Advanced mechanical characterization of asphalt mastics containing tourmaline modifier

Tourmaline modified bitumen as an environmentally friendly pavement material has got an increasing attention in recent years in China. In this regard, previous studies mainly focused on the linear viscoelastic properties of asphalt or asphalt mastic. In this paper, multiple stress creep and recovery (MSCR) test, linear amplitude sweep (LAS) test and double edge notched tension (DENT) test were adopted as fundamental performance evaluation methods for high-temperature rutting, fatigue, and low-temperature thermal cracking of asphalt binder, respectively. Moreover, straight run asphalt and polymer modified asphalt containing various percentages of two kinds of tourmaline as asphalt modifier were also prepared to gain the knowledge of the interaction between asphalt and tourmaline. To study the feasibility of applying tourmaline as an alternative modifier and compare its performance with conventional fillers, asphalt mastic containing limestone was also prepared. The results show that small amount of modifier can enhance the mechanical properties of asphalt binder, but different modifiers do not have similar effect. In addition, market available tourmaline additive has different chemical composition and physical properties; asphalt mastic containing tourmaline ions powder showed the best performance among modifiers utilized here.