Research On The Pavement Performance Of Asphalt Mixture Modified By Rock Asphalt

It is a long history adding waste rubber powder and SBS into matrix asphalt as a modifier. However, the manufacturing process requires special equipments for shearing and grinding, a lot of power and strict construction technology. Moreover, the modifier and matrix asphalt in the modified asphalt made in this way will separate during its storage. Rock asphalt, as a natural modifier, is a kind of petroleum based solid itself and is similar to the matrix asphalt in chemical structures. Therefore, it can dissolve with matrix asphalt easily. During the construction process, we just need to put the rock asphalt directly to the agitating pan and stir the mixture. It’s easy and no special equipment is required. This paper mainly focuses on the pavement performance research of asphalt mix ture AM-25using rock asphalt as modifier, and compares the pavement perform ance of other asphalt mixture using other kinds of modifier (lake asphalt, waste rubber powder and SBS)This paper researches the compatibility of using natural asphalt to modify asphalt, and analyses the penetration degree, softening point, ductility, shear elasticity, anti-track factor, phase angle, and Brookfield rotary viscosity of the mixtures blended with different amounts of rock asphalt and lake asphalt. It turns out that the added natural asphalt lows the penetration degree of the asphalt, improves its temperature sensitivity, and elevates its softening point while reducing its ductility. DSR experiment proves that the natural asphalt can raise the high temperature stability and resistance against elastic deformation of the modified asphalt. The Brookfield rotary viscosity experiment shows that the asphalt modified by natural asphalt meets the requirements on workability during the construction.Since the Guangxi area is high on temperature and rainy, this paper carries out the wheel tracking test and the Immersion Marshall Test, and compares the dynamic stability and residual stability of the mixture added with different amounts of rock asphalt, lake asphalt, rubber powder and SBS. It indicates that the natural asphalt can remarkably improve the high temperature stability and water-resistant stability of the asphalt mixture, while the modifying effects of the rubber powder and SBS are not as good as the natural asphalt.At present, China lacks researches on the mechanical property of the asphalt modified by rock asphalt. Therefore, this paper conducts the Marshall Test, the diametral compression test, and the joist bending test, and compares the Marshall stability, the splitting strength, the splitting stiffness modulus, the flexural-tensile strength, the maximum flexural-tensile strain and bending stiffness modulus of the asphalt mixed with different amounts of rock asphalt, lake asphalt, rubber powder and SBS. The study demonstrates that all these4modifiers can improve the mechanical index of the modified asphalt mixture to different degrees and that the effects of the rock asphalt are the best...