*Article* **Physical Properties and Storage Stability of Buton Rock Asphalt Modified Asphalt**

**Yue Su <sup>1</sup> , Xiaodi Hu <sup>1</sup> , Jiuming Wan 1,\*, Shaopeng Wu <sup>2</sup> , Yinglong Zhang <sup>1</sup> , Xing Huang <sup>3</sup> and Zhangjun Liu <sup>1</sup>**


**Abstract:** Buton Rock Asphalt (BRA) refers to the natural rock asphalt natively produced on the Buton island of Indonesia. It is often used as a modifier to enhance the performance of asphaltpavement. However, the segregation of BRA in BRA-Modified Asphalt (BRA-MA) has restricted its application. This study aims to investigate how the particle size and content of BRA affect the physical properties and storage stability of BRA-MA. Penetration, softening point, viscosity, and viscosity-temperature susceptibility (VTS) were analyzed. The evaluation method of storage stability was discussed and determined. The segregation of BRA in BRA-MA of static storage and transportation process were simulated and tested. The results suggest that the softening point and viscosity were positively correlated to BRA content and inversely determined by particle size. Penetration, VTS, and ductility were reduced due to the decline in particle size and increment of BRA content. The index of segregation value based on viscosity difference showed better statistical and quantitative significances than the softening-point difference in evaluating the storage stability. The particle size and content of BRA are positively correlated to the segregation of BRA-MA. Both the storage temperature and time were positively correlated to the segregation of BRA-MA. We prove that the relationship between specific surface area and segregation are power functional. BRA-MA with BRA whose 50% particle sizes are lower than 13.6 µm showed low segregation in transportation.

**Keywords:** Buton rock asphalt; storage stability; particle size; physical property
