ASTM D4502-92(2019)
(Test Method)Standard Test Method for Heat and Moisture Resistance of Wood-Adhesive Joints
Standard Test Method for Heat and Moisture Resistance of Wood-Adhesive Joints
SIGNIFICANCE AND USE
5.1 This test method can serve as a useful tool for durability assessment and service life forecasting.
5.1.1 This test method can be used to measure the effects of heat and moisture and the effect of their interaction on adhesives and bonded joints. Knowledge of these effects is useful to an adhesive formulator or manufacturer. Moist heat aging is particularly useful for determining the effects of acidic adhesive systems on the hydrolysis of wood adherends.
5.1.2 This test method provides a means of comparing the rate of degradation of an unknown adhesive-adherend combination to the rate of degradation of a known combination in thermal or hydrolytic aging environments. Such a comparison can be useful to adhesive manufacturers for introducing a new product to the market and for helping designers selecting adhesives.
5.1.3 This test method does not duplicate any natural service environment, but it does provide a means of estimating the service life of joints in similar environments. Service-life estimates are useful to designers of bonded structures or structures using bonded products.
5.2 Service-life estimates rely on the assumption that the chemical degradation mechanism is the same at the elevated aging temperatures as at the service temperature. However, this may not be true in every case. This possibility, together with the variability in specimen preparation, in the aging exposures, and in the strength measurements, require that caution be used in accepting the estimate of service life.
SCOPE
1.1 The purpose of this test method is to estimate the resistance of adhesive-bonded joints to thermal and hydrolytic degradation.
1.2 This test method is primarily for wood-to-wood joints but may be applied to joints of wood to other materials.
1.3 The effects of chemicals such as fire retardants, preservatives, and extractives in the wood upon joint degradation resistance can be estimated.
1.4 This test method does not account for the effects of stress, the other principal degrading factor, nor does it account for cyclic or variable temperature or moisture levels.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
1.6 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.
1.7 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
Relations
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: D4502 − 92 (Reapproved 2019)
Standard Test Method for
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Heat and Moisture Resistance of Wood-Adhesive Joints
This standard is issued under the fixed designation D4502; 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 D907Terminology of Adhesives
D2304Test Method for Thermal Endurance of Rigid Elec-
1.1 The purpose of this test method is to estimate the
trical Insulating Materials
resistance of adhesive-bonded joints to thermal and hydrolytic
D2307 Test Method for Thermal Endurance of Film-
degradation.
Insulated Round Magnet Wire
1.2 This test method is primarily for wood-to-wood joints
D2339Test Method for Strength Properties ofAdhesives in
but may be applied to joints of wood to other materials.
Two-PlyWood Construction in Shear byTension Loading
1.3 The effects of chemicals such as fire retardants, 2.2 IEEE Standard:
preservatives, and extractives in the wood upon joint degrada-
IEEENo.1GeneralPrinciplesforTemperatureLimitsinthe
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tion resistance can be estimated. Rating of Electrical Equipment
1.4 This test method does not account for the effects of
3. Terminology
stress, the other principal degrading factor, nor does it account
3.1 Definitions
for cyclic or variable temperature or moisture levels.
3.1.1 For definitions of terms used in this test method, refer
1.5 The values stated in SI units are to be regarded as
to Terminology D907.
standard. The values given in parentheses after SI units are
3.2 shear strength, n—in an adhesive joint, the maximum
providedforinformationonlyandarenotconsideredstandard.
average stress when a force is applied parallel to the joint.
1.6 This standard does not purport to address all of the
3.2.1 Discussion—In most adhesive test methods, the shear
safety concerns, if any, associated with its use. It is the
strength is actually the maximum average stress at failure of
responsibility of the user of this standard to establish appro-
the specimen, not necessarily the true maximum stress in the
priate safety, health, and environmental practices and deter-
material.
mine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
4.1 The degradation of adhesive joints is a physicochemical
ization established in the Decision on Principles for the
process. The speed of degradation is related to the levels of
Development of International Standards, Guides and Recom-
temperature, moisture (and other chemicals), and physical
mendations issued by the World Trade Organization Technical
stress to which the joint is exposed. This test method is based
Barriers to Trade (TBT) Committee.
on the principles of chemical kinetics and uses theArrehenius
temperature dependence relationship to estimate the long-term
2. Referenced Documents
effects of heat and moisture at the service temperature.
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2.1 ASTM Standards:
4.2 Specimens whose unaged properties have been esti-
D897Test Method forTensile Properties ofAdhesive Bonds
mated by control tests are subjected to an accelerated thermal
D905Test Method for Strength Properties of Adhesive
or hydrolytic aging environment in groups. Aging is acceler-
Bonds in Shear by Compression Loading
ated by using elevated temperature. Periodically, a group of
specimens is removed from the aging environment and tested.
The estimated property after aging and the time of aging are
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This test method is under the jurisdiction of ASTM Committee D14 on
recorded.Afterseveralgroupshavebeentestedinthismanner,
Adhesives and is the direct responsibility of Subcommittee D14.70 on Construction
Adhesives.
the rate of property loss in the aging environment can be
Current edition approved March 1, 2019. Published March 2019. Originally
estimated. This basic experiment is repeated at several other
approved in 1985. Last previous edition approved in 2011 as D4502–92(2011).
elevated temperatures, and the rates of property loss at those
DOI: 10.1520/D4502-92R19.
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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
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Standards volume information, refer to the standard’s Document Summary page on Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
the ASTM website. 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
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