ASTM C1699-09(2023)
(Test Method)Standard Test Method for Moisture Retention Curves of Porous Building Materials Using Pressure Plates
Standard Test Method for Moisture Retention Curves of Porous Building Materials Using Pressure Plates
SIGNIFICANCE AND USE
4.1 The purpose of this test is to obtain, by means of a specified laboratory procedure, the values of the equilibrium moisture content at higher RH levels ((≈ 95 to 100%). These values are used either as means to characterize the material or as material characteristics needed as input to appropriate computer models that can simulate wetting or drying potential of individual building materials or material assemblies under specified environmental conditions.
SCOPE
1.1 This test method specifies a laboratory procedure for the determination of the water retention curve (or moisture storage capacity) of porous building materials at very high relative humidity (RH) levels (≈ 95 to 100% RH) corresponding to the capillary moisture region of the sorption isotherm. This is achieved by using the pressure plate test apparatus. This technique was originally developed to study soil moisture content and eventually had been adapted to building construction materials.
1.2 At higher RH levels (≈ 95 to 100% RH) of the sorption isotherm (see Test Method C1498), use of climatic chamber is not an option. This technique uses overpressure to extract water out of the pore structure of porous materials until equilibrium between the moisture content in the specimens and the corresponding overpressure is achieved. Using the pressure plate extractors, equilibrium can only be reached by desorption.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
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.
General Information
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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: C1699 − 09 (Reapproved 2023)
Standard Test Method for
Moisture Retention Curves of Porous Building Materials
Using Pressure Plates
This standard is issued under the fixed designation C1699; 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 ASTM Standards:
1.1 This test method specifies a laboratory procedure for the
C1498 Test Method for Hygroscopic Sorption Isotherms of
determination of the water retention curve (or moisture storage
Building Materials
capacity) of porous building materials at very high relative
D2325 Test Method for Capillary-Moisture Relationships
humidity (RH) levels (≈ 95 to 100% RH) corresponding to the
for Coarse- and Medium-Textured Soils by Porous-Plate
capillary moisture region of the sorption isotherm. This is
Apparatus (Withdrawn 2007)
achieved by using the pressure plate test apparatus. This
D3152 Test Method for Capillary-Moisture Relationships
technique was originally developed to study soil moisture
for Fine-Textured Soils by Pressure-Membrane Apparatus
content and eventually had been adapted to building construc- 3
(Withdrawn 2007)
tion materials.
E337 Test Method for Measuring Humidity with a Psy-
chrometer (the Measurement of Wet- and Dry-Bulb Tem-
1.2 At higher RH levels (≈ 95 to 100% RH) of the sorption
peratures)
isotherm (see Test Method C1498), use of climatic chamber is
not an option. This technique uses overpressure to extract
3. Terminology
water out of the pore structure of porous materials until
3.1 Definitions of Terms Specific to This Standard:
equilibrium between the moisture content in the specimens and
3.1.1 desorption isotherm—the sorption isotherm measured
the corresponding overpressure is achieved. Using the pressure
exclusively during the hygroscopic desorption process started
plate extractors, equilibrium can only be reached by desorp-
from the condition of full water saturation of the material.
tion.
3.1.2 sorption isotherm—relationship between the relative
1.3 The values stated in SI units are to be regarded as
humidity (see Test Method E337) and the equilibrium moisture
standard. No other units of measurement are included in this
content of the material, at a specified temperature.
standard.
3.1.3 pressure-plate facility—Heavy steel vessel capable of
1.4 This standard does not purport to address all of the
holding different pressure levels.
safety concerns, if any, associated with its use. It is the
3.1.4 moisture content, by mass—mass of water retained in
responsibility of the user of this standard to establish appro-
the specimen divided by the dry mass of the specimen.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Significance and Use
1.5 This international standard was developed in accor-
4.1 The purpose of this test is to obtain, by means of a
dance with internationally recognized principles on standard-
specified laboratory procedure, the values of the equilibrium
ization established in the Decision on Principles for the
moisture content at higher RH levels ((≈ 95 to 100%). These
Development of International Standards, Guides and Recom-
values are used either as means to characterize the material or
mendations issued by the World Trade Organization Technical
as material characteristics needed as input to appropriate
Barriers to Trade (TBT) Committee.
computer models that can simulate wetting or drying potential
1 2
This test method is under the jurisdiction of ASTM Committee C16 on Thermal 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 March 15, 2023. Published April 2023. Originally the ASTM website.
approved in 2008. Last previous edition approved in 2015 as C1699 – 09 (2015). The last approved version of this historical standard is referenced on
DOI: 10.1520/C1699-09R23. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1699 − 09 (2023)
of individual building materials or material assemblies under 6. Test Specimens
specified environmental conditions.
6.1 A test specimen shall be cut to approximately 15 cm
and have a thickness as minimal as possible (≈ 5mm, depend-
5. Apparatus
ing on the structure of the material) to reduce the time to reach
5.1 Pressure vessel—Heavy-duty steel vessels of approxi-
equilibrium.
mately 305 mm in diameter and about 75 mm or 250 mm high
6.2 A minimum of five specimens shall be tested in each
with heavy top lid tightly-held against O-ring gasket by
pressure environment. The test procedure, as specified below,
clamping bolts (see Fig. 1).
and the precision of weighing shall be applied to each
5.2 Porous ceramic plates—This is the plate upon which the
specimen.
specimens sit and is composed of microscopic pores allowing
only water to flow through it. The plate assembly is exposed to
7. Preparations of Test Specimens
an overpressure that can be adjusted, while the other side of the
7.1 Dry specimens in oven to constant weight (see Note 1).
plate is always at atmospheric pressure resulting in a pressure
difference over the plate and the specimens.
7.2 Measure and record dry specimen dimensions.
5.3 Balance—An analytical balance capable of weighing
7.3 For vacuum saturation (see Note 2), follow steps 7.3.1 to
within 1 mg shall be used. The accuracy of the balance shall be
7.3.3
at least 6 0.1 percent of the total specimen weight.
7.3.1 Place them in a vacuum chamber (that is, desiccator
5.4 Drying oven—A ventilated drying oven, capable of
equipped with outflow knob and connected to vacuum pump)
maintaining the required drying temperature within 62K for and evacuate for 24 hours. This ensures that no air remains in
temperatures less than 75°C and 64K for temperatures above
the pores when specimens are being saturated.
75°C , and a relative humidity of less than 10%, shall be used.
7.3.2 Evacuate distilled water by pumping air out for 1 to 2
In warm-humid laboratory environment or at low drying
hours.
temperatures, it will be necessary to provide a supply of dried
7.3.3 Use this water to saturate the specimens under
air to achieve the less than 10 % relative humidity specification
vacuum. The assembly remains under vacuum for at least 3
in the drying oven.
days or until no air bubbles are observed. Keep the specimens
fully submerged in the vacuum chamber until ready for
5.5 Desiccator equipped with outflow knob—Used as a
measurement. This minimizes the amount of drying that can
vacuum chamber to remove air (that is, evacuate) from the
occur.
water and evacuate specimens.
7.4 For capillary saturation (see Note 3), specimens shall be
5.6 Kaolin paste and acetate fabric—This clay paste en-
immersed completely in distilled water (kept at room tempera-
sures good hydraulic contact between plate/specimen. The
ture) until a constant weight is attained.
acetate fabric prevents contamination of the specimens by the
clay.
7.5 Soak the porous ceramic plate(s) in distilled water for a
5.7 Pressure source—Compressed air or nitrogen in minimum of 8 hours.
cylinders, or high-pressure air compressor.
7.6 Prepare the kaolin paste (see Note 4) by mixing 125g of
5.8 Pressure manifold—Assembly of conduits and valves kaolin powder with 150g distilled water and apply it directly
regulating the air supplied to the extractors. onto the saturated plate.
FIG. 1 Pressure Plate Test Apparatus
C1699 − 09 (2023)
7.7 Cover the paste with a layer of acetate cloth to prevent different pressure plates/extractors will be required. When
the kaolin from sticking to the specimens. moving from one extractor to another, a new saturated ceramic
plate is used along with fresh clay paste. Above 15 bar
...
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