Evaluation of methods for cleaning pervious concrete clogged with oil and sediments

Pervious concrete is becoming a widely used paving surface largely because it is seen as a more sustainable alternative to conventional, impermeable road and parking surfaces such as asphalt. The capture of sediments by mechanical filtration is an important process that contributes to the water quality treatment performance of a pervious concrete pavement. However, the ability of such a pavement to be an effective stormwater source control can be compromised if its open pore structure is clogged by urban pollutants such as sediments and oils. While various permeable pavement cleaning techniques have been developed, their effectiveness at removing hydrocarbon-based pollutants has not received any attention to date. This research study examines the clogging process caused by five different sediment particle size distributions, with a key innovation being the experimental investigation of the change in clogging caused by the addition of oil to the sediment load. The effectiveness of different permeable pavement cleaning techniques is also assessed, with particular regard to the size of sediments for which they are best suited. It was found that vacuum suction combined with high pressure water cleaning was an effective cleaning method for coarse sediments but after several cleaning events its effectiveness reduced. An improved understanding of the clogging processes associated with sediments and oils should help designers improve the effective life of pervious concrete pavements. The findings of this research study will also assist pavement owners and operators in the selection of optimal maintenance regimes.