Lateral Permeability of Open-Graded Asphalt Mixture

This paper proposes a new approach to quantify the lateral permeability and retaining water effect on the drainage capability of open-graded asphalt mixture. Based on the water balance principle, a new device was designed to measure the lateral permeability of the open-graded asphalt mixture. The lateral permeability of open-graded asphalt mixture samples with different air voids ratio and height were compared. The permeability coefficient of vertical, lateral, and retaining water volume was identified to evaluate water permeability of open-graded asphalt mixture. Results show that lateral permeability is affected by a variation of voids ratio and height. Obvious lateral penetration appeared with the decline of voids ratio, and more flow that is lateral would induce as the increment of height for open-graded asphalt mixture. The retaining water can indirectly reflect the connected voids inside. Compared to vertical permeability, improving the capacity of lateral permeability is the effective way to drainage.