ASTM C1794-19
(Test Method)Standard Test Methods for Determination of the Water Absorption Coefficient by Partial Immersion
Standard Test Methods for Determination of the Water Absorption Coefficient by Partial Immersion
SIGNIFICANCE AND USE
5.1 The purpose of these tests is to obtain, by means of simple apparatus, reliable and easy to determine values of liquid water transport for capillary active materials expressed in suitable units. These values are for use as part of the material properties in hygrothermal analysis tools for building envelope design and forensic studies. As the topic of liquid transport phenomena in porous materials is very complex, Appendix X1 in ISO 15148 shows some more detailed background information.
SCOPE
1.1 This test method defines a procedure to determine the water absorption coefficient of a material by partial submersion. The scope is to evaluate the rate of absorption of water due to capillary forces for building materials in contact with normal or driving rain above grade. The procedure is typically suitable mainly for masonry material, plaster, or a coating in combination with a substrate; but it can also be used for insulation materials. This test method is designed to be used only on homogeneous materials and does not apply to materials that are composites or non-homogeneous (for example, Faced Rigid Closed-cell Insulation). It is not within the scope of this standard to determine liquid uptake phenomena in below-grade applications. The water absorption coefficient is mainly used as an input datum for numerical simulation of the combined heat and moisture transport in building envelopes for design and forensic investigation purposes.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. However, derived results can be converted from one system to the other using appropriate conversion factors (see Table 1).
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 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.
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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: C1794 − 19
Standard Test Methods for
Determination of the Water Absorption Coefficient by Partial
1
Immersion
This standard is issued under the fixed designation C1794; 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 2. Referenced Documents
2
1.1 This test method defines a procedure to determine the 2.1 ASTM Standards:
water absorption coefficient of a material by partial submer- C168 Terminology Relating to Thermal Insulation
3
sion. The scope is to evaluate the rate of absorption of water
2.2 Other Standards:
due to capillary forces for building materials in contact with
ISO9346 Hygrothermalperformanceofbuildingsandbuild-
normal or driving rain above grade. The procedure is typically
ing materials—Physical quantities for mass transfer—
suitable mainly for masonry material, plaster, or a coating in
Vocabulary
combination with a substrate; but it can also be used for
ISO 15148 Determination of water absorption coefficient by
insulation materials. This test method is designed to be used
partial immersion
onlyonhomogeneousmaterialsanddoesnotapplytomaterials
that are composites or non-homogeneous (for example, Faced 3. Terminology
Rigid Closed-cell Insulation). It is not within the scope of this
3.1 Definitions of Terms—For definitions associated with
standardtodetermineliquiduptakephenomenainbelow-grade
thermal insulation issues refer to Terminology C168. For
applications.Thewaterabsorptioncoefficientismainlyusedas
definitions associated with water absorption refer to the terms
an input datum for numerical simulation of the combined heat
and definitions given in ISO 9346.
and moisture transport in building envelopes for design and
3.2 Definitions of Terms Specific to This Standard:
forensic investigation purposes.
3.2.1 homogeneous material, n—materials, which proper-
1.2 The values stated in either SI units or inch-pound units
ties are uniform on a macroscopic scale.
are to be regarded separately as standard. The values stated in
3.2.2 water absorption coeffıcient, n—mass of water ab-
each system are not necessarily exact equivalents; therefore, to
sorbed by a test specimen per face area and per square root of
ensure conformance with the standard, each system shall be
time (see Eq 2).
used independently of the other, and values from the two
systems shall not be combined. However, derived results can 3.3 Symbols and Units—the Symbols and Units shown in
Table 2 are used.
be converted from one system to the other using appropriate
conversion factors (see Table 1).
4. Summary of Test Method and Use
1.3 This standard does not purport to address all of the
4.1 Water absorption by partial submersion will be calcu-
safety concerns, if any, associated with its use. It is the
lated by measuring the change in weight of the specimen in a
responsibility of the user of this standard to establish appro-
situation when the bottom surface is in contact with liquid
priate safety, health, and environmental practices and deter-
water. Liquid water that is only adsorbed on the surface shall
mine the applicability of regulatory limitations prior to use.
not be taken into account and shall be removed before
1.4 This international standard was developed in accor-
weighing, for example, by blotting with a sponge.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.2 The purpose is of this test is to derive reliable data on
Development of International Standards, Guides and Recom-
the capillary water uptake of building materials in appropriate
mendations issued by the World Trade Organization Technical
units using a simple apparatus. These data can also be used as
Barriers to Trade (TBT) Committee.
1 2
ThistestmethodisunderthejurisdictionofASTMCommitteeC16onThermal For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Insulation and is the direct responsibility of Subcommittee C16.33 on Insulation contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Finishes and Moisture. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Sept. 15, 2019. Published November 2019. Originally the ASTM website.
3
approved in 2015. Last previous edition approved in 2015 as C1794 – 15. DOI: Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
10.1520/C1794-19. 4th Floor, New York, NY 10036, http
...
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: C1794 − 15 C1794 − 19
Standard Test Methods for
Determination of the Water Absorption Coefficient by Partial
1
Immersion
This standard is issued under the fixed designation C1794; 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 defines a procedure to determine the water absorption coefficient of a material by partial submersion. The
scope is to evaluate the rate of absorption of water due to capillary forces for building materials in contact with normal or driving
rain above grade. The procedure is typically suitable mainly for masonry material, plaster, or a coating in combination with a
substrate; but it can also be used for insulation materials. This test method is designed to be used only on homogeneous materials
and does not apply to materials that are composites or non-homogeneous (for example, Faced Rigid Closed-cell Insulation). It is
not within the scope of this standard to determine liquid uptake phenomena in below-grade applications. The water absorption
coefficient is mainly used as an input datum for numerical simulation of the combined heat and moisture transport in building
envelopes for design and forensic investigation purposes.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined. However, derived results can be converted
from one system to the other using appropriate conversion factors (see Table 1).
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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:
C168 Terminology Relating to Thermal Insulation
3
2.2 Other Standards:
ISO 9346 Hygrothermal performance of buildings and building materials—Physical quantities for mass transfer—Vocabulary
ISO 15148 Determination of water absorption coefficient by partial immersion
3. Terminology
3.1 Definitions of Terms—For definitions associated with thermal insulation issues refer to Terminology C168. For definitions
associated with water absorption refer to the terms and definitions given in ISO 9346.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 homogeneous material, n—materials, which properties are uniform on a macroscopic scale.
3.2.2 water absorption coeffıcient, n—mass of water absorbed by a test specimen per face area and per square root of time (see
Eq 2).
1
This test method is under the jurisdiction of ASTM Committee C16 on Thermal Insulation and is the direct responsibility of Subcommittee C16.33 on Insulation Finishes
and Moisture.
Current edition approved March 1, 2015Sept. 15, 2019. Published April 2015November 2019. Originally approved in 2015. Last previous edition approved in 2015 as
C1794 – 15. DOI: 10.1520/C1794-15.10.1520/C1794-19.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C1794 − 19
A
TABLE 1 Metric Units and Conversion Factors
To Obtain (for the
Multiply by
same test condition)
Area
2 2
m 10.8 ft
2 -2 2
ft 9.29 × 10 m
Mass
kg 2.20 lb
lb 0.454 kg
Mass per Area
2 2
kg/m 0.205 lb/ft
2 2
lb/ft 4.88 kg/m
Water
...
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