Bleeding mechanism and mitigation technique of basalt fiber-reinforced asphalt mixture

Basalt fiber-reinforced asphalt mixture has shown promising mechanical characteristics but is susceptible to bleeding, which can compromise driving comfort and safety. This paper investigates the bleeding mechanism of basalt fiber-modified asphalt mixtures and proposes mitigation techniques. Scanning Electron Microscopy (SEM) is used to observe the microstructure and spatial structure of the asphalt mixture with fibers, while microstructure, interface properties, and spatial structure are analyzed to determine the mechanism of bleeding. Mixed fibers composed of basalt and lignin fibers are proposed as a solution to alleviate bleeding, and comprehensive pavement performance is evaluated using the Efficiency Coefficient Method (ECF). The results show that the smooth surface, low surface energy, poor surface bonding ability, small specific surface area, and large void network structure of basalt fibers make the pavement susceptible to bleeding. Besides, the mixed fiber reinforced asphalt mixture exhibits a 16.7% increase in resistance to bleeding compared to the basalt fiber asphalt mixture. Furthermore, the comprehensive pavement performance has been enhanced by 9.09% according to ECF result