This test method is developed for use in the determination of anticipated total elongation 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 evaluate creep strain potential at design loads.

5.1.2 The test data can be used in conjunction with interpretive methods to evaluate creep rupture potential at various loads.

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 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.

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 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.

The creep or stress rupture of a given geosynthetic is likely to be reduced in soil because of 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.