Random sampling of geosynthetics in Finland

NorGeoSpec is a Nordic system for certification and specification of geosynthetics and geosynthetic related products. Traffic authorities of the member states have composed the guidelines and agreed on a 5-class specification system for geotextiles used for filtration and separation. Recently the quality certification system has been extended to include the reinforcement function, too. The classification system has made the specification of geotextiles easy for the designer, thus increasing the use. The NorGeoSpec process includes a third-party quality control and audits, i.e. an inspection of the production process and testing of the products in an independent testing laboratory, in addition to the producers' continuous quality testing. Also, continuous surveillance including unannounced random product sampling and control checks is possible. With the support of NorGeoSpec, Finnish Transport Infrastructure Agency has carried out a random products sampling on geotextiles and reinforcing geosynthetics in 2015-2018. In addition, random sampling was made on roadside groundwater protection projects using geosynthetic clay liners and geomembranes. The random sampling project has increased the knowledge of geosynthetics. The results of random sampling have shown some deviations from requirements and the variation between laboratories. Based on the results, the requirements on sampling and testing prior the use at the project site to prove the compliance has been added to Finnish general quality requirements (InfraRYL).