Development of durable pervious concrete for Finland's stormwater management needs

Pervious concrete is a viable tool for to mitigating impacts of climate changes in urban environments, through their ability to filter high volumes of stormwater. Research has been done in Finland to develop pervious concrete that is durable for arctic environmental conditions. The new materials combined with subbased design are optimized during design, construction and maintenance, to allow for high filtration to the substrate rather than over-burdening the stormwater collection systems or polluting nearby natural water bodies with urban run-off. The project has conducted laboratory test programs to characterize materials prior to designing concrete recipes that meet Finnish demands and then implemented layer systems where the concrete and subbase layers function for filtration benefits. Performance tests characterize the porous concrete strength, open porosity, microstructure including protective air pores, permeability and freeze-thaw resistance with and without de-icing salt. Several mixes have been prepared and slabs and other specimens have been cast for these studies. The main emphasis has been on ensuring durability for harsh Finnish winter exposure conditions. The results are being used in structural dimensioning tools for stormwater management, combined with computer simulations of future flooding scenarios. Practical guidelines for use of pervious concrete in Finland are being developed for implementation prior to full-scale field demonstrations to be built by municipalities in 2015.