Cooling Effect of Permeable Asphalt Pavement under Both Dry and Wet Conditions

摘要

The improvement of the street thermal environment for walking and cycling is attracting increasedattention as a strategy for increasing livability. This approach has also been proposed as a strategy formitigating the local heat island effect and reducing energy use for buildings and vehicle air conditioningduring hot periods. This research explored a potential pavement design and management strategy thatpotentially could be used for improving the street thermal environment and mitigating heat islands.Through field measurements on pavement test sections with both conventional and alternative designs,the thermal behavior and cooling effect of permeable asphalt pavements under both dry and wet conditionwere investigated. The overall 7-day average cooling effect of wetting once on permeable pavements fornear-surface air is approximately 0.2 to 0.45°C; for the surface it is approximately 1.2 to 1.6°C; andapproximately 1.5 to 3.4°C for the in-depth layers. Based on the findings, permeable asphalt pavementshave the potential of being a type of cool pavements which produces lower temperatures and thus helpsimprove the thermal environment and mitigate the heat island effect. However, attention should be givento this type of pavements under dry conditions. As a pavement thermal management strategy, water fromrain or irrigation systems might need to be applied to the pavements to produce a better cooling effect forimproving the thermal environment and mitigating the heat island.