ASTM C908-15(2024)

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: C908 − 15 (Reapproved 2024)
Standard Test Method for
Yield Strength of Preformed Tape Sealants
This standard is issued under the fixed designation C908; 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 dissimilar materials in a variety of sealing applications. This
procedure is not intended to simulate an actual use condition
1.1 This test method covers a laboratory procedure for
but will give some indication of the cohesive and adhesive
determining the yield strength of preformed tape sealants.
bonding properties of the tape. It also provides an indication of
1.2 The values stated in acceptable metric units are to be
the modulus and tensile strength of the sealant tape composi-
regarded as the standard. The values given in parentheses are
tion.
for information only.
1.3 This standard does not purport to address all of the
5. Apparatus
safety concerns, if any, associated with its use. It is the
5.1 Glass Plates, two, each 6.35 by 76.2 by 76.2 mm ( ⁄4 by
responsibility of the user of this standard to establish appro-
3 by 3 in.).
priate safety, health, and environmental practices and deter-
NOTE 2—Other substrates such as aluminum, acrylic, ABS, etc., may be
mine the applicability of regulatory limitations prior to use.
substituted for the plates (5.1) and panels (5.2).
NOTE 1—There are no ISO standards similar or equivalent to this
5.2 Steel Panels, two, cold-rolled, each 0.762 by 76.2 by
ASTM standard.
76.2 mm (0.03 by 3 by 3 in.) (Note 2).
1.4 This international standard was developed in accor-
5.3 Laboratory Press, or equivalent.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5.4 Tension Testing Machine, or equivalent, with a jaw
Development of International Standards, Guides and Recom-
separation rate of 25 mm (1 in.)/min.
mendations issued by the World Trade Organization Technical
5.5 Recorder, for recording the tension load in pascals (or
Barriers to Trade (TBT) Committee.
pounds-force).
2. Referenced Documents
5.6 Rule.
2.1 ASTM Standards:
5.7 Spacers, 5.1 by 5.1 by 76.2 mm (0.20 by 0.20 by 3 in.).
C717 Terminology of Building Seals and Sealants
6. Sampling
3. Terminology
6.1 Take samples to be tested taken from a fresh roll of tape
3.1 Refer to Terminology C717 for definitions of the fol-
sealant after first removing and discarding approximately the
lowing terms used in this test method: adhesive failure;
first 0.61 m (2 ft) of the roll.
cohesive failure; elongation; modulus; primer; standard condi-
tions; substrate; and tape sealant.
6.2 Sealant tape configuration should be 9.53 by 9.53 mm
3 3
( ⁄8 by ⁄8 in.). If the sample does not approximate these
4. Significance and Use
dimensions, the sample should be re-extruded rather than plied
up to conform to the specified size.
4.1 Tape sealants are tacky, deformable solids that are used
under compression between two or more surfaces of similar or
7. Test Specimens
1 7.1 Prepare two test specimens per sample as follows:
This test method is under the jurisdiction of ASTM Committee C24 on Building
Seals and Sealants and is the direct responsibility of Subcommittee C24.30 on
7.1.1 Clean the glass plates with a suitable solvent, such as
Adhesion.
methyl ethyl ketone.
Current edition approved Jan. 1, 2024. Published January 2024. Originally
7.1.2 Clean the steel plates with a suitable solvent, such as
approved in 1979. Last previous edition approved in 2015 as C908–15. DOI:
10.1520/C0908-15R24. methyl ethyl ketone.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
NOTE 3—If the steel panels have been painted or prepared with other
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
specified surface treatments, omit this cleaning procedure.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. NOTE 4—Primers may be used.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C908 − 15 (2024)
3 3
7.1.3 Place two
...