VTT Technical Research Centre of Finland Ltd. reports developing permeable pavements to handle higher volumes of runoff. The researchers claim permeable pavement with surface and subsurface materials with higher porosity. Pilot projects for the surfacing will take place this spring in the cities of Espoo, Helsinki, Vantaa and Oulu.

Over the course of two years, the CLASS (CLimate Adaptive SurfaceS) project in Finland reports developing "geotechnical structural designs" of permeable pavers better suited to freeze-thaw conditions and subarctic climates than traditional permeable pavers.

Their materials include pervious concrete, porous asphalt and concrete and natural stone block pavers in which the material used in the joints or openings allows high water infiltration.

The permeable pavement consists of a "surfacing layer and subsurfacing materials" with high porosity. "Water infiltration capacity and winter durability performance was verified for the full service life of the pavement structure, from design to construction and lifetime maintenance," the researchers report.

The project was funded by Tekes, VTT Technical Research Centre of Finland Ltd., and 15 industrial partners.