ASTM D2918-99(2020)

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: D2918 − 99 (Reapproved 2020)
Standard Test Method for
Durability Assessment of Adhesive Joints Stressed in Peel
This standard is issued under the fixed designation D2918; 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.
INTRODUCTION
The combination of stress and moisture decreases the durability of most adhesive joints. Stresses in
the presence of water or water vapor may cause some adhesive joints to fail at some fraction of the
stress required to break the dry joint. The time to failure for a given adhesive joint tested under moist
conditions generally decreases with increasing stress, temperature, and relative humidity.
1. Scope D1828 Practice for Atmospheric Exposure of Adhesive-
Bonded Joints and Structures
1.1 This test method provides data for assessing the dura-
D1876 Test Method for Peel Resistance of Adhesives (T-
bilities of adhesive joints by means of T-peel type specimens
Peel Test)
stressed in contact with air, air in equilibrium with certain
D2651 GuideforPreparationofMetalSurfacesforAdhesive
solutions, water, aqueous solutions, or other environments at
Bonding
various temperatures.
E104 Practice for Maintaining Constant Relative Humidity
1.2 The values stated in SI units are to be regarded as the
by Means of Aqueous Solutions
standard. The values given in parentheses are for information
only.
3. Terminology
1.3 This standard does not purport to address all of the
3.1 Definitions—Many terms in this practice are defined in
safety concerns, if any, associated with its use. It is the
Terminology D907.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4.1 The combination of stress and moisture decreases the
dance with internationally recognized principles on standard-
durability of most adhesive joints. Stresses in the presence of
ization established in the Decision on Principles for the
water or water vapor may cause some adhesive joints to fail at
Development of International Standards, Guides and Recom-
some small fraction of the stress required to break the dry joint.
mendations issued by the World Trade Organization Technical
The time to failure for a given adhesive joint generally
Barriers to Trade (TBT) Committee.
decreases with increasing stress, temperature, and relative
humidity.
2. Referenced Documents
4.2 This test method may be used as an accelerated screen-
2.1 ASTM Standards:
ingtestforassessingthedurabilityofadhesivejoints.Itmaybe
B209 Specification for Aluminum and Aluminum-Alloy
used to measure durability of adhesive joints exposed outdoors
Sheet and Plate
or to environmental conditions experienced by adhesive joints
D907 Terminology of Adhesives
in service. It may also be used to determine the effects of
various surface preparations or substrates on durabilities of
adhesive joints.
This test method is under the jurisdiction of ASTM Committee D14 on
Adhesives and is the direct responsibility of Subcommittee D14.80 on Metal
4.3 The durability performance of various adhesives may be
Bonding Adhesives.
compared by using this test method under uniform sets of
Current edition approved Dec. 15, 2020. Published December 2020. Originally
conditions.To assess the overall durability of a given adhesive,
approved in 1971. Last previous edition approved in 2012 as D2918 – 99 (2012).
DOI: 10.1520/D2918-99R20.
T-peel joints should be tested under a range of stress, relative
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
humidity, and temperature. For a specific end use it may be
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
possible to obtain the needed durability data using only one set
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of test conditions.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2918 − 99 (2020)
5. Apparatus 5.4 For exposure to constant relative humidities, the speci-
men may be placed in a apparatus similar to that shown in Fig.
5.1 For outdoor exposure the test location should be in an
1. A saturated salt solution may be placed in the bottom of the
area free of or protected from high winds. Standard outdoor
glass tube to provide a constant relative humidity (see Practice
weathering racks are suggested (Practice D1828), but any
E104); a stopper having a small glass tube packed with grease
stable frame may be used (for example galvanized pipe or
may be used to seal the upper end of the large glass tube.
painted steel channel). No other special apparatus is required
for outdoor tests.
6. Test Specimens
5.2 For exposure in environmental cabinets or chambers no
additional special apparatus is necessary. Constant-temperature
6.1 The successful use of the following test method depends
baths may also be used.
on preparing good quality T-peel joint specimens. Prepare the
test panels carefully according to the adhesive manufacturer’s
5.3 For exposure to distilled or deionized water in the
directions or according to some other specified set of condi-
laboratory it may be convenient to use the apparatus shown in
Fig. 1. tions agreed upon between the manufacturer and the purchaser.
FIG. 1 Apparatus for Measuring Adhesive Peel Rates in Water
D2918 − 99 (2020)
TABLE 1 Standard Test Environments
6.2 Use the test-panel construction and the test spec
...