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5.1 This method for investigating creep rupture of FRP bars is intended for use in laboratory tests in which the principal variable is the size or type of FRP bars, magnitude of applied force, and duration of force application. Unlike steel reinforcing bars or prestressing tendons subjected to significant sustained stress, creep rupture of FRP bars may take place below the static tensile strength. Therefore, the creep rupture strength is an important factor when determining acceptable stress levels in FRP bars used as reinforcement or tendons in concrete members designed to resist sustained loads. Creep rupture strength varies according to the type of FRP bars used.5.2 This test method measures the creep rupture time of FRP bars under a given set of controlled environmental conditions and force ratios.5.3 This test method is intended to determine the creep rupture data for material specifications, research and development, quality assurance, and structural design and analysis. The primary test result is the million-hour creep rupture capacity of the specimen.5.4 Creep properties of reinforced, post-tensioned, or prestressed concrete structures are important to be considered in design. For FRP bars used as reinforcing bars or tendons, the creep rupture shall be measured according to the method given herein.1.1 This test method outlines requirements for tensile creep rupture testing of fiber reinforced polymer matrix (FRP) composite bars commonly used as tensile elements in reinforced, prestressed, or post-tensioned concrete.1.2 Data obtained from this test method are used in design of FRP reinforcements under sustained loading. The procedure for calculating the one-million hour creep-rupture capacity is provided in Annex A1.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.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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定价： 515元 / 折扣价： 438 元 加购物车

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定价： 515元 / 折扣价： 438 元 加购物车

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定价： 515元 / 折扣价： 438 元 加购物车

5.1 This test method is developed for use in the determination of anticipated total elongation over time or time to rupture that may occur in geosynthetics under sustained loading conditions.5.1.1 The test data can be used in conjunction with interpretive methods to determine creep strain potential at design loads.5.1.2 The test data can be used in conjunction with interpretive methods to determine creep rupture potential at various loads.5.2 This test method is not intended for routine acceptance testing of geosynthetics. This test method should be used to characterize geosynthetics intended for use in reinforcement applications in which creep or creep rupture is of concern. The plane strain or rupture condition imposed during testing must be considered when using the test results for design.5.3 The basic distinctions between this test method and other test methods for measuring tension creep and creep rupture behavior are: (1) the width of the specimens (Section 8), and (2) the measurement of total elongation over time or time to rupture from the moment of specimen loading. The greater widths of the specimens specified in this test method minimize the contraction edge effect (necking) that occurs in many geosynthetic materials and provides a closer relationship to actual material behavior in plane strain tension conditions.5.4 The creep or stress rupture of a given geosynthetic is likely to be reduced in soil because of confining stresses and load transfer to the soil. The unconfined environment represents a controlled test in which the results are conservative with regard to the behavior of the material in service. Confined or in-soil testing may model the field behavior of the geosynthetic more accurately.1.1 This test method is intended for use in determining the unconfined tension creep and creep rupture behavior of geosynthetics at constant temperature when subjected to a sustained tensile loading. This test method is applicable to all geosynthetics.1.2 The test method measures total elongation of the geosynthetic test specimen, from the time of loading, while being maintained at a constant temperature. It includes procedures for measuring the tension creep and creep rupture behavior at constant temperature of conditioned unconfined geosynthetics as well as directions for calculating tension forces to plot creep and creep rupture curves.1.3 The values stated in SI units are to be regarded as the 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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定价： 515元 / 折扣价： 438 元 加购物车

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4.1 This test method may be used for material development, material comparison, quality assurance, characterization, and design data generation.4.2 Continuous fiber-reinforced ceramic matrix composites are candidate materials for structural applications requiring high degrees of wear and corrosion resistance and toughness at high temperatures.4.3 Creep tests measure the time-dependent deformation of a material under constant load at a given temperature. Creep rupture tests provide a measure of the life of the material when subjected to constant mechanical loading at elevated temperatures. In selecting materials and designing parts for service at elevated temperatures, the type of test data used will depend on the criteria for load-carrying capability which best defines the service usefulness of the material.4.4 Creep and creep rupture tests provide information on the time-dependent deformation and on the time-of-failure of materials subjected to uniaxial tensile stresses at elevated temperatures. Uniform stress states are required to effectively evaluate any nonlinear stress-strain behavior which may develop as the result of cumulative damage processes (for example, matrix cracking, matrix/fiber debonding, fiber fracture, delamination, etc.) which may be influenced by test mode, test rate, processing or alloying effects, environmental influences, or elevated temperatures. Some of these effects may be consequences of stress corrosion or subcritical (slow) crack growth. It is noted that ceramic materials typically creep more rapidly in tension than in compression. Therefore, creep data for design and life prediction should be obtained in both tension and compression.4.5 The results of tensile creep and tensile creep rupture tests of specimens fabricated to standardized dimensions from a particular material or selected portions of a part, or both, may not totally represent the creep deformation and creep rupture properties of the entire, full-size end product or its in-service behavior in different environments or at various elevated temperatures.4.6 For quality control purposes, results derived from standardized tensile test specimens may be considered indicative of the response of the material from which they were taken for given primary processing conditions and post-processing heat treatments.1.1 This test method covers the determination of the time-dependent deformation and time-to-rupture of continuous fiber-reinforced ceramic composites under constant tensile loading at elevated temperatures. This test method addresses, but is not restricted to, various suggested test specimen geometries. In addition, test specimen fabrication methods, allowable bending, temperature measurements, temperature control, data collection, and reporting procedures are addressed.1.2 This test method is intended primarily for use with all advanced ceramic matrix composites with continuous fiber reinforcement: unidirectional (1-D), bidirectional (2-D), and tridirectional (3-D). In addition, this test method may also be used with glass matrix composites with 1-D, 2-D, and 3-D continuous fiber reinforcement. This test method does not address directly discontinuous fiber-reinforced, whisker-reinforced, or particulate-reinforced ceramics, although the test methods detailed here may be equally applicable to these composites.1.3 Values expressed in this test method are in accordance with the International System of Units (SI) and IEEE/ASTM SI 10.1.4 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 and health practices and determine the applicability of regulatory limitations prior to use. Hazard statements are noted in 7.1 and 7.2.

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5.1 Use of the Stepped Isothermal Method decreases the time required for creep to occur and the obtaining of the associated data.5.2 The statements set forth in 1.6 are very important in the context of significance and use, as well as scope of the standard.5.3 Creep test data are used to calculate the creep modulus of materials as a function of time. These data are then used to predict the long-term creep deformation expected of geosynthetics used in reinforcement applications.NOTE 1: Currently, SIM testing has focused mainly on woven and knitted geogrids and woven geotextiles made from polyester, aramid, polyaramid, poly-vinyl alcohol (PVA), and polypropylene yarns and narrow strips. Additional correlation studies on other materials are needed.5.4 Creep-rupture test data are used to develop a regression line relating creep stress to rupture time. These results predict the long-term rupture strength expected for geosynthetics in reinforcement applications.5.5 Tensile testing is used to establish the ultimate tensile strength (TULT) of a material and to determine elastic stress, strain, and variations thereof for SIM tests.5.6 Ramp and Hold (R+H) testing is done to establish the range of creep strains experienced in the brief period of very rapid response following the peak of the load ramp.1.1 This test method covers accelerated testing for tensile creep, and tensile creep-rupture properties using the Stepped Isothermal Method (SIM).1.2 The test method is focused on geosynthetic reinforcement materials such as yarns, ribs of geogrids, or narrow geotextile specimens.1.3 The SIM tests are laterally unconfined tests based on time-temperature superposition procedures.1.4 Tensile tests are to be completed before SIM tests and the results are used to determine the stress levels for subsequent SIM tests defined in terms of the percentage of Ultimate Tensile Strength (TULT). Additionally, the tensile test can be designed to provide estimates of the initial elastic strain distributions appropriate for the SIM results.1.5 Ramp and Hold (R+H) tests may be completed in conjunction with SIM tests. They are designed to provide additional estimates of the initial elastic and initial rapid creep strain levels appropriate for the SIM results.1.6 This method can be used to establish the sustained load creep and creep-rupture characteristics of a geosynthetic. Results of this method are to be used to augment results of Test Method D5262 and may not be used as the sole basis for determination of long-term creep and creep-rupture behavior of geosynthetic material.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 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.1.9 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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3.1 The cold strength of a refractory material is an indication of its suitability for use in refractory construction. (It is not a measure of performance at elevated temperatures.)3.2 These test methods are for determining the room temperature flexural strength in three-point bending (cold modulus of rupture) or compressive strength (cold crushing strength), or both, for all refractory products.3.3 Considerable care must be used to compare the results of different determinations of the cold crushing strength or modulus of rupture. The specimen size and shape, the nature of the specimen faces (that is, as-formed, sawed, or ground), the orientation of those faces during testing, the loading geometry, and the rate of load application may all significantly affect the numerical results obtained. Comparisons of the results between different determinations should not be made if one or more of these parameters differ between the two determinations.3.4 The relative ratio of the largest grain size to the smallest specimen dimension may significantly affect the numerical results. For example, smaller cut specimens containing large grains may present different results than the bricks from which they were cut. Under no circumstances should 6 by 1 by 1-in. (152 by 25 by 25-mm) specimens be prepared and tested for materials containing grains with a maximum grain dimension exceeding 0.25 in. (6.4 mm).3.5 This test method is useful for research and development, engineering application and design, manufacturing process control, and for developing purchasing specifications.1.1 These test methods cover the determination of the cold crushing strength and the modulus of rupture (MOR) of dried or fired refractory shapes of all types.1.2 The test methods appear in the following sections:    Test Method Sections     Cold Crushing Strength 4 to 9  Modulus of Rupture 10 to 151.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.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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4.1 For the purpose of this test, glasses and glass-ceramics are considered brittle (perfectly elastic) and to have the property that fracture normally occurs at the surface of the test specimen from the principal tensile stress. The flexural strength is considered a valid measure of the tensile strength subject to the considerations that follow.4.2 The flexural strength for a group of test specimens is influenced by variables associated with the test procedure. Such factors are specified in the test procedure or required to be stated in the report. These include but are not limited to the rate of stressing, the test environment, and the area of the specimen subjected to stress.4.2.1 In addition, the variables having the greatest effect on the flexural strength value for a group of test specimens are the condition of the surfaces and glass quality near the surfaces in regard to the number and severity of stress-concentrating discontinuities or flaws, and the degree of prestress existing in the specimens. Each of these can represent an inherent part of the strength characteristic being determined or can be a random interfering factor in the measurement.4.2.2 Test Method A is designed to include the condition of the surface of the specimen as a factor in the measured strength. Therefore, subjecting a fixed and significant area of the surface to the maximum tensile stress is desirable. Since the number and severity of surface flaws in glass are primarily determined by manufacturing and handling processes, this test method is limited to products from which specimens of suitable size can be obtained with minimal dependence of measured strength upon specimen preparation techniques. This test method is therefore designated as a test for flexural strength of flat glass.4.2.3 Test Method B describes a general procedure for test, applicable to specimens of rectangular or elliptical cross section. This test method is based on the assumption that a comparative measurement of strength on groups of specimens is of significance for many purposes such as: determining the effect of environment or stress duration, the effectiveness of varied prestressing techniques, and strengths characteristic of glass-ceramics of differing composition or heat treatment. In this test method, the surfaces of the specimens are not assumed to be characteristic of a product or material, but are considered to be determined by the procedures used to prepare the specimens. Though the stated procedure permits a wide variation in both specimen size and test geometry, use of identical test conditions and equivalent procedures for specimen preparation is necessary to obtain comparable strength values. The use of a controlled abrasion of the specimen as a final normalizing procedure is recommended for such comparative tests.4.2.4 A comparative abraded strength, determined as suggested in Test Method B, is not to be considered as a minimum value characteristic of the material tested nor as directly related to a maximum attainable strength value through test of specimens with identical flaws. The operationally defined abrasion procedure undoubtedly produces flaws of differing severity when applied to varied materials, and the measured comparative strengths describe the relative ability to withstand externally induced stress as affected by the specific abrasion procedure.4.2.5 Test environment (ambient air, inert gas, vacuum, etc.) including moisture content (for example, relative humidity) may have an influence on the flexural strength. Testing to evaluate the maximum strength potential of a glass can be conducted in inert environments and/or at sufficiently rapid testing rates to minimize any environmental effects. Conversely, testing can be conducted in environments, test modes, and test rates representative of service conditions to evaluate flexural performance under use conditions.1.1 These test methods cover the determination of the flexural strength (the modulus of rupture in bending) of glass and glass-ceramics.1.2 These test methods are applicable to annealed and prestressed glasses and glass-ceramics available in varied forms. Alternative test methods are described; the test method used shall be determined by the purpose of the test and geometric characteristics of specimens representative of the material.1.2.1 Test Method A is a test for flexural strength of flat glass.1.2.2 Test Method B is a comparative test for flexural strength of glass and glass-ceramics.1.3 The test methods appear in the following order:  SectionsTest Method A 7 to 10Test Method B 11 to 161.4 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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