The compression behavior test for geosynthetics is intended to be an index test. It is anticipated that the results of the compression behavior test will be used to evaluate product. The results of the analyses may also be used to compare the relative compressive yield points of materials that exhibit a detectable compressive yield point. It is anticipated that this test will be used for quality control testing to evaluate uniformity and consistency within a lot or between lots where sample geometry factors (for example, thickness) or materials may have changed.

Note 1-This is a one-dimensional test for compressive loading of a geosynthetic(s) in one plane.

5.1.1 The compressive yield point of geosynthetics may be evaluated from the stress/strain relationship. Many materials exhibit compressive deformation but may not show a distinct compressive yield point.

This test method can be used to evaluate the short-term stress/strain behavior of geosynthetics under compressive stress while loaded at a constant rate of deformation.

This test method may be used for acceptance testing of commercial shipments of geosynthetics but caution is advised because interlab testing is incomplete.

5.3.1 In the case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, two parties should take a group of test specimens from material shipped to the project. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using the Student't-test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If bias is found, either its cause must be found and corrected or the purchaser and supplier must agree to interpret future test results in the light of the known bias.