Evaluation of Anti-clogging Property of Porous Asphalt Concrete Using Microscopic Voids Analysis

Abstract

Since the occurrence of voids clogging has an adverse effect on Porous Asphalt Concrete (PAC), an experiment was designed to evaluate PAC’s anti-clogging capability with different material compositions. Image processing and X-ray Computer Tomography (CT) were employed to study the characteristics of micro-gap of PAC, such as amount, area, and equivalent diameter of air voids on average. It was found that different PAC material compositions induce large differences on anti-clogging capability. PAC’s anti-clogging capability can be improved in different degrees by increasing air voids and nominal maximum aggregate size or using coarse gradation. There was an apparent linear correlation between PAC’s voids equivalent diameter and anti-clogging capability: the larger equivalent voids, the better anti-clogging capability. In this research, anti-clogging capability was interpreted, and a new method was put forward for improving the anti-clogging performance of Porous Asphalt Concrete from the perspective of microscopic void geometric features.