ASTM D4373-21

Standard Test Method for Rapid Determination of Carbonate Content of Soils

SIGNIFICANCE AND USE
5.1 This test method is used to determine the presence and quantity of carbonate in a soil or soft rock specimen in terms of the calcite equivalent. The method is generally intended for use as an index of approximate carbonate content to assist with characterizing marine soils, but can be used for other soils and soft rock. Other test methods exist (such as Method C25 and Test Method D3042) to evaluate calcium carbonate equivalency for purposes of characterizing use of calcareous materials as soil modifiers or agricultural lining materials.  
5.1.1 Calcium carbonates (CaCO3) are known cementing agents, are water soluble at pH  
5.2 This test method has limitations as follows:  
5.2.1 If low carbonate contents (calcite equivalents) are measured, the user does not know whether the soil is low in carbonate content or contains cerrusite, witherite, and the like, which are carbonate species whose reactions with hydrochloric acid are either very slow or limited.  
5.2.2 Testing times may be extensive (longer than 1 hour) for some carbonate species (such as dolomite) if calcite equivalents within about 1 % are required.  
5.2.3 The effects of specimen grain size, duration of testing, pH and specimen mass are discussed in the literature.3
Note 1: The quality of the result produced by this standard is dependent on 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.
SCOPE
1.1 This test method covers the determination of carbonate content of soils and soft rock which can be readily broken down by mechanical effort. It is a gasometric method that uses a simple portable apparatus. Results should be clearly stated as the calcite equivalent in percent because different carbonate species cover a wide range of percent calcite equivalent as shown below for a number of carbonates:    
Species  
Cation  
Calcite
Equivalent, %  
Magnesite  
Mg  
117.0  
Dolomite  
Ca, Mg  
108.6  
Calcite  
Ca  
100.0  
Aragonite  
Ca  
100.0  
Rhodocrosite  
Mn  
87.1  
Siderite  
Fe  
86.4  
Smithsonite  
Zn  
79.8  
Witherite  
Ba  
50.7  
Cerrusite  
Pb  
37.5
For example, a 100 % dolomite would be expected to yield 108.6 % calcite equivalent while 100 % siderite would yield only 86.4 % calcite equivalent. Calcite and aragonite reactions will typically complete within about 10 minutes. This method does not distinguish between the carbonate species and such determination must be made using quantitative chemical analysis methods such as atomic absorption.  
1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard  
1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.  
1.3.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should 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 digit...

General Information

• Status: Published
• Publication Date: 14-Jun-2021
• ICS: 13.080.10 - Chemical characteristics of soils
• Technical Committee: D18 - Soil and Rock
• Drafting Committee: D18.06 - Physical-Chemical Interactions of Soil and Rock

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: D4373 − 21
Standard Test Method for Rapid Determination of
1
Carbonate Content of Soils
This standard is issued under the fixed designation D4373; 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* obtaining the data, special purpose studies, or any consider-
ations for the user’s objectives; and it is common practice to
1.1 This test method covers the determination of carbonate
increase or reduce significant digits of reported data to be
content of soils and soft rock which can be readily broken
commensuratewiththeseconsiderations.Itisbeyondthescope
down by mechanical effort. It is a gasometric method that uses
of this standard to consider significant digits used in analytical
a simple portable apparatus. Results should be clearly stated as
methods for engineering design.
the calcite equivalent in percent because different carbonate
1.4 This standard does not purport to address all of the
species cover a wide range of percent calcite equivalent as
safety concerns, if any, associated with its use. It is the
shown below for a number of carbonates:
responsibility of the user of this standard to establish appro-
Calcite
Species Cation
Equivalent, % priate safety, health, and environmental practices and deter-
Magnesite Mg 117.0
mine the applicability of regulatory limitations prior to use.
Dolomite Ca, Mg 108.6
1.5 This international standard was developed in accor-
Calcite Ca 100.0
Aragonite Ca 100.0 dance with internationally recognized principles on standard-
Rhodocrosite Mn 87.1
ization established in the Decision on Principles for the
Siderite Fe 86.4
Development of International Standards, Guides and Recom-
Smithsonite Zn 79.8
Witherite Ba 50.7 mendations issued by the World Trade Organization Technical
Cerrusite Pb 37.5
Barriers to Trade (TBT) Committee.
For example, a 100 % dolomite would be expected to yield
2. Referenced Documents
108.6 % calcite equivalent while 100 % siderite would yield
2
only 86.4 % calcite equivalent. Calcite and aragonite reactions 2.1 ASTM Standards:
will typically complete within about 10 minutes. This method C25 Test Methods for Chemical Analysis of Limestone,
does not distinguish between the carbonate species and such Quicklime, and Hydrated Lime
determinationmustbemadeusingquantitativechemicalanaly-
D653 Terminology Relating to Soil, Rock, and Contained
sis methods such as atomic absorption. Fluids
D3042 Test Method for Insoluble Residue in Carbonate
1.2 Units—The values stated in SI units are to be regarded
Aggregates
as standard. The values given in parentheses are provided for
D3740 Practice for Minimum Requirements for Agencies
information only and are not considered standard. Reporting of
Engaged in Testing and/or Inspection of Soil and Rock as
test results in units other than SI shall not be regarded as
Used in Engineering Design and Construction
nonconformance with this standard
D4753 Guide for Evaluating, Selecting, and Specifying Bal-
1.3 All observed and calculated values shall conform to the
ances and Standard Masses for Use in Soil, Rock, and
guidelines for significant digits and rounding established in
Construction Materials Testing
Practice D6026.
D6026 Practice for Using Significant Digits in Geotechnical
1.3.1 Theproceduresusedtospecifyhowdataarecollected/
Data
recorded or calculated, in this standard are regarded as the
E11 Specification for Woven Wire Test Sieve Cloth and Test
industry standard. In addition, they are representative of the
Sieves
significant digits that generally should be retained. The proce-
3. Terminology
dures used do not consider material variation, purpose for
3.1 Definitions—For definitions of common technical terms
used in this standard, refer to Terminology D653.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
RockandisthedirectresponsibilityofSubcommitteeD18.06onPhysical-Chemical
2
Interactions of Soil and Rock. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 15, 2021. Published June 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1984. Last previous edition approved in 2014 as D4373 – 14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4373-21. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO
...

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: D4373 − 14 D4373 − 21
Standard Test Method for Rapid Determination of
1
Carbonate Content of Soils
This standard is issued under the fixed designation D4373; 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 This test method covers the determination of carbonate content of soils and soft rock which can be readily broken down by
mechanical effort. It is a gasometric method that uses a simple portable apparatus. Results should be clearly stated as the calcite
equivalent in percent because different carbonate species cover a wide range of percent calcite equivalent as shown below for a
number of carbonates:
Calcite
Species Cation
Equivalent, %
Magnesite Mg 117.0
Dolomite Ca, Mg 108.6
Calcite Ca 100.0
Aragonite Ca 100.0
Rhodocrosite Mn 87.1
Siderite Fe 86.4
Smithsonite Zn 79.8
Witherite Ba 50.7
Cerrusite Pb 37.5
For example, a 100 % dolomite would be expected to yield 108.6 % calcite equivalent while 100 % siderite would yield only
86.4 % calcite equivalent. Calcite and aragonite reactions will typically complete within about 10 minutes. This method does not
distinguish between the carbonate species and such determination must be made using quantitative chemical analysis methods such
as atomic absorption.
1.2 Units—The values stated in SI units are to be regarded as the standard.standard. The values given in parentheses are provided
for information only and are not considered standard. Reporting of test results in units other than SI shall not be regarded as
nonconformance with this standard
1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice
D6026.
1.3.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry
standard. In addition, they are representative of the significant digits that generally should 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 analytical methods for engineering design.
1
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.06 on Physical-Chemical
Interactions of Soil and Rock.
Current edition approved May 1, 2014June 15, 2021. Published June 2014June 2021. Originally approved in 1984. Last previous edition approved in 20072014 as
D4373 – 02 (2007).D4373 – 14. DOI: 10.1520/D4373-14.10.1520/D4373-21.
*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
1

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D4373 − 21
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.For specific precaution statements, see Section 8.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
C25 Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated Lime
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D3042 Test Method for Insoluble Residue in Carbonate Aggregates
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction
Materials Testing
D6026 Practice for Using Significant Digits in Geotechnical Data
E11 Speci
...