ASTM D7792/D7792M-23

Standard Practice for Freeze/Thaw Conditioning of Pultruded Fiber Reinforced Polymer (FRP) Composites Used in Structural Designs

SIGNIFICANCE AND USE
4.1 The freeze/thaw conditioning procedures prescribed in this practice are designed to provide a standard procedure to be used to evaluate and compare the effect of 100 freeze/thaw cycles under controlled laboratory conditions on pultruded FRP composites to be used in structural design applications. The conditioning procedures prescribed in this practice are designed to obtain reproducible results to compare and evaluate these materials but are not intended to produce equilibrium conditions or actual service conditions for these materials.
SCOPE
1.1 In general, it is feasible that the mechanical properties of FRP composites will be affected by environmental conditions such as freeze/thaw cycling. In order to make reliable comparisons between different materials under freeze/thaw environmental conditions, it is necessary to standardize the freeze/thaw conditions to which specimens of these materials are subjected prior to and during testing. This practice defines procedures for freeze/thaw conditioning of pultruded FRP composites intended for use in structural design applications.  
1.2 Units—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, each system shall be used independently of the other. Combining values from the two systems has the potential to result in nonconformance with the standard.  
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.

General Information

• Status: Published
• Publication Date: 14-Dec-2023
• ICS: 83.120 - Reinforced plastics
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.18 - Reinforced Thermosetting Plastics

Relations

• Replaces: ASTM D7792/D7792M-15 - Standard Practice for Freeze/Thaw Conditioning of Pultruded Fiber Reinforced Polymer (FRP) Composites Used in Structural Designs
• Effective Date: 15-Dec-2023
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023

Overview

ASTM D7792/D7792M-23 is the internationally recognized standard practice for freeze/thaw conditioning of pultruded fiber reinforced polymer (FRP) composites intended for structural design applications. Issued by ASTM International, this standard specifies procedures to evaluate the impact of 100 controlled freeze/thaw cycles on pultruded FRP composites in laboratory conditions. It enables engineers and materials professionals to reliably compare the freeze/thaw resistance of various FRP materials, supporting informed decisions in structural applications exposed to cyclical environmental conditions. This practice is critical for ensuring the consistency and reliability of test results, thereby aiding in product development, quality assurance, and specification compliance.

Key Topics

• Freeze/Thaw Conditioning Procedures: The standard outlines precise methods to subject FRP test specimens to alternating freezing and thawing cycles, allowing reproducible evaluation of material performance.
• Laboratory Conditions: Testing is performed under controlled laboratory temperature and humidity, using distilled water and specific apparatus to ensure uniform exposure and accurate comparisons.
• Mechanical Property Retention: The assessment focuses on the ability of FRP composites to retain mechanical properties, such as strength, after exposure to freeze/thaw cycles compared to baseline properties of water-exposed but non-cycled specimens.
• Sampling and Test Specimens: Guidance is provided on specimen preparation, including selection, conditioning, and geometry, to align with related ASTM testing methods.
• Reporting Requirements: The standard details what information should be included in reports, such as material identification, specimen location, test methods, deviations from procedures, and observed effects.

Applications

The ASTM D7792/D7792M-23 standard is widely applicable in industries and sectors where pultruded FRP composites are used in structural designs that may face sever weather or changing climates. Practical uses include:

• Civil Infrastructure: Testing bridge components, pedestrian walkways, and building facades for durability in cold climates.
• Transportation: Assessing FRP profiles in rail, tram, or highway systems subjected to freezing and thawing environments.
• Construction and Engineering: Ensuring the long-term mechanical integrity of pultruded FRP used in utility poles, support beams, marine and waterfront structures.
• Quality Control: Supporting manufacturers and material suppliers in verifying product performance and consistency through standardized conditioning and testing protocols.
• Material Development: Assisting R&D professionals in benchmarking new formulations and designs for improved environmental resistance.

By enabling standardized comparison, this practice supports procurement, compliance, and innovation across industries where structural resilience and longevity are essential.

Related Standards

ASTM D7792/D7792M-23 references and aligns with several other key ASTM standards, including:

• ASTM D618: Practice for Conditioning Plastics for Testing.
• ASTM D883: Terminology Relating to Plastics.
• ASTM D6641/D6641M: Test Method for Compressive Properties of Polymer Matrix Composite Materials.
• ASTM D7290: Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering Structural Applications.
• ASTM D7745: Practice for Testing Pultruded Composites.

For complete compliance and best practices, users should consult these referenced standards alongside ASTM D7792/D7792M-23 to ensure proper conditioning, terminology, and mechanical testing protocols when working with pultruded FRP composites.

Keywords: freeze/thaw conditioning, pultruded FRP composites, ASTM D7792, structural design, environmental durability, mechanical property retention, materials testing.

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: D7792/D7792M − 23
Standard Practice for
Freeze/Thaw Conditioning of Pultruded Fiber Reinforced
Polymer (FRP) Composites Used in Structural Designs
This standard is issued under the fixed designation D7792/D7792M; 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* D3918 Terminology Relating to Reinforced Plastic Pul-
truded Products (Withdrawn 2020)
1.1 In general, it is feasible that the mechanical properties of
D6641/D6641M Test Method for Compressive Properties of
FRP composites will be affected by environmental conditions
Polymer Matrix Composite Materials Using a Combined
such as freeze/thaw cycling. In order to make reliable com-
Loading Compression (CLC) Test Fixture
parisons between different materials under freeze/thaw envi-
D7290 Practice for Evaluating Material Property Character-
ronmental conditions, it is necessary to standardize the freeze/
istic Values for Polymeric Composites for Civil Engineer-
thaw conditions to which specimens of these materials are
ing Structural Applications
subjected prior to and during testing. This practice defines
D7745 Practice for Testing Pultruded Composites
procedures for freeze/thaw conditioning of pultruded FRP
composites intended for use in structural design applications.
3. Terminology
1.2 Units—The values stated in either SI units or inch-
3.1 Definitions:
pound units are to be regarded separately as standard. The
3.1.1 standard laboratory temperature—a temperature of
values stated in each system are not necessarily exact equiva-
23 6 2°C [73.4 6 3.6°F].
lents; therefore, each system shall be used independently of the
other. Combining values from the two systems has the potential 3.1.2 standard laboratory atmosphere—an atmosphere hav-
to result in nonconformance with the standard. ing a temperature of 23 6 2°C [73.4 6 3.6°F] and a relative
humidity of 50 6 10 %.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 3.1.3 freeze/thaw resistance—the ability of a thermoset
responsibility of the user of this standard to establish appro- pultruded composite to withstand repeated water exposure and
priate safety, health, and environmental practices and deter- subsequent freeze cycling for 100 freeze/thaw cycles. This
mine the applicability of regulatory limitations prior to use.
ability will be quantified in terms of the % retention of the
1.4 This international standard was developed in accor- mechanical property of interest as compared to samples ex-
dance with internationally recognized principles on standard-
posed to water for a comparable time without subsequent
ization established in the Decision on Principles for the freeze/thaw cycling.
Development of International Standards, Guides and Recom-
3.2 Terminology relating to pultruded composites is found
mendations issued by the World Trade Organization Technical
in Terminology D3918.
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents
2 4.1 The freeze/thaw conditioning procedures prescribed in
2.1 ASTM Standards:
this practice are designed to provide a standard procedure to be
D618 Practice for Conditioning Plastics for Testing
used to evaluate and compare the effect of 100 freeze/thaw
D883 Terminology Relating to Plastics
cycles under controlled laboratory conditions on pultruded
FRP composites to be used in structural design applications.
The conditioning procedures prescribed in this practice are
This test method is under the jurisdiction of ASTM Committee D20 on Plastics
and is the direct responsibility of Subcommittee D20.18 on Reinforced Thermoset-
designed to obtain reproducible results to compare and evalu-
ting Plastics.
ate these materials but are not intended to produce equilibrium
Current edition approved Dec. 15, 2023. Published January 2024. Originally
conditions or actual service conditions for these materials.
approved in 2015. Last previous edition approved in 2015 as D7792/D7792M – 15.
DOI: 10.1520/D7792_D7792M-23.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
*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
D7792/D7792M − 23
5. Sampling equal number of control test specimens shall be placed in a
water tank at standard laboratory temperature of 23 6 2°C
5.1 Sampling shall be in accordance with the locations from
[73.4 6 3.6°F] for 30 days. Samples removed from the water
which test specimens shall be taken from the reinforced
tank after this initial 30 day moisture exposure period shall be
pultruded composites as defined in Practice D7745.
considered to be control test specimens at 0 freeze/thaw cycles.
5.2 Sampling shall be in accordance with the ASTM test
8.1.1 Distilled water shall be used for all conditioning.
methods for the specific mechanical properties to be deter-
Distilled water is to be used to serve as a standard medium for
mined.
the conditioning procedure; however, distilled water is not
intended to mimic field conditions.
6. Test Specimens
8.1.2 The presence of any residue in the water bath during
6.1 The numbers and types of test specimens shall be in
the exposure time shall be noted in the report as the presence
accordance with the ASTM test methods for the specific
of residue indicates a material loss of the test specimens.
mechanical properties to be determined. If Practice D7290 is to
8.2 Perform tests for desired mechanical properties on the 0
be used to determine characteristic values, at least ten samples
freeze/thaw cycle test specimens at the conclusion of the 30
are needed for the control and ten samples are needed for the
day water immersion to establish the baseline properties prior
freeze/thaw exposure for a total of at least 20 samples.
to the freeze/thaw cycling.
6.2 Test specimens shall be machined or otherwise fabri-
8.2.1 When conducting tests on specimens removed from
cated to the test coupon geometry specified by the ASTM test
the water immersion, wipe the specimens with a dry cloth and
method for the properties to be
...

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: D7792/D7792M − 15 D7792/D7792M − 23
Standard Practice for
Freeze/Thaw Conditioning of Pultruded Fiber Reinforced
Polymer (FRP) Composites Used in Structural Designs
This standard is issued under the fixed designation D7792/D7792M; 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 Scope*
1.1 In general, it is feasible that the mechanical properties of FRP composites will be affected by environmental conditions such
as freeze/thaw cycling. In order to make reliable comparisons between different materials under freeze/thaw environmental
conditions, it is necessary to standardize the freeze/thaw conditions to which specimens of these materials are subjected prior to
and during testing. This practice defines procedures for freeze/thaw conditioning of pultruded FRP composites intended for use in
structural design applications.
1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in
each system may not beare not necessarily exact equivalents; therefore, each system shall be used independently of the other.
Combining values from the two systems may has the potential to result in nonconformance with the standard.
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 and healthsafety, 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.
2. Referenced Documents
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
D883 Terminology Relating to Plastics
D3918 Terminology Relating to Reinforced Plastic Pultruded Products (Withdrawn 2020)
D6641/D6641M Test Method for Compressive Properties of Polymer Matrix Composite Materials Using a Combined Loading
Compression (CLC) Test Fixture
D7290 Practice for Evaluating Material Property Characteristic Values for Polymeric Composites for Civil Engineering
Structural Applications
D7745 Practice for Testing Pultruded Composites
3. Terminology
3.1 Definitions:
This test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.18 on Reinforced Thermosetting
Plastics.
Current edition approved Sept. 1, 2015Dec. 15, 2023. Published October 2015January 2024. Originally approved in 2015. Last previous edition approved in 2015 as
D7792/D7792M – 15. DOI: 10.1520/D7792_D7792M-15.10.1520/D7792_D7792M-23.
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.
*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
D7792/D7792M − 23
3.1.1 standard laboratory temperature—a temperature of 23 6 2°C [73.4 6 3.6°F].
3.1.2 standard laboratory atmosphere—an atmosphere having a temperature of 23 6 2°C [73.4 6 3.6°F] and a relative humidity
of 50 6 10 %.
3.1.3 freeze/thaw resistance—the ability of a thermoset pultruded composite to withstand repeated water exposure and subsequent
freeze cycling for 100 freeze/thaw cycles. This ability will be quantified in terms of the % retention of the mechanical property
of interest as compared to samples exposed to water for a comparable time without subsequent freeze/thaw cycling.
3.2 Terminology relating to pultruded composites is found in Terminology D3918.
4. Significance and Use
4.1 The freeze/thaw conditioning procedures prescribed in this practice are designed to provide a standard procedure to be used
to evaluate and compare the effect of 100 freeze/thaw cycles under controlled laboratory conditions on pultruded FRP composites
to be used in structural design applications. The conditioning procedures prescribed in this practice are designed to obtain
reproducible results to compare and evaluate these materials but are not intended to produce equilibrium conditions or actual
service conditions for these materials.
5. Sampling
5.1 Sampling shall be in accordance with the locations from which test specimens shall be taken from the reinforced pultruded
composites as defined in Practice D7745.
5.2 Sampling shall be in accordance with the ASTM test methods for the specific mechanical properties to be determined.
6. Test Specimens
6.1 The numbers and types of test specimens shall be in accordance with the ASTM test methods for the specific mechanical
properties to be determined. If Practice D7290 is to be used to determine characteristic values, at least ten samples are needed for
the control and ten samples are needed for the freeze/thaw exposure for a total of at least 20 samples.
6.2 Test specimens shall be machined or otherwise fabricated to the test coupon geometry specified by the ASTM test method for
the properties to be determined prior to their exposure to the environmental conditioning.
6.3 The thickness of the test specimens shall be the original product thickness without any machining of the surface. The specimen
thickness needs to be compatible with the thickness requirements of the mechanical property test method that will be used to
evaluate the samples.
6.4 All test specimens shall be conditioned in the standard laboratory atmosphere in accordance with Practice D618, Procedure
A, prior to initiating the freeze/thaw conditioning procedures described here.
6.5 Use test specimens up to 25 mm [1.0 in.] in thickness with this freeze/thaw standard practice. Experimental data has shown
that for pultruded composite samples up to 25 mm [1.0 in.] the interior center of the test specimen is freezing and thawing as
desired during the cycle time and temperatures described in this practice. If the interior center is not freezing and thawing during
this cycle for the specimen, property data obtained from samples ex
...