5.1 This test method is used for evaluating the relative effects of temperature on geotextiles manufactured from different polymers, by a different manufacturing process, or both.
5.2 During shipping and storage, the geotextile may be exposed to abnormal temperatures. The fabric could be tested at these temperatures to determine the detrimental effects of these conditions on the strength properties.
5.3 This test method may also be used to evaluate the cyclic effects of temperature (freeze-thaw), that is, samples can be conditioned to below normal temperatures (below freezing) and then to above normal temperatures (elevated temperatures) for a given number of cycles. Strength characteristics can be determined after these cyclic exposures.
5.4 Most nonwoven, woven, and composite fabric can be tested by this method. Modification of the techniques is likely to be necessary for any fabric having a strength in excess of 179 kg/cm [1000 lb/in.] width. This test method is not recommended for knitted fabrics.
5.5 This test method is an index test method and is not recommended for acceptance testing of commercial shipments, since information on between laboratory precision has not been established. In some cases the purchaser and seller may have to test a commercial shipment of one or more geotextiles by the best available method, even though the method has not been recommended for acceptance testing of commercial shipments. A comparative test performed as directed in 5.5.1 may be advisable.
5.5.1 In case of a dispute arising from differences in reported test results when using Test Method D4594/D4594M for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogenous as possible and that are from a lot of material of the type in question. 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 Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results in the light of the known bias.
