Self-Cleaning Performance of Double-Layer Porous Asphalt Pavements with Different Granular Diameters and Layer Combinations

During the service lives of double-layer porous asphalt pavements, drainage performance, and the noise-reduction capacity are noticeably weakened by dust and polluted rainwater. This paper aims to increase self-cleaning performance and reduce maintenance frequencies to cut down the expenses of dust-cleaning actions. Fluid-structure coupled simulations using Flow-3D software were used to simulate self-cleaning performance of double-layer porous asphalt pavements with different granular diameters (4, 8, and 16 mm) and layer combinations (3.5 cm + 6.5 cm, 4 cm + 6 cm, and 4.5 cm + 5.5 cm). The results showed that equivalent granular diameters significantly influenced water pressure inside interconnected pores and 8-mm granular diameter was preferred to provide good self-cleaning performance. However, layer combination exhibited negligible impact on the self-cleaning performance of double-layer porous asphalt pavement.