定价： 481元 / 折扣价： 409 元

定价： 260元 / 折扣价： 221 元 加购物车

This specification covers rigid closed-cell polyurethane and polyisocyanurate thermal insulation foams for application in sandwich structural panel cores used in shelter construction for exposure to specified ambient temperatures. The unfaced foam thermal insulation boards are classified into three types (Types 1, 2, 3, and 4) according to increasing nominal density. The morphology of the insulation shall consist of a multitude of individual cells of uniform size and dimension, essentially closed off from each other, homogeneous throughout, free of voids, accumulations of unexpanded material, foreign inclusions, or seams. Upon undergoing appropriate acceptance tests, sampled specimens should adhere accordingly to the limiting values set for the following physical and mechanical properties: density; thermal conductivity; compressive strength; shear strength; percent closed cell; linear and volumetric dimensional stability; flame resistance (extinguish time and burn distance); and impact resistance.1.1 This specification covers rigid, closed cell, polyurethane and polyisocyanurate thermal insulation for sandwich panels used in shelter construction for exposure to ambient temperatures of −25 to 160 °F (−32 to 71 °C). Painted surfaces of shelters in actual field use reach temperatures of 200 °F (93 °C). The materials in this specification must be capable of withstanding processing, (laminating) temperatures of 230 °F (110 °C).1.2 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.1.3 The following precautionary caveat pertains only to the test method portion, Section 12, of this specification: 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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This test method is used to determine the compliance of concrete construction with design specifications and is commonly used in determining the thickness of pavements and other slab construction. This test method requires that at least one end of the core be a finished or formed surface.1.1 This test method covers the determination of the thickness of a concrete pavement, slab, or structural element using drilling cores.1.2 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 shall be used independently of the other.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 and health 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.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 Certain sandwich panel analyses require the Poisson's ratio of the honeycomb core. It is not possible to measure the honeycomb's Poisson's ratio by conventional methods.5.2 This test method provides a standard method of determining the Poisson’s ratio of honeycomb core materials for design properties, material specifications, research and development applications, and quality assurance.5.3 Factors that influence the Poisson’s ratio of honeycomb core materials and shall therefore be reported include the following: core material, methods of material fabrication, core geometry, core thickness, core thickness uniformity, cell wall thickness, specimen geometry, specimen preparation, and specimen conditioning.1.1 This test method covers the determination of the sandwich honeycomb core Poisson's ratio from the anticlastic curvature radii; see Fig. 1.FIG. 1 Anticlastic Curvature1.2 Units—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.1.2.1 Within the text, the inch-pound units are shown in brackets.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.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 Flatwise compressive strength and modulus are fundamental mechanical properties of sandwich cores that are used in designing sandwich panels. Deformation data can be obtained, and from a complete force versus deformation curve, it is possible to compute the compressive stress at any applied force (such as compressive stress at proportional limit force or compressive strength at the maximum force) and to compute the effective modulus of the core.5.2 This test method provides a standard method of obtaining the flatwise compressive strength and modulus for sandwich core structural design properties, material specifications, research and development applications, and quality assurance.5.3 In order to prevent local crushing of some honeycomb cores, it is often desirable to stabilize the facing plane surfaces with a suitable material, such as a thin layer of resin or thin facings. Flatwise compressive strength data may be generated using either stabilized specimens (reported as stabilized compression strength) or non-stabilized specimens (reported as bare compression strength). It is customary aerospace industry practice to determine compression modulus only when using stabilized specimens.5.4 Factors that influence the flatwise compressive strength and shall therefore be reported include the following: core material, methods of material fabrication, core geometry (cell size), core density, specimen geometry, specimen preparation, specimen conditioning, environment of testing, specimen alignment, loading procedure, and speed of testing.1.1 This test method covers the determination of compressive strength and modulus of sandwich cores. These properties are usually determined for design purposes in a direction normal to the plane of the face sheets (also referred to as the facing plane) as the core would be placed in a structural sandwich construction. The test procedures pertain to compression in this direction in particular, but also can be applied with possible minor variations to determining compressive properties in other directions. Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as honeycomb).1.2 This test method does not cover the determination of compressive core crush properties. Reference Test Method D7336/D7336M for determination of static energy absorption properties of honeycomb sandwich core materials.1.3 Units—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.1.3.1 Within the text, the inch-pound units are shown in brackets.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 元 加购物车

5.1 Normally, a close tolerance is desirable for core thickness so that sandwich panels may be manufactured with all the sandwich components fitting properly and without crushing the core.5.2 These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensions of core specimens for other tests.5.3 These test methods provide standard methods of obtaining the core thickness of flat sandwich core materials, and provide a basis for determining average thickness dimensions. The thickness properties derived may be used in design properties, material specifications, research and development applications, and quality assurance.5.4 Factors that influence core thickness measurement and shall therefore be reported include the following: core material through-thickness rigidity, surface roughness, specimen geometry (including warpage), specimen preparation, methods of dimensional measurement, specimen conditioning, and moisture content during dimensional measurements.1.1 These test methods cover plant manufacturing procedures for measuring the thickness of flat sandwich cores. Permissible core material forms include those with continuous bonding surfaces (such as balsa wood and foams) as well as those with discontinuous bonding surfaces (such as honeycomb). The two test methods covered include the following:1.1.1 Test Method A—Roller-Type Thickness Tester.1.1.2 Test Method B—Disk-Type Thickness Tester.NOTE 1: These test methods are designed for measuring thickness of core as it is produced and are not intended for use in determining dimensions of core specimens for other tests.1.2 Units—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.1.2.1 Within the text, the inch-pound units are shown in brackets.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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This practice does not rely on absolute quantities of AE parameters. It relies on trends of cumulative AE counts that are measured during a specified sequence of loading cycles. This practice includes an example of examination settings and acceptance criteria as a nonmandatory appendix.FIG. 1 Recommended Features of the Apparatus4.2 Acoustic emission (AE) counts were used as a measure of AE activity during development of this practice. Cumulative hit duration may be used instead of cumulative counts if a correlation between the two is determined. Several processes can occur within the structure under examination. Some may indicate unacceptable flaws (for example, growing resin cracks, fiber fracture, delamination). Others may produce AE but have no structural significance (for example, rubbing at interfaces). The methodology described in this practice prevents contamination of structurally significant data with emission from insignificant sources.4.3 Background Noise—Background noise can distort interpretations of AE data and can preclude completion of an examination. Examination personnel should be aware of sources of background noise at the time examinations are conducted. AE examinations should not be conducted until such noise is substantially eliminated.4.4 Mechanical Background Noise—Mechanical background noise is generally induced by structural contact with the container under examination. Examples are: personnel contact, wind borne sand or rain. Also, leaks at pipe connections may produce background noise.4.5 Electronic Noise—Electronic noise such as electromagnetic interference (EMI) and radio frequency interference (RFI) can be caused by electric motors, overhead cranes, electrical storms, welders, etc.4.6 Airborne Background Noise—Airborne background noise can be produced by gas leaks in nearby equipment.4.7 Accuracy of the results from this practice can be influenced by factors related to setup and calibration of instrumentation, background noise, material properties, and structural characteristics.1.1 This practice covers guidelines for acoustic emission (AE) examinations of pressurized containers made of fiberglass reinforced plastic (FRP) with balsa cores. Containers of this type are commonly used on tank trailers for the transport of hazardous chemicals.1.2 This practice is limited to cylindrical shape containers, 0.5 m [20 in.] to 3 m [120 in.] in diameter, of sandwich construction with balsa wood core and over 30 % glass (by weight) FRP skins. Reinforcing material may be mat, roving, cloth, unidirectional layers, or a combination thereof. There is no restriction with regard to fabrication technique or method of design.1.3 This practice is limited to containers that are designed for less than 0.520 MPa [75.4 psi] (gage) above static pressure head due to contents.1.4 This practice does not specify a time interval between examinations for re-qualification of a pressure container.1.5 This practice is used to determine if a container is suitable for service or if follow-up NDT is needed before that determination can be made.1.6 Containers that operate with a vacuum are not within the scope of this practice.1.7 Repair procedures are not within the scope of this practice.1.8 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.9 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. Specific precautionary statements are given in Section 8.1.10 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 元 加购物车

3.1 This test method provides standardized procedures for obtaining and testing specimens to determine the compressive, splitting tensile, and flexural strength of in-place concrete.3.2 Generally, test specimens are obtained when doubt exists about the in-place concrete quality due either to low strength test results during construction or signs of distress in the structure. Another use of this method is to provide strength information on older structures.3.3 Concrete strength is affected by the location of the concrete in a structural element, with the concrete at the bottom tending to be stronger than the concrete at the top. Core strength is also affected by core orientation relative to the horizontal plane of the concrete as placed, with strength tending to be lower when measured parallel to the horizontal plane.3 These factors shall be considered in planning the locations for obtaining concrete samples and in comparing strength test results.3.4 The strength of concrete measured by tests of cores is affected by the amount and distribution of moisture in the specimen at the time of test. There is no standard procedure to condition a specimen that will ensure that, at the time of test, it will be in the identical moisture condition as concrete in the structure. The moisture conditioning procedures in this test method are intended to provide reproducible moisture conditions that minimize within-laboratory and between-laboratory variations and to reduce the effects of moisture introduced during specimen preparation.3.5 The measured compressive strength of a core will generally be less than that of a corresponding properly molded and cured standard cylinder tested at the same age. For a given concrete, however, there is no unique relationship between the strengths of these two types of specimens (see Note 3). The relationship is affected by many factors such as the strength level of the concrete, the in-place temperature and moisture histories, the degree of consolidation, batch-to-batch variability, the strength-gain characteristics of the concrete, the condition of the coring apparatus, and the care used in removing cores.NOTE 3: A procedure is available for estimating the equivalent cylinder strength from a measured core strength.4NOTE 4: In the absence of core strength requirements of an applicable building code or of other contractual or legal documents that may govern the project, the specifier of tests should establish in the project specifications the acceptance criteria for core strengths. An example of acceptance criteria for core strength is provided in ACI 318,5 which are used to evaluate cores taken to investigate low strength test results of standard-cured cylinder during construction. According to ACI 318, the concrete represented by the cores is considered structurally adequate if the average strength of three cores is at least 85 % of the specified strength and no single core strength is less than 75 % of the specified strength.3.6 The “specifier of the tests” referenced in this test method is the individual responsible for analysis or review and acceptance of core test results.NOTE 5: For investigation of low strength test results, ACI 318-14 defines the specifier of the tests as the licensed design professional or building official.3.7 The apparent compressive strength of concrete as measured by a core is affected by the length-diameter ratio (L/D) of the core as tested and this must be considered in preparing core specimens and evaluating test results.1.1 This test method covers obtaining, preparing, and testing cores drilled from concrete for length or compressive strength or splitting tensile strength determinations. This test method is not applicable to cores from shotcrete.NOTE 1: Test Method C1604/C1604M is applicable for obtaining, preparing, and testing cores from shotcrete.NOTE 2: Appendix X1 provides recommendations for obtaining and testing sawed beams for flexural performance.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of 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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 This test method provides two procedures for determining the length of a core obtained in accordance with either Test Method C42/C42M or Test Method C1604/C1604M. This length is used in conjunction with condition surveys, density and voids analysis, and other applications.4.2 This procedure does not intend to include in the length measurement adhered particles not part of the concrete mixture.4.3 Test Method C174/C174M also determines the length of concrete cores using a different measuring apparatus and procedure.NOTE 1: Test Method C174/C174M uses an apparatus that establishes two parallel planes a known distance apart. The length of the core is determined by calculation using the known distance between the two parallel planes and the measured distance from the upper plane to the top of the core.1.1 This test method is used to determine the length of a core drilled from concrete.1.2 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.1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this 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.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 The method of excitation simulates, to a practical degree, the operation of a magnetic core in a self-saturating magnetic amplifier. The properties measured are related to the quality of performance of the cores in magnetic amplifiers and are useful for the specification of materials for such cores.1.1 This test method covers the determination of the magnetic performance of fully processed cores for magnetic amplifier-type applications.1.2 Tests may be conducted at excitation frequencies of 60 Hz, 400 Hz, 1600 Hz, or higher frequencies.1.3 Permissible core sizes for this test method are limited only by the available power supplies and the range and sensitivity of the instrumentation.1.4 At specified values of full-wave sinusoidal-current excitation, Hmax, this test method provides procedures of determining the corresponding value of maximum induction, Bmax.1.5 At specified values of half-wave sinusoidal-current excitation, this test method provides procedures for determining the residual induction, Br.1.6 At increased specified values of half-wave sinusoidal-current excitation, this test method provides procedures for determining the dc reverse biasing magnetic field strength, H1, required to reset the induction in the core material past Br to a value where the total induction change, ΔB1, becomes approximately one third of the induction change, 2 Bp. It also provides procedures for determining the additional dc reset magnetic field strength, ΔH, which, combined with H1, is the value required to reset the induction in the core material past Br to a value where the total induction change, ΔB2, becomes approximately two thirds of the induction change 2 Bp.1.7 This test method specifies procedures for determining core gain from the corresponding biasing and induction changes, ΔH and ΔB.1.8 This test method covers test procedures and requirements for evaluation of finished cores which are to be used in magnetic-amplifier-type applications. It is not a test for basic-material magnetic properties.1.9 This test method shall be used in conjunction with Practice A34/A34M.1.10 Explanations of symbols and abbreviated definitions appear in the text of this test method. The official symbols and definitions are listed in Terminology A340.1.11 The values and equations stated in customary (cgs-emu and inch-pound) or SI units are to be regarded separately as standard. Within this test method, SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with this test method.1.12 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.1.13 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： 646元 / 折扣价： 550 元 加购物车

4.1 This test method provides standardized procedures for obtaining cored specimens to determine the compressive strength and splitting tensile strength of shotcrete during pre-construction, during construction, and from older shotcrete structures.4.2 Generally, test specimens are obtained in situ when doubt exists about the in-place shotcrete quality due either to low strength test results during construction or signs of distress in the structure. Other uses of this method are to provide specimens for acceptance testing, construction control and to assess the condition, quality and uniformity of the shotcrete in accordance with Practice C823/C823M (see Note 1).4.3 Specimens obtained by this method are used to verify the thickness of shotcrete and aid in the visual assessment of the shotcrete quality, workmanship, defects, shotcrete-to-substrate bond and the condition of any reinforcement used in the shotcrete.44.4 Shotcrete strength is affected by the location of the shotcrete in a structure. Vertical, sub-horizontal and overhead elements of the shotcrete structure may show variability. Core strength is affected by core orientation relative to direction of shotcrete application. These factors shall be considered in planning the locations for obtaining shotcrete samples and in interpreting strength test results.4.5 Shotcrete is applied in single or multiple layers, as plain shotcrete, reinforced shotcrete, or fiber-reinforced shotcrete. Core samples containing wire-mesh and reinforcing bars shall not be used for compressive strength testing.4.6 The strength of shotcrete is affected by moisture content, the specified moisture conditioning procedure for cores is intended to provide test specimens with reproducible moisture contents that minimize within-laboratory and between-laboratory variations.4.7 Sample acquisition may require a combination of core-drilling, sawing, and grinding that may have the potential to adversely affect the sample condition if care is not taken during sampling and testing.4.8 A sampling plan shall be established that indicates the number of samples and their locations (see Note 1). The acceptance criteria for shotcrete core strengths shall be established by the specifier of tests (see Note 2).NOTE 1: Practice C823/C823M provides guidance on the development of a sampling plan for concrete in constructions. A number of methods that supplement the examination of hardened shotcrete by means of representative core samples and testing are discussed in ACI 506.4R.NOTE 2: The core strength acceptance criteria cited in ACI 318 are based on a comparison of molded cylinder specimens and cores. Shotcrete strengths are always based on core specimens, therefore the 85 % factor used in core to cylinder comparisons is not relevant to the evaluation of shotcrete core strengths. A typical shotcrete specification reflecting standard industry practice is contained in ACI 506.2.1.1 This test method covers obtaining, preparing, and testing cores drilled from shotcrete for length, compressive strength, or splitting tensile strength determinations.1.2 The values stated in either inch-pound units or SI units shall be regarded separately as standard. SI units are shown in brackets. The values stated in each system may not be 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.1.3 The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of 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.

定价： 590元 / 折扣价： 502 元 加购物车