ASTM D5298-94
(Test Method)Standard Test Method for Measurement of Soil Potential (Suction) Using Filter Paper (Withdrawn 2003)
Standard Test Method for Measurement of Soil Potential (Suction) Using Filter Paper (Withdrawn 2003)
SCOPE
1.1 This test method covers laboratory filter papers as passive sensors to evaluate the soil matric (matrix) and total potential (suction), a measure of the free energy of the pore-water or tension stress exerted on the pore-water by the soil matrix (1, 2) . The term potential or suction is descriptive of the energy status of soil water.
1.2 This test method controls the variables for measurement of the water content of filter paper that is in direct contact with soil or in equilibrium with the partial pressure of water vapor in the air of an airtight container enclosing a soil specimen. The filter paper is enclosed with a soil specimen in the airtight container until moisture equilibrium is established; that is, the partial pressure of water vapor in the air is in equilibrium with the vapor pressure of pore-water in the soil specimen.
1.3 This test method provides a procedure for calibrating different types of filter paper for use in evaluating soil matric and total potential.
1.4 The values stated in SI units are to be regarded as the standard. The inch-pounds units given in parentheses are approximate.
1.5 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 applicability of regulatory limitations prior to use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5298 – 94
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Measurement of Soil Potential (Suction) Using Filter Paper
This standard is issued under the fixed designation D 5298; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope (Moisture) Content of Soil and Rock
D 2325 Test Method for Capillary-Moisture Relationships
1.1 This test method covers laboratory filter papers as
for Coarse and Medium-Textured Soils by Porous-Plate
passive sensors to evaluate the soil matric (matrix) and total
Apparatus
potential (suction), a measure of the free energy of the
D 3152 Test Method for Capillary-Moisture Relationships
pore-water or tension stress exerted on the pore-water by the
for Fine-Textured Soils by Pressure-Membrane Apparatus
soil matrix (1, 2) . The term potential or suction is descriptive
D 4542 Test Method for Pore-Water Extraction and Deter-
of the energy status of soil water.
mination of the Solute Salt Content of Soils by Refracto-
1.2 This test method controls the variables for measurement
meter
of the water content of filter paper that is in direct contact with
D 4753 Specification for Evaluating, Selecting, and Speci-
soil or in equilibrium with the partial pressure of water vapor
fying Balances and Scales for Use in Testing Soil, Rock
in the air of an airtight container enclosing a soil specimen. The
and Related Construction Materials
filter paper is enclosed with a soil specimen in the airtight
E 337 Test Method for Measuring Humidity With a Psy-
container until moisture equilibrium is established; that is, the
chrometer (the Measurement of Wet- and Dry-Bulb Tem-
partial pressure of water vapor in the air is in equilibrium with
peratures
the vapor pressure of pore-water in the soil specimen.
E 832 Specification for Laboratory Filter Papers
1.3 This test method provides a procedure for calibrating
different types of filter paper for use in evaluating soil matric
3. Terminology
and total potential.
3.1 Definitions:
1.4 The values stated in SI units are to be regarded as the
3.1.1 Refer to Terminology D 653 for standard definitions of
standard. The inch-pounds units given in parentheses are
terms.
approximate.
3.2 Definitions of Terms Specific to This Standard:
1.5 This standard does not purport to address all of the
3.2.1 atmosphere—a unit of pressure equal to 76 cm Mer-
safety concerns, if any, associated with its use. It is the
cury or 101 kPa at 0°C.
responsibility of the user of this standard to establish appro-
3.2.2 matric (matrix) suction, hm (kPa)—the negative pres-
priate safety and health practices and determine the applica-
sure (expressed as a positive value), relative to ambient
bility of regulatory limitations prior to use.
atmospheric pressure on the soil water, to which a solution
2. Referenced Documents identical in composition with the soil water must be subjected
in order to be in equilibrium through a porous permeable wall
2.1 ASTM Standards:
with the soil water; pressure equivalent to that measured by
C 114 Test Methods for Chemical Analysis of Hydraulic
Test Methods D 2325 and D 3152. Matric suction is a function
Cement
of the relative humidity due to the difference in air and water
D 653 Terminology Relating to Soil, Rock, and Contained
pressure across the water surface; the relative humidity or
Fluids
water vapor pressure decreases as the radius of curvature of the
D 1125 Test Method for Electrical Conductivity and Resis-
water surface decreases. The term “matric” is grammatically
tivity of Water
correct, while matrix is commonly used in the civil engineering
D 2216 Test Method for Laboratory Determination of Water
literature.
3.2.3 molality, moles/1000 g—number of moles of solute
This test method is under the jurisdiction of ASTM Committee D-18 on Soil
per 1000 g of solvent.
and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic
3.2.4 mole—molecular weight of a substance in grams.
Properties.
3.2.5 osmotic (solute) suction, hs (kPa)—the negative pres-
Current edition approved Sept. 15, 1994. Published November 1994. Originally
published as D 5298 – 92. Last previous edition D 5298 – 92. sure to which a pool of pure water must be subjected in order
The boldface numbers given in parentheses refer to a list of references at the
end of the text.
Annual Book of ASTM Standards, Vol 04.01.
4 6
Annual Book of ASTM Standards, Vol 04.08. Annual Book of ASTM Standards, Vol 11.03.
5 7
Annual Book of ASTM Standards, Vol 11.01. Annual Book of ASTM Standards, Vol 14.02.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5298
to be in equilibrium through a semipermeable membrane with processes (1) and to evaluate the potential for heave or
a pool containing a solution identical in composition with the shrinkage, shear strength, modulus, in situ stress and hydraulic
soil water; decrease in relative humidity due to the presence of conductivity of unsaturated soils.
dissolved salts in pore-water. 5.4 The filter paper method of evaluating suction is simple
and economical with a range from 10 to 100 000 kPa (0.1 to
3.2.6 pF—a unit of negative pressure expressed as the
1000 bars).
logarithm to the base ten of the height in centimeters that a
column of water will rise by capillary action or negative gage
2 3 6. Apparatus
pressure (Mg/m ) divided by the unit weight of water (Mg/m )
6.1 Filter Paper—The paper used must be ash-free quanti-
times 1000. pF ’ 3 + logarithm to the base ten of the negative
tative Type II filter paper, see Specification E 832; for example,
pressure in atmospheres. Refer to capillary head or capillary
Whatman No. 42, Fisherbrand 9-790A, Schleicher and
rise in Terminology D 653.
Schuell No. 589 White Ribbon. A suitable diameter is 5.5 cm
3.2.7 soil relative humidity, R —the ratio of the vapor
h
(2.2 in.).
pressure of pore water in the soil to the vapor pressure of free
pure water. Relative humidity in the soil is defined as relative NOTE 1—Filter papers may be treated by dipping each paper in a 2 %
concentration of formaldehyde prior to use to prevent organism growth on
humidity measured by Test Method E 337.
or biological decomposition of the filter paper. Biological decomposition
3.2.8 total potential (kPa)—the sum of gravitational, pres-
may be significant when filter papers are subject to a moist, warm
sure, osmotic and external gas potentials. Potential may be
environment for more than 14 days. Appropriate precautions should be
identified with suction when gravitational and external gas
taken when preparing formaldehyde solutions and treating filter paper.
potentials are neglected.
6.2 Specimen Container—120 to 240 mL (4 to 8 oz)
3.2.9 total soil suction, h (kPa)—the negative pressure,
capacity metal or glass (rust free) container and lid (for
relative to the external gas pressure on the soil water, to which
example, coated with zinc chromate to retard rusting) to
a pool of pure water must be subjected to be in equilibrium
contain the specimen and filter papers. The inside of these
with the soil water through a semipermeable membrane that is
containers may also be coated with wax to retard rusting.
permeable to water molecules only. Total soil suction (ex-
6.3 Filter Paper Container—This container holds filter
pressed as a positive value) is the sum of osmotic (solute) and
paper following the equilibration of suction and removal from
matric (matrix) suctions.
the specimen container.
3.2.10 vapor pressure of free pure water (kPa)—the satura- 6.3.1 Metal Container Alternate—Two nominal 70 mL (2
tion vapor pressure of free pure water at a given dry-bulb
oz) capacity metal moisture containers (aluminum or stainless)
temperature. with lids to dry the filter paper. The containers should be
numbered by imprinting with a metal stamp. The containers
3.2.11 vapor pressure of pore water in soil (kPa)—the
should not be written on with any type of marker or labelled in
partial pressure of water vapor that is in equilibrium with
any manner. Throw-away vinyl surgical non-powdered or
pore-water in soil at a given dry-bulb temperature.
similar gloves should be used anytime the small containers
designated for filter paper measurements are handled to prevent
4. Summary of Test Method
body oils from influencing any mass measurements made prior
4.1 Filter papers are placed in an airtight container with a
to handling.
specimen for seven days to allow sufficient time for the vapor
6.3.2 Plastic Bag Alternate—Plastic bag large enough to
pressure of pore-water in the specimen, vapor pressure of pore
accommodate the filter paper disks (approximately 50 mm in
water in the filter paper, and partial vapor pressure of water in
dimension) capable of an airtight seal.
3 3
the air inside the container to reach equilibrium. The mass of
6.4 Insulated Chest—A box of approximately 0.03 m (1 ft )
the filter papers is subsequently determined and the suction of
capacity insulated with foamed polystyrene or other material
the specimen is determined from a calibration relationship of
capable of maintaining temperature within 6 1°C when
the filter paper water content with suction applicable to the type
external temperatures vary 6 3°C.
of filter paper and the test procedure of this test method.
6.5 Balance—A balance or scale having a minimum capac-
ity of 20 g and meeting the requirements of 4.2.1.1 of
5. Significance and Use
Specification C 114 for a balance of 0.0001 g readability. In
addition, balances for performance of Test Method D 2216,
5.1 Soil suction is a measure of the free energy of the
meeting requirements of Specification D 4753.
pore-water in a soil. Soil suction in practical terms is a measure
6.6 Drying Oven—Thermostatically-controlled, preferably
of the affinity of soil to retain water and can provide informa-
of the forced-draft type, and capable of maintaining a uniform
tion on soil parameters that are influenced by the soil water; for
temperature of 110 6 5°C throughout the drying chamber and
example, volume change, deformation, and strength character-
meeting requirements of Test Method D 2216.
istics of the soil.
6.7 Metal Block—A metal block > 500 g mass with a flat
5.2 Soil suction is related with soil water content through
water retention characteristic curves (see Test Method D 2325).
Soil water content may be found from Test Method D 2216.
The boldface numbers in parentheses refer to the list of references at the end of
5.3 Measurements of soil suction may be used with other
this standard.
soil and environmental parameters to evaluate hydrologic Available from Thomas Scientific Supply, P.O. Box 99, Swedesboro, NJ 08085.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5298
surface to hasten cooling of the metal containers with filter
paper.
6.8 Thermometer—An instrument to determine the tem-
perature of the tested soil to an accuracy of 6 1°C.
6.9 Miscellaneous Equipment—Tweezers, trimming knife,
flexible plastic electrical tape, O-rings, screen wire, brass discs,
etc. Tweezers should be at least 110 mm (4.5 in.) in length.
6.10 Desiccator—A desiccator jar of suitable size contain-
ing silica gel or anhydrous calcium sulfate.
NOTE 2—Anhydrous calcium sulfate is sold under the trade name
Drierite.
NOTE 3—It is preferable to use a desiccant that changes color to
indicate when it needs reconstitution.
NOTE 1—Coefficient of determination r >0.99.
FIG. 1 Calibration Suction-Water Content Curves for Wetting of
7. Calibration
Filter Paper (4)
7.1 Obtain a calibration curve applicable to a specific filter
paper by following the procedure in Section 8, except for
suction . Variability in results is less than 2 % of the suction
replacing the soil specimen with salt solutions such as reagent
above 100 kPa. Soil disturbance has minimal influence on
grade potassium chloride or sodium chloride of known mola-
suction above 20 kPa. At moisture contents with suctions less
lity in distilled water.
than 20 kPa, sample disturbance increases variability of mea-
7.1.1 Suspend the filter paper above at least 50 cc of a salt
surement (2, 4). The right vertical axis of Fig. 1 provides the
solution in the specimen container, see 6.2, by placing it on an
suction in units pF and atmospheres pressure; for example, h
improvised platform made of inert material such as plastic
5 2 log atmospheres is a suction of 100 atmospheres, while
tubing or stainless steel screen.
pF 5 5 or 100 000 cm water.
7.1.2 Calculate the suction of the filter paper from the
NOTE 4—Filter paper may be calibrated by using the pressure mem-
relative humidity of the air above the solution by:
brane, see Test Method D 3152 for the range 100 to 1500 kPa (1 to 15
RT
atm), and the ceramic plate, see Test Method D 2325 for the range 10 to
h 5 · ln R (1)
h
v
100 kPa (0.1 to 1 atm).
where:
8. Procedure
h 5 suction, kPa,
8.1 Filter Paper Preparation—Dry filter papers selected for
R 5 ideal gas constant, 8.31432 Joules/mole·K,
testing at least 16 h or overnight in the drying oven. Place filter
T 5 absolute temperature, degrees kelvin (K),
papers in a desiccant jar over desiccant after drying for storage
v 5 volume of 1000 moles of liquid water, 0.018 m , and
until use.
R 5 relative humidity, fraction.
h
8.2 Measurement of Suction—Total suction will be mea-
7.1.3 Standard critical tables may be used to evaluate the
sured if filter papers are not in contact with the soil specimen;
relative humidity of water in equilibrium with the salt solution
moisture transfer will be limited to vapor transfer through the
as illustrated in Table 1. Refer to Test Method E 337 for further
air inside the specimen container. Matric suction will be
information on relative humidity.
measured if the filter paper is in physical contact with the soil.
7.2 Typical calibration curves for filter papers (for example,
9 9 Physical contact between the soil and filter paper allows fluid
Whatman No. 42, Schleicher and Schuell No. 589), see Fig.
transfer including transfer of salts that may be dissolved in the
1, consists of two parts. The upper segment represents moisture
pore water.
retained as films adsorbed to particle surfaces, while the lower
segmen
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.