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ASTM D7179-18 Standard Test Method for Determining Geonet Breaking Force Active 发布日期 :  1970-01-01 实施日期 : 

5.1 This method evaluates tensile breaking force of geonets for the purposes of quality control and quality assurance. Testing is performed parallel to the machine direction only, for that is the primary direction that geonets witness tensile loading. This method is an index test and is not intended for design purposes.1.1 This test method is used to measure the breaking force of a geonet.1.2 This test is applicable for manufacturing quality control (MQC) and construction quality assurance (CQA) testing, and is not recommended as a performance test.1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.1.4 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.1.5 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.

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1.1 This test method covers the determination of the breaking load and calculated modulus of rupture of preformed thermal insulation for pipes.1.2 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are provided for information only.

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5.1 This test method provides information that can be used in material specifications for product design and quality assurance applications. It can be used in comparing different products.5.2 The use of this test method must be related to the purpose for which the test is performed. One purpose is for determining the relative strength of the tape in the size in which it is purchased or used. Another purpose is to identify or characterize a particular backing material.5.2.1 The test may be performed on the tape as-received, that is, without cutting the material to a specimen width less than the as-received width. Usually tapes wider than 48 mm [2 in.] are not tested due principally to the limitations of equipment. Tapes as narrow as approximately 3 mm [0.125 in.] can be tested.5.2.2 The test may be performed on a specimen cut from within the sample material boundaries using a sharp razor cutter, such as that defined in Section 6. This method is usually used for material characterization, determining quality of conformance, and for specification compliance.5.3 Stretch characteristics of elongation at break or force to a specified elongation can be related to the tape's intended use or for identifying or characterizing a material.1.1 This test method covers the measurement of tensile strength at break (breaking strength) and stretch properties (elongation) for pressure-sensitive tapes and labels. It includes procedures for machine direction and cross direction, for high-strength filament reinforced backings and for high stretch backings. It also includes a procedure for obtaining force (“F” value) in conjunction with a specified elongation. These procedures employ a constant-rate-of-extension (CRE)-type testing machine.1.2 The values stated in either SI or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; conversions between measurement systems must be conducted carefully.1.3 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.1.4 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.

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5.1 Test Method D1578 for testing any spun yarn for breaking strength is considered satisfactory for acceptance testing of commercial shipments since the method has been used extensively in the trade.5.1.1 In case of a dispute arising from differences in reported test results when using Test Method D1578 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 which are as homogeneous as possible and which 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 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.5.2 This test method is not suitable for yarns that stretch more than 5 % when the force is increased from 2.5 to 7.5 mN/tex or 0.03 to 0.08 gf/denier, because (a ) they require special precautions as to tension in reeling, and (b) users of such yarns are more interested in their elastic behavior at low forces than in their ultimate breaking strength.5.3 For Option 1, it is advisable to use a tensile testing machine of the proper capacity to break skeins with 80 turns. If it is necessary to break skeins having only 40 or 20 turns, convert the observed results to an 80-turn basis by multiplying by factors of 2 or 4, respectively. (The available literature does not show that any significant error is introduced by the use of these factors.)5.4 The circumference of the skeins used to determine the breaking load is not critical, and as a consequence, close control of the tension at which the skeins are wound is not necessary. If, however, the same skeins are to be used to determine yarn number for any purpose, the skeins must be reeled under controlled tension on a reel meeting the requirements given in Test Method D1907.5.5 For some purposes it may be advisable to convert the skein breaking strength observed for yarn of one number to the estimated skein breaking strength of a different yarn number. Factors for making such a conversion for cotton yarns are given in 11.2. No corresponding factors have been developed for yarns spun from other fibers.5.6 The results obtained from different options are not fully comparable because the breaking force per wrap increases slightly as the perimeter of the skein is reduced. The skein breaking tenacity observed for 1 m skeins may be as much as 4 % higher, and from 1-yd skeins 5 % higher, than that observed for 1.5-yd skeins. These relationships may vary with the type of yarn or with yarn unevenness and should not be used as conversion factors. With a reasonable number of specimens, this method provides a useful index that combines the effects of unevenness and single strand strength.5.7 This method is rarely, if ever, used for filament yarns because their uniformity makes it possible to obtain reliable results economically by the single-strand method.1.1 This test method covers the determination of the breaking strength of yarn in skein form. The observed breaking strength is expressed in units of force, and equations are provided to convert breaking strength to skein breaking tenacity and to skein break factor.NOTE 1: For the determination of the breaking strength and elongation of yarn by the single strand method, refer to Test Method D2256.1.2 This test method is applicable to spun yarns, either single or plied, composed of any fiber or blend of fibers, but is not suitable for yarns which stretch more than 5 % when the tension is increased from 2.5 to 7.5 mN/tex or 0.03 to 0.08 gf/denier.1.3 This test method provides three options based on the perimeter of the reel, the number of wraps in the skein, and the machine speed or time-to-break.1.3.1 Option 1—Eighty, forty, or twenty turns on a 1.50 m or 1.5-yd reel, broken at 300 mm/min or 12 in./min.1.3.2 Option 2—Fifty turns on a 1.00 m or 1-yd reel, broken at 300 mm/min or 12 in./min.1.3.3 Option 3—Fifty turns on a 1 m reel, broken in 20 s.NOTE 2: Option 1 is in general use in the United States, Option 2 is used for woolen yarns, and Option 3 has been proposed in the International Standards Organization (ISO) for international use.NOTE 3: Metric reels are available with 1 and 1.125 m circumferences. Data from the two reels will be about 1 % different (see 5.6). ISO uses a 1 m circumference reel.1.4 This test method is frequently combined with the determination of linear density carried out on the same skeins. Special precautions for reeling such skeins are noted.1.5 Where appropriate, this test method states all requirements in SI units. The traditional units are inch-pound and are exact values.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.

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5.1 The grab method is applicable whenever it is desired to determine the “effective strength” of the fabric in use, that is, the strength of the material in a specific width, together with the additional strength contributed by adjacent material. There is no simple relationship between grab tests and strip tests since the amount of fabric assistance depends on the construction of the fabric. It is useful as a quality control or acceptance test.5.2 The procedure in Test Method D4632/D4632M for the determination of grab strength of geotextiles may be used for acceptance testing of commercial shipments, but caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.2.1 are advisable.5.2.1 In case of a dispute arising from differences in reported test results when using the procedures in Test Method D4632/D4632M for acceptance testing of commercial shipments, the purchaser and the manufacturer 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 homogeneous as possible and which 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 the appropriate Student's t-test and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be found and corrected or the purchaser and the manufacturer must agree to interpret future test results in the light of the known bias.5.3 Most geotextile fabrics can be tested by this test method. Some modification of clamping techniques may be necessary for a given fabric, depending upon its structure. Special adaptation may be necessary with strong fabrics, or fabrics made from glass fibers, to prevent them from slipping in the clamps or being damaged as a result of being gripped in the clamps, such as cushioning the clamp or boarding the specimen within the clamp.5.4 This test method is applicable for testing fabrics either dry or wet. It may be used with constant-rate-of-traverse (CRT) or constant-rate-of-extension (CRE) type tension machines. However, there may be no overall correlation between the results obtained with the CRT machine and the CRE machine. Consequently, these two tension testers cannot be used interchangeably. In case of controversy, the CRE machine shall prevail.1.1 This test method is an index test which provides a procedure for determining the breaking load (grab strength) and elongation (grab elongation) of geotextiles using the grab method. This test method is not suitable for knitted fabrics and alternate test methods should be used. While useful for quality control and acceptance testing for a specific fabric structure, the results can only be used comparatively between fabrics with very similar structures because each different fabric structure performs in a unique and characteristic manner in this test. The grab test method does not provide all the information needed for all design applications and other test methods should be used.1.2 Procedures for measuring the breaking load and elongation by the grab method in both the dry and wet state are included; however, testing is normally done in the dry condition unless specified otherwise in an agreement or specification.1.3 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.1.4 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.1.5 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.

定价: 590元 / 折扣价: 502 加购物车

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