Effect of clogging and cleaning on the permeability of pervious block pavements

Metropolitan regions where ground surfaces are covered by an impermeable layer are vulnerable to heavy rainfall. Pervious pavement that facilitates infiltration of stormwater runoff into underground reservoirs mitigates the risk of flooding. However, pervious pavement systems are prone to clogging, which reduces its permeability. Three types of pervious block pavers were field tested in order to investigate their clogging characteristics, consequent permeability reduction, and response to cleaning. The permeability of fresh specimens ranged from 0.71 to 0.92 mm/s. After six months in the field, the permeability decreased to 17% of the initial permeability, and was restored to similar to 30% of initial value after cleaning. The X-ray computed tomography images of used specimens provided the clogging characteristics such as clogging depth, clog fraction, and cleaning efficiency. The lattice Boltzmann model simulation results corroborated the experimental observations. The results of this study can be used to design concrete and aggregate mix, determine the cleaning period, and plan an appropriate maintenance procedure.