AASHTO T 281-2014 Standard Method of Test for Vitrified Clay Pipe.pdf

1、Standard Method of Test for Vitrified Clay Pipe AASHTO Designation: T 281-141ASTM Designation: C301-13 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-4a T 281-1 AASHTO Standard Method of Test for Vitrified Clay Pi

2、pe AASHTO Designation: T 281-141ASTM Designation: C301-13 1. SCOPE 1.1. These test methods cover the equipment for, and the techniques of, testing vitrified clay pipe prior to installation. Tests using whole pipe determine the resistance to crushing and hydrostatic forces. Tests using pipe fragments

3、 measure the amount of water absorption of the pipe body and the quantity of acid-soluble material that may be extracted from it. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. This standard does not purport to address all of the safety concerns, if any, associated with

4、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. Note 1The following standards also apply to clay pipe and can be referenced for further information: ASTM C12, C

5、425, C700, and C828. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: M 231, Weighing Devices Used in the Testing of Materials 2.2. ASTM Standards: C12, Standard Practice for Installing Vitrified Clay Pipe Lines C425, Standard Specification for Compression Joints for Vitrified Clay Pipe and Fittings C7

6、00, Standard Specification for Vitrified Clay Pipe, Extra Strength, Standard Strength, and Perforated C828, Standard Test Method for Low-Pressure Air Test of Vitrified Clay Pipe Lines C896, Standard Terminology Relating to Clay Products E6, Standard Terminology Relating to Methods of Mechanical Test

7、ing 3. TERMINOLOGY 3.1. Definitions: 3.1.1. For definitions of terms used in these test methods, refer to ASTM E6 and C896. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4a T 281-2 AASHTO 4. SIGNIFI

8、CANCE AND USE 4.1. Meaning and SuitabilityThe tests called for herein, from their results, indicate the suitability and acceptability of vitrified clay pipe for specifications acceptance, design purposes, regulatory statutes, manufacturing control, and research. 5. BEARING STRENGTH 5.1. Test Specime

9、ns: 5.1.1. The test specimens shall be sound, full-size pipe and shall be selected by the purchaser, or purchasers representative, at points designated by the purchaser when placing the order. 5.1.2. The number of specimens to be tested shall not exceed 0.5 percent of the number of pipe of each size

10、 furnished, except that no less than two specimens shall be tested. 5.2. Measurement and Inspection of Specimens: 5.2.1. The specimens shall be free of all visible moisture and frost. These specimens shall be inspected and measured for conformance with the applicable specifications. The results of t

11、hese observations shall be recorded. 5.2.2. Specimens that are observed to have defects in excess of the limits permitted in the applicable specifications shall be discarded and replaced with additional specimens from the lot to be tested. 5.3. Loading ApparatusSee Figure 1. 5.3.1. Testing Machine:

12、5.3.1.1. The loading apparatus shall consist of a testing machine capable of applying loads, with upper and lower bearings capable of transmitting these loads to the pipe. The bearings shall be bearing beams and contact edges. 5.3.1.2. Any motor-driven testing machine, capable of applying a load at

13、a uniform rate of 29.2 7.3 kilonewtons per minute per linear meter 2000 500 pounds-force per minute per linear foot of pipe length, may be used for making the test. 5.3.1.3. The load may be applied at a rapid rate until 50 percent of the required bearing strength is reached. Subsequently, the load s

14、hall be applied to the pipe at the rate of 29.2 7.3 kilonewtons per minute per linear meter 2000 500 pounds-force per minute per linear foot of pipe length without vibration or shock. 5.3.1.4. The testing machine shall be sufficiently rigid so that the load distribution will not be appreciably affec

15、ted by the deformation or yielding of any part. The machine and bearings shall be constructed to transmit the load in a vertical plane through the longitudinal axes of the bearings and pipe. The bearings shall be attached to the machine so as to receive and uniformly transmit the loads required in t

16、he tests, without vibration or shock. The upper bearing shall be free to rotate in a vertical plane through the longitudinal axis of the bearing and the pipe. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable

17、law.TS-4a T 281-3 AASHTO Figure 1Three-Edge-Bearing Testing (Section 5.3.4 Segmented Testing) 5.3.2. Bearing BeamsBearing beams shall not deflect more than a 355 by 205 mm 14 by 8 in., 73 kg/linear m 53 lb/linear ft, wide flange beam as specified by the American Institute of Steel Construction. Unde

18、r no circumstances shall the deflection in millimeters inches under maximum load exceed that given by the ratio L/720in which L is the beam length in millimeters inches. The length of the bearing beams shall be no less than the full length of the outside barrel of the pipe. Built-up bearing beams ma

19、y be used, provided their deflection does not exceed that specified. In order for the bell or socket of the pipe to clear the bearing beams, it is recommended that the bearing beams be faced with a metal or hardwood member for affixing the contact edges. 5.3.3. Three-Edge-Bearings: 5.3.3.1. Three-ed

20、ge-bearings shall consist of an upper member, composed of a bearing beam on which one contact edge is located so that it lies in the vertical plane passing through the longitudinal axis of the pipe, and a lower member comprised of a bearing beam on which two contact edges are symmetrically located p

21、arallel to that vertical plane. 5.3.3.2. The contact edges shall consist of rubber strips. Contact edges shall uniformly contact the outside barrel of the pipe. 5.3.3.3. The two contact edges on the lower member shall be spaced apart approximately 83 mm/m 1 in./ft of pipe diameter, but in no case le

22、ss than 25 mm 1 in. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4a T 281-4 AASHTO 5.3.3.4. Positioning strips may be used to align the upper contact edge and to align and space the lower contact e

23、dges. In the case of rubber contact edges, positioning strips shall not exceed one half of the thickness of the contact edge and may remain in place. 5.3.3.5. If rubber strips are used as contact edges, they shall be cut or formed from material having a Shore A, instantaneous, durometer hardness bet

24、ween 45 and 60. The strips shall be of rectangular cross section, having a 51-mm 2-in. width, and a thickness not less than 25 mm 1 in. nor more than 38 mm 11/2in. The contact edges shall be used with the 51-mm 2-in. dimension in contact with the bearing beam. Rubber contact edges may be attached to

25、 the bearing beam by an adhesive, provided the contact edge remains firmly fixed in position. 5.3.4. Segmented Bearings (Alternative to Three-Edge-Bearing)This apparatus shall consist of segmented upper and lower bearing members with the segments of each member connected to a common hydraulic manifo

26、ld to provide uniform load along the length of the barrel. The segmented bearings shall be of uniform length with the number of segments equal to the nominal length of the test pipe measured in meters feet. They shall be adjustable to accommodate the length variation allowed in the pipe specificatio

27、n. In no instance shall the length of the segmented bearing be greater than the external length of the barrel of the pipe. Rubber contact edges conforming to Section 5.3.3.5 shall be attached to the bearing segments. 5.4. Bearing TestsSee Figure 1. 5.4.1. Test pipe for bearing strength in accordance

28、 with the three-edge-bearing or segmented method. Use either of the specified bearing methods on retests as provided in the applicable specifications. 5.4.2. For tests using rigid bearing beams, multiple loading rams may be used. Each ram must have the same load range, connected by a common hydrauli

29、c system, and spaced above the top bearing beam to deliver a uniformly distributed load. 5.4.2.1. Using a straightedge, locate the most uniform bearing surface for testing. Using this location, place the pipe bearing surfaces to achieve uniform loading. 5.4.2.2. The resultant load from the hydraulic

30、 cylinder or cylinders shall be applied equidistant from each end as measured inside the barrel of the pipe as shown in Figure 1. 5.4.3. The loading of the pipe shall be a continuous operation. Do not allow the pipe to stand under load longer than is required to apply the load and record the observa

31、tions. 5.4.4. The loading shall be stopped after the required strength has been met. 5.4.5. For further evaluation or quality assurance, the loading may be continued to the point of pipe failure. 5.4.6. Record the maximum load sustained by the specimen. 5.5. Calculation and Report: 5.5.1. Calculate

32、the crushing strength by dividing the applied load by the inside length of the barrel. The length shall be the average of two measurements taken at points 180 degrees 3.1 rad apart. Report the individual results of the tests of pipe of each size or lot. 2015 by the American Association of State High

33、way and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4a T 281-5 AASHTO 6. ABSORPTION 6.1. Test Specimens: 6.1.1. Absorption specimens shall be sound pieces of the full thickness of the barrel of the pipe, with all edges broken. Each specimen shall be

34、as nearly square as possible, with the area on one barrel surface not less than 12 times the wall thickness, expressed as square units. They shall be free of observable cracks or shattered edges and shall not contain laminations and fissures more than is typical of the pipe from which the specimens

35、were taken. 6.1.2. Each specimen shall be marked so that it may be identified with the lot of pipe from which it was taken. The markings shall be applied so that the pigment used shall cover not more than 1 percent of the area of the specimen. 6.1.3. Test at least one specimen from each size of pipe

36、. 6.2. BalanceThe balance shall have sufficient capacity, be readable to 0.1 percent of the sample mass, or better, and conform to the requirements of M 231. 6.3. Procedure: 6.3.1. Dry the specimen at least 8 h in a ventilated oven at a temperature between 110 and 120C 230 and 248F, and make success

37、ive mass determinations at intervals of not less than 3 h until the loss at any mass determination is not greater than 0.1 percent of the original mass of the specimen. 6.3.2. Suspend the dried specimens in distilled, rain, or tap water that is known to have no effect on test results; heat to boilin

38、g; boil for 5 h, and then cool in the water to ambient temperature. Take care that no fragments are broken from the specimens by physical disturbance during the test. When cool, remove the specimens from the water, and drain for not more than 60 s. Then remove the superficial moisture with a damp cl

39、oth and determine the mass of the specimens immediately. 6.4. Calculation and Report: 6.4.1. Calculate the absorption of each specimen as a percentage of the initial dry mass as follows: ( )Absorption, % = 100SW DW DW(1) where: SW = mass of specimen after boiling 5 h, and DW = initial dry mass of sp

40、ecimen. 6.4.2. Report the result for each specimen, together with the averages for the pipe of each size and shipment. 7. HYDROSTATIC PRESSURE TEST 7.1. When the pipe is subjected to an internal hydrostatic pressure of 69 kPa 10 psi for the elapsed time shown in the following table, there shall be n

41、o leakage on the exterior of the pipe. At the option of the manufacturer, water within approximately 3C 5F of the ambient air temperature may be introduced into the pipe for control of condensation. Moisture appearing on the surface of the pipe in the form of beads adhering to the surface shall not

42、be considered leakage. However, moisture that starts to run on the pipe shall be construed as leakage regardless of quantity. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4a T 281-6 AASHTO Testing

43、Time for Pipes Thickness of Barrel, mm in. Test Time, min Up to and including 25 1 7 Over 25 1 and including 38 11/2 9 Over 38 11/2 and including 51 2 12 Over 51 2 and including 64 21/2 15 Over 64 21/2 and including 76 3 18 Over 76 3 21 8. ACID RESISTANCE 8.1. Determine the acid resistance of clay p

44、ipe by the extraction of acid-soluble matter. 8.2. ReagentWhen testing with sulfuric (H2SO4), hydrochloric (HCl), nitric (HNO3), or acetic acid (CH3COOH), as specified by the purchaser, a 1-Normal acid solution shall be used. Note 2These 1-Normal solutions should contain 40, 36.5, 63, and 60 g of th

45、e acid per liter of solution, respectively. For the purpose of these tests the solutions can be prepared by taking the following volumes of acid and diluting to 1 liter: H2SO4(sp gr 1.84), 28.5 mL; HCl (sp gr 1.19), 88.9 mL; HNO3(sp gr 1.42), 65 mL; and glacial acetic acid (sp gr 1.05), 57.7 mL. 8.3

46、. Test Specimens: 8.3.1. The specimens for acid resistance tests shall be about 51 mm 2 in. square, and weigh not more than 200 g. They shall be sound pieces with all edges freshly broken, free of cracks or shattered edges, and shall be thoroughly cleaned. 8.3.2. Test at least one specimen from each

47、 size of pipe. 8.4. BalancesThe balance for determining the mass of the specimens shall conform to the requirements for Class C balances in M 231. 8.5. Procedure: 8.5.1. Dry the specimens to constant mass at a temperature not less than 110C 230F. 8.5.2. Suspend the dried specimens in the acid at a t

48、emperature between 21 and 32C 70 and 90F for a period of 48 h, then remove them from the solution and thoroughly wash with hot water, allowing the washings to run into the solution in which the specimen was immersed. Filter the solution and wash the filter with hot water, adding the washings to the

49、filtrate. Add 5 mL of H2SO4(sp gr 1.84) to the filtrate. Then evaporate the solution (avoid loss by spattering) to about 5 mL, transfer to a porcelain crucible (previously ignited to constant mass), and heat cautiously to dryness. Then ignite the residue to constant weight. 8.6. Calculation and Report: 8.6.1. Calculate the percentage of acid-soluble matter as follows: Acid-soluble matter, % = (R/W) 100 (2) where: R = mass of residue, and W = initial mass of the specimen