ASTM D8262-22

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.
Designation:D8262 −22
Standard Test Method for
Determining the pH of Granular Material for Use in
Embankments, Subgrades, and Retaining Wall Backfill
This standard is issued under the fixed designation D8262; 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.
1. Scope 1.6.1 Theproceduresusedtospecifyhowdataarecollected/
recorded and calculated in the standard are regarded as the
1.1 This test method uses a pH meter to measure the pH of
industry standard. In addition, they are representative of the
as-received granular material that represents what will be used
significant digits that generally should be retained. The proce-
in the field for embankments, subgrades, and retaining wall
dures used do not consider material variation, purpose for
backfill applications. The principal use of the test method is to
obtaining the data, special purpose studies, or any consider-
supplement soil resistivity measurements to identify conditions
ations for the user’s objectives; and it is common practice to
under which the corrosion of metal embedded in granular
increase or reduce significant digits of reported data to be
material, or in contact with the granular material may be
commensuratewiththeseconsiderations.Itisbeyondthescope
sharply accentuated.
of these test methods to consider significant digits used in
1.2 The pH of granular material is often specified by
analysis methods for engineering data.
agenciestomeetcriteriathatarenecessarytopreventorreduce
1.7 This standard does not purport to address all of the
corrosion of metal objects embedded in the granular material
safety concerns, if any, associated with its use. It is the
used in embankments, subgrade, and retaining wall backfill.
responsibility of the user of this standard to establish appro-
1.3 The types of granular material that can be tested for pH
priate safety, health, and environmental practices and deter-
using this standard are natural or manufactured coarse sand,
mine the applicability of regulatory limitations prior to use.
natural or crushed stone, natural or crushed gravel, air-cooled
1.8 This international standard was developed in accor-
blast furnace slag, and aggregates: lightweight, heavyweight,
dance with internationally recognized principles on standard-
or normal weight. According to AASHTO M 145, these
ization established in the Decision on Principles for the
granular materials generally fall into AASHTO classification
Development of International Standards, Guides and Recom-
groups A-1, A-2-4, A-2-5, or A-3. The ideal material is a
mendations issued by the World Trade Organization Technical
well-graded, free draining material that has less than 10-15 %
Barriers to Trade (TBT) Committee.
passing the 75 µm (No. 200) sieve.
1.4 This test is based on the volumetric method because the 2. Referenced Documents
unit weight of the fill material will vary depending on source
2.1 ASTM Standards:
and project specifications.
C125 Terminology Relating to Concrete and Concrete Ag-
1.5 Units—The values stated in SI units are to be regarded
gregates
as standard. Except the sieve designations, they are identified C702/C702M Practice for Reducing Samples of Aggregate
usingthe“alternative”systeminaccordancewithSpecification to Testing Size
E11, such as 3 in. and No. 200, instead of the “standard” of 75 D75/D75M Practice for Sampling Aggregates
mm and 75 µm, respectively. No other units of measurement D653 Terminology Relating to Soil, Rock, and Contained
are included in this standard. Reporting of test results in units Fluids
other than SI shall not be regarded as nonconformance with D1193 Specification for Reagent Water
this standard. D3740 Practice for Minimum Requirements for Agencies
Engaged in Testing and/or Inspection of Soil and Rock as
1.6 All observed and calculated values shall conform to the
Used in Engineering Design and Construction
guidelines for significant digits and rounding established in
D4972 Test Methods for pH of Soils
Practice D6026, unless superseded by this test method.
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
RockandisthedirectresponsibilityofSubcommitteeD18.06onPhysical-Chemical For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Interactions of Soil and Rock. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved March 1, 2022. Published March 2022. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D8262-22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8262−22
D6026 Practice for Using Significant Digits and Data Re- 6. Apparatus
cords in Geotechnical Data
6.1 pH Meter—Potentiometer equipped with an electrode
D6913/D6913M Test Methods for Particle-Size Distribution
system having a readability to the nearest 0.1 pH unit and an
(Gradation) of Soils Using Sieve Analysis
accuracy of 60.1 pH units or better.
E11 Specification for Woven Wire Test Sieve Cloth and Test
6.2 Timing Device—A clock, stopwatch, digital timer, or
Sieves
comparable device readable to1sor better.
2.2 AASHTO Standards:
6.3 Thermometric Device—A thermometric device capable
M 145 Standard Specification for the Classification of Soils
of measuring the temperature range within which the test is
and Soil-Aggregate Mixtures for Highway Construction
being performed readable to 0.5°C or better and having an
Purposes
accuracy of at least 60.5°C.
3. Terminology 6.4 Specimen Container—A clean, chemically inert con-
tainer or bucket having enough capacity to hold the specimen
3.1 Definitions:
and test water. The container shall have solid walls that do not
3.1.1 For definitions of common technical terms used in this
have any defects or holes that will allow water or the material
standard, refer to Terminology D653 and Terminology C125.
to be lost after filling.
6.5 Miscellaneous Items—Items such as a chemically inert
4. Summary of Test Method
spatula or spoon, aluminum foil, lid, straightedge, graduated
4.1 A bulk sample that is representative of the material for
cylinders/beakers, and tissues are useful.
the intended application is obtained from the field. The bulk
sample is reduced to obtain a representative sample. The
7. Reagents and Materials
representativesampleisthenreducedtoobtainoneormoretest
7.1 Purity of Reagents—Reagent-grade chemicals shall be
specimens. The test water and specimen(s) are mixed together
used in all tests. Unless otherwise indicated, it is intended that
in a specimen container at a ratio of five parts water to one part
all reagents conform to the specifications of the Committee on
specimen.After 24 h, the pH of the test specimen in test water
Analytical Reagents of the American Chemical Society where
is measured.
such specifications are available. Other grades may be used,
provided it is first ascertained that the reagent is of sufficiently
5. Significance and Use
high purity to permit its use without lessening the accuracy of
5.1 Granular material being used in embankments,
the determination.
subgrades, and retaining wall backfill must often meet certain
7.2 Buffer Solutions—Commercially available, providing
specifications relating to corrosion potential, such as pH and
they meet the purity of reagents as described above, or made
electrical resistivity. This standard is used by manufacturers,
in-housebuffersolutionsof4.0,7.0,and10.0shallbeused(see
suppliers, and recipients of the materials to measure the pH of
Note 2). See Test Methods D4972 for making buffer solutions.
the material for acceptance for its intended use.
7.3 Test Water—Distilled water as defined by Types I, II, or
5.2 Retaining wall manufactures often use a granular mate-
III of Specification D1193 is the only permissible test fluid.
rial specification similar to: 100 % passing the 100 mm (4 in.)
The use of tap water is not permitted. The pH of the distilled
sieve, 75-100 % passing the 75 mm (3 in.) sieve, and 0-15 %
water must be between 5.5 and 7.5. The test water must be at
passing the 75 µm (No. 200) sieve. The specification may vary
a temperature of 21 6 2°C.
depending on availability of local materials.
NOTE 2—In some cases it may be appropriate to also include a pH
5.3 Since the total surface area of the material being tested
buffer of 12 if the suspected pH of the material could be higher than 10 or
a buffer of 2 if the pH could be lower than 4. These solutions may cause
affects the test results, the sample and specimen must have the
eye and skin irritation. Care should be taken to avoid contact. The use of
same grading as the material specified or proposed for use.
latex gloves and possibly safety glasses when using the solutions is
Reducing the particle size by crushing is not permitted since
recommended.
this process may alter the pH of the material and will likely not
be representative of the material actually being placed in the
8. Sampling and Test Specimens
field.
8.1 Obtain the bulk sample in accordance with Practice
NOTE 1—The quality of the result produced by this standard is
D75/D75M making sure the gradation of the sample is repre-
dependent on the competence of the personnel performing it, and the
sentative of the material intended for use.
suitability of the equipment and facilities used. Agencies that meet the
criteria of Practice D3740 are generally considered capable of competent
8.2 Reduce the bulk sample using either Practice C702/
and objective testing/sampling/inspection/etc. Users of this standard are
C702M orTest Method D6913/D6913M,AnnexA2 in order to
cautioned that compliance with Practice D3740 does not in itself assure
obtainarepresentativesample.Therepresentativesamplemust
reliable results. Reliable results depend on many factors; Practice D3740
provides a means of evaluating some of those factors.
have a minimum volume of 1.5 L.
Reagent Chemicals, American Chemical Society Specifications, American
Available from American Association of State Highway and Transportation Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001, listed by the American Chemical Socie
...