Comparison of the Results of DSR and MSCR Tests, Based on Rutting Performance of Asphalt Binders Modified with Mesoporous Silica

In this study, for comparison of the results of dynamic shear rheometer (DSR) and multiple stress creep and recovery (MSCR) tests, based on rutting performance of asphalt binders modified with mesoporous silica, four different asphalt binders were produced using a mixture of 2%, 4%, 6% and 8% (w/w) of this additive and neat bitumen. After a 20-minute vibration, the produced mixtures were mechanically mixed for 30 minutes, in a high-shear homogenizer mixer. Then, the modified binders and neat bitumen were subjected to DSR and MSCR tests, after the aging process in RTFO test. The comparison between outputs indicated that the results of DSR and MSCR tests have been consistent, as the variation trends of R and G*⁄sin δ have been the same at different temperature levels. On the other hand, the variation trend of Jnr has been the opposite, and in both tests, maximum value of R and G*⁄sin δ and minimum value of Jnr have occurred in the 4% bitumen modifier. This suggests that the greatest potential resistance to rutting has been observed in the binder containing 4% (w/w) mesoporous silica. Furthermore, at both DSR and MSCR tests, asphalt binders at high temperatures revealed a more viscous behavior like Newtonian fluids. The difference between the results of the two experiments was that in the MSCR test, the highest resistance to increasing the stress level was assigned to the binder containing 6% mesoporous silica.