Porous pavement in a cold climate

Major stormwater issues today concern runoff control, pollution control, and how to sustain the urban water resources on a long-term basis. A number of alternative stormwater management techniques have been developed during the last decades. Most of the research on these techniques has so far been carried out in regions with relatively warm weather. Thus, there is a need for more knowledge about the performance of the alternative stormwater facilities in cold climate regions. Local disposal of stormwater can be achieved by using porous pavements instead of impermeable pavements with conventional stormwater pipes and manholes. The objective of this thesis was to analyse the performance of porous pavements during freezing, thawing and snowmelt conditions in order to evaluate if the porous pavement is suitable for stormwater management and road construction in cold climate regions. Another purpose of the thesis was to study the differences in winter performance of porous pavement and impermeable pavements. A full-scale porous pavement construction was built in 1993/1994 in a residential area on the outskirts of Luleaa, Northern Sweden. The construction consisted of a layer of porous asphalt placed on top of a sub-base of coarse macadam or blast furnace slag. A geotextile separated the sub-base from the underlying soil and a drainage pipe was laid at the sub-grade. The thickness of the porous asphalt, the adjustment layer and the macadam sub-base was 45 mm, 30 mm and 600-1000 mm respectively. For comparison, one stretch of road in the area was surfaced with impermeable asphalt and one stretch of road was constructed with a sub-base of blast furnace slag. The width of the grassed roadside swales was increased to create a larger area for stormwater infiltration. In situ-measurements of ground temperature, frost heave, groundwater levels and runoff were performed between 1994 and 1997. Climatic conditions, including air temperature, precipitation and snow-pack thickness, were monitored during the same period. The infiltration capacity and drainage behaviour of the porous asphalt at different ambient air temperatures in the range -10 degrees centigrade to +20 degrees centigrade were investigated in the laboratory. It was found that porous pavements have a potential to reduce meltwater runoff, avoid excessive water on the road surface during the snowmelt period and accomplish groundwater recharge by local disposal of stormwater. The porous pavement was more resistant to freezing than the impermeable pavement, probably due to higher water content in the soil below the sub-grade of a porous pavement and due to the insulating effect of the air in the porous pavement. Thawing of porous pavement was a rapid process, which was explained by meltwater infiltration during the beginning of the snowmelt period. The full-scale porous pavement construction was not damaged by frost heave and the frost heave of the porous pavement was less or equal to the frost heave of the comparable impermeable pavement. This behaviour can be explained by the decreased frost penetration and by the fact that the porous pavement was a homogenous road construction due to the elimination of conventional stormwater pipes and manholes. A sub-base depth of 1.0 m is recommended in regions with similar climate conditions as Luleaa. No clear differences in frost penetration and frost heave between porous pavement with macadam sub-base and porous pavement with blast furnace slag sub-base were observed (A).

Language

  • English

Media Info

  • Pagination: 17p+app
  • Serial:
    • Licentiate thesis
    • Issue Number: 1999:21
    • Publisher: Luleå University of Technology, Sweden
    • ISSN: 1402-1757

Subject/Index Terms

Filing Info

  • Accession Number: 01054867
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Files: ITRD
  • Created Date: Aug 6 2007 1:49PM