TY - CONF A1 - Robertson, Daniela A1 - Schröder, Hartmut A1 - Böhning, Martin A1 - Brummermann, K. A1 - Kaundinya, I. A1 - Saathoff, F. T1 - Test method for the assessment of the service life of polymeric geosynthetic barriers (GBR-P) for road tunnels T2 - Euro GEO 5 - 5th European geosynthetics congress CY - Valencia, Spain DA - 2012-09-16 KW - Durability KW - Oxidation KW - Acceleration ageing KW - GBR-P PY - 2012 SN - 978-0415-64340-5 VL - 1 IS - Topic: Transport SP - 150 EP - 154 AN - OPUS4-27312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Retzlaff, J. A1 - Bronstein, Z. A1 - Müller-Rochholz, J. A1 - Böhning, Martin A1 - Robertson, Daniela A1 - Schröder, Hartmut T1 - Oxidative resistance of geosynthetics: practical aspects and developments of testing at elevated temperature and oxygen pressure N2 - Service life of geosynthetics made of polyolefin materials is mainly limited by oxidative degradation. Durability of polyolefin products depend on formulation, morphology resulting from manufacturing, design and particularly on the antioxidants used. Although the fundamental oxidative reactions are known, the complex effect of geosynthetic characteristics and external influences mean that durability assessments require practical tests. The assessment of oxidative durability involves exposure to accelerating conditions as well as the material characterisation with respect to the state of stabilisation and/or degradation (e.g. by tensile testing and/or oxidation induction time). The autoclave test developed by BAM for durability assessments of polyolefin geosynthetics is based on the simultaneous application of moderately elevated temperatures (up to 80 degrees Celsius) and elevated oxygen pressures (up to 5.0 MPa) in combination with a surrounding aqueous medium. Thus this test method provides several advantages in comparison to conventional oven testing, especially with respect to test duration, impact of surrounding environment and the potential to differentiate and rank oxidative resistance between products of very different dimensions (surface/volume) and stabilisation. In view of the increasing demand for durability assessments of geosynthetic products with lifetimes significantly exceeding 25 years, the contribution is focused on practical aspects concerning implementation and optimisation of test procedures, conditions and evaluation of results. Furthermore, advanced approaches based on multiple exposure conditions will also be included and corresponding calculations of expected service life in typical applications will be evaluated with respect to significance and repeatability. Thereby involved standards and recommendations - such as EN ISO 13438, Part C or EAG-EDT - are considered. T2 - EuroGeo4, 4th European Geosynthetics Conference CY - Edinburgh, UK DA - 2008-09-07 KW - Ageing KW - Degradation KW - HDPE KW - Laboratory test KW - Oxidation KW - Polypropylene PY - 2008 IS - Paper 178 SP - 1 EP - 4 AN - OPUS4-18423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -