【国外标准】 Standard Test Method for Determining the Unconfined Tension Creep and Creep Rupture Behavior of Planar Geosynthetics Used for Reinforcement Purposes

5.1 This test method is developed for use in the determination of anticipated total elongation over time or time to rupture that may occur in geosynthetics under sustained loading conditions.5.1.1 The test data can be used in conjunction with interpretive methods to determine creep strain potential at design loads.5.1.2 The test data can be used in conjunction with interpretive methods to determine creep rupture potential at various loads.5.2 This test method is not intended for routine acceptance testing of geosynthetics. This test method should be used to characterize geosynthetics intended for use in reinforcement applications in which creep or creep rupture is of concern. The plane strain or rupture condition imposed during testing must be considered when using the test results for design.5.3 The basic distinctions between this test method and other test methods for measuring tension creep and creep rupture behavior are: (1) the width of the specimens (Section 8), and (2) the measurement of total elongation over time or time to rupture from the moment of specimen loading. The greater widths of the specimens specified in this test method minimize the contraction edge effect (necking) that occurs in many geosynthetic materials and provides a closer relationship to actual material behavior in plane strain tension conditions.5.4 The creep or stress rupture of a given geosynthetic is likely to be reduced in soil because of confining stresses and load transfer to the soil. The unconfined environment represents a controlled test in which the results are conservative with regard to the behavior of the material in service. Confined or in-soil testing may model the field behavior of the geosynthetic more accurately.1.1 This test method is intended for use in determining the unconfined tension creep and creep rupture behavior of geosynthetics at constant temperature when subjected to a sustained tensile loading. This test method is applicable to all geosynthetics.1.2 The test method measures total elongation of the geosynthetic test specimen, from the time of loading, while being maintained at a constant temperature. It includes procedures for measuring the tension creep and creep rupture behavior at constant temperature of conditioned unconfined geosynthetics as well as directions for calculating tension forces to plot creep and creep rupture curves.1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.