Research on the Mechanism of Asphalt Pavement Interlayer Bonding Reinforcement Based on Fiber Seal Coat

To investigate the reinforcement law and internal mechanism of fiber seals on the interlayer bonding performance of asphalt pavement, the SMA-13/AC-20 pavement structure was taken as the object to reveal the effects of fiber type (basalt fiber and glass fiber), dosage (0, 80, 100, and 120 g/m²), and length (3, 5, 7, and 9 cm). The control variable method and indoor direct shear and tensile tests were used to optimize the parameters. The results indicate that the optimal parameter combination is a fiber dosage of 100 g/m² and a length of 5 cm. In this case, the reinforcement effect of basalt fiber is significantly superior to that of glass fiber, and the interlayer shear and tensile strengths reach 1.47 MPa and 0.793 MPa, respectively, which are 41.3% and 37.2% higher than those of the group without fiber. By forming a three-dimensional network structure, fibers exert a synergistic effect of reinforcement, bridging, and friction enhancement, constructing a robust interlayer composite system. This study provides experimental support for material optimization and multi-parameter collaborative design of a fiber seal coat.