ASTM D2412-11(2018)

Standard Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel-Plate Loading

SIGNIFICANCE AND USE
5.1 The external loading properties of plastic pipe obtained by this test method are used for the following:  
5.1.1 To determine the stiffness of the pipe. This is a function of the pipe dimensions and the physical properties of the material of which the pipe is made.  
5.1.2 To determine the load-deflection characteristics and pipe stiffness which are used for engineering design (see Appendix X1).  
5.1.3 To compare the characteristics of various plastics in pipe form.  
5.1.4 To study the interrelations of dimensions and deflection properties of plastic pipe and conduit.  
5.1.5 To measure the deflection and load-resistance at any of several significant events if they occur during the test.
SCOPE
1.1 This test method covers the determination of load-deflection characteristics of plastic pipe under parallel-plate loading.  
1.2 This test method covers thermoplastic resin pipe, reinforced thermosetting resin pipe (RTRP), and reinforced polymer mortar pipe (RPMP).  
1.3 The characteristics determined by this test method are pipe stiffness, stiffness factor, and load at specific deflections.  
1.4 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.
Note 1: While this test method can be used in measuring the pipe stiffness of corrugated plastic pipe or tubing, special conditions and procedures are used. These details are included in the product standards, for example, Specification F405.  
1.5 The text of this test method 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 test method.  
1.6 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.  
1.7 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.

General Information

• Status: Historical
• Publication Date: 31-May-2018
• ICS: 23.040.20 - Plastics pipes
• Technical Committee: F17 - Plastic Piping Systems
• Drafting Committee: F17.40 - Test Methods

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D2412 − 11 (Reapproved 2018)
Standard Test Method for
Determination of External Loading Characteristics of Plastic
Pipe by Parallel-Plate Loading
This standard is issued under the fixed designation D2412; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the determination of load-
D695 Test Method for Compressive Properties of Rigid
deflection characteristics of plastic pipe under parallel-plate
Plastics
loading.
D1600 Terminology forAbbreviatedTerms Relating to Plas-
1.2 This test method covers thermoplastic resin pipe, rein-
tics
forced thermosetting resin pipe (RTRP), and reinforced poly-
D2122 Test Method for Determining Dimensions of Ther-
mer mortar pipe (RPMP).
moplastic Pipe and Fittings
1.3 The characteristics determined by this test method are
E177 Practice for Use of the Terms Precision and Bias in
pipe stiffness, stiffness factor, and load at specific deflections.
ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to
1.4 The values stated in inch-pound units are to be regarded
Determine the Precision of a Test Method
as standard. The values given in parentheses are mathematical
F405 Specification for Corrugated Polyethylene (PE) Pipe
conversions to SI units that are provided for information only
and Fittings (Withdrawn 2015)
and are not considered standard.
F412 Terminology Relating to Plastic Piping Systems
NOTE 1—While this test method can be used in measuring the pipe
stiffness of corrugated plastic pipe or tubing, special conditions and
3. Terminology
procedures are used. These details are included in the product standards,
for example, Specification F405.
3.1 Definitions—Definitions are in accordance with Termi-
nology F412, and abbreviations are in accordance with Termi-
1.5 The text of this test method references notes and
nology D1600, unless otherwise specified.
footnotes that provide explanatory material. These notes and
footnotes (excluding those in tables and figures) shall not be
3.2 Definitions of Terms Specific to This Standard:
considered as requirements of the test method.
3.2.1 ∆y—measured change of the inside diameter in the
direction of load application expressed in inches (millimetres).
1.6 This standard does not purport to address all of the
3.2.2 initial inside diameter (d)—the average of the inside
safety concerns, if any, associated with its use. It is the
diameters as determined for the several test specimens and
responsibility of the user of this standard to establish appro-
expressed in inches (millimetres).
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.2.3 load (F)—the load applied to the pipe to produce a
givenpercentagedeflection.Expressedasnewtonspermetreor
1.7 This international standard was developed in accor-
pounds-force per linear inch.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.2.4 mean radius (r)—the mid-wall radius determined by
Development of International Standards, Guides and Recom-
subtractingtheaveragewallthicknessfromtheaverageoutside
mendations issued by the World Trade Organization Technical
diameter and dividing the difference by two. Expressed as
Barriers to Trade (TBT) Committee.
inches (millimetres).
1 2
This test method is under the jurisdiction of ASTM Committee F17 on Plastic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Methods. Standards volume information, refer to the standard’s Document Summary page on
CurrenteditionapprovedJune1,2018.PublishedJuly2018.Originallyapproved the ASTM website.
in 1965. Last previous edition approved in 2011 as D2412 – 11. DOI: 10.1520/ The last approved version of this historical standard is referenced on
D2412-11R18. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2412 − 11 (2018)
RPMP pipe 24-in. (610-mm) size and larger.
3.2.5 pipe deflection (P)—the ratio of the reduction in pipe
inside diameter to the initial inside diameter expressed as the
6.2 Loading Plates—The load shall be applied to the speci-
percentage of the initial inside diameter.
men through two parallel steel bearing plates. The plates shall
be flat, smooth, and clean. The thickness of the plates shall be
3.2.6 pipe significant events:
sufficient so that no bending or deformation occurs during the
3.2.6.1 liner cracking or crazing—the occurrence of a break
test, but it shall not be less than 0.25 in. (6.0 mm). The plate
or network of fine breaks in the liner visible to the unaided eye.
length shall equal or exceed the specimen length and the plate
3.2.6.2 rupture—a crack or break extending entirely or
width shall not be less than the pipe contact width at maximum
partly through the pipe wall.
pipe deflection plus 6.0 in. (150 mm).
NOTE 2—The significant events listed may or may not occur in a
specific pipe material. NOTE 5—For some types of testing machines a greater plate thickness
may be required to limit plate bending.
3.2.6.3 wall cracking—the occurence of a break in the pipe
6.3 Deformation (Deflection) Indicator— The change in
wall visible to the unaided eye.
inside diameter, or deformation parallel to the direction of
3.2.6.4 wall delamination—theoccurrenceofanyseparation
in the components of the pipe wall visible to the unaided eye. loading, shall be measured with a suitable instrument meeting
the requirements of Test Method D695, except that the instru-
3.2.7 pipe stiffness (PS)—the value obtained by dividing the
force per unit length of specimen by the resulting deflection in ment shall be accurate to the nearest 0.010 in. (0.25 mm). The
instrument shall not support the pipe test specimen or the plate
the same units at the prescribed percentage deflection.
or affect in any way the load deflection measurements.
3.2.8 stiffness factor (SF)—the product of pipe stiffness and
3 Changes in diameter are measured during loading by continu-
the quantity 0.149 r .
ously recording plate travel or by periodically computing it.
3.2.9 Discussion—The“pipestiffness”and“stiffnessfactor”
are related as follows:
7. Test Specimens
PS 5F/∆y (1)
7.1 For thermoplastic pipe, the test specimen shall be a
3 3
SF 5 EI 5 0.149 Fr /∆y 5 0.149 r ~PS! (2) 1
piece of pipe 6 6 ⁄8 in. (150 6 3 mm) long.
NOTE 3—See Appendix X2 for information relating PS, E, and ∆y.
7.2 For reinforced thermosetting resin pipe, the minimum
test specimen length shall be three times the nominal pipe
4. Summary of Test Method
diameter or 12.0 in. (300 mm), whichever is smaller. For pipe
4.1 A short length of pipe is loaded between two rigid
larger than 60 in. (1524 mm) in diameter, the minimum
parallel flat plates at a controlled rate of approach to one
specimen length shall be 20 % of the nominal diameter
another. Load-deflection (of the pipe diameter) data are ob-
adjusted to the nearest 1 in. (25.4 mm).
tained. If cracking, crazing, delamination, or rupture occurs,
the corresponding load and deflection are recorded. 7.3 The ends of specimens shall be cut square and shall be
free of burrs and jagged edges.
5. Significance and Use
7.4 No less than three specimens shall be tested for each
5.1 The external loading properties of plastic pipe obtained
sample of pipe.
by this test method are used for the following:
NOTE6—Forqualitycontroltestingasinglespecimenmaybeusedwith
5.1.1 To determine the stiffness of the pipe. This is a
the thinnest wall at the top.
function of the pipe dimensions and the physical properties of
7.5 Certain RTRP pipes exhibit surface irregularity because
the material of which the pipe is made.
the production process is inside diameter controlled. To assure
5.1.2 To determine the load-deflection characteristics and
accurate test results by parallel-plate loading, the test specimen
pipe stiffness which are used for engineering design (see
must be uniformly loaded along its entire bearing surface. If
Appendix X1).
surface irregularities (resin-rich areas) along the outside diam-
5.1.3 To compare the characteristics of various plastics in
eter prevent the bearing load from being uniformly distributed
pipe form.
along the length of the specimen, the outside surface along the
5.1.4 To study the interrelations of dimensions and deflec-
loading line shall be sanded smooth by hand. This sanding
tion properties of plastic pipe and conduit.
shall only be done if the reinforcement is not damaged. Note
5.1.5 Tomeasurethedeflectionandload-resistanceatanyof
that sanding shall be done only along the plate contact lines.
several significant events if they occur during the test.
8. Conditioning
6. Apparatus
8.1 Condition pipe for at least4hinair,ata temperature of
6.1 Testing Machine—A properly calibrated compression
73.4 6 3.6 °F (23 6 2 °C), and conduct the test in a room
testing machine of the constant-rate-of-crosshead movement
maintained at the same temperature.
type meeting the requirements of Test Method D695 shall be
used to make the tests. The rate of head approach shall be 0.50
8.2 When a referee test is required, condition specimens for
6 0.02 in. (12.5 6 0.5 mm)/min.
at least 40 h at 73.4 6 3.6 °F (23 6 2 °C) and 50 6 5%
relative humidity and conduct the test under the same condi-
NOTE 4—Hydraulic testing machines that may vary slightly from these
rate limits are commonly used and are satisfactory for testing RTRP and tions.
D2412 − 11 (2018)
materials, creep may affect the results of this test because of the loading
9. Procedure
rate specified.
9.1 Make the following measurements on each specimen:
9.5 Record load-deflection measurements continuously or
9.1.1 Determine the length of each specimen to the nearest
intermittently with reference to the relative movement of the
⁄32 in. (1 mm) or better, by making and averaging at least four
bearing plates. If measurements are made intermittently, make
equally spaced measurements around the perimeter.
and record such measurements at increments of not more than
9.1.2 Measure the wall thickness of each specimen in
5 % of the average inside diameter of the specimen. Refer to
accordance with Test Method D2122. Make at least eight
Annex A1.
measurements equally spaced around one end and calculate the
average wall thickness.
9.6 Observe and note the load and deflection at the first
9.1.3 Determine whether a line of minimum wall thickness evidence of each of the following significant events when and
exists along the length of the specimen and if so mark it for use
if they occur:
in 9.2.1.
9.6.1 Liner cracking or crazing.
9.6.2 Wall cracking.
NOTE7—OnRTRPandRPMPpipemeasurementsmaybemadeatboth
9.6.3 Wall delamination.
ends.
9.6.4 Rupture.
9.1.4 Determine the average outside diameter to the nearest
0.01 in. (0.2 mm) using a circumferential wrap tape or by
9.7 Record type and position of each event with respect to
averaging the maximum and minimum outside diameters as
the corresponding load and deflection. Discontinue the test
measured with a micrometer or caliper.
when either of the following occur:
9.1.5 For OD-controlled pipe calculate the average pipe
9.7.1 The load on the specimen fails to increase with
insidediameter(ID)bysubtractingtwotimestheaverageofall
increasing deflection (maximum point on load-deflection plot
wall thicknesses (9.1.2) from the average of all outside
has been reached).
diameters (9.1.4). For ID-controlled pipe determine the aver-
9.7.2 The specimen deflection reaches 30 % of the average
age ID by measuring the maximum and minimum inside
inside diameter or the required maximum deflection.
diameters. Use this average ID as the basis for computing the
percentage of deflection for all specimens in that lot of pipe.
10. Calculation
9.2 Locatethepipesectionwithitslongitudinalaxisparallel
10.1 Calculate the pipe stiffness, PS, for any given deflec-
to the bearing plates and center it laterally in the testing
tion as follows:
machine.
PS 5F/∆y lbf/in./in. kPa (3)
~ !
9.2.1 If an orientation of minimum wall thickness has been
NOTE 9—Refer to Appendix X3 for additional information on units.
found, place the first specimen so the thinnest wall is at the top
10.2 When required, calculate the stiffness factor, SF, for
and rotate successive specimens 35 and 70°. If no minimum
any given deflection as follows:
wall thickness was identified, use any base line.
3 3 2 3
SF 5 0.149 r ·PS in. ·lbf/in. Pa·m (4)
~ !
9.3 With the deflection indicator in place, bring the upper
plate into contact with the specimen with no more load than is
10.3 When required, calculate the percentage pipe
necessary to hold it in place. This establishes the beginning
deflection, P, as follows:
point for subsequent deflection measurements.
P 5∆y/d 3100 (5)
9.4 Compressthespecimenataconstantrateof0.50 60.02
in. (12.5 6 0.5 mm)/min. 11. Report
NOTE 8—For larger sizes of pipe made from relatively low-modulus 11.1 Report the following information:
A
TABLE 1 Pipe Stiffness—Precision Statistics
Reproduce-
Standard Repeatability Reproduce-
Deflection ability Repeatability
B B
Material Average S S S r R Deviation of Standard ability
mean r R C
Level, % Standard Limit (95 %)
C C C
Cell Averages Deviation Limit (95 %)
C
Deviation
A 2.5 772.3 54.95 84.69 101.0 237.1 282.7 7.11 11.0 13.1 30.7 36.6
B 2.5 380.2 20.52 18.12 27.37 50.72 76.64 5.40 4.77 7.20 13.3 20.2
C 2.5 463.9 79.07 57.82 97.96 161.9 274.3 17.0 12.5 21.1 34.9 59.1
A 5.0 755.7 33.30 80.30 86.93 224.8 243.4 4.41 10.6 11.5 29.7 32.2
B 5.0 356.1 19.13 15.32 24.51 42.89 68.62 5.37 4.30 6.88 12.0 19.3
C 5.0 419.4 37.80 27.74 46.89 77.68 131.3 9.01 6.61 11.2 18.5 31.3
A 7.5 724.8 27.85 76.14 81.07 213.2 227.0 3.84 10.5 11.2 29.4 31.3
B 7.5 332.6 16.87 13.94 21.88 39.02 61.27 5.07 4.19 6.58 11.7 18.4
C 7.5 371.7 26.70 18.82 32.66 52.69 91.45 7.18 5.06 8.79 14.2 24.6
A
Terms are used as specified in Practice E177.
B
S = standard deviation of repeatability (variation of replicate samples by same laboratory).
r
S = standard deviation of reproducibility (variability between laboratory).
R
C
Precision statistics as percent of average.
-----------------
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D2412 − 11 D2412 − 11 (Reapproved 2018)
Standard Test Method for
Determination of External Loading Characteristics of Plastic
Pipe by Parallel-Plate Loading
This standard is issued under the fixed designation D2412; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of load-deflection characteristics of plastic pipe under parallel-plate loading.
1.2 This test method covers thermoplastic resin pipe, reinforced thermosetting resin pipe (RTRP), and reinforced polymer
mortar pipe (RPMP).
1.3 The characteristics determined by this test method are pipe stiffness, stiffness factor, and load at specific deflections.
1.4 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.
NOTE 1—While this test method can be used in measuring the pipe stiffness of corrugated plastic pipe or tubing, special conditions and procedures
are used. These details are included in the product standards, for example, Specification F405.
1.5 The text of this test method 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 test method.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
D695 Test Method for Compressive Properties of Rigid Plastics
D1600 Terminology for Abbreviated Terms Relating to Plastics
D2122 Test Method for Determining Dimensions of Thermoplastic Pipe and Fittings
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
F405 Specification for Corrugated Polyethylene (PE) Pipe and Fittings (Withdrawn 2015)
F412 Terminology Relating to Plastic Piping Systems
3. Terminology
3.1 Definitions—Definitions are in accordance with Terminology F412, and abbreviations are in accordance with Terminology
D1600, unless otherwise specified.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 Δy—measured change of the inside diameter in the direction of load application expressed in inches (millimetres).
This test method is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test Methods.
Current edition approved April 1, 2011June 1, 2018. Published April 2011July 2018. Originally approved in 1965. Last previous edition approved in 20102011 as
D2412 – 10a.D2412 – 11. DOI: 10.1520/D2412-11.10.1520/D2412-11R18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2412 − 11 (2018)
3.2.2 initial inside diameter (d)—the average of the inside diameters as determined for the several test specimens and expressed
in inches (millimetres).
3.2.3 load (F)—the load applied to the pipe to produce a given percentage deflection. Expressed as newtons per metre or
pounds-force per linear inch.
3.2.4 mean radius (r)—the mid-wall radius determined by subtracting the average wall thickness from the average outside
diameter and dividing the difference by two. Expressed as inches (millimetres).
3.2.5 pipe deflection (P)—the ratio of the reduction in pipe inside diameter to the initial inside diameter expressed as the
percentage of the initial inside diameter.
3.2.6 pipe significant events:
3.2.6.1 liner cracking or crazing—the occurrence of a break or network of fine breaks in the liner visible to the unaided eye.
3.2.6.2 rupture—a crack or break extending entirely or partly through the pipe wall.
NOTE 2—The significant events listed may or may not occur in a specific pipe material.
3.2.6.3 wall cracking—the occurence of a break in the pipe wall visible to the unaided eye.
3.2.6.4 wall delamination—the occurrence of any separation in the components of the pipe wall visible to the unaided eye.
3.2.7 pipe stiffness (PS)—the value obtained by dividing the force per unit length of specimen by the resulting deflection in the
same units at the prescribed percentage deflection.
3.2.8 stiffness factor (SF)—the product of pipe stiffness and the quantity 0.149 r .
3.2.9 Discussion—The “pipe stiffness” and “stiffness factor” are related as follows:
PS 5 F/Δy (1)
3 3
SF 5 EI 5 0.149 Fr /Δy 5 0.149 r PS (2)
~ !
NOTE 3—See Appendix X2 for information relating PS, E, and Δy.
4. Summary of Test Method
4.1 A short length of pipe is loaded between two rigid parallel flat plates at a controlled rate of approach to one another.
Load-deflection (of the pipe diameter) data are obtained. If cracking, crazing, delamination, or rupture occurs, the corresponding
load and deflection are recorded.
5. Significance and Use
5.1 The external loading properties of plastic pipe obtained by this test method are used for the following:
5.1.1 To determine the stiffness of the pipe. This is a function of the pipe dimensions and the physical properties of the material
of which the pipe is made.
5.1.2 To determine the load-deflection characteristics and pipe stiffness which are used for engineering design (see Appendix
X1).
5.1.3 To compare the characteristics of various plastics in pipe form.
5.1.4 To study the interrelations of dimensions and deflection properties of plastic pipe and conduit.
5.1.5 To measure the deflection and load-resistance at any of several significant events if they occur during the test.
6. Apparatus
6.1 Testing Machine—A properly calibrated compression testing machine of the constant-rate-of-crosshead movement type
meeting the requirements of Test Method D695 shall be used to make the tests. The rate of head approach shall be 0.50 6 0.02
in. (12.5 6 0.5 mm)/min.
NOTE 4—Hydraulic testing machines that may vary slightly from these rate limits are commonly used and are satisfactory for testing RTRP and RPMP
pipe 24-in. (610-mm) size and larger.
6.2 Loading Plates—The 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 plates shall be sufficient so that no bending or deformation occurs during the test, but it
shall not be less than 0.25 in. (6.0 mm). The plate length shall equal or exceed the specimen length and the plate width shall not
be less than the pipe contact width at maximum pipe deflection plus 6.0 in. (150 mm).
NOTE 5—For some types of testing machines a greater plate thickness may be required to limit plate bending.
6.3 Deformation (Deflection) Indicator— The change in inside diameter, or deformation parallel to the direction of loading, shall
be measured with a suitable instrument meeting the requirements of Test Method D695, except that the instrument shall be accurate
to the nearest 0.010 in. (0.25 mm). The instrument shall not support the pipe test specimen or the plate or affect in any way the
load deflection measurements. Changes in diameter are measured during loading by continuously recording plate travel or by
periodically computing it.
D2412 − 11 (2018)
7. Test Specimens
7.1 For thermoplastic pipe, the test specimen shall be a piece of pipe 6 6 ⁄8 in. (150 6 3 mm) long.
7.2 For reinforced thermosetting resin pipe, the minimum test specimen length shall be three times the nominal pipe diameter
or 12.0 in. (300 mm), whichever is smaller. For pipe larger than 60 in. (1524 mm) in diameter, the minimum specimen length shall
be 20 % of the nominal diameter adjusted to the nearest 1 in. (25.4 mm).
7.3 The ends of specimens shall be cut square and shall be free of burrs and jagged edges.
7.4 No less than three specimens shall be tested for each sample of pipe.
NOTE 6—For quality control testing a single specimen may be used with the thinnest wall at the top.
7.5 Certain RTRP pipes exhibit surface irregularity because the production process is inside diameter controlled. To assure
accurate test results by parallel-plate loading, the test specimen must be uniformly loaded along its entire bearing surface. If surface
irregularities (resin-rich areas) along the outside diameter prevent the bearing load from being uniformly distributed along the
length of the specimen, the outside surface along the loading line shall be sanded smooth by hand. This sanding shall only be done
if the reinforcement is not damaged. Note that sanding shall be done only along the plate contact lines.
8. Conditioning
8.1 Condition pipe for at least 4 h in air, at a temperature of 73.4 6 3.6°F3.6 °F (23 6 2°C),2 °C), and conduct the test in a
room maintained at the same temperature.
8.2 When a referee test is required, condition specimens for at least 40 h at 73.4 6 3.6°F3.6 °F (23 6 2°C)2 °C) and 50 6 5 %
relative humidity and conduct the test under the same conditions.
9. Procedure
9.1 Make the following measurements on each specimen:
9.1.1 Determine the length of each specimen to the nearest ⁄32 in. (1 mm) or better, by making and averaging at least four
equally spaced measurements around the perimeter.
9.1.2 Measure the wall thickness of each specimen in accordance with Test Method D2122. Make at least eight measurements
equally spaced around one end and calculate the average wall thickness.
9.1.3 Determine whether a line of minimum wall thickness exists along the length of the specimen and if so mark it for use in
9.2.1.
NOTE 7—On RTRP and RPMP pipe measurements may be made at both ends.
9.1.4 Determine the average outside diameter to the nearest 0.01 in. (0.2 mm) using a circumferential wrap tape or by averaging
the maximum and minimum outside diameters as measured with a micrometer or caliper.
9.1.5 For OD-controlled pipe calculate the average pipe inside diameter (ID) by subtracting two times the average of all wall
thicknesses (9.1.2) from the average of all outside diameters (9.1.4). For ID-controlled pipe determine the average ID by measuring
the maximum and minimum inside diameters. Use this average ID as the basis for computing the percentage of deflection for all
specimens in that lot of pipe.
9.2 Locate the pipe section with its longitudinal axis parallel to the bearing plates and center it laterally in the testing machine.
9.2.1 If an orientation of minimum wall thickness has been found, place the first specimen so the thinnest wall is at the top and
rotate successive specimens 35 and 70°. If no minimum wall thickness was identified, use any base line.
9.3 With the deflection indicator in place, bring the upper plate into contact with the specimen with no more load than is
necessary to hold it in place. This establishes the beginning point for subsequent deflection measurements.
9.4 Compress the specimen at a constant rate of 0.50 6 0.02 in. (12.5 6 0.5 mm)/min.
NOTE 8—For larger sizes of pipe made from relatively low-modulus materials, creep may affect the results of this test because of the loading rate
specified.
9.5 Record load-deflection measurements continuously or intermittently with reference to the relative movement of the bearing
plates. If measurements are made intermittently, make and record such measurements at increments of not more than 5 % of the
average inside diameter of the specimen. Refer to Annex A1.
9.6 Observe and note the load and deflection at the first evidence of each of the following significant events when and if they
occur:
9.6.1 Liner cracking or crazing.
9.6.2 Wall cracking.
9.6.3 Wall delamination.
9.6.4 Rupture.
D2412 − 11 (2018)
9.7 Record type and position of each event with respect to the corresponding load and deflection. Discontinue the test when
either of the following occur:
9.7.1 The load on the specimen fails to increase with increasing deflection (maximum point on load-deflection plot has been
reached).
9.7.2 The specimen deflection reaches 30 % of the average inside diameter or the required maximum deflection.
10. Calculation
10.1 Calculate the pipe stiffness, PS, for any given deflection as follows:
PS 5 F/Δy lbf/in./in. ~kPa! (3)
NOTE 9—Refer to Appendix X3 for additional information on units.
10.2 When required, calculate the stiffness factor, SF, for any given deflection as follows:
3 3 2 3
SF 5 0.149 r ·PS in. ·lbf/in. Pa·m (4)
~ !
10.3 When required, calculate the percentage pipe deflection, P, as follows:
P 5 Δy/d 3 100 (5)
11. Report
11.1 Report the following information:
11.1.1 Complete identification of the material tested, including type, source, manufacturer’s code, previous history (if any), and
product identification by standard number.
11.1.2 Dimensions of each specimen, including average outside diameter, average wall thickness, average inside diameter, liner
thickness and reinforcement thickness where applicable, and average length.
11.1.3 Whether or not the outside diameter of the specimen was sanded.
11.1.4 Conditioning temperature, time, and environment.
11.1.5 The load and deflection at which any of the following events occurred:
11.1.5.1 Liner cracking or crazing,
11.1.5.2 Wall cracking,
11.1.5.3 Wall de
...