Investigating the rutting behavior of modified bitumen with SBS / MgO nanocomposite

Rutting is one of the most important failures of flexible pavements, which is dramatically affected by bitumen characteristics. To prevent this failure, it is necessary to use bitumen with good performance characteristics in the construction of asphalt mixtures. Numerous studies have shown that polymer modified bitumen has many advantages. The storage stability of polymer modified bitumen is difficult because the compatibility between bitumen and polymer is low. During storage, it forms two phases of bitumen and polymer, which reduces the performance characteristics of asphalt mixtures such as rutting resistance. For this reason, polymer bitumen modified with nanocomposites have been used. By adding magnesium nano oxide to the polymer bitumen, the compatibility between the polymer and the bitumen and the performance characteristics of the bitumen will be improved, and the possibility of damage such as rutting will be reduced. The present study was conducted to evaluate the effect of magnesium oxide nanoparticles on the rutting performance of polymer bitumen. In this study, pure bitumen 60/70 was modified with SBS polymer and magnesium oxide nanoparticles in 5 different levels. Rotational viscosity and multiple stress creep recovery test (MSCR) have been used to evaluate the effect of nanoparticles on polymer modified bitumen. Research shows that magnesium oxide nanoparticles increase the viscosity of polymer modified bitumen and improve the Jnr and the percentage recovery of bitumen. These results show that magnesium oxide nanoparticles have a significant effect on improving the high temperature performance of nano modified polymer bitumen and increase the rutting resistance. In general, bitumen modified with SBS/MgO nanocomposites have a good potential for improving bitumen performance and can be used in warm areas.