This paper discusses the aspects of porous asphalt concretes (PACs) which cause alteration in the operation of winter maintenance. The physical properties of PACs cause them to act as heat exchangers, thus modifying the thermal conditions. The effectiveness of road salts is reduced because of dispersion; and it becomes more difficult to treat and remove snow. Three experimental motorway sites were monitored in France over winters between 1988 and 1991 which confirmed the theoretical observations. Winter operational strategy needs to be adapted to allow more accurate continuous monitoring, rapid and more frequent intervention for salting and snow removal and higher doses of melting products. There is considerable extra expense linked to this mode of operation.
Abstract