Laboratory Study of Permeability Variation Trends of Porous Asphalt Mixtures during Clogging and Cleaning

Porous pavements are a desirable form of pavement construction because of its positive environmental effects. Unfortunately, the porosity of porous pavements during service will decrease due to clogging, resulting in a shortened functional life. Hence, it is crucial to ensure its surface infiltration capacity during the useful service life by regular cleaning. Currently, no established test method is available to evaluate the long-term infiltration performance of porous asphalt pavements against clogging, and the effectiveness of maintenance cleaning. To have a better understanding of effects of clogging and maintenance cleaning, the present study proposed a laboratory procedure for evaluating changes in permeability of different porous asphalt mixtures during clogging and maintenance cleaning. The permeability k of a mixture was adopted as the measure of its performance and a basis of assessing the effects of cleaning. The experimental program considered three target porosity levels (15%, 20%, and 25%) and three maintenance thresholds (50% initial permeability, 25% initial permeability, and 0.3 mm/s). The test results showed that larger porosity mixtures can provide higher initial permeability, reduced maintenance work, and ensure higher permeability level over its entire service life. The results also indicated that a higher cleaning activation threshold could maintain the infiltration capacity of porous pavement at a higher level over the entire pavement service life, although it increased the cleaning frequency.