ASTM D5970-16(R2021) pdf free download

ASTM D5970-16(R2021) pdf free download.Standard Test Method for Deterioration of Geotextiles from Outdoor Exposure
1. Scope
1.1 This test method covers evaluating the deterioration in tensile strength and strain after outdoor exposure. 1.2 The deterioration is assessed as a reduction in strength and strain at failure from the unexposed geotextile. 1.3 The specific location of the light and weather exposure is made on the basis of a site-specific decision between the parties involved. 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.5 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 Geotextile coupons are attached to a test frame oriented 45° from the horizontal and facing the equator at a designated location for exposure times of 1, 2, 4, 8, 12, and 18 months. Exposure shall begin so as to ensure that material is exposed during the maximum intensity of ultraviolet light of the year. Unless otherwise specified, the test should be initiated in May in the northern hemisphere, and in November in the southern hemisphere. 4.1.1 Unexposed coupons, or ‘file specimens’ according to Terminology G113, shall be retained for testing. 4.2 After each exposure time, the appropriate coupons are brought into a laboratory for strength determination. The results of these tests are compared to the strength determined for the unexposed coupons. The user may be interested in exposure times other than specified in this test method. These times should be noted in reporting the results. 4.3 The results are presented in the form of various plots. 4.4 Additional recommendations may be found in Practice G7/G7M and Terminology G113.
5. Significance and Use
5.1 Outdoor exposure tests at one location may not be applicable to a project site at another location. This test method evaluates geotextiles under site-specific atmospheric condi- tions over an 18-month period. A degradation curve as per 10.8, based on strength, elongation, or modulus, or all of these, may be developed for the geotextile being evaluated. 5.2 This test method can be used for comparative testing of the degradation of geotextiles. 5.3 This test method is considered to be a performance test and as such the responsibility for its performance rests with the specifying or purchasing agency. N OTE 1—The intent of this procedure is to provide the user of this test method and geotextiles a standard by which to evaluate weathering degradation in terms of site-specific conditions, not in terms of incident radiation and temperature. If desired, the user may want to have the necessary measurement and recording equipment at each site to do this. However, the expense of doing so at each site may be prohibitive. Therefore, this is not a specific requirement of this test method.
6. Apparatus
6.1 The frame for holding the coupons during the exposure phase of this test consists of a wooden frame (for example, a sheet of exterior plywood) suitably braced so that it resides at a 45° angle with the horizontal. 6.1.1 The frame is to be unpainted with the surface pro- tected from the effects of water and sunlight by varnishing the surface. 6.1.2 The supported frame is firmly positioned in a location free from obstruction from trees or other sources of shade. It shall face the equator. It shall be placed such that no heat or sunlight is reflected on it from surrounding buildings. If this is not possible, it shall be noted in the test results report. 6.1.3 The frame shall be suitably anchored using anchors, stakes, or adequate weights on the support legs. 6.2 The geotextiles coupons shall be fastened with care in such a way that undue stresses that could result in premature failure of the geotextile are not induced. Staples may be used.