance of the asphalt binder would be enhanced while the sensibility of asphalt binder to shear stress would be reduced with the added Lucobit. Finally, the topography analysis on the original and aged binders were analyzed with Atomic Force Microscopy (AFM) test. The results indicated obviously reduced bee-like structure can be observed in the samples with Lucobit, which is in accor-dance with the measured complex modulus after aging tests. Overall, this study indicates the added Lucobit can further enhance the high-temperature stability, antiaging performance, and reduce shear stress sensitivity of the asphalt binder.