ASTM D5084-16a

Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter

SIGNIFICANCE AND USE
4.1 These test methods apply to one-dimensional, laminar flow of water within porous materials such as soil and rock.  
4.2 The hydraulic conductivity of porous materials generally decreases with an increasing amount of air in the pores of the material. These test methods apply to water-saturated porous materials containing virtually no air.  
4.3 These test methods apply to permeation of porous materials with water. Permeation with other liquids, such as chemical wastes, can be accomplished using procedures similar to those described in these test methods. However, these test methods are only intended to be used when water is the permeant liquid. See Section 6.  
4.4 Darcy's law is assumed to be valid and the hydraulic conductivity is essentially unaffected by hydraulic gradient.  
4.5 These test methods provide a means for determining hydraulic conductivity at a controlled level of effective stress. Hydraulic conductivity varies with varying void ratio, which changes when the effective stress changes. If the void ratio is changed, the hydraulic conductivity of the test specimen will likely change, see Appendix X2. To determine the relationship between hydraulic conductivity and void ratio, the hydraulic conductivity test would have to be repeated at different effective stresses.  
4.6 The correlation between results obtained using these test methods and the hydraulic conductivities of in-place field materials has not been fully investigated. Experience has sometimes shown that hydraulic conductivities measured on small test specimens are not necessarily the same as larger-scale values. Therefore, the results should be applied to field situations with caution and by qualified personnel.  
4.7 In most cases, when testing high swell potential materials and using a constant-volume hydraulic system, the effective confining stress should be about 1.5 times the swell pressure of the test specimen or a stress which prevents swelling. If the confining stress is less ...
SCOPE
1.1 These test methods cover laboratory measurement of the hydraulic conductivity (also referred to as coefficient of permeability) of water-saturated porous materials with a flexible wall permeameter at temperatures between about 15 and 30°C (59 and 86°F). Temperatures outside this range may be used; however, the user would have to determine the specific gravity of mercury and RT  (see 10.3) at those temperatures using data from  Handbook of Chemistry and Physics. There are six alternate methods or hydraulic systems that may be used to measure the hydraulic conductivity. These hydraulic systems are as follows:  
1.1.1 Method A—Constant Head  
1.1.2 Method B—Falling Head, constant tailwater elevation  
1.1.3 Method C—Falling Head, rising tailwater elevation  
1.1.4 Method D—Constant Rate of Flow  
1.1.5 Method E—Constant Volume–Constant Head (by mercury)  
1.1.6 Method F—Constant Volume–Falling Head (by mercury), rising tailwater elevation  
1.2 These test methods use water as the permeant liquid; see 4.3 and Section 6 on Reagents for water requirements.  
1.3 These test methods may be utilized on all specimen types (intact, reconstituted, remolded, compacted, etc.) that have a hydraulic conductivity less than about 1 × 10−6 m/s (1 × 10−4 cm/s), providing the head loss requirements of 5.2.3 are met. For the constant-volume methods, the hydraulic conductivity typically has to be less than about 1 × 10−7 m/s.  
1.3.1 If the hydraulic conductivity is greater than about 1 × 10−6 m/s, but not more than about 1 × 10−5 m/s; then the size of the hydraulic tubing needs to be increased along with the porosity of the porous end pieces. Other strategies, such as using higher viscosity fluid or properly decreasing the cross-sectional area of the test specimen, or both, may also be possible. The key criterion is that the requirements covered in Section 5 have to be met.  
1.3.2 If the hydraulic conductivity is less than abo...

General Information

• Status: Published
• Publication Date: 14-Aug-2016
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.04 - Hydrologic Properties and Hydraulic Barriers

Relations

• Refers: ASTM D4753-24 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-Feb-2024
• Refers: ASTM D854-23 - Standard Test Methods for Specific Gravity of Soil Solids by the Water Displacement Method
• Effective Date: 01-Nov-2023
• Refers: ASTM D3740-23 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Nov-2023
• Refers: ASTM D4767-11(2020) - Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils
• Effective Date: 01-Apr-2020
• Refers: ASTM D3740-19 - Standard Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction
• Effective Date: 01-Oct-2019
• Refers: ASTM D2216-19 - Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
• Effective Date: 01-Mar-2019
• Refers: ASTM D4318-17 - Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
• Effective Date: 01-Jun-2017
• Refers: ASTM D4318-17e1 - Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
• Effective Date: 01-Jun-2017
• Refers: ASTM D4753-15 - Standard Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing
• Effective Date: 01-May-2015
• Refers: ASTM D1140-14 - Standard Test Methods for Determining the Amount of Material Finer than 75-μm (No. 200) Sieve in Soils by Washing
• Effective Date: 01-Nov-2014
• Refers: ASTM D653-14 - Standard Terminology Relating to Soil, Rock, and Contained Fluids
• Effective Date: 01-Aug-2014
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM D1587-08(2012)e1 - Standard Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes
• Effective Date: 15-May-2012

Overview

ASTM D5084-16a outlines the standardized test methods for the laboratory determination of hydraulic conductivity (also referred to as the coefficient of permeability) in water-saturated porous materials-such as soil and rock-using a flexible wall permeameter. These methods are foundational for geotechnical, environmental, and civil engineering projects that require precise assessment of water flow characteristics through saturated materials under controlled laboratory conditions.

This standard provides several alternate procedures adapted to accommodate various specimen types and hydraulic conditions, ensuring reliable measurement of hydraulic conductivity for materials exhibiting low permeability. ASTM D5084 is widely recognized internationally, making it a critical tool for quality assurance in soil and groundwater investigations.

Key Topics

• Test Scope and Applicability

  • Applies to one-dimensional, laminar flow of water through saturated soils and rocks
  • Designed for use with water as the permeant liquid, but methods may guide similar testing with other fluids
  • Suitable for intact, reconstituted, remolded, and compacted specimens with hydraulic conductivity less than approximately 1 × 10⁻⁶ m/s

• Test Methods
  Six alternate systems for measuring hydraulic conductivity with a flexible wall permeameter:

  • Constant Head (Method A)
  • Falling Head with Constant Tailwater (Method B)
  • Falling Head with Rising Tailwater (Method C)
  • Constant Rate of Flow (Method D)
  • Constant Volume–Constant Head (by mercury, Method E)
  • Constant Volume–Falling Head (by mercury, Method F)

• Significance and Limitations

  • Assumes laminar flow and validity of Darcy's law
  • Tests are performed at controlled effective stress; results may vary with void ratio changes
  • Results may not precisely represent in-situ field conditions-careful judgement required for field application

• Apparatus Requirements

  • Flexible wall permeameter with controllable hydraulic systems and pressure application
  • Devices for specimen preparation, trimming, measurement, and water de-airing
  • Safety precautions are highlighted, particularly regarding mercury use in Methods E and F

Applications

• Geotechnical Engineering
  Hydraulic conductivity results are pivotal for designing earth dams, levees, landfill liners, and groundwater containment systems. The test informs on seepage behavior, groundwater movement, and suitability of construction materials.

• Environmental Site Assessments
  Used in the evaluation and remediation of contaminated sites, landfill siting, and assessment of barrier system effectiveness for controlling liquid migration.

• Research and Material Development
  Supports studies of soil, rock, and barrier material properties and their responses under varying stress and saturation conditions.

• Quality Control and Specification Compliance
  Ensures materials meet regulatory and engineering performance specifications, increasing project reliability and reducing risk.

Related Standards

• ASTM D653 – Terminology Relating to Soil, Rock, and Contained Fluids
• ASTM D854 – Test Methods for Specific Gravity of Soil Solids by Water Pycnometer
• ASTM D2216 – Test Methods for Laboratory Determination of Water Content of Soil and Rock
• ASTM D2434 – Test Method for Permeability of Granular Soils (for higher hydraulic conductivity materials)
• ASTM D3740 – Minimum Requirements for Testing and Inspection Agencies
• ASTM D4767 – Consolidated Undrained Triaxial Compression Test for Cohesive Soils

Conclusion

ASTM D5084-16a delivers a robust framework for laboratory measurement of hydraulic conductivity in saturated soils and rocks using flexible wall permeameters. By employing this standard, engineers, environmental consultants, and researchers obtain reliable data essential for safe, effective soil and groundwater management. For best results, always use the latest official ASTM edition and follow proper safety procedures, especially when mercury is involved.

Standards Content (Sample)

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: D5084 − 16a
Standard Test Methods for
Measurement of Hydraulic Conductivity of Saturated Porous
Materials Using a Flexible Wall Permeameter
This standard is issued under the fixed designation D5084; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* possible. The key criterion is that the requirements covered in
Section 5 have to be met.
1.1 Thesetestmethodscoverlaboratorymeasurementofthe
1.3.2 If the hydraulic conductivity is less than about
hydraulic conductivity (also referred to as coeffıcient of per-
−11
1×10 m/s, then standard hydraulic systems and tempera-
meability) of water-saturated porous materials with a flexible
tureenvironmentswilltypicallynotsuffice.Strategiesthatmay
wall permeameter at temperatures between about 15 and 30°C
be possible when dealing with such impervious materials may
(59 and 86°F). Temperatures outside this range may be used;
include the following: (a) controlling the temperature more
however, the user would have to determine the specific gravity
precisely, (b) adoption of unsteady state measurements by
of mercury and R (see 10.3) at those temperatures using data
T
using high-accuracy equipment along with the rigorous analy-
from Handbook of Chemistry and Physics. There are six
ses for determining the hydraulic parameters (this approach
alternate methods or hydraulic systems that may be used to
reducestestingdurationaccordingtoZhangetal.(1) ),and (c)
measure the hydraulic conductivity. These hydraulic systems
shortening the length or enlarging the cross-sectional area, or
are as follows:
both, of the test specimen (with consideration to specimen
1.1.1 Method A—Constant Head
grain size (2)). Other approaches, such as use of higher
1.1.2 Method B—Falling Head, constant tailwater elevation
hydraulic gradients, lower viscosity fluid, elimination of any
1.1.3 Method C—Falling Head, rising tailwater elevation
possible chemical gradients and bacterial growth, and strict
1.1.4 Method D—Constant Rate of Flow
verification of leakage, may also be considered.
1.1.5 Method E—ConstantVolume–ConstantHead(bymer-
1.4 The hydraulic conductivity of materials with hydraulic
cury)
−5
conductivitiesgreaterthan1×10 m/smaybedeterminedby
1.1.6 Method F—Constant Volume–Falling Head (by
Test Method D2434.
mercury), rising tailwater elevation
1.5 All observed and calculated values shall conform to the
1.2 Thesetestmethodsusewaterasthepermeantliquid;see
guideforsignificantdigitsandroundingestablishedinPractice
4.3 and Section 6 on Reagents for water requirements.
D6026.
1.3 These test methods may be utilized on all specimen
1.5.1 Theproceduresusedtospecifyhowdataarecollected,
types (intact, reconstituted, remolded, compacted, etc.) that
recorded, and calculated in this standard are regarded as the
−6
have a hydraulic conductivity less than about 1×10 m/s
industry standard. In addition, they are representative of the
−4
(1×10 cm/s), providing the head loss requirements of 5.2.3
significant digits that should generally be retained. The proce-
are met. For the constant-volume methods, the hydraulic
dures used do not consider material variation, purpose for
−7
conductivity typically has to be less than about 1×10 m/s.
obtaining the data, special purpose studies, or any consider-
1.3.1 If the hydraulic conductivity is greater than about
ations for the user’s objectives; and it is common practice to
−6 −5
1×10 m/s, but not more than about 1×10 m/s; then the
increase or reduce significant digits of reported data to be
size of the hydraulic tubing needs to be increased along with
commensuratewiththeseconsiderations.Itisbeyondthescope
the porosity of the porous end pieces. Other strategies, such as
of this standard to consider significant digits used in analysis
using higher viscosity fluid or properly decreasing the cross-
methods for engineering design.
sectional area of the test specimen, or both, may also be
1.6 This standard also contains a Hazards section (Section
7).
1.7 The time to perform this test depends on such items as
This standard is under the jurisdiction of ASTM Committee D18 on Soil and
the Method (A, B, C, D, E, or F) used, the initial degree of
Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic
Properties and Hydraulic Barriers.
Current edition approved Aug. 15, 2016. Published August 2016. Originally
approved in 1990. Last previous edition approved in 2016 as D5084–16. DOI: The boldface numbers in parentheses refer to the list of references appended to
10.1520/D5084-16A. this standard.
*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
D5084 − 16a
saturation of the test specimen and the hydraulic conductivity D4318Test Methods for Liquid Limit, Plastic Limit, and
of the test specimen. The constant volume Methods (E and F) Plasticity Index of Soils
and Method D require the shortest period-of-time. Typically a D4753Guide for Evaluating, Selecting, and Specifying Bal-
test can be performed using Methods D, E, or F within two to ances and Standard Masses for Use in Soil, Rock, and
three days. MethodsA, B, and C take a longer period-of-time, Construction Materials Testing
from a few days to a few weeks depending on the hydraulic D4767Test Method for Consolidated Undrained Triaxial
conductivity.Typically,aboutoneweekisrequiredforhydrau- Compression Test for Cohesive Soils
–9
licconductivitiesontheorderof1×10 m/s.Thetestingtime D5079Practices for Preserving andTransporting Rock Core
is ultimately controlled by meeting the equilibrium criteria for Samples
each Method (see 9.5). D6026Practice for Using Significant Digits in Geotechnical
Data
1.8 Units—The values stated in SI units are to be regarded
D6151PracticeforUsingHollow-StemAugersforGeotech-
as the standard. The inch-pound units given in parentheses are
nical Exploration and Soil Sampling
mathematical conversions, which are provided for information
D6169Guide for Selection of Soil and Rock Sampling
purposes only and are not considered standard, unless specifi-
Devices Used With Drill Rigs for Environmental Investi-
cally stated as standard, such as 0.5 mm or 0.01 in.
gations
1.9 This standard does not purport to address all of the
E177Practice for Use of the Terms Precision and Bias in
safety concerns, if any, associated with its use. It is the
ASTM Test Methods
responsibility of the user of this standard to establish appro-
E691Practice for Conducting an Interlaboratory Study to
priate safety and health practices and determine the applica-
Determine the Precision of a Test Method
bility of regulatory limitations prior to use.
3. Terminology
2. Referenced Documents
3.1 Definitions:
2.1 ASTM Standards:
3.1.1 For common definitions of technical terms in this
D653Terminology Relating to Soil, Rock, and Contained
standard, refer to Terminology D653.
Fluids
D698Test Methods for Laboratory Compaction Character- 3.1.2 head loss, ∆h—the change in total head of water
across a given distance.
istics of Soil Using Standard Effort (12,400 ft-lbf/ft (600
kN-m/m ))
3.1.2.1 Discussion—In hydraulic conductivity testing, typi-
D854Test Methods for Specific Gravity of Soil Solids by cally the change in total head is across the influent and effluent
Water Pycnometer
linesconnectedtothepermeameter,whilethegivendistanceis
D1140Test Methods for Determining the Amount of Mate- typically the length of the test specimen.
rialFinerthan75-µm(No.200)SieveinSoilsbyWashing
3.1.3 permeameter—the apparatus (cell) containing the test
D1557Test Methods for Laboratory Compaction Character-
specimen in a hydraulic conductivity test.
istics of Soil Using Modified Effort (56,000 ft-lbf/ft
3.1.3.1 Discussion—Theapparatusinthiscaseistypicallya
(2,700 kN-m/m ))
triaxial-type cell with all of its components (top and bottom
D1587Practice for Thin-Walled Tube Sampling of Fine-
specimen caps, stones, and filter paper; membrane; chamber;
Grained Soils for Geotechnical Purposes
top and bottom plates; valves; etc.).
D2113Practice for Rock Core Drilling and Sampling of
3.1.4 hydraulic conductivity, k—the rate of discharge of
Rock for Site Exploration
water under laminar flow conditions through a unit cross-
D2216Test Methods for Laboratory Determination ofWater
sectional area of porous medium under a unit hydraulic
(Moisture) Content of Soil and Rock by Mass
gradient and standard temperature conditions (20°C).
D2434Test Method for Permeability of Granular Soils
3.1.4.1 Discussion—In hydraulic conductivity testing, the
(Constant Head) (Withdrawn 2015)
term coeffıcient of permeability is often used instead of
D2435Test Methods for One-Dimensional Consolidation
hydraulic conductivity, but hydraulic conductivity is used
Properties of Soils Using Incremental Loading
exclusivelyinthisstandard.Amorecompletediscussionofthe
D3550Practice for Thick Wall, Ring-Lined, Split Barrel,
Drive Sampling of Soils (Withdrawn 2016) terminology associated with Darcy’s law is given in the
literature. (3, 4)
D3740Practice for Minimum Requirements for Agencies
Engaged in Testing and/or Inspection of Soil and Rock as
3.1.5 porevolumeofflow—inhydraulicconductivitytesting,
Used in Engineering Design and Construction
thecumulativequantityofflowintoatestspecimendividedby
D4220 Practices for Preserving and Transporting Soil
the volume of voids in the specimen.
Samples
4. Significance and Use
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4.1 These test methods apply to one-dimensional, laminar
contactASTM Customer Service at [e-mail]. ForAnnual Book ofASTM
flow of water within porous materials such as soil and rock.
Standards volume information, refer to the standard’s Document Summary page on
theASTM website.
4.2 The hydraulic conductivity of porous materials gener-
The last approved version of this historical standard is referenced on
www.astm.org. ally decreases with an increasing amount of air in the pores of
D5084 − 16a
the material. These test methods apply to water-saturated 5.1.1.1 Practice D6026 discusses the use or application of
porous materials containing virtually no air. estimated digits. When the last digit is estimated and that
reading is a function of the eye’s elevation/location, then a
4.3 These test methods apply to permeation of porous
mirror or another device is required to reduce the reading error
materials with water. Permeation with other liquids, such as
caused by parallax.
chemical wastes, can be accomplished using procedures simi-
5.1.2 Falling Head—The system shall allow for measure-
lartothosedescribedinthesetestmethods.However,thesetest
mentoftheappliedheadloss,thushydraulicgradient,to 65%
methods are only intended to be used when water is the
or better at any time. In addition, the ratio of initial head loss
permeant liquid. See Section 6.
divided by final head loss over an interval of time shall be
4.4 Darcy’s law is assumed to be valid and the hydraulic
measured such that this computed ratio is accurate to 65%or
conductivity is essentially unaffected by hydraulic gradient.
better. The head loss shall be measured with a pressure gage,
4.5 These test methods provide a means for determining
electronic pressure transducer, engineer’s scale, graduated
hydraulic conductivity at a controlled level of effective stress.
pipette, or any other device of suitable accuracy to a minimum
Hydraulic conductivity varies with varying void ratio, which
of three significant digits. The last digit may be due to
changes when the effective stress changes. If the void ratio is
estimation, see 5.1.1.1. Falling head tests may be performed
changed, the hydraulic conductivity of the test specimen will
witheitheraconstanttailwaterelevation(MethodB)orarising
likely change, see Appendix X2.To determine the relationship
tailwater elevation (Method C), see Fig. 1.This schematic of a
between hydraulic conductivity and void ratio, the hydraulic
hydraulic system presents the basic components needed to
conductivity test would have to be repeated at different
meet the objectives of Method C. Other hydraulic systems or
effective stresses.
schematics that meet these objectives are acceptable.
5.1.3 Constant Rate of Flow—The system must be capable
4.6 Thecorrelationbetweenresultsobtainedusingthesetest
of maintaining a constant rate of flow through the specimen to
methods and the hydraulic conductivities of in-place field
65% or better. Flow measurement shall be by calibrated
materials has not been fully investigated. Experience has
syringe,graduatedpipette,orotherdeviceofsuitableaccuracy.
sometimes shown that hydraulic conductivities measured on
The head loss across the permeameter shall be measured to a
small test specimens are not necessarily the same as larger-
minimum of three significant digits and to an accuracy of
scale values. Therefore, the results should be applied to field
65% or better using an electronic pressure transducer(s) or
situations with caution and by qualified personnel.
other device(s) of suitable accuracy. The last digit may be due
4.7 In most cases, when testing high swell potential mate-
to estimation, see 5.1.1.1. More information on testing with a
rials and using a constant-volume hydraulic system, the effec-
constant rate of flow is given in the literature (5).
tive confining stress should be about 1.5 times the swell
5.1.4 Constant Volume-Constant Head (CVCH)—The
pressure of the test specimen or a stress which prevents
system, with mercury to create the head loss, must be capable
swelling. If the confining stress is less than the swell pressure,
of maintaining a constant head loss cross the permeameter to
anomalous flow conditions my occur; for example, mercury
65% or better and shall allow for measurement of the applied
column(s) move in the wrong direction.
head loss to 65% or better at any time.The head loss shall be
NOTE 1—The quality of the result produced by this standard is
dependent of the competence of the personnel performing it and the measured to a minimum of three significant digits with an
suitability of the equipment and facilities used. Agencies that meet the
electronic pressure transducer(s) or equivalent device, (6)or
criteria of Practice D3740 are generally considered capable of competent
based upon the pressure head caused by the mercury column,
andobjectivetesting,sampling,inspection,etc.Usersofthisstandardare
see 10.1.2.The last digit may be due to estimation, see5.1.1.1.
cautioned that compliance with Practice D3740 does not in itself assure
reliable results. Reliable results depend on many factors; Practice D3740 5.1.4.1 SchematicsoftwoCVCHsystemsareshowninFig.
provides a means of evaluating some of those factors.
2 and Fig. 3. In each of these systems, the mercury-filled
portion of the tubing may be continuous for constant head loss
5. Apparatus
to be maintained. For the system showed in Fig. 2, the head
loss remains constant provided the mercury column is vertical
5.1 Hydraulic System—Constant head (Method A), falling
and is retained in only one half of the burette system (left
head (Methods B and C), constant rate of flow (Method D),
burette in Fig. 2). If the mercury spans both columns, a falling
constant volume-constant head (Method E), or constant
head exists. In the system shown in Fig. 3, the head loss
volume-falling head (Method F) systems may be utilized
remains constant provided the water-mercury interface on the
provided they meet the following criteria:
effluent end remains in the upper horizontal tube, and the
5.1.1 Constant Head—The system must be capable of
water-mercury interface on the influent end remains in the
maintainingconstanthydraulicpressuresto 65%orbetterand
lower horizontal tube. These schematics present the basic
shall include means to measure the hydraulic pressures to
components needed to meet the objectives of Method E. Other
within the prescribed tolerance. In addition, the head loss
hydraulic systems or schematics that meet these objectives are
across the permeameter must be held constant to 65% or
acceptable.
better and shall be measured with the same accuracy or better.
A pressure gage, electronic pressure transducer, or any other 5.1.4.2 These types of hydraulic systems are typically not
device of suitable accuracy shall measure pressures to a used to study the temporal or pore-fluid effect on hydraulic
minimum of three significant digits. The last digit may be due conductivity. The total volume of the specimen is maintained
to estimation, see 5.1.1.1. constant using this procedure, thereby significantly reducing
D5084 − 16a
FIG. 1 Falling Head – Rising Tail System, Method C
effects caused by seepage stresses, pore fluid interactions, etc. tivityofflowmeasurements,andtoenableflushingcleanwater
Rather, these systems are intended for determining the hydrau- through the system without excessive mercury displacement in
lic conductivity of a material as rapidly as possible. the headwater tube. The schematic of the hydraulic system in
5.1.4.3 Hazards—Since this hydraulic system contains
Fig. 4 presents the basic components needed to meet the
mercury, special health and safety precautions have to be objectivesofMethodF.Otherhydraulicsystemsorschematics
considered. See Section 7.
that meet these objectives are acceptable. The development of
5.1.4.4 Caution—For these types of hydraulic systems to
the hydraulic conductivity equation for this type of system is
function properly, the separation of the mercury column has to
given in Appendix X1.
beprevented.Topreventseparation,themercuryand“constant
5.1.5.2 See 5.1.4.2.
head” tube have to remain relatively clean, and the inside
5.1.5.3 Hazards—Since this hydraulic system contains
diameter of this tube cannot be too large; typically a capillary
mercury, special health and safety precautions have to be
tubeisused.Thelargerdiameterflushingtube(Fig.2)isadded
considered. See Section 7.
to enable flushing clean water through the system without
5.1.5.4 Caution—For these types of hydraulic systems to
excessive mercury displacement.Traps to prevent the acciden-
function properly, the separation of the mercury column and
talflowofmercuryoutofthe“ConstantHead”tubeorflushing
entrapment of water within the mercury column have to be
tube are not shown in Fig. 2 and Fig. 3.
prevented. To prevent such problems, the mercury and tubes
5.1.5 Constant Volume-Falling Head (CVFH)—Thesystem,
have to remain relatively clean. In addition, if different size
with mercury to create the head loss, shall meet the criteria
headwater and tailwater tubes are used, capillary head might
given in 5.1.2. The head loss shall be measured to a minimum
have to be accounted for, see Appendix X1, X1.2.3.2, and
of three significant digits with an electronic pressure transduc-
X1.4.Trapstopreventtheaccidentalflowofmercuryoutofthe
er(s) or equivalent device(s), (6) or based upon the differential
tubes are not shown in Fig. 4.
elevation between the top surfaces of the mercury level in the
headwater and tailwater tubes. The last digit may be due to 5.1.6 System De-airing—The hydraulic system shall be
designed to facilitate rapid and complete removal of free air
estimation, see 5.1.1.1.
5.1.5.1 A schematic drawing of a typical CVFH hydraulic bubbles from flow lines; for example, using properly sized
system is shown in Fig. 4 (6). Typically, the tailwater tube has tubing and ball valves and fittings without pipe threads.
a smaller area than the headwater tube to increase the sensi- Properly sized tubing, etc., means they are small enough to
D5084 − 16a
FIG. 2 Constant Volume – Constant or Falling Head System, Method E or F (6)
prevent entrapment of air bubbles, but not so small that the conjunction with an electronic pressure transducer, or other
requirements of 5.2.3 cannot be met. volume-measuring device of suitable accuracy.
5.1.7 Back Pressure System—The hydraulic system shall 5.2.1 FlowAccuracy—Requiredaccuracyforthequantityof
have the capability to apply back pressure to the specimen to flow measured over an interval of time is 65% or better.
facilitate saturation. The system shall be capable of maintain- 5.2.2 De-airing and Compliance of the System—The flow-
ing the applied back pressure throughout the duration of measurement system shall contain a minimum of dead space
hydraulic conductivity measurements. The back pressure sys- andbecapableofcompleteandrapidde-airing.Complianceof
tem shall be capable of applying, controlling, and measuring the system in response to changes in pressure shall be
the back pressure to 65% or better of the applied pressure. minimized by using a stiff flow measurement system. Rigid
The back pressure may be provided by a compressed gas tubing, such as metallic or rigid thermoplastic tubing, or glass
supply, a deadweight acting on a piston, or any other method shall be used.
capable of applying and controlling the back pressure to the 5.2.3 Head Losses—Headlossesinthetubes,valves,porous
tolerance prescribed in this paragraph. end pieces, and filter paper may lead to error.To guard against
such errors, the permeameter shall be assembled with no
NOTE2—Applicationofgaspressuredirectlytoafluidwilldissolvegas
specimen inside and then the hydraulic system filled.
in the fluid.Avariety of techniques are available to minimize dissolution
5.2.3.1 Constant or Falling Head—If a constant or falling
of gas in the back pressure fluid, including separation of gas and liquid
phaseswithabladderandfrequentreplacementoftheliquidwithde-aired
head test is to be used, the hydraulic pressures or heads that
water.
willbeusedintestingaspecimenshallbeapplied,andtherate
5.2 Flow Measurement System—Both inflow and outflow offlowmeasuredwithanaccuracyof 65%orbetter.Thisrate
volumes shall be measured unless the lack of leakage, conti- of flow shall be at least ten times greater than the rate of flow
nuityofflow,andcessationofconsolidationorswellingcanbe that is measured when a specimen is placed inside the
verified by other means. Flow volumes shall be measured by a permeameter and the same hydraulic pressures or heads are
graduated accumulator, graduated pipette, vertical standpipe in applied.
D5084 − 16a
FIG. 3 Constant Volume—Constant Head System, Method E
pressurizedcellliquidtothecellhelpstodelaytheappearanceofairinthe
5.2.3.2 Constant Rate of Flow—If a constant rate of flow
cell fluid and to reduce the flow of dissolved air into the cell.
test is to be used, the rate of flow to be used in testing a
specimen shall be supplied to the permeameter and the head
5.4 Permeameter Cell—An apparatus shall be provided in
loss measured. The head loss without a specimen shall be less
which the specimen and porous end pieces, enclosed by a
than 0.1 times the head loss when a specimen is present.
membrane sealed to the cap and base, are subjected to
controlled fluid pressures. A schematic diagram of a typical
5.3 Permeameter Cell Pressure System—The system for
pressurizing the permeameter cell shall be capable of applying permeameter cell and falling head (raising tailwater) hydraulic
and controlling the cell pressure to 65% or better of the system is shown in Fig. 1.
applied pressure. However, the effective stress on the test
5.4.1 The permeameter cell may allow for observation of
specimen(whichisthedifferencebetweenthecellpressureand
changes in height of the specimen, either by observation
the pore water pressure) shall be maintained to the desired
through the cell wall using a cathetometer or other instrument,
value with an accuracy of 610% or better. The device for
or by monitoring of either a loading piston or an extensometer
pressurizingthecellmayconsistofareservoirconnectedtothe
extending through the top plate of the cell bearing on the top
permeameter cell and partially filled with de-aired water, with
cap and attached to a dial indicator or other measuring device.
the upper part of the reservoir connected to a compressed gas
The piston or extensometer should pass through a bushing and
supply or other source of pressure (see Note 3). The gas
seal incorporated into the top plate and shall be loaded with
pressure shall be controlled by a pressure regulator and
sufficient force to compensate for the cell pressure acting over
measuredbyapressuregage,electronicpressuretransducer,or
the cross-sectional area of the piston where it passes through
any other device capable of measuring to the prescribed
the seal. If deformations are measured, the deformation indi-
tolerance. A hydraulic system pressurized by deadweight
cator shall be a dial indicator or cathetometer graduated to 0.5
acting on a piston or any other pressure device capable of
mm or 0.01 in. or better and having an adequate travel range.
applying and controlling the permeameter cell pressure within
Any other measuring device meeting these requirements is
the tolerance prescribed in this paragraph may be used.
acceptable.
NOTE 3—De-aired water is commonly used for the cell fluid to
5.4.2 In order to facilitate gas removal, and thus saturation
minimize potential for diffusion of air through the membrane into the
of the hydraulic system, four drainage lines leading to the
specimen. Other fluids that have low gas solubilities such as oils, are also
specimen,twoeachtothebaseandtopcap,arerecommended.
acceptable,providedtheydonotreactwithcomponentsofthepermeame-
ter. Also, use of a long (approximately 5 to 7 m) tube connecting the The drainage lines shall be controlled by no-volume-change
D5084 − 16a
FIG. 4 Constant Volume – Falling Head System, Method F (6)
valves, such as ball valves, and shall be designed to minimize 5.4.5 Porous End Pieces—Theporousendpiecesshallbeof
dead space in the lines. silicon carbide, aluminum oxide, or other material that is not
5.4.3 Top Cap and Base—An impermeable, rigid top cap attacked by the specimen or permeant liquid. The end pieces
and base shall be used to support the specimen and provide for shall have plane and smooth surfaces and be free of cracks,
transmissionofpermeantliquidtoandfromthespecimen.The chips, and discontinuities. They shall be checked regularly to
diameter or width of the top cap and base shall be equal to the ensure that they are not clogged.
diameter or width of the specimen to 65% or better.The base 5.4.5.1 The porous end pieces shall be the same diameter or
shall prevent leakage, lateral motion, or tilting, and the top cap width(65%orbetter)asthespecimen,andthethicknessshall
shallbedesignedtoreceivethepistonorextensometer,ifused, be sufficient to prevent breaking.
such that the piston-to-top cap contact area is concentric with
5.4.5.2 The hydraulic conductivity of the porous end pieces
the cap. The surface of the base and top cap that contacts the shall be significantly greater than that of the specimen to be
membranetoformasealshallbesmoothandfreeofscratches.
tested. The requirements outlined in 5.2.3 ensure this criterion
5.4.4 Flexible Membranes—The flexible membrane used to is met.
encase the specimen shall provide reliable protection against
5.4.6 Filter Paper—If necessary to prevent intrusion of
leakage. The membrane shall be carefully inspected prior to material into the pores of the porous end pieces, one or more
use.Ifanyflawsorpinholesareevident,themembraneshallbe
sheets of filter paper shall be placed between the top and
discarded. To minimize restraint to the specimen, the diameter bottom porous end pieces and the specimen. The paper shall
or width of the non-stretched membrane shall be between 90
have a negligibly small hydraulic impedance. The require-
and 95% of that of the specimen. The membrane shall be ments outlined in 5.2.3 ensure that the impedance is small.
sealed to the specimen base and cap with rubber O-rings for
5.5 Equipment for Compacting a Specimen—Equipment
which the unstressed, inside diameter or width is less than
(including compactor and mold) suitable for the method of
90% of the diameter or width of the base and cap, or by any
compaction specified by the requester shall be used.
other method that will produce an adequate seal.
5.6 Sample Extruder—When the material being tested is a
NOTE 4—Membranes may be tested for flaws by placing them around
soil core, the soil core shall usually be removed from the
aformsealedatbothendswithrubberO-rings,subjectingthemtoasmall
samplerwithanextruder.Thesampleextrudershallbecapable
air pressure on the inside, and then dipping them into water. If air bubbles
of extruding the soil core from the sampling tube in the same
come up from any point on the membrane, or if any visible flaws are
observed, the membrane shall be discarded. direction of travel in which the sample entered the tube and
D5084 − 16a
withminimumdisturbanceofthesample.Ifthesoilcoreisnot 6.1.2 Thetypeofpermeantwatershouldbespecifiedbythe
extruded vertically, care should be taken to avoid bending requestor.Ifnospecificationismade,oneofthefollowingshall
stresses on the core due to gravity. Conditions at the time of
be used: (i) potable tap water, (ii) a mixture of 0.0013 molar
sample extrusion may dictate the direction of removal, but the NaCl and 0.0010 molar CaCl,or(iii) 0.01 molar CaCl . The
2 2
principalconcernistokeepthedegreeofdisturbanceminimal.
NaCl-CaCl solution is representative of both typical tap
waters and soil pore waters (7). The CaCl solution has been
5.7 Trimming Equipment—Specific equipment for trimming
used historically in areas with extremely hard or soft waters.
thespecimentothedesireddimensionswillvarydependingon
The type of water used shall be indicated in the report.
quality and characteristics of the sample (material). However,
6.1.2.1 The NaCl-CaCl solution can be prepared by dis-
the following items listed may be used: lathe, wire saw with a
solving 0.76 g of reagent-grade NaCl and 1.11 g of reagent-
wireabout0.3mm(0.01in.)indiameter,spatulas,knives,steel
grade CaCl in 10 L of de-aired Type II deionized water.
rasp for very hard clay specimens, cradle or split mold for
trimming specimen ends, and steel straight edge for final
6.1.2.2 The0.01CaCl solutioncanbepreparedbydissolv-
trimming of specimen ends.
ing 11.1 g of reagent-grade CaCl in 10 L of de-aired Type II
deionized water.
5.8 Devices for Measuring the Dimensions of the
Specimen—Devices used to measure the dimensions of the 6.1.2.3 Chemical interactions between a permeant liquid
and the porous material may lead to variations in hydraulic
specimen shall be capable of measuring to the nearest 0.5 mm
or 0.01 in. or better (see 8.1.1) and shall be constructed such conductivity. Distilled water can significantly lower the hy-
that their use will not disturb the specimen. draulic conductivity of clayey soils (3). For this reason,
distilled water is not usually recommended as a permeant
5.9 Balances—Thebalanceshallbesuitablefordetermining
liquid.
the mass of the specimen and shall be selected as discussed in
6.1.3 Deaired Water—To aid in removing as much air from
Specification D4753. The mass of specimens less than 100 g
the test specimen as possible, deaired water shall be used. The
shall be determined to the nearest 0.01 g. The mass of
water is usually deaired by boiling, by spraying a fine mist of
specimens between 100 g and 999 g shall be determined to the
water into an evacuated vessel attached to a vacuum source, or
nearest 0.1 g. The mass of specimens equal to or greater than
by forceful agitation of water in a container attached to a
1000 g shall be determined to the nearest gram.
vacuum source. If boiling is used, care shall be taken not to
5.10 EquipmentforMountingtheSpecimen—Equipmentfor
evaporate an excessive amount of water, which can lead to a
mounting the specimen in the permeameter cell shall include a
largersaltconcentrationinthepermeantwaterthandesired.To
membrane stretcher or cylinder, and ring for expanding and
prevent dissolution of air back into the water, deaired water
placing O-rings on the base and top cap to seal the membrane.
shall not be exposed to air for prolonged periods.
5.11 Vacuum Pump—To assist with de-airing of permeant
liquid (water) and saturation of specimens.
7. Hazards
NOTE5—Forguidanceoravoidingexcessiveconsolidationintheuseof
vacuum for specimen saturation, consult 8.2 of Test Method D4767. 7.1 Warning—Mercury has been designated by many regu-
latory agencies as a hazardous material that can cause serious
5.12 Temperature Maintaining Device—The temperature of
medical issues. Mercury, or its vapor, may be hazardous to
the permeameter, test specimen, and reservoir of permeant
health and corrosive to materials. Caution should be taken
liquid shall not vary more than 63°C or 66°F or better.
when handling mercury containing products. See the appli-
Normally, this is accomplished by performing the test in a
cable product Safety Data Sheet (SDS) for additional informa-
room with a relatively constant temperature. If such a room is
tion. Users should be aware that selling mercury or mercury
not available, the apparatus shall be placed in a water bath,
containing products into your state or country may be prohib-
insulatedchamber,orotherdevicethatmaintainsatemperature
ited by law.
within the tolerance specified above. The temperature shall be
7.1.1 Tubing composed of glass or other brittle materials
periodically measured and recorded.
may explode/shatter when under pressure, especially air.
5.13 Water Content Containers—The containers shall be in
Therefore,suchtubingshouldbeenclosed.Establishallowable
accordance with Method D2216.
working pressures and make sure they are not exceeded.
5.14 Drying Oven—The oven shall be in accordance with
7.2 Precaution—In addition to other precautions, store mer-
Test Method D2216.
cury in sealed shatterproof containers to control evaporation.
5.15 Time Measuring Device(s)—Devices to measure the
When adding/subtracting mercury to/from the hydraulic sys-
duration of each permeation trial, such as either a clock with a
tem used in Method E or F, work in a well-ventilated area
second hand or a stopwatch (or equivalent), or both.
(preferably under a fume hood), and avoid contact with skin.
Rubber gloves should be worn at all times when contact with
6. Reagents
mercury is possible.
6.1 Permeant Water: 7.2.1 Minimize uncontrolled flow of mercury out of the
6.1.1 The permeant water is the liquid used to permeate the specialized hydraulic system by installing mercury traps or an
test specimen and is also the liquid used in backpressuring the inline check-valve mechanism. Minimize uncontrolled spills
specimen. by using shatterproof materials or protective shields, or both.
D5084 − 16a
7.2.2 If mercury comes into contact with brass/copper trimmed,wheneverpossible,inanenvironmentwherechanges
fittings, valves, etc., such items may rapidly become leaky. in water content are minimized. A controlled high-humidity
Therefore, where-ever practical use stainless steel fittings, etc. room is usually used for this purpose. The mass and dimen-
7.2.3 Clean up spills immediately using a recommended sionsofthetestspecimenshallbedeterminedtothetolerances
given in 5.8 and 5.9. The test specimen shall be mounted
procedure explicitly for mercury.
immediately in the permeameter. The water content of the
7.2.4 Dispose of contaminated waste materials containing
trimmings shall be determined in accordance with Method
mercury in a safe and environmentally acceptable manner.
D2216, to the nearest 0.1 % or better.
8. Test Specimens
8.3 Laboratory-Compacted Specimens—The material to be
tested shall be prepared and compacted inside a mold in a
8.1 Size—Specimens shall have a minimum diameter of 25
manner specified by the requester. If the specimen is placed
mm (1.0 in.) and a minimum height of 25 mm. The height and
and compacted in layers, the surface of each previously-
diameterofthespecimenshallbemeasuredtothreesignificant
compacted layer shall be lightly scarified (roughened) with a
digits or better (see 8.1.1). The length shall vary by no more
fork, ice pick, or other suitable object, unless the requester
than 65%. The diameter shall vary by no more than 65%.
specifically states that scarification is not to be performed.Test
The surface of the test specimen may be uneven, but indenta-
Methods D698 and D1557 describe two methods of
tions must not be so deep that the length or diameter vary by
compaction, but any other method specified by the requester
more than 65%. The diameter and height of the specimen
may be used as long as the method is described in the report.
shall each be at least 6 times greater than the largest particle
Large clods of material should not be broken down prior to
size within the specimen. If, after completion of a test, it is
compaction unless it is known that they will be broken in field
found based on visual observation that oversized particles are
construction, as well, or the requester specifically requests that
present,thatinformationshallbeindicatedonthedatasheet(s)/
the clod size be reduced. Neither hard clods nor individual
form(s).
particles of the material shall exceed ⁄6 of either the height or
8.1.1 If the density or unit weight needs to be determined/
diameter of the specimen.After compaction, the test specimen
recorded to four significant digits, or the void ratio to three
shall be removed from the mold, the ends scarified, and the
significant digits; then the test specimens dimensions need to
dimensions and weight determined within the tolerances given
have four significant digits; that is, typically measured to the
in 5.8 and 5.9.After the dimensions and mass are determined,
nearest 0.01 mm or 0.001 in.
the test specimen shall be immediately mounted in the per-
8.1.2 Specimens of soil-cement and mixtures of cement,
meameter. The water content of the trimmings shall be deter-
bentonite, and soils often have more irregular surfaces than
mined in accordance with Method D2216 to the nearest 0.1 %
specimensofsoil.Thus,forthesespecimensthelengthandthe
or better.
diameter may vary by no more than 610%.
8.4 Other Preparation Methods—Other methods of prepa-
NOTE 6—Most hydraulic conductivity tests are performed on cylindri-
rationofatestspecimenarepermittedifspecificallyrequested.
cal test specimens. It is possible to utilize special equipment for testing
prismatic test specimens, in which case reference to “diameter” in 8.1 The method of specimen preparation shall be identified in the
applies to the least width of the prismatic test specimen.
data sheet(s)/form(s).
8.2 Intact Specimens—Intact test specimens shall be pre-
8.5 After the height, diameter, mass, and water content of
paredfromarepresentativeportionofintactsamplessecuredin
the test specimen have been determined, the dry unit weight
accordance with Practice D1587, Practice D3550, Practice
shall be calculated. Also, the initial degree of saturation shall
D6151, or Practice D2113. In addition, intact samples may be
be estimated (this information may be used later in the
obtained by “block sampling” (8). Additional guidance on
back-pressure stage).
other drilling and sampling methods is given in Guide D6169.
8.6 In some cases, the horizontal hydraulic conductivity of
Samples shall be preserved and transported in accordance with
a sample needs to be determined. In that case, the specimen
these requirements; for soils follow Group C in Practice
maybetrimmedsuchthatitslongitudinalaxisisperpendicular
D4220,whileforrockfolloweither“specialcare”or“soil-like
to the longitudinal axis of the sample. Obtaining a specimen
care,” as appropriate in Practice D5079. Specimens obtained
having a diameter of 36 mm (1.4 in.) typically requires a
by tube sampling or coring may be tested without trimming
cylindrical sample with a diameter equal to or greater than
except for cutting the end surfaces plane and perpendicular to
about70mm(2.8in.)orarectangularsamplewithaminimum
the longitudinal axis of the specimen, provided soil character-
dimension of about 40 mm (1.6 in.).
istics are such that no significant disturbance results from
sampling. Where the sampling operation has caused distur-
9. Procedure
bance of the soil, the disturbed material shall be trimmed.
Where removal of pebbles or crumbling resulting from trim- 9.1 Specimen Setup:
mingcausesvoidsonthesurfaceofthespecimenthatcausethe 9.1.1 Cut two filter paper sheets to approximately the same
length or diameter to vary by more than 65%, the voids shall shape as the cross section of the test specimen. Soak the two
be filled with remolded material obtained from the trimmings. porousendpiecesandfilterpapersheets,ifused,inacontainer
The ends of the test specimen shall be cut and not troweled of permeant water.
(troweling can seal off cracks, slickensides, or other secondary 9.1.2 Place the membrane on the membrane expander.
features that might conduct water flow). Specimens shall be Apply a thin coat of silicon high-vacuum grease to the sides of
D5084 − 16a
than or equal to the swell pressure, the specimen will swell. In addition,
theendcaps.Placeoneporousendpieceonthebaseandplace
see Note 5.
one filter paper sheet, if used, on the porous end piece,
followed by the test specimen. Place the second filter paper
9.3 Back-Pressure Saturation—To saturate the specimen,
sheet, if used, on top of the specimen followed by the second
back pressuring is usually necessary. Fig. 5 (9) provides
porous end piece and the top cap. Place the membrane around
guidance on back pressure required to attain saturation. Addi-
the specimen, and using the membrane expander or other
tional guidance on the back-pressure process is given by Black
suitableO-ringexpander,placeoneormoreO-ringstosealthe
and Lee (10) and Head (11).
membrane to the base and one or more additional O-rings to
NOTE 8—The relationships presented in Fig. 5 are based on the
seal the membrane to the top cap.
assumption that the water used for back pressuring is deaired and that the
9.1.3 Attach flow tubing to the top cap, if not already
only source for air to dissolve into the water is air from the test specimen.
attached, assemble the permeameter cell, and fill it with
If air pressure is used to control the back pressure, pressurized air will
de-aired water or other cell fluid. Attach the cell pressure
dissolve into the water, thus reducing the capacity of the water used for
reservoirtothepermeametercelllineandthehydraulicsystem
backpressuretodissolveairlocatedintheporesofthetestspecimen.The
problem is minimized by using a long (>5 m) tube that is impermeable to
to the influent and effluent lines. Fill the cell pressure reservoir
air between the air-water interface and test specimen, by separating the
with deaired water, or other suitable liquid, and the hydraulic
back-pressure water from the air by a material or fluid that is relatively
system with deaired permeant water. Apply a small confining
impermeabletoair,byperiodicallyreplacingtheback-pressurewaterwith
pressure of 7 to 35 kPa (1 to 5 psi) to the cell and apply a
deaired water, or by other means.
pressure less than the confining pressure to both the influent
9.3.1 During the saturation process, any change in the
and effluent systems, and flush permeant water through the
volume (swelling or compression of the void ratio, density,
flow system. After all visible air has been removed from the
etc.)ofthetestspecimenshouldbeminimized.Theeasiestway
flow lines, close the control valves. At no time during satura-
to verify that volume changes are minor is to measure the
tion of the system and specimen or hydraulic conductivity
height of the specimen during the back-pressuring process.
measurements shall the maximum applied effective stress be
Volumechangesareconsideredminoriftheresultingchangein
allowed to exceed that to which the specimen is to be
hydraulic conductivity is less than about one-half the accept-
consolidated.
ableerrorof25%givenin9.5.4,unlessmorestringentcontrol
9.2 Specimen Soaking (Optional)—To aid in saturation,
on density or hydraulic conductivity, or both, is required. For
speci
...

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: D5084 − 16 D5084 − 16a
Standard Test Methods for
Measurement of Hydraulic Conductivity of Saturated Porous
Materials Using a Flexible Wall Permeameter
This standard is issued under the fixed designation D5084; 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*
1.1 These test methods cover laboratory measurement of the hydraulic conductivity (also referred to as coeffıcient of
permeability) of water-saturated porous materials with a flexible wall permeameter at temperatures between about 15 and 30°C (59
and 86°F). Temperatures outside this range may be used; however, the user would have to determine the specific gravity of mercury
and R (see 10.3) at those temperatures using data from Handbook of Chemistry and Physics. There are six alternate methods or
T
hydraulic systems that may be used to measure the hydraulic conductivity. These hydraulic systems are as follows:
1.1.1 Method A—Constant Head
1.1.2 Method B—Falling Head, constant tailwater elevation
1.1.3 Method C—Falling Head, rising tailwater elevation
1.1.4 Method D—Constant Rate of Flow
1.1.5 Method E—Constant Volume–Constant Head (by mercury)
1.1.6 Method F—Constant Volume–Falling Head (by mercury), rising tailwater elevation
1.2 These test methods use water as the permeant liquid; see 4.3 and Section 6 on Reagents for water requirements.
1.3 These test methods may be utilized on all specimen types (undisturbed,(intact, reconstituted, remolded, compacted, etc.) that
−6 −4
have a hydraulic conductivity less than about 1 × 10 m/s (1 × 10 cm/s), providing the head loss requirements of 5.2.3 are met.
−7
For the constant-volume methods, the hydraulic conductivity typically has to be less than about 1 × 10 m/s.
−6 −5
1.3.1 If the hydraulic conductivity is greater than about 1 × 10 m/s, but not more than about 1 × 10 m/s; then the size of the
hydraulic tubing needs to be increased along with the porosity of the porous end pieces. Other strategies, such as using higher
viscosity fluid or properly decreasing the cross-sectional area of the test specimen, or both, may also be possible. The key criterion
is that the requirements covered in Section 5 have to be met.
−11
1.3.2 If the hydraulic conductivity is less than about 1 × 10 m/s, then standard hydraulic systems and temperature
environments will typically not suffice. Strategies that may be possible when dealing with such impervious materials may include
the following: (a) controlling the temperature more precisely, (b) adoption of unsteady state measurements by using high-accuracy
equipment along with the rigorous analyses for determining the hydraulic parameters (this approach reduces testing duration
according to Zhang et al. (1) ), and (c) shortening the length or enlarging the cross-sectional area, or both, of the test specimen.
specimen (with consideration to specimen grain size (2)). Other items,approaches, such as use of higher hydraulic gradients, lower
viscosity fluid, elimination of any possible chemical gradients and bacterial growth, and strict verification of leakage, may also be
considered.
−5
1.4 The hydraulic conductivity of materials with hydraulic conductivities greater than 1 × 10 m/s may be determined by Test
Method D2434.
1.5 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice
D6026.
1.5.1 The procedures used to specify how data are collected, recorded, and calculated in this standard are regarded as the
industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures
used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s
objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these
considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
This standard is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic Properties
and Hydraulic Barriers.
Current edition approved Aug. 1, 2016Aug. 15, 2016. Published August 2016. Originally approved in 1990. Last previous edition approved in 20102016 as D5084–10.–16.
DOI: 10.1520/D5084-16.10.1520/D5084-16A.
The boldface numbers in parentheses refer to the list of references appended to this standard.
*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
D5084 − 16a
1.6 This standard also contains a Hazards section about using mercury, see Section (Section 7.).
1.7 The time to perform this test depends on such items as the Method (A, B, C, D, E, or F) used, the initial degree of saturation
of the test specimen and the hydraulic conductivity of the test specimen. The constant volume Methods (E and F) and Method D
require the shortest period-of-time. Typically a test can be performed using Methods D, E, or F within two to three days. Methods
A, B, and C take a longer period-of-time, from a few days to a few weeks depending on the hydraulic conductivity. Typically, about
–9
one week is required for hydraulic conductivities on the order of 1 × 10 m/s. The testing time is ultimately controlled by meeting
the equilibrium criteria for each Method (see 9.5).
1.8 Units—The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are
mathematical conversions, which are provided for information purposes only and are not considered standard, unless specifically
stated as standard, such as 0.5 mm or 0.01 in.
1.9 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.
2. Referenced Documents
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
3 3
D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft (600 kN-m/m ))
D854 Test Methods for Specific Gravity of Soil Solids by Water Pycnometer
D1140 Test Methods for Determining the Amount of Material Finer than 75-μm (No. 200) Sieve in Soils by Washing
D1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft (2,700
kN-m/m ))
D1587 Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical Purposes
D2113 Practice for Rock Core Drilling and Sampling of Rock for Site Exploration
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D2434 Test Method for Permeability of Granular Soils (Constant Head) (Withdrawn 2015)
D2435 Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental Loading
D3550 Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of Soils (Withdrawn 2016)
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D4220 Practices for Preserving and Transporting Soil Samples
D4318 Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils
D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction
Materials Testing
D4767 Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils
D5079 Practices for Preserving and Transporting Rock Core Samples
D6026 Practice for Using Significant Digits in Geotechnical Data
D6151 Practice for Using Hollow-Stem Augers for Geotechnical Exploration and Soil Sampling
D6169 Guide for Selection of Soil and Rock Sampling Devices Used With Drill Rigs for Environmental Investigations
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
3. Terminology
3.1 Definitions:
3.1.1 For common definitions of technical terms in this standard, refer to Terminology D653.
3.1.2 head loss, Δh—the change in total head of water across a given distance.
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.
3.1.2.1 Discussion—
In hydraulic conductivity testing, typically the change in total head is across the influent and effluent lines connected to the
permeameter, while the given distance is typically the length of the test specimen.
3.1.3 permeameter—the apparatus (cell) containing the test specimen in a hydraulic conductivity test.
D5084 − 16a
3.1.3.1 Discussion—
The apparatus in this case is typically a triaxial-type cell with all of its components (top and bottom specimen caps, stones, and
filter paper; membrane; chamber; top and bottom plates; valves; etc.).
3.1.4 hydraulic conductivity, k—the rate of discharge of water under laminar flow conditions through a unit cross-sectional area
of porous medium under a unit hydraulic gradient and standard temperature conditions (20°C).
3.1.4.1 Discussion—
In hydraulic conductivity testing, the term coeffıcient of permeability is often used instead of hydraulic conductivity, but hydraulic
conductivity is used exclusively in this standard. A more complete discussion of the terminology associated with Darcy’s law is
given in the literature. (23, 34)
3.1.5 pore volume of flow—in hydraulic conductivity testing, the cumulative quantity of flow into a test specimen divided by
the volume of voids in the specimen.
4. Significance and Use
4.1 These test methods apply to one-dimensional, laminar flow of water within porous materials such as soil and rock.
4.2 The hydraulic conductivity of porous materials generally decreases with an increasing amount of air in the pores of the
material. These test methods apply to water-saturated porous materials containing virtually no air.
4.3 These test methods apply to permeation of porous materials with water. Permeation with other liquids, such as chemical
wastes, can be accomplished using procedures similar to those described in these test methods. However, these test methods are
only intended to be used when water is the permeant liquid. See Section 6.
4.4 Darcy’s law is assumed to be valid and the hydraulic conductivity is essentially unaffected by hydraulic gradient.
4.5 These test methods provide a means for determining hydraulic conductivity at a controlled level of effective stress.
Hydraulic conductivity varies with varying void ratio, which changes when the effective stress changes. If the void ratio is changed,
the hydraulic conductivity of the test specimen will likely change, see Appendix X2. To determine the relationship between
hydraulic conductivity and void ratio, the hydraulic conductivity test would have to be repeated at different effective stresses.
4.6 The correlation between results obtained using these test methods and the hydraulic conductivities of in-place field materials
has not been fully investigated. Experience has sometimes shown that hydraulic conductivities measured on small test specimens
are not necessarily the same as larger-scale values. Therefore, the results should be applied to field situations with caution and by
qualified personnel.
4.7 In most cases, when testing high swell potential materials and using a constant-volume hydraulic system, the effective
confining stress should be about 1.5 times the swell pressure of the test specimen or a stress which prevents swelling. If the
confining stress is less than the swell pressure, anomalous flow conditions my occur; for example, mercury column(s) move in the
wrong direction.
NOTE 1—The quality of the result produced by this standard is dependent of the competence of the personnel performing it and the suitability of the
equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing,
sampling, inspection, etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable
results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.
5. Apparatus
5.1 Hydraulic System—Constant head (Method A), falling head (Methods B and C), constant rate of flow (Method D), constant
volume-constant head (Method E), or constant volume-falling head (Method F) systems may be utilized provided they meet the
following criteria:
5.1.1 Constant Head—The system must be capable of maintaining constant hydraulic pressures to 65 % or better and shall
include means to measure the hydraulic pressures to within the prescribed tolerance. In addition, the head loss across the
permeameter must be held constant to 65 % or better and shall be measured with the same accuracy or better. A pressure gage,
electronic pressure transducer, or any other device of suitable accuracy shall measure pressures to a minimum of three significant
digits. The last digit may be due to estimation, see 5.1.1.1.
5.1.1.1 Practice D6026 discusses the use or application of estimated digits. When the last digit is estimated and that reading is
a function of the eye’s elevation/location, then a mirror or another device is required to reduce the reading error caused by parallax.
5.1.2 Falling Head—The system shall allow for measurement of the applied head loss, thus hydraulic gradient, to 65 % or
better at any time. In addition, the ratio of initial head loss divided by final head loss over an interval of time shall be measured
such that this computed ratio is accurate to 65 % or better. The head loss shall be measured with a pressure gage, electronic
pressure transducer, engineer’s scale, graduated pipette, or any other device of suitable accuracy to a minimum of three significant
digits. The last digit may be due to estimation, see 5.1.1.1. Falling head tests may be performed with either a constant tailwater
D5084 − 16a
elevation (Method B) or a rising tailwater elevation (Method C), see Fig. 1. This schematic of a hydraulic system presents the basic
components needed to meet the objectives of Method C. Other hydraulic systems or schematics that meet these objectives are
acceptable.
5.1.3 Constant Rate of Flow—The system must be capable of maintaining a constant rate of flow through the specimen to 65 %
or better. Flow measurement shall be by calibrated syringe, graduated pipette, or other device of suitable accuracy. The head loss
across the permeameter shall be measured to a minimum of three significant digits and to an accuracy of 65 % or better using an
electronic pressure transducer(s) or other device(s) of suitable accuracy. The last digit may be due to estimation, see 5.1.1.1. More
information on testing with a constant rate of flow is given in the literature (45).
5.1.4 Constant Volume-Constant Head (CVCH)—The system, with mercury to create the head loss, must be capable of
maintaining a constant head loss cross the permeameter to 65 % or better and shall allow for measurement of the applied head
loss to 65 % or better at any time. The head loss shall be measured to a minimum of three significant digits with an electronic
pressure transducer(s) or equivalent device, (56) or based upon the pressure head caused by the mercury column, see 10.1.2. The
last digit may be due to estimation, see 5.1.1.1.
5.1.4.1 Schematics of two CVCH systems are shown in Fig. 2 and Fig. 3. In each of these systems, the mercury-filled portion
of the tubing may be continuous for constant head loss to be maintained. For the system showed in Fig. 2, the head loss remains
constant provided the mercury column is vertical and is retained in only one half of the burette system (left burette in Fig. 2). If
the mercury spans both columns, a falling head exists. In the system shown in Fig. 3, the head loss remains constant provided the
water-mercury interface on the effluent end remains in the upper horizontal tube, and the water-mercury interface on the influent
end remains in the lower horizontal tube. These schematics present the basic components needed to meet the objectives of Method
E. Other hydraulic systems or schematics that meet these objectives are acceptable.
5.1.4.2 These types of hydraulic systems are typically not used to study the temporal or pore-fluid effect on hydraulic
conductivity. The total volume of the specimen is maintained constant using this procedure, thereby significantly reducing effects
caused by seepage stresses, pore fluid interactions, etc. Rather, these systems are intended for determining the hydraulic
conductivity of a material as rapidly as possible.
5.1.4.3 Hazards—Since this hydraulic system contains mercury, special health and safety precautions have to be considered. See
Section 7.
FIG. 1 Falling Head – Rising Tail System, Method C
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FIG. 2 Constant Volume – Constant or Falling Head System, Method E or F (56)
5.1.4.4 Caution—For these types of hydraulic systems to function properly, the separation of the mercury column has to be
prevented. To prevent separation, the mercury and “constant head” tube have to remain relatively clean, and the inside diameter
of this tube cannot be too large; typically a capillary tube is used. The larger diameter flushing tube (Fig. 2) is added to enable
flushing clean water through the system without excessive mercury displacement. Traps to prevent the accidental flow of mercury
out of the “Constant Head” tube or flushing tube are not shown in Fig. 2 and Fig. 3.
5.1.5 Constant Volume-Falling Head (CVFH)—The system, with mercury to create the head loss, shall meet the criteria given
in 5.1.2. The head loss shall be measured to a minimum of three significant digits with an electronic pressure transducer(s) or
equivalent device(s), (56) or based upon the differential elevation between the top surfaces of the mercury level in the headwater
and tailwater tubes. The last digit may be due to estimation, see 5.1.1.1.
5.1.5.1 A schematic drawing of a typical CVFH hydraulic system is shown in Fig. 4 (56). Typically, the tailwater tube has a
smaller area than the headwater tube to increase the sensitivity of flow measurements, and to enable flushing clean water through
the system without excessive mercury displacement in the headwater tube. The schematic of the hydraulic system in Fig. 4 presents
the basic components needed to meet the objectives of Method F. Other hydraulic systems or schematics that meet these objectives
are acceptable. The development of the hydraulic conductivity equation for this type of system is given in Appendix X1.
5.1.5.2 See 5.1.4.2.
5.1.5.3 Hazards—Since this hydraulic system contains mercury, special health and safety precautions have to be considered. See
Section 7.
5.1.5.4 Caution—For these types of hydraulic systems to function properly, the separation of the mercury column and
entrapment of water within the mercury column have to be prevented. To prevent such problems, the mercury and tubes have to
remain relatively clean. In addition, if different size headwater and tailwater tubes are used, capillary head might have to be
accounted for, see Appendix X1, X1.2.3.2, and X1.4. Traps to prevent the accidental flow of mercury out of the tubes are not shown
in Fig. 4.
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FIG. 3 Constant Volume—Constant Head System, Method E
5.1.6 System De-airing—The hydraulic system shall be designed to facilitate rapid and complete removal of free air bubbles
from flow lines; for example, using properly sized tubing and ball valves and fittings without pipe threads. Properly sized tubing,
etc., means they are small enough to prevent entrapment of air bubbles, but not so small that the requirements of 5.2.3 cannot be
met.
5.1.7 Back Pressure System—The hydraulic system shall have the capability to apply back pressure to the specimen to facilitate
saturation. The system shall be capable of maintaining the applied back pressure throughout the duration of hydraulic conductivity
measurements. The back pressure system shall be capable of applying, controlling, and measuring the back pressure to 65 % or
better of the applied pressure. The back pressure may be provided by a compressed gas supply, a deadweight acting on a piston,
or any other method capable of applying and controlling the back pressure to the tolerance prescribed in this paragraph.
NOTE 2—Application of gas pressure directly to a fluid will dissolve gas in the fluid. A variety of techniques are available to minimize dissolution of
gas in the back pressure fluid, including separation of gas and liquid phases with a bladder and frequent replacement of the liquid with de-aired water.
5.2 Flow Measurement System—Both inflow and outflow volumes shall be measured unless the lack of leakage, continuity of
flow, and cessation of consolidation or swelling can be verified by other means. Flow volumes shall be measured by a graduated
accumulator, graduated pipette, vertical standpipe in conjunction with an electronic pressure transducer, or other volume-
measuring device of suitable accuracy.
5.2.1 Flow Accuracy—Required accuracy for the quantity of flow measured over an interval of time is 65 % or better.
5.2.2 De-airing and Compliance of the System—The flow-measurement system shall contain a minimum of dead space and be
capable of complete and rapid de-airing. Compliance of the system in response to changes in pressure shall be minimized by using
a stiff flow measurement system. Rigid tubing, such as metallic or rigid thermoplastic tubing, or glass shall be used.
5.2.3 Head Losses—Head losses in the tubes, valves, porous end pieces, and filter paper may lead to error. To guard against such
errors, the permeameter shall be assembled with no specimen inside and then the hydraulic system filled.
5.2.3.1 Constant or Falling Head—If a constant or falling head test is to be used, the hydraulic pressures or heads that will be
used in testing a specimen shall be applied, and the rate of flow measured with an accuracy of 65 % or better. This rate of flow
shall be at least ten times greater than the rate of flow that is measured when a specimen is placed inside the permeameter and the
same hydraulic pressures or heads are applied.
5.2.3.2 Constant Rate of Flow—If a constant rate of flow test is to be used, the rate of flow to be used in testing a specimen
shall be supplied to the permeameter and the head loss measured. The head loss without a specimen shall be less than 0.1 times
the head loss when a specimen is present.
D5084 − 16a
FIG. 4 Constant Volume – Falling Head System, Method F (56)
5.3 Permeameter Cell Pressure System—The system for pressurizing the permeameter cell shall be capable of applying and
controlling the cell pressure to 65 % or better of the applied pressure. However, the effective stress on the test specimen (which
is the difference between the cell pressure and the pore water pressure) shall be maintained to the desired value with an accuracy
of 610 % or better. The device for pressurizing the cell may consist of a reservoir connected to the permeameter cell and partially
filled with de-aired water, with the upper part of the reservoir connected to a compressed gas supply or other source of pressure
(see Note 3). The gas pressure shall be controlled by a pressure regulator and measured by a pressure gage, electronic pressure
transducer, or any other device capable of measuring to the prescribed tolerance. A hydraulic system pressurized by deadweight
acting on a piston or any other pressure device capable of applying and controlling the permeameter cell pressure within the
tolerance prescribed in this paragraph may be used.
NOTE 3—De-aired water is commonly used for the cell fluid to minimize potential for diffusion of air through the membrane into the specimen. Other
fluids that have low gas solubilities such as oils, are also acceptable, provided they do not react with components of the permeameter. Also, use of a long
(approximately 5 to 7 m) tube connecting the pressurized cell liquid to the cell helps to delay the appearance of air in the cell fluid and to reduce the
flow of dissolved air into the cell.
5.4 Permeameter Cell—An apparatus shall be provided in which the specimen and porous end pieces, enclosed by a membrane
sealed to the cap and base, are subjected to controlled fluid pressures. A schematic diagram of a typical permeameter cell and
falling head (raising tailwater) hydraulic system is shown in Fig. 1.
5.4.1 The permeameter cell may allow for observation of changes in height of the specimen, either by observation through the
cell wall using a cathetometer or other instrument, or by monitoring of either a loading piston or an extensometer extending through
the top plate of the cell bearing on the top cap and attached to a dial indicator or other measuring device. The piston or
extensometer should pass through a bushing and seal incorporated into the top plate and shall be loaded with sufficient force to
compensate for the cell pressure acting over the cross-sectional area of the piston where it passes through the seal. If deformations
are measured, the deformation indicator shall be a dial indicator or cathetometer graduated to 0.5 mm or 0.01 in. or better and
having an adequate travel range. Any other measuring device meeting these requirements is acceptable.
5.4.2 In order to facilitate gas removal, and thus saturation of the hydraulic system, four drainage lines leading to the specimen,
two each to the base and top cap, are recommended. The drainage lines shall be controlled by no-volume-change valves, such as
ball valves, and shall be designed to minimize dead space in the lines.
D5084 − 16a
5.4.3 Top Cap and Base—An impermeable, rigid top cap and base shall be used to support the specimen and provide for
transmission of permeant liquid to and from the specimen. The diameter or width of the top cap and base shall be equal to the
diameter or width of the specimen to 65 % or better. The base shall prevent leakage, lateral motion, or tilting, and the top cap shall
be designed to receive the piston or extensometer, if used, such that the piston-to-top cap contact area is concentric with the cap.
The surface of the base and top cap that contacts the membrane to form a seal shall be smooth and free of scratches.
5.4.4 Flexible Membranes—The flexible membrane used to encase the specimen shall provide reliable protection against
leakage. The membrane shall be carefully inspected prior to use. If any flaws or pinholes are evident, the membrane shall be
discarded. To minimize restraint to the specimen, the diameter or width of the non-stretched membrane shall be between 90 and
95 % of that of the specimen. The membrane shall be sealed to the specimen base and cap with rubber O-rings for which the
unstressed, inside diameter or width is less than 90 % of the diameter or width of the base and cap, or by any other method that
will produce an adequate seal.
NOTE 4—Membranes may be tested for flaws by placing them around a form sealed at both ends with rubber O-rings, subjecting them to a small air
pressure on the inside, and then dipping them into water. If air bubbles come up from any point on the membrane, or if any visible flaws are observed,
the membrane shall be discarded.
5.4.5 Porous End Pieces—The porous end pieces shall be of silicon carbide, aluminum oxide, or other material that is not
attacked by the specimen or permeant liquid. The end pieces shall have plane and smooth surfaces and be free of cracks, chips,
and discontinuities. They shall be checked regularly to ensure that they are not clogged.
5.4.5.1 The porous end pieces shall be the same diameter or width (65 % or better) as the specimen, and the thickness shall
be sufficient to prevent breaking.
5.4.5.2 The hydraulic conductivity of the porous end pieces shall be significantly greater than that of the specimen to be tested.
The requirements outlined in 5.2.3 ensure this criterion is met.
5.4.6 Filter Paper—If necessary to prevent intrusion of material into the pores of the porous end pieces, one or more sheets of
filter paper shall be placed between the top and bottom porous end pieces and the specimen. The paper shall have a negligibly small
hydraulic impedance. The requirements outlined in 5.2.3 ensure that the impedance is small.
5.5 Equipment for Compacting a Specimen—Equipment (including compactor and mold) suitable for the method of compaction
specified by the requester shall be used.
5.6 Sample Extruder—When the material being tested is a soil core, the soil core shall usually be removed from the sampler
with an extruder. The sample extruder shall be capable of extruding the soil core from the sampling tube in the same direction of
travel in which the sample entered the tube and with minimum disturbance of the sample. If the soil core is not extruded vertically,
care should be taken to avoid bending stresses on the core due to gravity. Conditions at the time of sample extrusion may dictate
the direction of removal, but the principal concern is to keep the degree of disturbance minimal.
5.7 Trimming Equipment—Specific equipment for trimming the specimen to the desired dimensions will vary depending on
quality and characteristics of the sample (material). However, the following items listed may be used: lathe, wire saw with a wire
about 0.3 mm (0.01 in.) in diameter, spatulas, knives, steel rasp for very hard clay specimens, cradle or split mold for trimming
specimen ends, and steel straight edge for final trimming of specimen ends.
5.8 Devices for Measuring the Dimensions of the Specimen—Devices used to measure the dimensions of the specimen shall be
capable of measuring to the nearest 0.5 mm or 0.01 in. or better (see 8.1.1) and shall be constructed such that their use will not
disturb the specimen.
5.9 Balances—The balance shall be suitable for determining the mass of the specimen and shall be selected as discussed in
Specification D4753. The mass of specimens less than 100 g shall be determined to the nearest 0.01 g. The mass of specimens
between 100 g and 999 g shall be determined to the nearest 0.1 g. The mass of specimens equal to or greater than 1000 g shall
be determined to the nearest gram.
5.10 Equipment for Mounting the Specimen—Equipment for mounting the specimen in the permeameter cell shall include a
membrane stretcher or cylinder, and ring for expanding and placing O-rings on the base and top cap to seal the membrane.
5.11 Vacuum Pump—To assist with de-airing of permeant liquid (water) and saturation of specimens.
NOTE 5—For guidance or avoiding excessive consolidation in the use of vacuum for specimen saturation, consult 8.2 of Test Method D4767.
5.12 Temperature Maintaining Device—The temperature of the permeameter, test specimen, and reservoir of permeant liquid
shall not vary more than 63°C or 66°F or better. Normally, this is accomplished by performing the test in a room with a relatively
constant temperature. If such a room is not available, the apparatus shall be placed in a water bath, insulated chamber, or other
device that maintains a temperature within the tolerance specified above. The temperature shall be periodically measured and
recorded.
5.13 Water Content Containers—The containers shall be in accordance with Method D2216.
5.14 Drying Oven—The oven shall be in accordance with Test Method D2216.
D5084 − 16a
5.15 Time Measuring Device(s)—Devices to measure the duration of each permeation trial, such as either a clock with a second
hand or a stopwatch (or equivalent), or both.
6. Reagents
6.1 Permeant Water:
6.1.1 The permeant water is the liquid used to permeate the test specimen and is also the liquid used in backpressuring the
specimen.
6.1.2 The type of permeant water should be specified by the requestor. If no specification is made, one of the following shall
be used: (i) potable tap water, (ii) a mixture of 0.0013 molar NaCl and 0.0010 molar CaCl , or (iii) 0.01 molar CaCl . The
2 2
NaCl-CaCl solution is representative of both typical tap waters and soil pore waters (67). The CaCl solution has been used
2 2
historically in areas with extremely hard or soft waters. The type of water used shall be indicated in the report.
6.1.2.1 The NaCl-CaCl solution can be prepared by dissolving 0.76 g of reagent-grade NaCl and 1.11 g of reagent-grade CaCl
2 2
in 10 L of de-aired Type II deionized water.
6.1.2.2 The 0.01 CaCl solution can be prepared by dissolving 11.1 g of reagent-grade CaCl in 10 L of de-aired Type II
2 2
deionized water.
6.1.2.3 Chemical interactions between a permeant liquid and the porous material may lead to variations in hydraulic
conductivity. Distilled water can significantly lower the hydraulic conductivity of clayey soils (23). For this reason, distilled water
is not usually recommended as a permeant liquid. A permeant liquid used by some is a 0.01 molar CaCl solution, which can be
obtained for example, by dissolving 11.1 g of reagent-grade CaCl in 10 L of de-aired, distilled water (commercial grade) or
deionized water. This CaCl solution is thought to neither increase nor decrease significantly the hydraulic conductivity of clayey
soils. In areas with extremely hard or soft water, the CaCl solution is recommended. Its use is also recommended when the flow
1 1
of permeant water is significant (greater than about ⁄3 to ⁄2 times the volume of voids). Additional de-airing may modify the
concentration of this solution slightly, but this should not affect the hydraulic conductivity.
6.1.3 Deaired Water—To aid in removing as much air from the test specimen as possible, deaired water shall be used. The water
is usually deaired by boiling, by spraying a fine mist of water into an evacuated vessel attached to a vacuum source, or by forceful
agitation of water in a container attached to a vacuum source. If boiling is used, care shall be taken not to evaporate an excessive
amount of water, which can lead to a larger salt concentration in the permeant water than desired. To prevent dissolution of air
back into the water, deaired water shall not be exposed to air for prolonged periods.
7. Hazards
7.1 Warning—Mercury has been designated by EPA and many stateregulatory agencies as a hazardous material that can cause
central nervous system, kidney, and liver damage. serious medical issues. Mercury, or its vapor, may be hazardous to health and
corrosive to materials. Caution should be taken when handling mercury and mercury-containing containing products. See the
applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website—http://www.epa.gov/mercury/faq.htm—for
(SDS) for additional information. Users should be aware that selling mercury or mercury-containing products or both mercury
containing products into your state or country may be prohibited by state law.
7.1.1 Tubing composed of glass or other brittle materials may explode/shatter when under pressure, especially air. Therefore,
such tubing should be enclosed. Establish allowable working pressures and make sure they are not exceeded.
7.2 Precaution—In addition to other precautions, store mercury in sealed shatterproof containers to control evaporation. When
adding/subtracting mercury to/from the hydraulic system used in Method E or F, work in a well-ventilated area (preferably under
a fume hood), and avoid contact with skin. Rubber gloves should be worn at all times when contact with mercury is possible.
7.2.1 Minimize uncontrolled flow of mercury out of the specialized hydraulic system by installing mercury traps or an inline
check-valve mechanism. Minimize uncontrolled spills by using shatterproof materials or protective shields, or both.
7.2.2 If mercury comes into contact with brass/copper fittings, valves, etc., such items may rapidly become leaky. Therefore,
where-ever practical use stainless steel fittings, etc.
7.2.3 Clean up spills immediately using a recommended procedure explicitly for mercury.
7.2.4 Dispose of contaminated waste materials containing mercury in a safe and environmentally acceptable manner.
8. Test Specimens
8.1 Size—Specimens shall have a minimum diameter of 25 mm (1.0 in.) and a minimum height of 25 mm. The height and
diameter of the specimen shall be measured to three significant digits or better (see 8.1.1). The length shall vary by no more than
65 %. The diameter shall vary by no more than 65 %. The surface of the test specimen may be uneven, but indentations must
not be so deep that the length or diameter vary by more than 65 %. The diameter and height of the specimen shall each be at least
6 times greater than the largest particle size within the specimen. If, after completion of a test, it is found based on visual
observation that oversized particles are present, that information shall be indicated on the data sheet(s)/form(s).
8.1.1 If the density or unit weight needs to be determined/recorded to four significant digits, or the void ratio to three significant
digits; then the test specimens dimensions need to have four significant digits; that is, typically measured to the nearest 0.01 mm
or 0.001 in.
D5084 − 16a
8.1.2 Specimens of soil-cement and mixtures of cement, bentonite, and soils often have more irregular surfaces than specimens
of soil. Thus, for these specimens the length and the diameter may vary by no more than 610 %.
NOTE 6—Most hydraulic conductivity tests are performed on cylindrical test specimens. It is possible to utilize special equipment for testing prismatic
test specimens, in which case reference to “diameter” in 8.1 applies to the least width of the prismatic test specimen.
8.2 UndisturbedIntact Specimens—UndisturbedIntact test specimens shall be prepared from a representative portion of
undisturbedintact samples secured in accordance with Practice D1587, Practice D3550, Practice D6151, or Practice D2113. In
addition, undisturbedintact samples may be obtained by “block sampling” (78). Additional guidance on other drilling and sampling
methods is given in Guide D6169. Samples shall be preserved and transported in accordance with these requirements; for soils
follow Group C in Practice D4220, while for rock follow either “special care” or “soil-like care,” as appropriate in Practice D5079.
Specimens obtained by tube sampling or coring may be tested without trimming except for cutting the end surfaces plane and
perpendicular to the longitudinal axis of the specimen, provided soil characteristics are such that no significant disturbance results
from sampling. Where the sampling operation has caused disturbance of the soil, the disturbed material shall be trimmed. Where
removal of pebbles or crumbling resulting from trimming causes voids on the surface of the specimen that cause the length or
diameter to vary by more than 65 %, the voids shall be filled with remolded material obtained from the trimmings. The ends of
the test specimen shall be cut and not troweled (troweling can seal off cracks, slickensides, or other secondary features that might
conduct water flow). Specimens shall be trimmed, whenever possible, in an environment where changes in water content are
minimized. A controlled high-humidity room is usually used for this purpose. The mass and dimensions of the test specimen shall
be determined to the tolerances given in 5.8 and 5.9. The test specimen shall be mounted immediately in the permeameter. The
water content of the trimmings shall be determined in accordance with Method D2216, to the nearest 0.1 % or better.
8.3 Laboratory-Compacted Specimens—The material to be tested shall be prepared and compacted inside a mold in a manner
specified by the requester. If the specimen is placed and compacted in layers, the surface of each previously-compacted layer shall
be lightly scarified (roughened) with a fork, ice pick, or other suitable object, unless the requester specifically states that
scarification is not to be performed. Test Methods D698 and D1557 describe two methods of compaction, but any other method
specified by the requester may be used as long as the method is described in the report. Large clods of material should not be
broken down prior to compaction unless it is known that they will be broken in field construction, as well, or the requester
specifically requests that the clod size be reduced. Neither hard clods nor individual particles of the material shall exceed ⁄6 of
either the height or diameter of the specimen. After compaction, the test specimen shall be removed from the mold, the ends
scarified, and the dimensions and weight determined within the tolerances given in 5.8 and 5.9. After the dimensions and mass are
determined, the test specimen shall be immediately mounted in the permeameter. The water content of the trimmings shall be
determined in accordance with Method D2216 to the nearest 0.1 % or better.
8.4 Other Preparation Methods—Other methods of preparation of a test specimen are permitted if specifically requested. The
method of specimen preparation shall be identified in the data sheet(s)/form(s).
8.5 After the height, diameter, mass, and water content of the test specimen have been determined, the dry unit weight shall be
calculated. Also, the initial degree of saturation shall be estimated (this information may be used later in the back-pressure stage).
8.6 In some cases, the horizontal hydraulic conductivity of a sample needs to be determined. In that case, the specimen may
be trimmed such that its longitudinal axis is perpendicular to the longitudinal axis of the sample. Obtaining a specimen having a
diameter of 36 mm (1.4 in.) typically requires a cylindrical sample with a diameter equal to or greater than about 70 mm (2.8 in.)
or a rectangular sample with a minimum dimension of about 40 mm (1.6 in.).
9. Procedure
9.1 Specimen Setup:
9.1.1 Cut two filter paper sheets to approximately the same shape as the cross section of the test specimen. Soak the two porous
end pieces and filter paper sheets, if used, in a container of permeant water.
9.1.2 Place the membrane on the membrane expander. Apply a thin coat of silicon high-vacuum grease to the sides of the end
caps. Place one porous end piece on the base and place one filter paper sheet, if used, on the porous end piece, followed by the
test specimen. Place the second filter paper sheet, if used, on top of the specimen followed by the second porous end piece and
the top cap. Place the membrane around the specimen, and using the membrane expander or other suitable O-ring expander, place
one or more O-rings to seal the membrane to the base and one or more additional O-rings to seal the membrane to the top cap.
9.1.3 Attach flow tubing to the top cap, if not already attached, assemble the permeameter cell, and fill it with de-aired water
or other cell fluid. Attach the cell pressure reservoir to the permeameter cell line and the hydraulic system to the influent and
effluent lines. Fill the cell pressure reservoir with deaired water, or other suitable liquid, and the hydraulic system with deaired
permeant water. Apply a small confining pressure of 7 to 35 kPa (1 to 5 psi) to the cell and apply a pressure less than the confining
pressure to both the influent and effluent systems, and flush permeant water through the flow system. After all visible air has been
removed from the flow lines, close the
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