An experimental set-up and monitoring program for full-scale tests of six permeable pavements systems in Copenhagen, Denmark

Permeable pavement has not been widely used in Denmark due to strict environmental regulation protecting the aquifer and a 50-year tradition of using base course material made of gravel with fines (stabilised gravel). Because stabilised gravel have little permeability and loses its carrying capacity when water-saturated, it is not suitable as part of a permeable pavement system (PPS). Therefore, research is needed to identify suitable alternative construction aggregate materials based on materials that are locally available in Denmark. In order to compensate for the lack of research and practical experience with PPS in Denmark a monitored full-scale test-site was recently established to test a representative sampling of PPSs. Each PPS was 25m2 and placed in an existing parking area at a sport facility in Copenhagen in May 2013. There was made six lots that differ in terms of combination of surface layer and sub-base material. This paper presents the experimental set-up and results from initial surface infiltration tests. Since infiltration through permeable pavements is a key factor in assessing whether a given PPS will be effective, efforts were made to obtain more accurate and reliable infiltration rates (IR). Bean (2005) has documented the 'Double Ring Infiltrometer Test' (DRIT) and 'Single-Ring Infiltrometer Test' (SRIT) for, respectively, low- and high-permeable pavements; these tests were also conducted by Drake (2013) and Al-Rubaei (2012). We developed a new method, called CONstant head Single Ring Infiltrometer Test (CONSRI), by combining certain features of the DRIT and SRIT methods. The results from the CONSRIT method give infiltration rates of 300-1734 mm/h depending on the PPS type tested. The method works well, but further tests and data-analyzing is needed to determine the accuracy of measurement in relation to the extra work required to carry out an infiltration test with the CONSRIT method.