Though the presence of a vertical porosity distribution in porous pavements has been recognized, the
impact of this distribution on the permeability of the pavement has not been considered. This research
investigates the impact of a vertical porosity distribution on the overall permeability of pervious concrete.
First, an unimpaired porosity–permeability relationship was generated using pervious concrete
specimens which had uniform porosity throughout. This relationship was then used in conjunction with
the vertical porosity distribution of surface compacted pervious concrete specimens to generate a vertical
permeability distribution. An effective permeability value was used to summarize the overall behavior of
the permeability distribution and was shown to have a much better correlation with the actual permeability
of the specimens than the permeability predicted using the average porosity of the specimen.
Additionally, an analysis of the relationship between the permeability distribution and the effective
permeability showed that the minimum permeability (and therefore minimum porosity) tends to have
the largest impact on the effective permeability.