1.1 This test method covers accelerated testing for compressive creep properties using the stepped isothermal method (SIM).

1.2 The test method is focused on geosynthetic drainage materials such as HDPE geonet specimens.

1.3  The SIM tests are laterally unconfined tests based on time-temperature superposition procedures.

1.4 Ramp and hold (R+H) tests may be completed in conjunction with SIM tests. They are designed to provide additional estimates of the initial rapid compressive creep strain levels appropriate for the SIM results.

1.5 This method can be used to establish the sustained load compressive creep characteristics of a geosynthetic that demonstrates a relationship between time-dependent behavior and temperature. Results of this method are to be used to augment results of compressive creep tests performed at 20 ± 1 °C and may not be used as the sole basis for determination of long-term compressive creep behavior of geosynthetic material.

1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.7 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.

1.8 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.