Improved approach for evaluating saturated surface infiltration capacity of interlocking-block permeable pavements.

ABSTRACT

Different infiltration tests of permeable pavements provide different measurements of the infiltration capacity. These measurements often do not represent the fundamental flow properties, and hence cannot be directly compared. This presents an undesirable obstacle to the sharing of experience and to obtaining a better understanding of the infiltration performances of different permeable pavements. This problem is especially acute in the case of interlocking-block permeable pavements (IBPPs), owing to the presence of joints and the different sizes, shapes, and laying patterns of paving blocks. To overcome this problem, the present study proposed a new approach for evaluating the infiltration capacity of an IBPP while retaining the same measuring devices in use today. This approach makes use of a finite-volume computational fluid dynamic method to develop a simulation model for an infiltration test. Once calibrated to define the hydraulic parameters of the IBPP being tested, the model can be applied to calculate the saturated infiltration capacity of the IBPP under actual rainfall conditions. The model also permits the calculation of a conventional infiltration capacity measurement, such as the average infiltration rate in mm/h as measured by a particular infiltration test, or the time required to drain the tested water depth. Thus, the proposed approach provides a meaningful common basis for comparing the infiltration capacities of different permeable pavements, including porous asphalt, pervious concrete, and IBPPs.