Evaluating drainage property of porous asphalt pavement for wet-weather travel safety

摘要

Porous asphalt pavements allow surface runoff to drain within the pavement wearing course, thereby maintaining a high level of skid resistance for wet-weather travel. They also reduce significantly splash and spray, and reflection of light from the road surface on rainy days. The road authority of Singapore has been laying porous asphalt surface sourse in its expressways since 1993. A measuring procedure for assessing the drainage property of such porous pavement surface was devleoped as a result of a research collaboration between the Land Transport Authority and the National University of Singapore (NUS) in 1999. It used a permeability measuring device developed by the authors at the NUS. This in-situ field permeability measuring device enabled each measurement to be completed within 2 minutes. This paper describes the method of conducting permeability measurements and the reliability of the measurements. Also described is a laboratory procedure for evaluating the clogging potential of the porous asphalt mix. Such information enables a rational pavement drainage design procedure to be implemented to reduce hydroplaning or skidding hazards in highways.