Investigation on the distributing behaviors of clogging particles in permeable asphalt mixtures from the microstructure perspective

Abstract

The premise of elucidating the clogging mechanism of permeable asphalt mixtures refers to the determination of the distributing behaviors of clogging particles. This study aimed to determine the distributing behaviors of clogging particles in permeable asphalt mixtures from the microstructure perspective. By collecting pavement sediment and conducting particle size analysis, the size range of clogging particles was determined in the range from 0.15 to 2.36 mm. Three types of permeable asphalt mixtures were synthesized, and the tomographic images of asphalt mixtures were captured with the computed tomography. To determine the optimal parameters of image registration, mutual information and the calculated time were adopted. On that basis, the algorithm to identify clogging particles in permeable asphalt mixtures was developed, and the spatial distributing behaviors of clogging particles were explored. As suggested from the results, the clogging particles were primarily deposited deeply in the structure under the action of fluid carrying, and the particles near the periphery exhibited larger content than the center of the structure. With the clogging process, the deposition positions of clogging particles were from deep to shallow, and the particle distribution varied from the centralized distribution to uniform distribution. The particle deposition area experienced three stages (i.e., the emergence, expansion and stability of particle deposition). Lastly, the effect of gradation type of asphalt mixture and the size of clogging particles on particle distributing behaviors were analyzed.