定价： 481元 / 折扣价： 409 元 加购物车

定价： 345元 / 折扣价： 294 元

定价： 260元 / 折扣价： 221 元

定价： 345元 / 折扣价： 294 元

定价： 260元 / 折扣价： 221 元

定价： 260元 / 折扣价： 221 元

定价： 345元 / 折扣价： 294 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 260元 / 折扣价： 221 元 加购物车

定价： 156元 / 折扣价： 133 元 加购物车

5.1 Bend tests for ductility provide a simple way to evaluate the quality of materials by their ability to resist cracking or other surface irregularities during one continuous bend. No reversal of the bend force shall be employed when conducting these tests.5.2 The type of bend test used determines the location of the forces and constraints on the bent portion of the specimen, ranging from no direct contact to continuous contact.5.3 The test can terminate at a given angle of bend over a specified radius of bend or continue until the specimen legs are in contact. The angle of bend can be measured while the specimen is under the bending force (usually when the semi-guided bend test is employed), or after removal of the force as when performing a free-bend test. Product requirements for the material being tested determine the method used.5.4 Materials with an as-fabricated cross section of rectangular, round, hexagonal, or similar defined shape can be tested in full section to evaluate their bend properties by using the procedures outlined in these test methods, in which case relative width and thickness requirements do not apply.1.1 These test methods cover bend testing for ductility of materials. Included in the procedures are four conditions of constraint on the bent portion of the specimen; a guided-bend test using a mandrel or plunger of defined dimensions to force the mid-length of the specimen between two supports separated by a defined space; a semi-guided bend test in which the specimen is bent, while in contact with a mandrel, through a specified angle of bend or to a specified inside radius of bend (r) measured while under the bending force; a free-bend test in which the ends of the specimen are brought toward each other, but in which no transverse force is applied to the bend itself and there is no contact of the concave inside surface of the bend with other material; a bend-and-flatten test, in which a transverse force is applied to the bend such that the legs make contact with each other over the length of the specimen.1.2 After bending, the convex surface of the bend is examined for evidence of a crack or surface irregularities. If the specimen fractures, the material has failed the test. When complete fracture does not occur, the criterion for failure is the number and size of cracks or surface irregularities visible to the unaided eye occurring on the convex surface of the specimen after bending, as specified by the product specification. Any cracks within one thickness of the edge of the specimen are not considered a bend test failure. Cracks occurring in the corners of the bent portion shall not be considered significant unless they exceed the size specified for corner cracks in the product specification.1.3 The values stated in SI units are to be regarded as standard. Inch-pound values given in parentheses were used in establishing test parameters and 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.

定价： 646元 / 折扣价： 550 元 加购物车

5.1 This test method is intended to determine the bend strength of FRP composite concrete reinforcements, developed at a standard twelve bar diameters of embedment. From this test, a variety of data are acquired that are needed for design purposes. Material-related factors that influence the tensile response of bars include the following: constituent materials, void content, volume percent reinforcement, methods of fabrication, and fiber reinforcement architecture. Similarly, factors relevant to the measured tensile response of bars include specimen preparation, specimen conditioning, environment of testing, specimen alignment, and speed of testing. The results may be used for material specifications, research and development, and structural design and analysis.NOTE 1: Two FRP bends are tested simultaneously in this test method, but in some cases, only one bend may fail. While resulting in a valid failure, notice should be taken that only one bend has been effectively measured and that the final compiled test results using this method could differ from those resulting from single FRP bend testing.1.1 This test method determines the quasi-static ultimate strength of fiber reinforced polymer (FRP) composite bent bars commonly used as anchorages for stirrups in reinforced, prestressed, or post-tensioned concrete structures. This test method only applies to bars with a solid cross section.1.2 FRP bent bars are often used in reinforced concrete applications to shorten the development length of the bar or to act as a tie or a stirrup to resist shear forces. Bent bars can be produced with varying angles of bend in order to fit their intended purpose.1.3 For this test method, the FRP bars are bent at a 90 degree angle. In general, bars have a regular pattern of surface undulations, a coating of bonded particles, or both, that promote mechanical interlock between the bar and concrete.1.4 This test method may be completed on standardized bars, produced according to Specification D7957/D7957M. In this case, the nominal cross-sectional areas and effective diameters are taken from D7957/D7957M. This test method may also be used for bars that are not standardized. In this case, the cross-sectional areas and effective diameters should be measured and calculated as described in Test Method D7205/D7205M.1.5 The strength values provided by this method are short-term, quasi-static tensile strengths that do not account for sustained static or cyclic loading. If bars are to be used under high levels of sustained or repeated loading, additional material characterization may be required.1.6 The characteristic values obtained from this test method are intended to represent the quasi-static ultimate strength of FRP bent bars with a tail length of twelve bar diameters.1.7 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.1.7.1 Within the text, the inch-pound units are shown in brackets.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.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This standard practice is a procedure to evaluate the ductility of side bend test specimens that are a transverse section of the pipe wall and butt fusion. Side bend test specimens are prepared from bend test coupons from sample polyethylene pipe butt fusion joints that are made using polyethylene pipe having a wall thickness of approximately 1 in. (25 mm) and greater. A three-point bend is applied to the side bend test specimen by pressing the side bend test specimen into a gap between two rotatable supports with a loading nose. The bending load is applied such that the bending strain is transverse to the plane of the fusion joint.5.2 Equipment for cutting bend test coupons, preparing side bend test specimens and conducting this practice is available for laboratory and for field use.5.3 Benchmark criteria for evaluating field testing results are developed by testing a statistically valid number of sample butt fusions in a controlled environment, preferably using equipment for field use. Guided side bend test results from field tests are then evaluated by comparison to benchmark test results from the controlled environment.1.1 This practice provides information on apparatus, specimen preparation and procedure for conducting a guided three point side bend evaluation of a transverse specimen cut from a coupon removed from a butt fusion joint in polyethylene pipe having a wall thickness of approximately 1 in. (25 mm) and thicker. See Fig. 1. This practice provides a means to assess ductility of a butt fusion joint by applying a lateral (side) bending strain across a specimen taken from the full butt fusion cross-section, from outside diameter to inside diameter.NOTE 1: For wall thicknesses less than 1 in. the user is referred to Practice F2620, Appendix X4.1 for bend back testing.FIG. 1 Guided Side Bend Conceptual Schematic1.2 No test values are provided by this practice. The result is a non-numerical report. Criteria for test result evaluation are provided in standards or codes that specify the use of this practice by comparison to benchmark laboratory results as described in 5.3 or by comparison to example results presented in Appendix X1 to this practice.1.3 Units—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.NOTE 2: Laboratory methods that are commonly used for testing polyethylene butt fusion joints include Test Method D638, Test Method D790 and Test Method F2634.NOTE 3: This practice has been developed for use on butt fusion joints in polyethylene pipe with a wall thickness of 1.00 in. or greater. The practice may be used on butt fusion joints in polyethylene pipe with thinner wall thicknesses. However, the applicability of the practice should be determined by the user of the practice.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： 646元 / 折扣价： 550 元 加购物车