Investigating the properties of asphalt binder modified by high- and low-density polyethylene polymer and nano-silica

This paper describes nano-silica (NS) reinforcement effects on the properties of an asphalt binder modified by 5% of low density polyethylene (LDPE) and high density polyethylene (HDPE) polymers. NS was added at 0, 2, 4 and 6% of modified asphalt weight and some physical, rheological, chemical and microstructure of the binders were evaluated. Results show adding NS into the polymer modified binder (PMB) results in better dispersion of polymer in the binder, improvement of elastic recovery and storage stability, decrease of temperature susceptibility, decrease of ductility, and slightly improvement in rutting resistance. Statistical analysis revealed that the polymer type has significant effect on SHRP rutting parameter at 76°C, elastic recovery and storage stability. It was also found that the effect of NS content is significant on the penetration, penetration index, viscosity temperature sensitivity (VTS) and storage stability.