AASHTO T 241-1995 Standard Method of Test for Helical Continuously Welded Seam Corrugated Steel Pipe《不断地焊接接缝波状钢管的标准测试方法》.pdf

1、Standard Method of Test for Helical Continuously Welded Seam Corrugated Steel Pipe AASHTO Designation: T 241-95 (2012) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4b T 241-1 AASHTO Standard Method of Test for H

2、elical Continuously Welded Seam Corrugated Steel Pipe AASHTO Designation: T 241-95 (2012) 1. SCOPE 1.1. This method describes the procedure to be used in determining the quality of the seam or helical, continuously welded seam, corrugated steel pipe. The procedure to be used involves distorting a sh

3、ort length of welded seam by using a 25-mm diameter, hemispherical punch and a 38-mm inside diameter contoured die. The resulting distorted weld area will hereafter be called the “cup.” 1.2. At the option of the engineer, or in the event of a disagreement between the engineer and fabricator, the ref

4、eree test described in Section 4 will be performed. 2. APPARATUS 2.1. DieA die having an inside diameter of 38 mm and machined to conform to the corrugation of the sample (see Figure 1). 2.2. PunchA punch consisting of a 25-mm steel ball attached to a section of 19-mm diameter steel rod (see Figure

5、1). 2.3. Bending Test DeviceBending jig with roller bending edges, adjustable supports, and 13-mm diameter mandrel (see Figure 2). 2.4. GaugeFigure 3 shows a gauge recommended for use in measuring various dimensions in connection with the cup test, and also for checking acceptable width of the area

6、burned by welding. It is used in the following manner: 2.4.1. The projections at the top of the gauge are dimensioned horizontally in accordance with the widths of burned area (three times thickness of metal) acceptable under the specification for each indicated gauge of metal. 2.4.2. The 76.2-mm ov

7、erall length dimension is used to check the positioning of the test. 2.4.3. When the gauge is positioned on the pipe so that the bottom legs straddle the convex side of the cup, the 10.31-mm projection should always touch the cup. The interval corresponds to the minimum allowable depth of the cup af

8、ter relaxation. 2.4.4. The 6.35-mm side projection can be used to check conformance to the limits set forth in Section 3.3. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 241-2 AASHTO Note: All

9、dimensions shown in millimeters unless otherwise noted. Figure 1Die and Punch for Cup Test Size Varies According to Bearing5719 Dia1319-mm Radius303825-DiaSteel Ball 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of appl

10、icable law.TS-4b T 241-3 AASHTO Note: All dimensions shown in millimeters unless otherwise noted. Figure 2Bend Test Apparatus 12.7 102-mmAllen Head Bolt12.7 51-mmBolt12.7-mmRollers9.5-mm AllenHead Bolts151.46.4-mm Plates2035112.712.72525383812.712.712.712.72576152516.4-mm RadiusSize Varies According

11、to Bearing Surface 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 241-4 AASHTO Note: All dimensions shown in millimeters unless otherwise noted. Figure 3Cup Gauge 2.5. Loading DeviceThe loading

12、device may be either a hydraulic or a screw-type testing machine with sufficient opening between the upper bearing surface and the lower bearing surface of the machine to permit the introduction of the specimen to be tested, or any suitable device that is capable of applying sufficient load to cause

13、 the die to penetrate the weld to the depth specified. 3. CUP TEST PROCEDURE 3.1. Position the punch on one side and center over the welded seam at the desired testing location. The direction of the cup shall be with the concavity of the corrugation. Tests shall be made not less than 75 mm from the

14、end of the pipe and the minimum distance between tests shall be 75 mm. 3.2. Center the punch opposite the die, on the other side of the pipe wall, and, using the loading device described in Section 2.5, force the punch into the weld to a nominal depth under load of 5 mm. The resulting cup after rela

15、xation must be at least 3 mm in depth. 3.3. For a length of a pipe to be acceptable, the sum of the lengths of cracks or other defects on either side of the cup shall be not more than 6 mm. 3.3.1. If the first cup indicates a failure, punch a second cup at another location on the weld not less than

16、76 mm or more than 300 mm from the first cup and in the direction of the center of the pipe. If this second cup test indicates a failure, the pipe shall be rejected. 3.4. ReportNo formal test report is necessary for the cup test. This test will be part of the routine quality control and inspection p

17、rocedure for acceptance of the pipe. 76.25.995.61 Typ. 12.80 10.52 8.264.853.188 10 12 14 163.183.186.356.3515.8825.4010.31 14.1538.6144.42.92Material2.38-mm Stainless Steel38 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violati

18、on of applicable law.TS-4b T 241-5 AASHTO 4. REFEREE TEST METHOD 4.1. The referee test consists of destructive tests requiring two 600-by-600-mm samples of pipe containing approximately 600-mm length of weld running through the center. No reformed corrugations will be allowed in the samples. 4.2. Ea

19、ch sample shall be cut into test specimens of the number and type shown in Table 1. Table 1Number and Type of Specimens Number of Test Specimens Required Type 3 Tensile test across the weld 3 Tensile test of the base metal above the weld 3 Tensile test of the base metal below the weld 3 Face bends 3

20、 Root bends 3 Cup test of the weld 3 Cup test of base metal 4.3. Tensile Test SpecimensThe tensile test specimens will be prepared in accordance with T 244, Figure 3. The grip of each specimen area will be flattened with care to prevent damage to the welds. The ultimate strength of the across-the-we

21、ld test specimens shall be equal to 90 percent of the ultimate strength of the lowest base metal test specimen. 4.4. In determining the mechanical properties, the base metal thickness of the specimen shall be measured after stripping the coating from the ends of the specimen contacting the grips of

22、the testing machine, before testing. 4.5. Bend TestAll face and root bend specimens shall have a 5.0-mm gauge length on their appropriate sides across the weld area. The face bend specimen corrugations shall be flattened before testing. The test shall be performed by centering the weld on a 13-mm ma

23、ndrel and bending the specimen 180 degrees. The root bend test shall be performed by forcing the corrugated specimen to a flat position. Any visible cracks in the weld resulting from the bend tests will be cause for rejection. The data resulting from the bend tests shall be the percent elongation of

24、 the gauge length. 4.5.1. Bend Test SpecimenThe bend specimens shall be 150 mm long and 25 mm wide cut across the welded seam. 4.6. ReportThe following elements are essential in reporting results of referee tests: 4.6.1. Ultimate strength of base metal and weld specimens, 4.6.2. Percentage of ultima

25、te strength of weld metal compared with lowest ultimate strength of base metal, 4.6.3. Results of bend tests, 4.6.4. Results of cup tests of both the weld and base metal, and 4.6.5. Evaluation of test data. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.