ASTM C1585-20

Standard Test Method for Measurement of Rate of Absorption of Water by Hydraulic-Cement Concretes

SIGNIFICANCE AND USE
4.1 The performance of concrete subjected to many aggressive environments is a function, to a large extent, of the penetrability of the pore system. In unsaturated concrete, the rate of ingress of water or other liquids is largely controlled by absorption due to capillary rise. This test method is based on that developed by Hall3 who called the phenomenon “water sorptivity.”  
4.2 The water absorption of a concrete surface depends on many factors including: (a) concrete mixture proportions; (b) the presence of chemical admixtures and supplementary cementitious materials; (c) the composition and physical characteristics of the cementitious component and of the aggregates; (d)  the entrained air content; (e) the type and duration of curing; (f) the degree of hydration or age; (g) the presence of microcracks; (h) the presence of surface treatments such as sealers or form oil; and (i) placement method including consolidation and finishing. Water absorption is also strongly affected by the moisture condition of the concrete at the time of testing.  
4.3 This method is intended to determine the susceptibility of an unsaturated concrete to the penetration of water. In general, the rate of absorption of concrete at the surface differs from the rate of absorption of a sample taken from the interior. The exterior surface is often subjected to less than intended curing and is exposed to the most potentially adverse conditions. This test method is used to measure the water absorption rate of both the concrete surface and interior concrete. By drilling a core and cutting it transversely at selected depths, the absorption can be evaluated at different distances from the exposed surface. The core is drilled vertically or horizontally.  
4.4 This test method differs from Test Method C642 in which the specimens are oven dried, immersed completely in water at 21°C, and then boiled under water for 5 h. In this test method, only one surface is exposed to water at room temperature wh...
SCOPE
1.1 This test method is used to determine the rate of absorption (sorptivity) of water by hydraulic cement concrete by measuring the increase in the mass of a specimen resulting from absorption of water as a function of time when only one surface of the specimen is exposed to water. The specimen is conditioned in an environment at a standard relative humidity to induce a consistent moisture condition in the capillary pore system. The exposed surface of the specimen is immersed in water and water ingress of unsaturated concrete is dominated by capillary suction during initial contact with water.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the 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

• Status: Published
• Publication Date: 31-Aug-2020
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.66 - Concrete's Resistance to Fluid Penetration

Relations

• Refers: ASTM C31/C31M-24a - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Apr-2024
• Refers: ASTM C31/C31M-24 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2024
• Refers: ASTM C125-19a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2019
• Refers: ASTM C125-19 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2019
• Refers: ASTM C125-18b - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Oct-2018
• Refers: ASTM C1202-18 - Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration
• Effective Date: 01-Jul-2018
• Refers: ASTM C125-18a - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jul-2018
• Refers: ASTM C1005-18 - Standard Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of Hydraulic Cements
• Effective Date: 01-May-2018
• Refers: ASTM C42/C42M-18 - Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• Effective Date: 15-Mar-2018
• Refers: ASTM C31/C31M-18 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2018
• Refers: ASTM C125-18 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 01-Jan-2018
• Refers: ASTM C1202-17a - Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration
• Effective Date: 01-Dec-2017
• Refers: ASTM C1202-17 - Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration
• Effective Date: 15-Jun-2017
• Refers: ASTM C1005-17 - Standard Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of Hydraulic Cements
• Effective Date: 15-Mar-2017
• Refers: ASTM C125-16 - Standard Terminology Relating to Concrete and Concrete Aggregates
• Effective Date: 15-Dec-2016

Overview

ASTM C1585-20 is the Standard Test Method for Measurement of Rate of Absorption of Water by Hydraulic-Cement Concretes, published by ASTM International. This standard provides a reproducible laboratory method for determining the rate at which water is absorbed (sorptivity) by hydraulic-cement concrete due to capillary suction. Water ingress through capillarity is a key durability factor, as it significantly influences the long-term performance of concrete exposed to aggressive environments. The test method simulates conditions where water contacts concrete on one side, allowing a realistic assessment of how quickly water can penetrate unsaturated surfaces, such as exterior faces of building elements.

Key Topics

• Sorptivity and Absorption Rate: Measures the capillary rise-driven absorption of water into concrete, characterizing the material’s ability to draw in moisture over time.
• Influencing Factors: Results are affected by mixture proportions, chemical admixtures, supplementary cementitious materials, aggregate properties, air content, curing type and duration, degree of hydration, microcracks, surface treatments, and placement or finishing methods.
• Surface vs. Interior Penetration: The absorption rates at the exposed surface may differ from those deeper within the structure. The method allows evaluation at various depths using drilled cores.
• Specimen Preparation and Conditioning: Details standardized conditioning procedures for test specimens at controlled relative humidity and temperature to ensure reliable comparison.
• Test Procedure: Only one surface of the specimen is exposed to water, mirroring real-world conditions such as slabs, pavements, or wall elements. Absorption is recorded as a function of time at specified intervals.
• Calculation and Reporting: Initial and secondary absorption rates are calculated from mass changes and plotted against the square root of time. Results include average values for at least two specimens.

Applications

ASTM C1585-20 is widely used in:

• Concrete Durability Assessment: Evaluates susceptibility to water ingress, important for structures exposed to freeze-thaw cycles, de-icing salts, sulphate attack, or harsh weather.
• Quality Control and Mixture Development: Assists concrete producers and contractors in optimizing mixture designs, admixtures, and curing regimens for enhanced resistance to moisture penetration.
• Performance Specification and Compliance: Provides a standardized, comparative method for demonstrating compliance with durability-oriented specifications.
• Research and Development: Supports studies on the effects of new materials or construction methods on long-term concrete performance.
• Post-Construction Evaluation: Enables diagnosis of service-life issues or assessment of in-situ concrete vulnerability by coring and lab testing.

Related Standards

More comprehensive assessment and compatibility with other methods can be achieved by referencing related ASTM standards:

• ASTM C42/C42M: Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• ASTM C31/C31M: Making and Curing Concrete Test Specimens in the Field
• ASTM C192/C192M: Making and Curing Concrete Test Specimens in the Laboratory
• ASTM C642: Density, Absorption, and Voids in Hardened Concrete
• ASTM C1202: Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration
• ASTM C125: Terminology Relating to Concrete and Concrete Aggregates

By following ASTM C1585-20, construction professionals, material suppliers, and researchers gain valuable, quantitative data to support concrete durability and performance, enabling safer and longer-lasting structures. Its reproducibility and relevance to field conditions make it a preferred choice for assessing water absorption in hydraulic-cement concretes.

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: C1585 − 20
Standard Test Method for
Measurement of Rate of Absorption of Water by Hydraulic-
Cement Concretes
This standard is issued under the fixed designation C1585; 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* C31/C31MPractice for Making and Curing Concrete Test
Specimens in the Field
1.1 This test method is used to determine the rate of
C42/C42MTest Method for Obtaining and Testing Drilled
absorption (sorptivity) of water by hydraulic cement concrete
Cores and Sawed Beams of Concrete
by measuring the increase in the mass of a specimen resulting
C125Terminology Relating to Concrete and Concrete Ag-
from absorption of water as a function of time when only one
gregates
surface of the specimen is exposed to water. The specimen is
C192/C192MPracticeforMakingandCuringConcreteTest
conditioned in an environment at a standard relative humidity
Specimens in the Laboratory
to induce a consistent moisture condition in the capillary pore
C642Test Method for Density, Absorption, and Voids in
system. The exposed surface of the specimen is immersed in
Hardened Concrete
water and water ingress of unsaturated concrete is dominated
C1005Specification for Reference Masses and Devices for
by capillary suction during initial contact with water.
Determining Mass and Volume for Use in the Physical
1.2 The values stated in SI units are to be regarded as
Testing of Hydraulic Cements
standard. No other units of measurement are included in this
C1202Test Method for Electrical Indication of Concrete’s
standard.
Ability to Resist Chloride Ion Penetration
1.3 The text of this standard refers to notes and footnotes
3. Terminology
that provide explanatory material. These notes and footnotes
3.1 Definitions—For definitions of terms used in this
(excluding those in tables and figures) shall not be considered
standard, refer to Terminology C125.
as requirements of the standard.
1.4 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
4.1 The performance of concrete subjected to many aggres-
responsibility of the user of this standard to establish appro-
sive environments is a function, to a large extent, of the
priate safety, health, and environmental practices and deter-
penetrability of the pore system. In unsaturated concrete, the
mine the applicability of regulatory limitations prior to use.
rate of ingress of water or other liquids is largely controlled by
1.5 This international standard was developed in accor-
absorption due to capillary rise. This test method is based on
dance with internationally recognized principles on standard-
that developed by Hall who called the phenomenon “water
ization established in the Decision on Principles for the
sorptivity.”
Development of International Standards, Guides and Recom-
4.2 The water absorption of a concrete surface depends on
mendations issued by the World Trade Organization Technical
many factors including: (a) concrete mixture proportions; (b)
Barriers to Trade (TBT) Committee.
the presence of chemical admixtures and supplementary ce-
2. Referenced Documents
mentitious materials; (c) the composition and physical charac-
teristics of the cementitious component and of the aggregates;
2.1 ASTM Standards:
(d) the entrained air content; (e) the type and duration of
curing; (f) the degree of hydration or age; (g) the presence of
This test method is under the jurisdiction of ASTM Committee C09 on
microcracks; (h) the presence of surface treatments such as
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
sealers or form oil; and (i) placement method including
C09.66 on Concrete’s Resistance to Fluid Penetration.
consolidation and finishing. Water absorption is also strongly
Current edition approved Sept. 1, 2020. Published September 2020. Originally
approved in 2004. Last previous edition approved in 2013 as C1585 – 13. DOI:
affectedbythemoistureconditionoftheconcreteatthetimeof
10.1520/C1585-20.
testing.
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 Hall, C., “Water Sorptivity of Mortars and Concretes:AReview,” Magazine of
the ASTM website. Concrete Research, Vol 41, No. 147, June 1989, pp. 51–61.
*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
C1585 − 20
4.3 This method is intended to determine the susceptibility 5.9 Caliper, to measure the specimen dimensions to the
of an unsaturated concrete to the penetration of water. In nearest 0.1 mm.
general, the rate of absorption of concrete at the surface differs
6. Reagents and Materials
from the rate of absorption of a sample taken from the interior.
The exterior surface is often subjected to less than intended
6.1 Potassium Bromide, Reagent Grade, required if the
curing and is exposed to the most potentially adverse condi- oven and desiccator system described in 5.7 is used.
tions.Thistestmethodisusedtomeasurethewaterabsorption
6.2 Sealing Material, strips of low permeability adhesive
rate of both the concrete surface and interior concrete. By
sheets, epoxy paint, vinyl electrician’s tape, duct tape, or
drillingacoreandcuttingittransverselyatselecteddepths,the
aluminium tape. The material shall not require a curing time
absorption can be evaluated at different distances from the
longer than 10 minutes.
exposed surface. The core is drilled vertically or horizontally.
6.3 Plastic Bag or Sheeting, any plastic bag or sheeting that
4.4 This test method differs from Test Method C642 in
could be attached to the specimen to control evaporation from
which the specimens are oven dried, immersed completely in
the surface not exposed to water.An elastic band is required to
water at 21°C, and then boiled under water for 5 h. In this test
keep the bag or sheeting in place during the measurements.
method,onlyonesurfaceisexposedtowateratroomtempera-
ture while the other surfaces are sealed simulating water
7. Test Specimens
absorption in a member that is in contact with water on one
7.1 The standard test specimen is a 100 6 6 mm diameter
side only. Test Method C642, on the other hand, is used to
disc,withalengthof50 63mm.Specimensareobtainedfrom
estimate the maximum amount of water that can be absorbed
either molded cylinders according to Practices C31/C31M or
by a dry specimen and therefore provides a measure of the
C192/C192M or drilled cores according to Test Method C42/
total, water permeable pore space.
C42M. The cross sectional area of a specimen shall not vary
more than 1% from the top to the bottom of the specimen.
5. Apparatus
When cores are taken, they should be marked (see Note 1)so
that the surface to be tested relative to the original location in
5.1 Pan, a watertight polyethylene or other corrosion-
the structure is clearly indicated.
resistant pan large enough to accommodate the test specimens
NOTE 1—The surface to be exposed during testing shall not be marked
with the surfaces to be tested exposed to water.
orotherwisedisturbedinsuchamannerasmaymodifytheabsorptionrate
5.2 Support Device, rods, pins, or other devices, which are of the specimen.
made of materials resistant to corrosion by water or alkaline
7.2 Theaveragetestresultsonatleast2specimens(Note2)
solutions, and which allow free access of water to the exposed
shall constitute the test result. The test surfaces shall be at the
surface of the specimen during testing. Alternatively, the
same distance from the original exposed surface of the con-
specimens can be supported on several layers of blotting paper
crete.
or filter papers with a total thickness of at least 1 mm.
NOTE 2—Concrete is not a homogeneous material. Also, an exterior
surface of a concrete specimen seldom has the same porosity as the
5.3 Top-pan Balance, complying with Specification C1005
interior concrete. Therefore, replicate measurements are taken on speci-
andwithsufficientcapacityforthetestspecimensandaccurate
mens from the same depth to reduce the scatter of the data.
to at least 60.01 g.
8. Sample Conditioning
5.4 Timing Device, stop watch or other suitable timing
8.1 Before conditioning drilled core specimens obtained
device accurate to 61s.
from the field, first saturate them in accordance with the
5.5 Paper Towel or Cloth, for wiping excess water from
vacuum-saturation procedure in Test Method C1202, but omit
specimen surfaces.
the step for coating specimen side surfaces.
5.6 Water-Cooled Saw, with diamond impregnated blade to
8.2 After saturating, measure the mass of each test speci-
cut test specimens from larger samples.
men to the nearest 0.01 g.
5.7 Environmental Chamber, a chamber allowing for air
8.3 Place test specimens in the environmental chamber at a
circulationandabletomaintainatemperatureof50 62°Cand
temperature of 50 6 2°C and RH of 80 6 3% for 3 days.
a relative humidity at 80 6 3%.Alternatively, an oven able to
Alternatively, place test specimens in a desiccator inside an
maintain a temperature of 50 6 2°C and a desiccator large
oven at a temperature of 50 6 2°C for 3 days. If the desiccator
enough to contain the specimens to be tested is permitted. The
is used, control the relative humidity in the desiccator with a
relative humidity (RH) is controlled in the desiccator at 80 6
saturated solution of potassium bromide (see 5.7), but do not
0.5% by a saturated solution of potassium bromide. The
allow test specimens to contact the solution.
solubility of potassium bromide is 80.2 g/100 g of water at
NOTE 3—If the RH is controlled using a saturated potassium bromide
50°C. The solution shall be maintained at the saturation point
solution, the solution should be placed in the bottom of the desiccator,
for the duration of the test. The presence of visible crystals in
rather than in a separate container, to maximize the exposed surface area
the solution provides acceptable evidence of saturation.
of the solution.
5.8 Polyethylene Storage Containers, with sealable lids, 8.4 After the 3 days, place each specimen inside a sealable
largeenoughtocontainatleastonetestspecimenbutnotlarger container (as defined in 5.8). Use a separate container for each
than 5 times the specimen volume. specimen. Precautions mu
...

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: C1585 − 13 C1585 − 20
Standard Test Method for
Measurement of Rate of Absorption of Water by Hydraulic-
Cement Concretes
This standard is issued under the fixed designation C1585; 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 is used to determine the rate of absorption (sorptivity) of water by hydraulic cement concrete by measuring
the increase in the mass of a specimen resulting from absorption of water as a function of time when only one surface of the
specimen is exposed to water. The specimen is conditioned in an environment at a standard relative humidity to induce a consistent
moisture condition in the capillary pore system. The exposed surface of the specimen is immersed in water and water ingress of
unsaturated concrete is dominated by capillary suction during initial contact with water.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding
those in tables and figures) shall not be considered as requirements of the 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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2.1 ASTM Standards:
C31/C31M Practice for Making and Curing Concrete Test Specimens in the Field
C42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C125 Terminology Relating to Concrete and Concrete Aggregates
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C642 Test Method for Density, Absorption, and Voids in Hardened Concrete
C1005 Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing of
Hydraulic Cements
C1202 Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration
This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.66 on
Concrete’s Resistance to Fluid Penetration.
Current edition approved Feb. 1, 2013Sept. 1, 2020. Published February 2013September 2020. Originally approved in 2004. Last previous edition approved in 20112013
as C1585 – 11.13. DOI: 10.1520/C1585-13.10.1520/C1585-20.
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.
*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
C1585 − 20
3. Terminology
3.1 Definitions—For definitions of terms used in this standard, refer to Terminology C125.
4. Significance and Use
4.1 The performance of concrete subjected to many aggressive environments is a function, to a large extent, of the penetrability
of the pore system. In unsaturated concrete, the rate of ingress of water or other liquids is largely controlled by absorption due to
capillary rise. This test method is based on that developed by Hall who called the phenomenon “water sorptivity.”
4.2 The water absorption of a concrete surface depends on many factors including: (a) concrete mixture proportions; (b) the
presence of chemical admixtures and supplementary cementitious materials; (c) the composition and physical characteristics of the
cementitious component and of the aggregates; (d) the entrained air content; (e) the type and duration of curing; (f) the degree of
hydration or age; (g) the presence of microcracks; (h) the presence of surface treatments such as sealers or form oil; and (i)
placement method including consolidation and finishing. Water absorption is also strongly affected by the moisture condition of
the concrete at the time of testing.
4.3 This method is intended to determine the susceptibility of an unsaturated concrete to the penetration of water. In general, the
rate of absorption of concrete at the surface differs from the rate of absorption of a sample taken from the interior. The exterior
surface is often subjected to less than intended curing and is exposed to the most potentially adverse conditions. This test method
is used to measure the water absorption rate of both the concrete surface and interior concrete. By drilling a core and cutting it
transversely at selected depths, the absorption can be evaluated at different distances from the exposed surface. The core is drilled
vertically or horizontally.
4.4 This test method differs from Test Method C642 in which the specimens are oven dried, immersed completely in water at
21°C, and then boiled under water for 5 h. In this test method, only one surface is exposed to water at room temperature while
the other surfaces are sealed simulating water absorption in a member that is in contact with water on one side only. Test Method
C642, on the other hand, is used to estimate the maximum amount of water that can be absorbed by a dry specimen and therefore
provides a measure of the total, water permeable pore space.
5. Apparatus
5.1 Pan, a watertight polyethylene or other corrosion-resistant pan large enough to accommodate the test specimens with the
surfaces to be tested exposed to water.
5.2 Support Device, rods, pins, or other devices, which are made of materials resistant to corrosion by water or alkaline solutions,
and which allow free access of water to the exposed surface of the specimen during testing. Alternatively, the specimens can be
supported on several layers of blotting paper or filter papers with a total thickness of at least 1 mm.
5.3 Top-pan Balance, complying with Specification C1005 and with sufficient capacity for the test specimens and accurate to at
least 60.01 g.
5.4 Timing Device, stop watch or other suitable timing device accurate to 61 s.
5.5 Paper Towel or Cloth, for wiping excess water from specimen surfaces.
5.6 Water-Cooled Saw, with diamond impregnated blade to cut test specimens from larger samples.
5.7 Environmental Chamber, a chamber allowing for air circulation and able to maintain a temperature of 50 6 2°C and a relative
humidity at 80 6 3 %. Alternatively, an oven able to maintain a temperature of 50 6 2°C and a desiccator large enough to contain
the specimens to be tested is permitted. The relative humidity (RH) is controlled in the desiccator at 80 6 0.5 % by a saturated
Hall, C., “Water Sorptivity of Mortars and Concretes: A Review,” Magazine of Concrete Research, Vol 41, No. 147, June 1989, pp. 51–61.
C1585 − 20
solution of potassium bromide. The solubility of potassium bromide is 80.2 g/100 g of water at 50°C. The solution shall be
maintained at the saturation point for the duration of the test. The presence of visible crystals in the solution provides acceptable
evidence of saturation.
5.8 Polyethylene Storage Containers, with sealable lids, large enough to contain at least one test specimen but not larger than 5
times the specimen volume.
5.9 Caliper, to measure the specimen dimensions to the nearest 0.1 mm.
6. Reagents and Materials
6.1 Potassium Bromide, Reagent Grade, required if the oven and desiccator system described in 5.7 is used.
6.2 Sealing Material, strips of low permeability adhesive sheets, epoxy paint, vinyl electrician’s tape, duct tape, or aluminium
tape. The material shall not require a curing time longer than 10 minutes.
6.3 Plastic Bag or Sheeting, any plastic bag or sheeting that could be attached to the specimen to control evaporation from the
surface not exposed to water. An elastic band is required to keep the bag or sheeting in place during the measurements.
7. Test Specimens
7.1 The standard test specimen is a 100 6 6 mm diameter disc, with a length of 50 6 3 mm. Specimens are obtained from either
molded cylinders according to Practices C31/C31M or C192/C192M or drilled cores according to Test Method C42/C42M. The
cross sectional area of a specimen shall not vary more than 1 % from the top to the bottom of the specimen. When cores are taken,
they should be marked (see Note 1) so that the surface to be tested relative to the original location in the structure is clearly
indicated.
NOTE 1—The surface to be exposed during testing shall not be marked or otherwise disturbed in such a manner as may modify the absorption rate of the
specimen.
7.2 The average test results on at least 2 specimens (Note 2) shall constitute the test result. The test surfaces shall be at the same
distance from the original exposed surface of the concrete.
NOTE 2—Concrete is not a homogeneous material. Also, an exterior surface of a concrete specimen seldom has the same porosity as the interior concrete.
Therefore, replicate measurements are taken on specimens from the same depth to reduce the scatter of the data.
8. Sample Conditioning
8.1 Before conditioning drilled core specimens obtained from the field, first saturate them in accordance with the vacuum-
saturation procedure in Test Method C1202, but omit the step for coating specimen side surfaces.
8.2 After saturating, measure the mass of each test specimen to the nearest 0.01 g.
8.3 Place test specimens in the environmental chamber at a temperature of 50 6 2°C and RH of 80 6 3 % for 3 days. Alternatively,
place test specimens in a desiccator inside an oven at a temperature of 50 6 2°C for 3 days. If the desiccator is used, control the
relative humidity in the desiccator with a saturated solution of potassium bromide (see 5.7), but do not allow test specimens to
contact the solution.
NOTE 3—If the RH is controlled using a saturated potassium bromide solution, the solution should be placed in the bottom of the desiccator, rather than
in a separate container, to maximize the exposed surface area of the solution.
8.4 After the 3 days, place each specimen inside a sealable container (as defined in 5.8). Use a separate container for each
specimen. Precautions must be taken to allow free flow of air around the specimen by ensuring minimal contact of the specimen
with the walls of the container.
8.5 Store the container at 23 6 2°C for at least 15 days before the start of the absorption procedure.
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