1、Standard Method of Test for Determination of Compression Capacity for Profile Wall Plastic Pipe by Stub Compression Loading AASHTO Designation: T 341-10 (2014) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4b T 3
2、41-1 AASHTO Standard Method of Test for Determination of Compression Capacity for Profile Wall Plastic Pipe by Stub Compression Loading AASHTO Designation: T 341-10 (2014) 1. SCOPE 1.1. This test method covers determination of compression capacity of profile wall plastic pipe in the stub compression
3、 test. 1.2. This test method covers thermoplastic resin pipe. 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 appli
4、cability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. ASTM Standards: D695, Standard Test Method for Compressive Properties of Rigid Plastics D1600, Standard Terminology for Abbreviated Terms Relating to Plastics E177, Standard Practice for Use of the Terms Precision and Bias
5、 in ASTM Test Methods F412, Standard Terminology Relating to Plastic Piping Systems 3. TERMINOLOGY 3.1. Definitions are in accordance with ASTM F412, and abbreviations are in accordance with ASTM D1600, unless otherwise specified. 3.2. Definitions of Terms Specific to This Standard: 3.2.1. local buc
6、klinglocal wrinkling resulting from compressive load in one or more elements of the wall section visible to the eye. When advanced, it may result in failure of the entire profile. 3.2.2. periodthe length of a single repetition of the corrugation or rib pattern, defined as the distance from the cente
7、rline of a valley or liner element to the centerline of the adjacent valley or liner element (see Figure 1). 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 341-2 AASHTO Figure 1Typical Lined Pro
8、file Wall 3.2.3. profile heightthe distance from the surface of the inside wall of the pipe (inner surface of the valley or liner element) to the surface of the outside wall of the pipe (outer surface of the crest or rib element in Figure 1). May also be determined as (OD ID)/2. 3.2.4. profile wallt
9、hin-walled pipe with corrugated or ribbed geometry. 4. SUMMARY OF TEST METHOD 4.1. A small sample of pipe wall is compressed between two rigid plates at a controlled rate. Both plates are fixed with respect to rotation. The sample has a longitudinal length of three periods and a chord (circumferenti
10、al) length of 1.5 times the profile height. Load, displacement (of the load plates), and time data are obtained. The test ends when the ultimate load is exceeded and the level of load begins to decrease. The ultimate load, crosshead displacement at ultimate load, and test time at ultimate load are r
11、ecorded. 5. SIGNIFICANCE AND USE 5.1. The maximum load achieved in this test may be used for the following: 5.1.1. To evaluate compression load capacity of profile wall thermoplastic pipe. 5.1.2. To evaluate the manufactured consistency of pipe wall cross-section thickness distribution. 6. APPARATUS
12、 6.1. Testing MachineA properly calibrated compression testing machine of the constant-rate-of-crosshead-movement type meeting the requirements of ASTM D695 shall be used to conduct the test. The rate of head approach shall be 0.05 0.01 in./min (1.27 0.25 mm/min). The testing machine shall be capabl
13、e of compressing the sample to its capacity. The testing machine shall monitor the applied load to accuracy of 25 lb (110 N). 6.2. Loading PlatesThe load shall be applied to the specimen through two parallel steel bearing plates. The plates shall be flat, smooth, and clean. The thickness of the plat
14、es shall be sufficient so that no bending or deformation occurs during the test, but shall not be less than 0.25 in. (6.0 mm). The plate length shall equal or exceed the specimen longitudinal length, and the plate width shall not be less than the profile height plus 6.0 in. (150 mm). 2015 by the Ame
15、rican Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 341-3 AASHTO 6.3. Deflection IndicatorThe crosshead displacement shall be measured with a suitable instrument meeting the requirements of ASTM D695, except that t
16、he instrument shall be accurate to 0.001 in. (0.025 mm). Note 1Monitoring crosshead motion of the test machine is an acceptable method of recording deflection; however, the test machine flexibility may result in apparent deflection in addition to the specimen deflection. This must be accounted for i
17、f the deflection data are used to evaluate strain at maximum load. 7. SAMPLING, TEST SPECIMENS, AND TEST UNITS 7.1. The test specimen shall be a wall section cut from a finished pipe product. 7.2. The specimen longitudinal length shall be three periods. 7.3. The specimen chord (circumferential) leng
18、th shall be 1.5 times the profile height with tolerance of 1/4in. 7.4. Specimen ends shall be cut flat and parallel to each other and to the radial line through the center of the sample. The cut ends are not radial. Note 2The most important aspect of specimen preparation is cutting the ends to plana
19、r parallel surfaces. This is complicated by the thin flexible elements of many profile wall pipes. Guidance for specimen preparation is provided in Annex A. 8. CONDITIONING 8.1. Condition pipe for at least 4 h in air, at a temperature of 73.4 3.6F (23 2C), and conduct the test in a room maintained a
20、t the same temperature. 9. PROCEDURE 9.1. Record the pipe nominal diameter, pipe model/classification, profile type, manufacturer, conditioning temperature, and date of test. 9.2. Make and record the following measurements for each specimen: 9.2.1. Determine the longitudinal length of each specimen
21、to the nearest 1/16in. (1.5 mm) by making and averaging three measurements equally spaced over the chord length. 9.2.2. Determine the chord length of each specimen to the nearest 1/16in. (1.5 mm) by making and averaging three measurements equally spaced along the longitudinal length. 9.2.3. Determin
22、e the profile height of each specimen to the nearest 1/16in. (1.5 mm) by making and averaging three measurements equally spaced along the longitudinal length. 9.3. Place the specimen on the lower plate, centering the specimen under the testing machine crosshead vertical axis, as illustrated in Figur
23、e 2. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 341-4 AASHTO Figure 2Stub Compression Test Setup 9.4. With the displacement indicator in place, bring the upper plate into contact with the sp
24、ecimen with no more than 50-lb (220-N) seating force. 9.5. Compress the sample at a constant rate of 0.05 0.01 in./min (1.27 0.25 mm/min). 9.6. Record the load, displacement, and time measurements continuously or intermittently with reference to the relative movement of the bearing plates. If measur
25、ements are made intermittently, make and record such measurements at increments of not more than 1 percent of the original specimen chord length. 9.7. Note the ultimate load carried by the sample. 9.8. Discontinue the test when the load on the specimen fails to increase with increasing deflection. 1
26、0. CALCULATION OR INTERPRETATION OF RESULTS 10.1. Calculate the ultimate compressive load capacity per unit length of pipe wall as the ultimate load (lb) divided by the average longitudinal length (in.). 11. REPORT 11.1. Report the following information: 11.1.1. Agency conducting test; 11.1.2. Date
27、of test; 11.1.3. Complete identification of the material tested, including type, source, manufacturers code, previous history (if any), product identification by standard number, and pipe nominal diameter; 2015 by the American Association of State Highway and Transportation Officials.All rights rese
28、rved. Duplication is a violation of applicable law.TS-4b T 341-5 AASHTO 11.1.4. Specimen dimensions, including longitudinal length, chord length, and profile height; 11.1.5. Conditioning temperature, time, and environment; 11.1.6. The ultimate load carried by the specimen; 11.1.7. The ultimate compr
29、essive load capacity of the pipe wall; and 11.1.8. The average load rate throughout the test duration. 12. PRECISION AND BIAS 12.1. PrecisionAn interlaboratory study of stub-compression-test ultimate loads was conducted with six laboratories participating. The pipe samples were 24A = 24-in. high-den
30、sity polyethylene (HDPE) corrugated pipe, 24C = 24-in. HDPE corrugated pipe, 24D = 24-in. polyvinylchloride (PVC) ribbed pipe, 42B = 42-in. HDPE corrugated pipe, and 42C = 42-in. HDPE corrugated pipe. Information regarding the precision is found in Table 1. Table 1Stub Compression TestPrecision Stat
31、isticsaMaterial Sample Average smeansrbsRcr R Standard Deviation of AveragesdRepeat-ability Standard DeviationdReproduci-bility Standard DeviationdRepeat-ability Limit (95%)dReproduci-bility Limit (95%)dHDPE 24A 726 59.1 56.6 49.1 111 96 8.1 7.8 6.8 15.3 13.3 HDPE 24C 891 76.1 70.8 60.9 139 119 8.5
32、7.9 6.8 15.6 13.4 PVC 24D 1991 118.6 84.9 122.5 166 240 6.0 4.3 6.2 8.4 12.1 HDPE 42B 952 68.8 55.5 59.4 109 116 7.2 5.8 6.2 11.4 12.2 HDPE 42C 998 80.5 65.1 60.9 128 119 8.1 6.5 6.1 12.8 12.0 aTerms are as specified in ASTM E177. bsr = standard deviation of repeatability (variation of replicate sam
33、ples by the same laboratory). csR = standard deviation of reproducibility (variation between laboratories). dPrecision statistics as percent of average. 13. KEYWORDS 13.1. Compression; local buckle; stub compression; thermoplastic pipe. ANNEX (Mandatory Information) A1. SPECIMEN PREPARATION A1.1. Th
34、is annex provides a detailed procedure for preparing specimens for the stub compression test. Test specimens must be carefully prepared and have square, parallel faces equidistant from the radial line at the center of the specimen. Specimens are composed of thin elements and are very flexible; there
35、fore, clamping and care are required to produce parallel ends for loading between the parallel plates. Suggested tools are those found to work best during the research to develop this standard. Other labs may use different procedures or equipment. Precise specimen preparation is critical to obtainin
36、g repeatable and reproducible test results. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4b T 341-6 AASHTO A1.2. A suggested specimen cutting procedure follows: Rough cut specimens from the pipe to
37、 a chord length approximately 2 in. longer than the final A1.2.1.chord length of 1.5 times the corrugation depth, using a reciprocating saw or circular saw (Figure A1.1). Figure A1.1Specimen Dimensions 2015 by the American Association of State Highway and Transportation Officials.All rights reserved
38、. Duplication is a violation of applicable law.TS-4b T 341-7 AASHTO Square the longitudinal ends to be parallel to the circumference of the pipe. Use a milling machine A1.2.2.or belt sander to ensure the ends are square, and evaluate with a carpenters square (Figure A1.2). Figure A1.2Evaluate the En
39、ds of Milled Specimen with a Carpenters Square Cut the circumferential ends of each specimen square and parallel with a milling machine. Clamp A1.2.3.the test specimen to the table of the milling machine, supporting it at the center of the entire chord length. The sample must be clamped down firmly
40、enough that it does not move during the milling process, but not so firmly that its shape is warped from the clamping pressure. To ensure a square cut, alternate milling each side of the specimen until the chord length is within A1.2.4.the specified tolerance of 1.5 times the profile height, and the
41、 longitudinal faces are parallel to and equidistant from a radial passing through the center of the pipe and the midheight of the specimen. Place the specimen on a flat, level surface to check that the ends are plane, parallel, and square. A1.2.5.Place a 6-in. level on the specimen in several locati
42、ons to check that ends are plane along the specimen length and across the corrugation depth. Use a carpenters square to check that the specimen center is parallel with a radial line from the center of the pipe from which the specimen was removed. Flip the specimen so that the opposing end is flat ag
43、ainst the table, and repeat these checks. If necessary, make small adjustments to the ends of the sample using a belt sander. Following any A1.2.6.adjustments, repeat checks for plane, parallel, and square ends described in the previous step. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
