【国外标准】 Standard Test Method for Determining Performance Strength of Geomembranes by the Wide Strip Tensile Method

5.1 This test method is a performance test intended as a design aid used to determine the ability of geomembranes to withstand the stresses and strains imposed under design conditions. This test method assists the design engineer in comparing several candidate geomembranes under specific test conditions.5.2 As a performance test, this method is not intended for routine acceptance testing of commercial shipments of geomembranes. Other more easily performed test methods, such as Test Methods D751 or Test Method D882, can be used for routine acceptance testing of geomembranes. This test method will be used relatively infrequently and to establish performance characteristics of geomembrane materials.5.2.1 There is no known correlation between this test method and index test methods, such as Test Methods D751.5.3 All geomembranes can be tested by this method. Some modification of techniques may be necessary for a given geomembrane depending upon its physical makeup. Special adaptations may be necessary with strong geomembranes or geomembranes with extremely slick surfaces, to prevent them from slipping in the clamps or being damaged by the clamps.1.1 This test method covers the determination of the performance strength of synthetic geomembranes by subjecting wide strips of material to tensile loading.1.2 This test method covers the measurement of tensile strength and elongation of geomembranes and includes directions for calculating initial modulus, offset modulus, secant modulus, and breaking toughness.1.3 The basic distinctions between this test method and other methods measuring tensile strength of geomembranes are the width of the specimens tested and the speed of applied force. The greater width of the specimens specified in this test method minimizes the contraction edge effect (necking) which occurs in many geosynthetics and provides a closer relationship to actual material behavior in service. The slower speed of applied strain also provides a closer relationship to actual material behavior in service.1.4 As a performance test, this method will be used relatively infrequently, and to test large lots of material. This test method is not intended for routine quality control testing of geomembranes.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.1.6 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.1.7 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.