Research on performance of SBS modified colored asphalt and permeable asphalt mixture

As asphalt binder has good viscoelastic properties, it is widely used in road engineering. With the development of the economy, the pavement load gradually tends to be heavy, and the rutting disease has become the main damage type of the asphalt pavement . The black asphalt pavement has a higher absorption rate of solar radiation energy, which makes the temperature of the asphalt pavement higher than that of the surrounding light-colored objects . Especially in summer, the maximum temperature in the asphalt pavement structure exceeds 60 °C, the elasticity of the asphalt binder decreases, and the high temperature resistance The deformation ability is weakened, which further aggravates the occurrence of rutting disease. In recent years, the number of vehicles has increased rapidly, and the driving environment on the road is complex. In order to ensure that all kinds of vehicles drive in accordance with regulations, it brings great challenges to road traffic planning and management.

Colored asphalt refers to the use of decolorized asphalt or artificially formulated light-colored cementitious materials, which are compounded with different color dyes and additives [5, 6]. Compared with the traditional black colored asphalt, the color is lighter, which can reduce the absorption of solar radiation energy by the asphalt pavement, alleviate the temperature rise of the asphalt pavement to a certain extent, and reduce the rutting disease. Since the color of colored asphalt is significantly different from that of traditional asphalt mixture, the use of asphalt concrete of corresponding color in specific functional sections or lanes can guide drivers to drive according to regulations and improve road safety. Therefore, colored asphalt concrete has the advantages of performance, function and visual beautification. Three different inorganic dyes were used to color the decolorized asphalt, and SBS modifier commonly used in engineering was used to modify the colored asphalt to prepare the colored modified asphalt binder meeting the engineering requirements. The technical properties such as physical and rheological properties of modified asphalt with different colors were studied by three index tests and dynamic shear rheometer (DSR). The permeable asphalt mixture (PAC-13) was selected to study the road performance of permeable asphalt mixtures of different colors, so as to provide reference for similar projects.

Using SBS modifier agent and three inorganic dyes as composite modifiers, three colored asphalts of red, yellow and green were prepared by melt blending. The properties of colored asphalt binder and permeable asphalt mixture were analyzed. The following conclusions.

(1) After adding inorganic dyes and SBS modifier, the penetration of decolorized asphalt decreases and the softening point increases. The performance is improved, among which the improvement of chromium oxide green is the largest, followed by iron oxide yellow and iron oxide red.

(2) After adding inorganic dyes and SBS modifiers, the ductility of asphalt binder increases. Iron oxide red, iron oxide yellow and chromium oxide green increase the ductility by 16.4%, 11.4% and 14.4%, respectively, indicating that the low temperature of asphalt There is still some improvement in performance.

(3) The complex modulus of the decolorized asphalt increases and the phase angle decreases, so the rutting factor increases, indicating that the composite modification of inorganic dyes and SBS modifier can significantly improve the rutting resistance of decolorized asphalt.

(4) After the composite modification of inorganic dyes and SBS modifier, the road performance of the three PAC-13 permeable asphalt mixtures can meet the requirements of the specification. Iron oxide yellow modified asphalt mixture and iron oxide red modified asphalt mixture; the low temperature performance of red asphalt mixture is better than that of yellow asphalt mixture and green asphalt mixture; and the water stability is not much different.